System and method for producing lithium carbonate and use thereof

Abstract

The present disclosure relates to systems and methods for producing lithium carbonate. The lithium carbonate can be produced by contacting a lithium precursor with carbon dioxide gas. The lithium carbonate produced by the method can include micron-sized lithium carbonate particles with nanosized lithium carbonate particles coated on the surface of the micron-sized lithium carbonate particles.

Description

[0001] Cross-reference of related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 637,933, filed April 11, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to systems and methods for producing lithium carbonate from lithium hydroxide. More specifically, this disclosure relates to systems and methods for producing lithium carbonate by contacting lithium hydroxide with gaseous carbon dioxide. Background Technology

[0004] Lithium hydroxide is typically converted to lithium carbonate via a precipitation reaction. This precipitation process is 100%... Figure 1 As shown in the diagram. In the first step 101, lithium hydroxide can be dissolved in a solvent such as water. In the second step 102, carbon dioxide can be added to the lithium hydroxide solution (e.g., via bubbling) to precipitate lithium carbonate. In this reaction, lithium hydroxide reacts with carbon dioxide to form lithium carbonate and water. Lithium carbonate can precipitate out of the solution as a solid, while water can remain in the solution. Once the reaction is complete, the solid lithium carbonate can be separated from the solution by filtration or other separation methods (step 103), and then washed to remove any impurities. In step 104, the separated lithium carbonate can be dried, and then the dried lithium carbonate can be ground 105 to the desired particle size distribution. Summary of the Invention

[0005] This document describes systems and methods for producing lithium carbonate. Specifically, lithium carbonate can be produced in a single-step conversion process without dissolving the lithium precursor in a solvent. For example, lithium hydroxide can be directly converted to lithium carbonate by contacting it with carbon dioxide gas. In some embodiments, carbon dioxide can be injected into a jet mill, allowing lithium hydroxide to be converted to lithium carbonate while reducing particle size. The applicant has unexpectedly discovered that this method can produce high-purity lithium carbonate powder comprising nanoscale lithium carbonate particles coated on the surface of micron-sized lithium carbonate particles. This lithium carbonate production method reduces the number of steps required to form lithium carbonate, thereby reducing the overall cost of lithium carbonate production.

[0006] In some embodiments, a method for producing lithium carbonate includes contacting a solid lithium precursor with a gas containing at least 5% by weight carbon dioxide, thereby converting at least a portion of the solid lithium precursor into lithium carbonate. In some embodiments, the solid lithium precursor is milled in a jet mill having a gas-containing atmosphere. In some embodiments, the lithium precursor comprises an inorganic lithium salt, an organic lithium salt, lithium metal, a lithium alloy, a lithium oxide, a lithium hydroxide, or a combination thereof. In some embodiments, the lithium precursor comprises lithium hydroxide. In some embodiments, the lithium hydroxide is lithium hydroxide monohydrate. In some embodiments, the gas contains at least 25% by weight carbon dioxide. In some embodiments, the gas contains at least 50% by weight carbon dioxide. In some embodiments, at least 75% of the solid lithium precursor is converted into lithium carbonate. In some embodiments, the lithium carbonate comprises micron-sized lithium carbonate particles and nano-sized lithium carbonate particles coated with micron-sized lithium carbonate particles. In some embodiments, the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 micrometers. In some embodiments, at least a portion of the micron-sized lithium carbonate particles is hollow. In some embodiments, the lithium carbonate has a particle size distribution of about 2 to 12 micrometers. 2 / g Brunauer-Emmett-Teller (BET) specific surface area. In some embodiments, the method includes drying lithium carbonate in a fluidized bed with or without carbon dioxide gas.

[0007] In some embodiments, the powder comprises micron-sized lithium carbonate particles; and nano-sized lithium carbonate particles coated on the surface of the micron-sized lithium carbonate particles. In some embodiments, at least a portion of the micron-sized lithium carbonate particles is hollow. In some embodiments, the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 micrometers. In some embodiments, the lithium carbonate has a particle size distribution of about 2 to 12 μm. 2 Brunol-Emmette-Taylor (BET) specific surface area per g.

[0008] In some embodiments, the method for preparing the cathode active material includes mixing a metal precursor and lithium carbonate powder, wherein the lithium carbonate powder comprises: micron-sized lithium carbonate particles; and nano-sized lithium carbonate particles coated on the surface of the micron-sized lithium carbonate particles; and heating the mixture to a peak temperature between 600 and 800°C for at least 5 hours to form the cathode active material. In some embodiments, the metal precursor comprises a compound or a mixture of compounds each having formula (4):

[0009] qFePO4.(1-q)A x B y (PO4) 1-k (4)

[0010] Where A = Fe, Mn, Co and / or Ni; B = Mg, Al, Ti, Zr, Nb and / or W; x + y = 1; 0 ≤ y ≤ 0.1; 0 ≤ q ≤ 1; and 0 ≤ k ≤ 0.2. In some embodiments, the method includes mixing a carbon source with a metal precursor and lithium carbonate powder. In some embodiments, the carbon source includes glucose, dextran, sucrose, or combinations thereof. In some embodiments, the cathode active material comprises a compound having formula (5):

[0011] qLiFePO4.(1-q)LiA x B y (PO4) (5)

[0012] Where A = Fe, Mn, Co and / or Ni; B = Mg, Al, Ti, Zr, Nb and / or W; x + y = 1; 0 ≤ y ≤ 0.1; 0 ≤ q ≤ 1. In some embodiments, mixing includes grinding the mixture. In some embodiments, at least a portion of the micron-sized lithium carbonate particles is hollow. In some embodiments, the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 micrometers. In some embodiments, the lithium carbonate has a particle size distribution of about 2 to 12 μm. 2 Brunol-Emmette-Taylor (BET) specific surface area per g.

[0013] In some embodiments, a method for preparing a cathode active material includes mixing a metal source, a phosphate source, and lithium carbonate powder, wherein the lithium carbonate powder comprises: micron-sized lithium carbonate particles; and nano-sized lithium carbonate particles coated on the surface of the micron-sized lithium carbonate particles. In some embodiments, the metal source includes an iron source, a cobalt source, a manganese source, a nickel source, or a combination thereof. In some embodiments, the iron source includes Fe₂O₃, Fe, Fe₃O₄, Fe(CH₃COO)₂, FeC₂O₄, FeSO₄, Fe(NO₃)₃, or a combination thereof; the cobalt source includes Co₃O₄, CoO, or a combination thereof; the manganese source includes MnCO₃, MnO₂, Mn₃O₄, or a combination thereof; and the nickel source includes Ni(OH)₂, NiO, NiCO₃, or a combination thereof. In some embodiments, the phosphate source includes H₃PO₄, NH₄H₂PO₄, (NH₄)₂HPO₄, (NH₄)PO₄, or a combination thereof. In some embodiments, the method includes mixing a carbon source with a metal precursor and lithium carbonate powder. In some embodiments, the carbon source includes glucose, dextran, sucrose, or combinations thereof. In some embodiments, mixing includes milling the mixture. In some embodiments, the method includes heating the mixture to a peak temperature between 600 and 800°C for at least 5 hours to form a cathode active material. In some embodiments, the method includes drying the mixture to form a cathode active material precursor. In some embodiments, drying includes spray drying the mixture to form a cathode active material precursor. In some embodiments, the method includes heating the cathode active material precursor to a peak temperature between 600 and 800°C for at least 5 hours to form a cathode active material. In some embodiments, the cathode active material comprises a compound having formula (5):

[0014] qLiFePO4.(1-q)LiA x B y (PO4) (5)

[0015] Where A = Fe, Mn, Co and / or Ni; B = Mg, Al, Ti, Zr, Nb and / or W; x + y = 1; 0 ≤ y ≤ 0.1; 0 ≤ q ≤ 1. In some embodiments, at least a portion of the micron-sized lithium carbonate particles is hollow. In some embodiments, the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 micrometers. In some embodiments, the lithium carbonate has a particle size distribution of about 2 to 12 μm. 2 Brunol-Emmette-Taylor (BET) specific surface area per g.

[0016] In some embodiments, a method of preparing a cathode active material comprises mixing a metal precursor and lithium carbonate powder, wherein the lithium carbonate powder comprises: micron-sized lithium carbonate particles; and nano-sized lithium carbonate particles coated on the surface of the micron-sized lithium carbonate particles; and heating the mixture to a peak temperature of 500 to 1200°C for at least 30 minutes to form the cathode active material. In some embodiments, the metal precursor comprises a compound each having Formula 1 or a mixture of compounds or an oxide counterpart thereof:

[0017] qMn(OH)2·(1-q)Ni a Mn b Co c M y X 1+k (1)

[0018] wherein 0≤q≤0.8, c=1-a-b, 0≤a≤1, 0<b≤1, 0≤y≤0.05, and M comprises one or more selected from the group consisting of Al, Mg, Ti, Mo, Nb, Zr, Hf, Ta, W, B, P and F; wherein X is selected from OH - , CO3 2- , NO3 - , SO4 2- , C2O4 2- , C2H3O2 - , CHO2 - , stearate, oleate, tartrate and lactate, and -0.025≤k≤1.25. In some embodiments, the cathode active material comprises a compound having Formula (3):

[0019] qLi2MnO3·(1-q)LiNi a Mn b Co c M y O 2+z (3)

[0020] wherein 0≤q≤0.8, c=1-a-b, 0≤a≤1, 0<b≤1, 0≤y≤0.05, -0.025≤z≤0.125, and M is selected from the group consisting of Al, Mg, Ti, Mo, Nb, Zr, Hf, Ta, W, B, P, F, and a combination of any two or more of the foregoing. In some embodiments, at least a portion of the micron-sized lithium carbonate particles are hollow. In some embodiments, the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 microns. In some embodiments, the lithium carbonate has about 2 to 12 m 2 / g Brunauer-Emmett-Teller (BET) specific surface area.

[0021] In some embodiments, the method of preparing the cathode includes mixing a cathode active material prepared by any of the above methods with a conductive additive, a binder, and a solvent to form a slurry; coating the slurry onto a current collector; and calendering the coated current collector to form the cathode. In some embodiments, the conductive additive comprises carbon black, vapor-grown carbon fiber (VGCF), graphite, graphene, carbon nanotubes, or combinations thereof. In some embodiments, the binder comprises polyvinylidene fluoride (PVDF), carboxymethoxycellulose (CMC), lithium-substituted polyacrylic acid (LiPAA), or combinations thereof. In some embodiments, the solvent comprises N-methyl-2-pyrrolidone, water, or combinations thereof.

[0022] In some embodiments, the battery includes a cathode prepared by any of the methods described above. In some embodiments, the battery is a lithium-ion battery.

[0023] It should be understood that any variations, aspects, features, and options described in relation to the system, method, and / or powder also apply to the system, method, powder, other apparatus / configuration, and vice versa. It should also be clarified that any one or more of the foregoing variations, aspects, features, and options may be combined.

[0024] Additional advantages will become apparent to those skilled in the art from the following detailed description. The aspects and descriptions herein should be considered illustrative in nature and not restrictive.

[0025] All publications (including patent documents, scientific articles, and databases) mentioned in this application are incorporated herein by reference in their entirety for all purposes, as if each individual publication were individually incorporated by reference. If any definition set forth herein is contrary to or inconsistent with a definition set forth in a patent, application, published application, or other publication incorporated herein by reference, the definition set forth herein shall prevail over the definition incorporated herein by reference. Attached Figure Description

[0026] This disclosure will now be described by way of example only with reference to the accompanying drawings, in which:

[0027] Figure 1 An exemplary flow chart of a typical lithium carbonate precipitation production method is shown.

[0028] Figure 2 An exemplary flow chart of a lithium carbonate production method according to some embodiments disclosed herein is shown.

[0029] Figure 3 Thermogravimetric analysis of lithium hydroxide monohydrate in an atmosphere with varying carbon dioxide concentrations is shown according to some embodiments disclosed herein.

[0030] Figure 4A graph showing the conversion rate of lithium hydroxide monohydrate to lithium carbonate during jet milling with varying carbon dioxide gas concentrations, according to some embodiments disclosed herein.

[0031] Figure 5A SEM images of lithium carbonate produced by jet milling lithium hydroxide monohydrate with a gas containing 50% carbon dioxide, according to some embodiments disclosed herein, are shown.

[0032] Figure 5B Some embodiments disclosed herein are shown. Figure 5A The image shown is a magnified SEM image of lithium carbonate.

[0033] Figure 6A SEM images of lithium carbonate produced by jet milling lithium hydroxide monohydrate with a gas containing 25% carbon dioxide, according to some embodiments disclosed herein, are shown.

[0034] Figure 6B Some embodiments disclosed herein are shown. Figure 6A The image shown is a magnified SEM image of lithium carbonate.

[0035] Figure 7A The first SEM image of lithium carbonate produced from spodumene by a typical precipitation method is shown.

[0036] Figure 7B It shows Figure 7A The image shown is a magnified SEM image of lithium carbonate.

[0037] Figure 8A A second SEM image of lithium carbonate produced from brine by a typical precipitation method is shown.

[0038] Figure 8B It shows Figure 8A The image shown is a magnified SEM image of lithium carbonate.

[0039] Figure 9A The graph shows the conversion rates of lithium hydroxide monohydrate and anhydrous lithium hydroxide to lithium carbonate during jet milling with a gas jet milling solution of 25% carbon dioxide, according to some embodiments disclosed herein.

[0040] Figure 9B The graph shows the conversion rates of lithium hydroxide monohydrate and anhydrous lithium hydroxide to lithium carbonate during jet milling with a gas jet milling concentration of 50% carbon dioxide, according to some embodiments disclosed herein.

[0041] Figure 10ASEM images of lithium carbonate produced by grinding lithium hydroxide monohydrate using a gas jet containing carbon dioxide, according to some embodiments disclosed herein, are shown.

[0042] Figure 10B This document illustrates some embodiments of the production of lithium hydroxide monohydrate by jet milling with a gas containing carbon dioxide. Figure 10A The image shows a cross-sectional SEM image of lithium carbonate.

[0043] Figure 11 An exemplary XRD scan of a lithium iron phosphate (LFP) according to some embodiments disclosed herein is shown, having a reference pattern overlaid thereon to display all peaks aligned with a lithium iron phosphate reference. Detailed Implementation

[0044] Specific implementations and schemes of various aspects and variations of the apparatus, powder, system, and method described herein will now be referenced in detail. While several exemplary variations of the apparatus, powder, system, and method are described herein, other variations of the apparatus, powder, system, and method may include aspects of the apparatus, powder, system, and method described herein combined in any suitable manner having combinations of all or some of the aspects described.

[0045] This document describes systems and methods for producing lithium carbonate powder or granules. Specifically, it discloses systems and methods for converting lithium precursors into lithium carbonate in a single step. The lithium carbonate produced herein can be used to produce electrode materials for lithium-ion batteries.

[0046] Figure 2 A method 200 for producing lithium carbonate as disclosed herein is shown. To form the lithium carbonate disclosed herein, a lithium precursor may be contacted with a gas containing carbon dioxide. In some embodiments, the carbon dioxide-containing gas may entrain the lithium precursor. In some embodiments, the lithium precursor may be entrained in a carrier gas, which is then contacted with a gas containing carbon dioxide. In some embodiments, the carrier gas and the carbon dioxide-containing gas may be the same as or different from the carbon dioxide-containing gas. In some embodiments, the carrier gas may be air, nitrogen, argon, etc. In some embodiments, the lithium precursor may be ground in an atmosphere including carbon dioxide.

[0047] In some embodiments, the lithium precursor may be a lithium metal-containing compound, such as an inorganic lithium salt, an organic lithium salt, a non-salt lithium compound including lithium metal, a lithium alloy, a lithium oxide, a lithium hydroxide, or a combination thereof. Any mixture of two or more lithium compounds, or a mixture from different types of lithium precursors (e.g., lithium alloys and inorganic lithium salts), may be used as a lithium precursor. In some embodiments, lithium metal and / or lithium alloys (e.g., with silicon, magnesium, and / or aluminum) may be one or more lithium precursors, alone or in combination with one or more organic and / or inorganic lithium salts. In some embodiments, one or more lithium precursors may be in powder form.

[0048] In some embodiments, inorganic lithium salts may include lithium chloride, lithium bromide, lithium iodide, lithium chlorate, lithium carbonate, lithium bicarbonate, lithium nitrite, lithium nitrate, lithium sulfide, lithium sulfite, lithium sulfate, lithium phosphite, lithium phosphate, lithium hydroxide (e.g., anhydrous lithium hydroxide and / or lithium hydroxide monohydrate, including blends of anhydrous lithium hydroxide and lithium hydroxide monohydrate) or combinations thereof. In some embodiments, hydrated forms of these inorganic lithium salts (e.g., lithium hydroxide monohydrate) may also be used. In some embodiments, organic lithium salts may include lithium acetate, lithium acetoacetate, lithium benzoate, lithium citrate, lithium formate, lithium oxalate, lithium salicylate, lithium tartrate, lithium-containing polymers, or combinations thereof.

[0049] In some embodiments, the lithium precursor may be a solid phase when contacted with a gas containing carbon dioxide. In some embodiments, the lithium precursor particles may have a particle size distribution with a D50 of about 0.1 to 50,000 micrometers or about 100 to 10,000 micrometers.

[0050] In some embodiments, contacting the lithium precursor with carbon dioxide gas may include grinding the lithium precursor. In some embodiments, the lithium precursor may be ground via a ball mill, jet mill, grinder, hammer mill, cryogenic mill, colloid mill, fluid dynamics mill, and / or ultrasonic mill. In some embodiments, grinding may be performed in an atmosphere containing carbon dioxide gas. In some embodiments, the gas or atmosphere contacting the lithium precursor contains at least about 1 wt%, at least about 2 wt%, at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 25 wt%, at least about 50 wt%, at least about 75 wt%, at least about 90 wt%, at least about 95 wt%, at least about 98 wt%, at least about 99 wt%, or about 100 wt% carbon dioxide.

[0051] In some embodiments, the lithium precursor can be fed into the grinding apparatus at a specific feed rate. Inside the grinding apparatus, the lithium precursor fed into the apparatus can be ground and / or pulverized to reduce particle size, while reacting with carbon dioxide to form lithium carbonate. In some embodiments, inside the grinding apparatus, the lithium precursor can be exposed to an atmosphere or gas containing carbon dioxide, thereby converting the lithium precursor into lithium carbonate.

[0052] In some embodiments, the grinding apparatus is a jet mill. In some embodiments, a gas containing carbon dioxide is injected into the jet mill during the grinding process. In some embodiments, the gas contains at least about 1 wt%, at least about 2 wt%, at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 25 wt%, at least about 50 wt%, at least about 75 wt%, at least about 90 wt%, at least about 95 wt%, at least about 98 wt%, at least about 99 wt%, or about 100 wt% carbon dioxide. In some embodiments, the lithium precursor may come into contact with and be entrained therein by the carbon dioxide-containing gas within the mill. In some embodiments, the lithium precursor is rolled up together with the injected gas and may vortex with the gas inside the mill. In some embodiments, while vortexing, the lithium precursor particles (and / or the formed lithium carbonate particles) may be ground by colliding with each other. In some embodiments, the reacted and ground particles can be guided upwards by an updraft to a classifier connected to the jet mill, where the particles can be classified and coarse (i.e., larger) particles can be returned (or fall) back to the mill for further grinding. In some embodiments, the classifier can be a centrifugal classifier, a micro-separator, and / or any other type of classifier. In some embodiments, lithium precursor particles (and / or formed lithium carbonate particles) can be ground to a predetermined particle size distribution.

[0053] In some embodiments, the gas pressure entering the mill can be about 1 to 500 psig, about 10 to 200 psig, about 50 to 150 psig, or about 60 to 120 psig. In some embodiments, the temperature at which the lithium precursor contacts the carbon dioxide gas can be an elevated temperature. In some embodiments, the milling step can be performed at an elevated temperature. In some embodiments, the milling step can be performed at a temperature of about 15 to 200°C, about 15 to 20°C, about 15 to 30°C, about 20 to 25°C, about 75 to 125°C, about 90 to 110°C, or about 95 to 105°C. In some embodiments, the milling step can be performed at a temperature of at least about 15°C, at least about 20°C, at least about 25°C, at least about 50°C, at least about 75°C, at least about 90°C, at least about 95°C, at least about 100°C, at least about 105°C, or at least about 110°C. In some implementations, the grinding step may be performed at temperatures of up to about 200°C, up to about 150°C, up to about 110°C, up to about 105°C, up to about 100°C, up to about 95°C, up to about 75°C, up to about 50°C, up to about 30°C, up to about 25°C, up to about 23°C, or up to about 20°C.

[0054] In some implementations, the residence time of particles in the jet mill can be from about 0.001 seconds to 5 minutes or from about 0.01 seconds to 30 seconds.

[0055] In some embodiments, lithium bicarbonate may also be generated during the method. In other words, in some embodiments, at least a portion of the lithium precursor may react with carbon dioxide to form lithium bicarbonate. However, the methods disclosed herein can achieve high conversion rates from lithium precursor to lithium carbonate. In some embodiments, the conversion rate from lithium precursor to lithium carbonate may be at least about 50%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at least about 99.5%. The percentage conversion of lithium precursor to lithium carbonate can be measured using techniques known to those skilled in the art, including, for example, the use of X-ray diffraction analysis.

[0056] In some embodiments, the powder produced by the methods disclosed herein may be at least about 50%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, at least about 99.5%, or about 100% lithium carbonate. The percentage of lithium carbonate in the powder can be measured by techniques known to those skilled in the art, including, for example, using X-ray diffraction analysis.

[0057] In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D50 of about 0.1 to 50 micrometers, about 1 to 25 micrometers, about 1 to 15 micrometers, about 1 to 10 micrometers, about 2 to 8 micrometers, about 5 to 15 micrometers, about 3 to 8 micrometers, or about 3 to 5 micrometers. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D50 of at least about 0.1 micrometers, at least about 1 micrometer, at least about 2 micrometers, at least about 3 micrometers, at least about 4 micrometers, at least about 5 micrometers, at least about 6 micrometers, at least about 7 micrometers, at least about 8 micrometers, at least about 9 micrometers, or at least about 10 micrometers. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D50 of at most about 30 micrometers, at most about 20 micrometers, at most about 15 micrometers, at most about 10 micrometers, at most about 9 micrometers, at most about 8 micrometers, at most about 7 micrometers, at most about 6 micrometers, or at most about 5 micrometers. The D50 can be a whole / monolithic particle (nanoscale lithium carbonate coated on micron-sized lithium carbonate). Particle size and particle size distribution can be measured using techniques known to those skilled in the art, including, for example, the Malvern Mastersizer 300. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D10 of about 0.1 to 10 micrometers, about 0.5 to 5 micrometers, or about 1 to 3 micrometers. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D10 of at least about 0.1 micrometers, at least about 0.5 micrometers, at least about 1 micrometer, at least about 2 micrometers, at least about 3 micrometers, at least about 4 micrometers, or at least about 5 micrometers. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D10 of at most about 10 micrometers, at most about 8 micrometers, at most about 5 micrometers, at most about 3 micrometers, at most about 2 micrometers, or at most about 1 micrometer. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D90 of about 5 to 50 micrometers, about 10 to 50 micrometers, or about 15 to 30 micrometers. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D90 of at least about 5 micrometers, at least about 10 micrometers, at least about 15 micrometers, at least about 20 micrometers, at least about 25 micrometers, or at least about 30 micrometers. In some embodiments, lithium carbonate produced by the methods disclosed herein can have a particle size distribution with a D90 of at most about 100 micrometers, at most about 50 micrometers, at most about 40 micrometers, at most about 35 micrometers, or at most about 30 micrometers.

[0058] The applicant unexpectedly discovered that lithium carbonate produced by the methods disclosed herein has a unique structure. Specifically, lithium carbonate can comprise micron-sized lithium carbonate particles, wherein the surface of the micron-sized lithium carbonate particles can be coated with nanon-sized lithium carbonate particles. In some embodiments, the micron-sized lithium carbonate particles have a coating layer comprising nanon-sized lithium carbonate particles. In some embodiments, a plurality of nanon-sized lithium carbonate particles can coat the micron-sized lithium carbonate particles. In some embodiments, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 50%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95% of the surface of the micron-sized lithium carbonate particles can be coated with nanon-sized lithium carbonate particles. In some embodiments, the lithium carbonate powder may have a core-shell structure, wherein micron-sized lithium carbonate particles can form the core, and the shell is a layer or coating comprising nanon-sized lithium carbonate particles. In some embodiments, the micron-sized lithium carbonate particles may be hollow. In some embodiments, at least some of the micron-sized lithium carbonate particles may be hollow. In some embodiments, the micron-sized lithium carbonate particles may be a lithium carbonate shell. In some embodiments, unreacted lithium hydroxide may be inside the micron-sized particles. In some embodiments, the micron-sized lithium carbonate particles may have a lithium carbonate shell with unreacted lithium hydroxide on the inside or inner surface of the lithium carbonate shell. In other words, when solid lithium hydroxide comes into contact with gaseous carbon dioxide, the reaction can proceed from the outside of the lithium hydroxide to the inside.

[0059] In some embodiments, lithium carbonate produced by the methods disclosed herein may have a tap density of about 0.1 to 2 g / mL, about 0.25 to 0.75 g / mL, about 0.4 to 0.75 g / mL, about 0.45 to 0.7 g / mL, or about 0.45 to 0.55 g / mL. In some embodiments, lithium carbonate produced by the methods disclosed herein may have a tap density of at least about 0.05 g / mL, at least about 0.1 g / mL, at least about 0.25 g / mL, at least about 0.4 g / mL, at least about 0.45 g / mL, or at least about 0.5 g / mL. In some embodiments, lithium carbonate produced by the methods disclosed herein may have a tap density of at most about 2 g / mL, at most about 1 g / mL, at most about 0.75 g / mL, at most about 0.7 g / mL, at most about 0.65 g / mL, at most about 0.6 g / mL, or at most about 0.55 g / mL. Tap density can be measured using techniques known to those skilled in the art. For example, to measure tap density, a known mass of powder is introduced into a graduated cylinder. The cylinder is then struck a predetermined number of times or for a set time, allowing the powder to pack more densely. The resulting volume is then measured.

[0060] In some embodiments, the micron-sized lithium carbonate particles may have a D50 size distribution of about 1 to 50 micrometers, about 1 to 25 micrometers, about 1 to 10 micrometers, about 2 to 8 micrometers, about 3 to 8 micrometers, or about 3 to 5 micrometers. In some embodiments, the micron-sized lithium carbonate particles may have a D50 size distribution of at least about 1 micrometer, at least about 2 micrometers, at least about 3 micrometers, at least about 4 micrometers, at least about 5 micrometers, at least about 6 micrometers, at least about 7 micrometers, at least about 8 micrometers, at least about 9 micrometers, or at least about 10 micrometers. In some embodiments, the micron-sized lithium carbonate particles may have a D50 size distribution of up to about 30 micrometers, up to about 20 micrometers, up to about 15 micrometers, up to about 10 micrometers, up to about 9 micrometers, up to about 8 micrometers, up to about 7 micrometers, up to about 6 micrometers, or up to about 5 micrometers. In some embodiments, the nanoscale lithium carbonate particles may have a particle size of about 1 to 1000 nm, about 50 to 500 nm, about 75 to 125 nm, or about 100 nm, as measured by techniques known to those skilled in the art (including, for example, by SEM imaging).

[0061] In some embodiments, the lithium carbonate powder may have a particle size of about 1 to 50 μm. 2 / g, approximately 1 to 20m 2 / g, approximately 1 to 15m 2 / g, approximately 1 to 15m 2 / g or approximately 2 to 12 mg 2 The specific surface area is approximately 0.1 m² / g Brunol-Emmett-Taylor (BET). In some embodiments, the lithium carbonate powder may have a specific surface area of ​​at least about 0.1 m² / g. 2 / g, at least about 0.5m 2 / g, at least about 1m 2 / g, at least about 2m 2 / g, at least about 3m 2 / g, at least about 4m 2 / g, at least about 5m 2 / g, at least about 6m 2 / g, at least about 7m 2 / g or at least about 10m 2 The BET specific surface area is [value missing] / g. In some embodiments, the lithium carbonate powder may have a BET specific surface area of ​​up to about 20 m² / g. 2 / g, up to approximately 15m 2 / g, up to approximately 12m 2 / g, up to about 10m 2 / g, up to about 8m 2 / g, up to about 7m 2 / g, up to about 6m 2 / g, up to about 5m 2 / g, up to about 4m 2 / g or at most about 3m 2 / g BET specific surface area. In some embodiments, if the starting lithium precursor is lithium hydroxide monohydrate, the lithium carbonate powder may have a BET specific surface area of ​​about 2 to 7 m². 2 The BET specific surface area is [value missing] / g. In some embodiments, if starting with anhydrous lithium hydroxide, the lithium carbonate powder may have a BET specific surface area greater than or equal to about 7 or 10 m² / g. 2 BET specific surface area per g. Specific surface area can be measured using techniques known to those skilled in the art (including, for example, Micromeritics ASAP 2020Plus).

[0062] In some implementations, the abrasive particles may include multiple grinding cycles. For example, particles removed from the grinder can be reintroduced for a second grinding cycle. This process can be repeated as needed.

[0063] In some embodiments, after contact step 201, lithium carbonate may be post-treated in post-treatment step 202. In some embodiments, the post-treatment step may include drying the lithium carbonate. For example, the lithium carbonate may include some moisture from the conversion reaction. Therefore, the drying step can remove moisture from the lithium carbonate. In some embodiments, drying may be carried out in a fluidized bed dryer. In some embodiments, drying may be carried out in a carbon dioxide environment. In some embodiments, the carbon dioxide environment may be any carbon dioxide concentrate gas disclosed herein. In some embodiments, drying may be carried out under vacuum. In some embodiments, lithium carbonate may be dried for about 1 minute to about 50 hours, about 1 to 50 hours, about 5 to 30 hours, about 10 to 25 hours, or about 15 to 20 hours. In some embodiments, lithium carbonate may be dried at a temperature of about 20 to 500°C, about 50 to 250°C, about 75 to 200°C, about 100 to 200°C, about 125 to 175°C, or about 150°C. In some embodiments, the post-treatment step may include aging in a carbon dioxide environment. In some embodiments, the carbon dioxide environment may be any carbon dioxide concentrate gas disclosed herein.

[0064] Synthesis of Electrode Active Materials

[0065] In some embodiments, lithium carbonate powder can be used to prepare electrode (e.g., cathode) active materials. In some embodiments, lithium carbonate powder can be used to prepare lithium metal electrode active materials. In some embodiments, lithium carbonate powder can be used to prepare lithium transition metal electrode active materials. In some embodiments, lithium carbonate powder can be used to prepare lithium metal phosphate electrode (e.g., cathode) active materials. In some embodiments, lithium carbonate powder can be used to prepare lithium metal oxide electrode (e.g., cathode) active materials.

[0066] Electrode active material precursors formed from metal precursors

[0067] In some embodiments, preparing a cathode active material precursor from lithium carbonate may comprise the step of mixing lithium carbonate with at least one metal precursor.

[0068] In some embodiments, the lithium carbonate disclosed herein can be mixed with a stoichiometric amount of at least one metal precursor. In some embodiments, the metal precursor is a transition metal precursor. In some embodiments, the metal precursor may each be a compound represented by formula (4) or a mixture of compounds:

[0069] qFePO4·(1-q)A x B y (PO4) 1-k (4)

[0070] wherein A = Fe, Mn, Co and / or Ni; B = Mg, Al, Ti, Zr, Nb and / or W; x+y = 1; 0≤y≤0.1; 0≤q≤1; and 0≤k≤0.2.

[0071] In some embodiments, the metal precursor may each be a compound represented by formula 1, a mixture of compounds, or an oxide counterpart thereof:

[0072] qMn(OH)2·(1-q)Ni a Mn b Co c M y X 1+k (1)

[0073] wherein 0≤q≤0.8, c=1-a-b, 0≤a≤1, 0<b≤1, 0≤y≤0.05, and M comprises one or more selected from the group consisting of Al, Mg, Ti, Mo, Nb, Zr, Hf, Ta, W, B, P and F; wherein X is selected from OH - , CO3 2- , NO3 - , SO4 2- , C2O4 2- , C2H3O2-, CHO2-, stearate, oleate, tartrate and lactate, and -0.025≤k≤1.25. In some embodiments, the metal precursor may include, but is not limited to, Ni x Co y Mn z (OH)2, Ni x Co y Mn z (OOH)2, Ni x Co y Mnz O2 and / or Ni x Co y Mn z (OOH)3. Non-limiting examples of metal precursors include Ni. 0.6 Mn 0.2 Co 0.2 (OH)2, Ni 0.82 Mn 0.06 Co 0.12( OH )2 Ni 0.88 Co 0.06 Mn 0.03 Al 0.03( OH )2 Etc. Non-limiting examples of oxide counterparts of metal precursors include Ni. 0.6 Mn 0.2 Co 0.2 O, Ni 0.82 Mn 0.06 Co 0.12 O, Ni 0.88 Co 0.06 Mn 0.03 Al 0.03 O etc.

[0074] In some embodiments, the metal precursor may be a compound or mixture of compounds having Formula 2, or its oxide counterpart:

[0075] (Ni x Co y Mn z A b (2)

[0076] Where x + y + z = 1; A = OH - OOH - CO3 2- and / or C2O4 2- When A = OH - and / or OOH - If b = 2, then b = 2; otherwise b = 1.

[0077] In some embodiments, the mixture of lithium carbonate and at least one metal precursor may further include a carbon source. In some embodiments, the carbon source may include glucose, sucrose, dextran, other carbohydrates, polymers, organic acids (e.g., citric acid and / or oxalic acid), or combinations thereof.

[0078] In some embodiments, the mixture of lithium carbonate and at least one metal precursor may further include a solvent. In some embodiments, the solvent may be isopropanol, acetone, water, or a combination thereof.

[0079] In some embodiments, the mixture may be ground. In some embodiments, the mixture may be mixed using a ball mill, mortar and pestle, acoustic mixer, and / or mechanical mixer. In some embodiments, the mixture may be dried prior to heat treatment (e.g., calcination).

[0080] In some embodiments, the metal precursor, carbon source, and / or lithium carbonate may be in aqueous solution or dissolved in solution. For example, in some embodiments, lithium carbonate may be dissolved in a solvent or in solution. In some embodiments, the metal precursor may be dissolved in a solvent or in solution. In some embodiments, a mixture may be formed by adding lithium carbonate to the metal precursor solution. In some embodiments, adding lithium carbonate to the metal precursor solution may cause the electrode active material precursor to precipitate from the metal precursor solution. In some embodiments, the mixture may be dried. In some embodiments, the electrode active material precursor may be dried. In some embodiments, the mixture may be spray-dried to form the electrode active material precursor.

[0081] The ratio of the metal precursor and lithium carbonate disclosed herein can vary. In some embodiments, the molar number of lithium is equal to or greater than the total molar number of nickel, manganese, cobalt, and / or iron in the mixture. In some embodiments, mixing can be carried out in an atmosphere in which the moisture level is minimized (e.g., less than 3% by weight). In some embodiments, mixing can be carried out at a variety of temperatures and pressures, such as or within typical ambient temperatures and pressures.

[0082] Electrode active material precursors are formed from metal sources and phosphate sources.

[0083] In some embodiments, the preparation of cathode active material precursors from lithium carbonate may include the step of mixing lithium carbonate with at least one metal source and a phosphate source. In some embodiments, the lithium carbonate disclosed herein may be mixed with at least one stoichiometric amount of a metal source (and a phosphate source). In some embodiments, the metal source may include an iron source, a cobalt source, a manganese source, and / or a nickel source. In some embodiments, the iron source may include Fe₂O₃, Fe, Fe₃O₄, Fe(CH₃COO)₂, FeC₂O₄, FeSO₄, Fe(NO₃)₃, or combinations thereof. In some embodiments, the manganese source may include MnCO₃, MnO₂, Mn₃O₄, or combinations thereof. In some embodiments, the cobalt source may include Co₃O₄, CoO, or combinations thereof. In some embodiments, the nickel source may include Ni(OH)₂, NiO, NiCO₃, or combinations thereof. In some embodiments, the phosphate source may be H₃PO₄, NH₄H₂PO₄, (NH₄)₂HPO₄, (NH₄)PO₄, or combinations thereof.

[0084] In some embodiments, the mixture of lithium carbonate, at least one metal source, and a phosphate source may further include a carbon source. In some embodiments, the carbon source may include glucose, sucrose, dextran, other carbohydrates, polymers, organic acids (e.g., citric acid and / or oxalic acid), or combinations thereof.

[0085] In some embodiments, the mixture may be ground. In some embodiments, the mixture may be mixed using a ball mill, mortar and pestle, acoustic mixer, and / or mechanical mixer.

[0086] In some embodiments, the mixture of lithium carbonate, at least one metal source, and a phosphate source may further include a solvent. In some embodiments, the solvent may be isopropanol, acetone, water, or a combination thereof.

[0087] In some embodiments, the phosphate source, metal source, carbon source, and / or lithium carbonate may be in aqueous solution or dissolved in solution. For example, in some embodiments, lithium carbonate may be dissolved in a solvent or in solution. In some embodiments, the phosphate source may be dissolved in a solvent or in solution. In some embodiments, the metal source may be dissolved in a solvent or in solution. In some embodiments, a mixture may be formed by mixing the phosphate source and the metal source together to form a first solution, and then adding lithium carbonate to the first solution. In some embodiments, adding lithium carbonate to the first solution may cause the electrode active material precursor to precipitate from the first solution.

[0088] In some embodiments, the mixture may be dried. In some embodiments, the electrode active material precursor may be dried. In some embodiments, the mixture may be spray-dried to form the electrode active material precursor.

[0089] The ratio of the metal source and lithium carbonate disclosed herein can vary. In some embodiments, the molar number of lithium is equal to or greater than the total molar number of nickel, manganese, cobalt, and / or iron in the mixture. In some embodiments, mixing can be carried out in an atmosphere in which the moisture level is minimized (e.g., less than 3% by weight). In some embodiments, mixing can be carried out at a variety of temperatures and pressures, such as or within typical ambient temperatures and pressures.

[0090] Heat treatment of electrode active material precursors

[0091] After forming the electrode active material precursor, the electrode active material precursor may be heated (e.g., calcined). In some embodiments, the electrode active material precursor is a mixture of the aforementioned lithium carbonate and at least one metal precursor. In some embodiments, the electrode active material precursor is a mixture of the aforementioned lithium carbonate, a metal source, and a phosphate source. In some embodiments, the electrode active material precursor may be a dried electrode active material precursor (e.g., a spray-dried electrode active material precursor).

[0092] In some embodiments, during the heating process, the metal precursor can be oxidized at high temperatures, and lithium from lithium carbonate can diffuse into the layered metal oxide framework to form the electrode (e.g., cathode) active material. In some embodiments (for LFP), during the heating process, the metal (e.g., iron) phosphate can be “reduced” at high temperatures, and lithium from lithium carbonate can diffuse into the polyhedral PO4 phosphate framework to form the electrode active material.

[0093] In some embodiments, the electrode active material precursor may be heated (e.g., calcined) at a peak temperature between 500°C and 1200°C, between 600°C and 1100°C, between 750°C and 1000°C, or between 600°C and 800°C. In some embodiments, the electrode active material precursor may be heated at a peak temperature less than or equal to 1200°C, less than or equal to 1100°C, less than or equal to 1000°C, less than or equal to 900°C, less than or equal to 800°C, less than or equal to 750°C, less than or equal to 700°C, or less than or equal to 650°C. In some embodiments, the electrode active material precursor may be heated at a peak temperature greater than or equal to 500°C, greater than or equal to 600°C, greater than or equal to 650°C, greater than or equal to 700°C, greater than or equal to 750°C, greater than or equal to 800°C, greater than or equal to 900°C, greater than or equal to 1000°C, or greater than or equal to 1100°C. These temperature ranges may also cover cases where the heating step (e.g., calcination step) is performed at a range of different temperatures falling within the corresponding range (e.g., initial calcination temperature, peak calcination temperature, and / or a temperature gradient between the initial and peak temperatures over time), rather than at a single fixed temperature. For example, the heating step may begin at an initial temperature, and subsequently, the temperature of the heating step may be increased to the peak heating temperature.

[0094] In some embodiments, the duration of the heating step is not necessarily limited to any specific time period. In some embodiments, the electrode active material precursor may be heated (e.g., calcined) for 30 minutes to 20 hours, 1 hour to 15 hours, 5 hours to 15 hours, or 2 hours to 12 hours. In some embodiments, the electrode active material precursor may be heated for less than or equal to 20 hours, 15 hours, 12 hours, 10 hours, 8 hours, 6 hours, 5 hours, 4 hours, 3 hours, 2 hours, or 1 hour. In some embodiments, the electrode active material precursor may be heated for more than or equal to 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 8 hours, 10 hours, 12 hours, or 15 hours.

[0095] In some embodiments, the heating step (e.g., calcination) can be performed in a furnace or kiln. In some embodiments, the heating step can be performed in an inert atmosphere (e.g., nitrogen, argon, etc.), under an inert gas stream, under a reducing atmosphere (e.g., hydrogen), under a reducing gas stream, or a combination thereof. In some embodiments, the heating step can be performed under a gas stream.

[0096] In some embodiments, the electrode (e.g., cathode) active material formed after heating may include lithium and at least one metal (e.g., iron, cobalt, manganese, and / or nickel). In some embodiments, the electrode active material may be a compound having formula (5):

[0097] qLiFePO4.(1-q)LiA x B y (PO4) (5)

[0098] Where A = Fe, Mn, Co and / or Ni; B = Mg, Al, Ti, Zr, Nb and / or W; x + y = 1; 0 ≤ y ≤ 0.1; 0 ≤ q ≤ 1. In some embodiments, the electrode active material may comprise lithium iron phosphate (LFP) and / or lithium manganese iron phosphate (LMFP).

[0099] In some embodiments, the electrode active material can be a compound having formula (3):

[0100] qLi2MnO3·(1-q)LiNi a Mn b Co c M y O 2+z (3)

[0101] wherein 0≤q≤0.8, c=1-a-b, 0≤a≤1, 0<b≤1, 0≤y≤0.05, -0.025≤z≤0.125, and M is selected from the group consisting of Al, Mg, Ti, Mo, Nb, Zr, Hf, Ta, W, B, P, F, and combinations of any two or more of the foregoing.

[0102] Electrode manufacturing

[0103] In some embodiments, an electrode (e.g., a cathode) active material can be used to prepare an electrode. In some embodiments, an electrode can be formed by mixing the electrode active material, a conductive additive, a binder and / or a solvent to form a slurry. In some embodiments, the conductive additive can comprise carbon black, vapor grown carbon fiber (VGCF), graphite, graphene and / or carbon nanotubes. In some embodiments, the binder can comprise polyvinylidene fluoride (PVDF), carboxymethoxy cellulose (CMC), lithium-substituted polyacrylic acid (LiPAA). In some embodiments, the solvent can comprise N-methyl-2-pyrrolidone (NMP), water, another aqueous solution, or a combination thereof.

[0104] In some embodiments, the slurry comprises about 80 to 95% by weight of the electrode active material described herein. In some embodiments, the slurry can comprise less than or equal to 98% by weight, less than or equal to 97% by weight, less than or equal to 95% by weight, less than or equal to 90% by weight, or less than or equal to 85% by weight of the electrode active material described herein. In some embodiments, the slurry comprises greater than or equal to 80% by weight, greater than or equal to 85% by weight, greater than or equal to 90% by weight, greater than or equal to 95% by weight, greater than or equal to 96% by weight, greater than or equal to 97% by weight, greater than or equal to 98% by weight of the electrode active material described herein.

[0105] In some embodiments, the slurry comprises 0.1 to 10% by weight of the conductive additive. In some embodiments, the slurry can comprise less than or equal to 10% by weight, less than or equal to 9% by weight, less than or equal to 8% by weight, less than or equal to 7% by weight, less than or equal to 6% by weight, less than or equal to 5% by weight, less than or equal to 4% by weight, less than or equal to 3% by weight, less than or equal to 2% by weight, or less than or equal to 1% by weight of the conductive additive. In some embodiments, the slurry can comprise greater than or equal to 0.1% by weight, greater than or equal to 1% by weight, greater than or equal to 2% by weight, greater than or equal to 3% by weight, greater than or equal to 4% by weight, greater than or equal to 5% by weight, greater than or equal to 6% by weight, greater than or equal to 7% by weight, greater than or equal to 8% by weight, or greater than or equal to 9% by weight of the conductive additive.

[0106] In some embodiments, the slurry contains 0.1 to 10% by weight of binder. In some embodiments, the slurry may contain less than or equal to 10% by weight, less than or equal to 9% by weight, less than or equal to 8% by weight, less than or equal to 7% by weight, less than or equal to 6% by weight, less than or equal to 5% by weight, less than or equal to 4% by weight, less than or equal to 3% by weight, less than or equal to 2% by weight, or less than or equal to 1% by weight of binder. In some embodiments, the slurry may contain greater than or equal to 0.1% by weight, greater than or equal to 1% by weight, greater than or equal to 2% by weight, greater than or equal to 3% by weight, greater than or equal to 4% by weight, greater than or equal to 5% by weight, greater than or equal to 6% by weight, greater than or equal to 7% by weight, greater than or equal to 8% by weight, or greater than or equal to 9% by weight of binder.

[0107] In some embodiments, the slurry may contain a solvent such that the solids content is about 5 to 85% by weight of the slurry.

[0108] In some embodiments, the slurry can be coated onto the current collector using any method commonly used in the art. In some embodiments, the current collector may be a metal foil. In some embodiments, the current collector may be an aluminum current collector. In some embodiments, the aluminum current collector may comprise aluminum metal, etched aluminum, carbon-coated aluminum, or a combination thereof. The coating can then be dried, and the coated current collector can be pressed or rolled to form an electrode (e.g., a cathode).

[0109] In some embodiments, the electrode may contain 0.1 to 10 wt% conductive additive. In some embodiments, the electrode may contain less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, less than or equal to 6 wt%, less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt%, less than or equal to 2 wt%, or less than or equal to 1 wt% conductive additive. In some embodiments, the electrode may contain greater than or equal to 0.1 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 3 wt%, greater than or equal to 4 wt%, greater than or equal to 5 wt%, greater than or equal to 6 wt%, greater than or equal to 7 wt%, greater than or equal to 8 wt%, or greater than or equal to 9 wt% conductive additive.

[0110] In some embodiments, the electrode may contain 0.1 to 10% by weight of binder. In some embodiments, the electrode may contain less than or equal to 10% by weight, less than or equal to 9% by weight, less than or equal to 8% by weight, less than or equal to 7% by weight, less than or equal to 6% by weight, less than or equal to 5% by weight, less than or equal to 4% by weight, less than or equal to 3% by weight, less than or equal to 2% by weight, or less than or equal to 1% by weight of binder. In some embodiments, the electrode may contain greater than or equal to 0.1% by weight, greater than or equal to 1% by weight, greater than or equal to 2% by weight, greater than or equal to 3% by weight, greater than or equal to 4% by weight, greater than or equal to 5% by weight, greater than or equal to 6% by weight, greater than or equal to 7% by weight, greater than or equal to 8% by weight, or greater than or equal to 9% by weight of binder.

[0111] In some embodiments, the electrode may contain 80 to 99.8% by weight of the electrode (e.g., cathode) active material described herein. In some embodiments, the electrode may contain less than or equal to 99.8% by weight, less than or equal to 99.5% by weight, less than or equal to 99% by weight, less than or equal to 98% by weight, less than or equal to 97% by weight, less than or equal to 95% by weight, less than or equal to 90% by weight, or less than or equal to 85% by weight of the electrode (e.g., cathode) active material described herein. In some embodiments, the electrode may contain greater than or equal to 80% by weight, greater than or equal to 85% by weight, greater than or equal to 90% by weight, greater than or equal to 95% by weight, greater than or equal to 96% by weight, greater than or equal to 97% by weight, greater than or equal to 98% by weight, greater than or equal to 99% by weight, or greater than or equal to 99.5% by weight of the electrode (e.g., cathode) active material described herein.

[0112] In some embodiments, electrodes (e.g., cathodes) may be used in a battery (e.g., a lithium-ion battery). In some embodiments, the lithium carbonate powder disclosed herein may be used to prepare an electrolyte. In some embodiments, the battery may include an anode, a cathode, a separator, and / or an electrolyte. In some embodiments, the battery may be a solid-state battery.

[0113] For the purposes of clarity and concise description, features are described herein as part of the same or separate embodiments; however, it should be understood that the scope of this disclosure includes embodiments having a combination of all or some of the features described.

[0114] Example

[0115] The following examples are given for illustrative purposes and are not intended to limit the scope of this disclosure.

[0116] The applicant initially discovered that the reaction kinetics of the reaction between lithium hydroxide monohydrate and lithium carbonate and / or lithium bicarbonate are related to or correlated with the concentration of carbon dioxide in the gas or atmosphere during grinding. The theoretical reaction of lithium hydroxide monohydrate with carbon dioxide to form lithium carbonate and water has an 88% solids yield. The theoretical reaction of lithium hydroxide monohydrate with carbon dioxide to form lithium bicarbonate and water has a 162% solids yield.

[0117] The applicant performed thermogravimetric analysis (TGA) to determine the kinetic parameters of the reaction between lithium hydroxide monohydrate and carbon dioxide by varying the amount of carbon dioxide in the reaction gas. The reaction gas used was a mixture of nitrogen and carbon dioxide. Figure 3 Thermogravimetric analysis of lithium hydroxide monohydrate in a gaseous atmosphere containing different levels of carbon dioxide (e.g., 2%, 5%, and 100% CO2). Figure 3 As shown, a plateau exists between 88% and 162% solids yield, indicating the formation of both carbonates and bicarbonates. At low carbon dioxide contents (e.g., 2% to 5%), a slow weight increase is observed, indicating slow formation of lithium carbonate and / or lithium bicarbonate. At high carbon dioxide contents (e.g., 100%), a rapid weight increase is observed, indicating rapid formation of lithium carbonate and / or lithium bicarbonate. An explosive reaction was observed when 100% carbon dioxide was used in the thermogravimetric analysis. This result may be somewhat uncertain because the powder was blown out of the pan due to the explosiveness of the reaction.

[0118] The applicant also demonstrated the conversion of lithium hydroxide monohydrate to lithium carbonate by modifying a jet mill with 100% carbon dioxide gas. Specifically, 40.07 g of LiOH-H2O was weighed out. A jet mill (Jet Pulverizer Co., model 02-606 Micron-Master) was wrapped with heating tape around the top, bottom, and product outlet pipe of the mill. The mill was heated to 90-110°C, measured using a K-type thermocouple on the top of the mill, and set to operate with 100% CO2 as the gas supply. The gas pressure was set to 115 psig, the feed rate was set to 350 (the unitless control setting corresponds to the percentage of powder applied to the auger, so a value of 500 would correspond to 50% power or half its maximum speed), and feeding began. The total grinding time was approximately 3 minutes. After grinding all the LiOH-H2O, the mill was turned off and 35.61 g of moist Li2CO3 was collected. The obtained Li₂CO₃ was dried at 150 °C under vacuum for 16 hours. 24.56 g of Li₂CO₃ was collected after drying. A portion of the dried Li₂CO₃ was analyzed by XRD on a Bruker D8 Advance with a copper source. Rietveld refinement was performed to fit the spectrum and calculate the Li₂CO₃ content. The results showed that the dried powder was phase-pure Li₂CO₃.

[0119] The applicant also demonstrated a high conversion rate of lithium hydroxide monohydrate to lithium carbonate by using gas improvements to the jet mill with different levels of carbon dioxide concentration and pressure. The results of these jet milling conditions are shown in Table 1 below:

[0120] Table 1

[0121]

[0122]

[0123]

[0124] As shown in the table above, lithium hydroxide monohydrate was fed into the jet mill at different feed rates, and the gas pressure was varied throughout the experiment using gas with carbon dioxide concentrations of 25%, 50%, and 100%. As shown in the table, the higher the percentage of carbon dioxide, the lower the pressure required to achieve a comparable conversion to lithium carbonate. Figure 4 A graph showing the conversion rate of lithium hydroxide monohydrate to lithium carbonate during jet milling is presented. XRD and titration confirmed the formation of carbonates (non-bicarbonates) and the carbonate content. Figure 4As shown in the table above, conversion rates up to 100% are displayed. Furthermore, it is shown that both gas pressure and powder feed rate can affect the conversion. As mentioned above, the feed rate is a unitless control setting of the JetPulverizer Co. model 02-606 Micron-Master used for sample preparation. A feed rate setting of 350 refers to a feed rate of approximately 1.05 g / s; a feed rate setting of 500 refers to a feed rate of approximately 1.75 g / s; and a feed rate setting of 750 refers to a feed rate of approximately 2.8 g / s.

[0125] The specific surface area of ​​a portion of the above Li₂CO₃ samples was analyzed using Micromeritics ASAP 2020plus. The samples were activated at 160 °C for 2 hours. The surface area was calculated using a standard liquid nitrogen dosing method, with data points ranging from 0.05 to 0.30 p / p₀. The obtained surface areas are listed in the table below. As shown in the table, the BET specific surface area ranges from 2 to 12 m². 2 Between / g. Furthermore, the particle size distribution of a portion of the above Li₂CO₃ samples was analyzed using a Malvern Mastersizer 3000 with a wet module. Particle size distribution was collected by wet method. Mineral oil was chosen as the dispersant due to its solubility in water. The samples were sonicated for 1 minute prior to testing. The resulting particle size distributions are listed in Table 2 below.

[0126] Table 2

[0127]

[0128]

[0129] Some of these samples were also analyzed by scanning electron microscopy (SEM). SEM images were acquired on a Jeol JSM 7200F at 3kV and a working distance of 6mm. Figure 10A and 10B Two of the obtained SEM images are shown in the image. Specifically, Figure 10A The above-mentioned Li2CO3 shows that it contains micron-sized particles coated with nano-sized particles, and Figure 10B This shows that at least some of the micron-sized particles are hollow. Figure 10B The cross-section of the lithium carbonate powder shown was obtained using cryogenic polished SEM. Essentially, the lithium carbonate powder was cooled to a very cold temperature, and the particles, already coated on a carbon ribbon, were cut in half using an argon beam to reveal the cross-sections of at least some of the particles, showing hollow, micron-sized particles. Some water (gas or liquid) is also formed during the formation of lithium carbonate. Without being bound by any theory, the applicant believes that the hollow portions are related to the generation of water during the conversion to lithium carbonate.

[0130] In addition to lithium hydroxide monohydrate, anhydrous lithium hydroxide was also tested in a jet mill. Figure 9A Figures 9B (using a gas with a carbon dioxide concentration of 25%) and 9B (using a gas with a carbon dioxide concentration of 50%) show graphs illustrating the conversion rates of lithium hydroxide monohydrate and anhydrous lithium hydroxide to lithium carbonate during jet milling. Figure 9A and 9B As shown, the improvement in conversion between lithium hydroxide monohydrate and anhydrous lithium hydroxide is not significant, with the conversion rate of monohydrate being only slightly better.

[0131] The applicant also observed a moist solid after jet milling, indicating that water condensed in the resulting solid. Unbound by any theory, the applicant believes that the condensate formed from the conversion of lithium hydroxide to lithium carbonate can dissolve some carbon dioxide, thereby increasing the reaction between carbon dioxide and lithium hydroxide, as it is dissolved in water. The applicant believes this can increase the amount of nano-sized lithium carbonate particles coated with micron-sized lithium carbonate. Figure 5A SEM images of lithium carbonate produced by jet milling lithium hydroxide monohydrate using a gas with a carbon dioxide concentration of 50% are shown. In this example, the conversion rate from lithium hydroxide to lithium carbonate is 98%. Figure 5B It shows Figure 5A The image shown is a magnified SEM image of lithium carbonate. (As shown...) Figure 5B As shown, nanoscale particles exist on the surface of larger micron-sized lithium carbonate particles. Figure 6A SEM images of lithium carbonate produced by jet milling lithium hydroxide monohydrate using a gas with a carbon dioxide concentration of 25% are shown. In this example, the conversion rate from lithium hydroxide to lithium carbonate is 88%. Figure 6B It shows Figure 6A The image shown is a magnified SEM image of lithium carbonate. (As shown...) Figure 6B As shown, nanoscale particles exist on the surface of larger micron-sized lithium carbonate particles.

[0132] Figures 7A to 7B Images 8A to 8B show SEM images of lithium carbonate prepared by two different methods. Figures 7A to 7B The sample shown was prepared using the following spodumene method. First, the spodumene was acid-treated, and the resulting leachate solution underwent a series of processes, including refining, purification, conversion, and precipitation, ultimately becoming pure lithium carbonate. Figures 8A to 8B The sample shown was prepared using the following brine method. The brine underwent a series of processes, including concentration, purification, separation, and precipitation, to obtain pure lithium carbonate. Figures 7A to 8B As shown in the SEM images, the final lithium carbonate powder from these methods is micron-sized and not coated with nano-sized lithium carbonate particles.

[0133] Lithium iron phosphate synthesis: A portion (2.98 g) of dried Li₂CO₃ sample 16 was weighed together with 15.03 g of FePO₄, 1.43 g of glucose, and 37 mL of isopropanol into a zirconium ball mill. Approximately 20 mL of 0.5 mm Zr balls were added as grinding media, and the wide-mouth bottle was sealed. The mixture was milled in a Retsch PM-100 at 350 rpm for 2.5 hours, with 2-minute intervals and a 30-second pause between each milling. The ball mill was reversed at each interval. The milled slurry was dried at 100 °C for approximately 2 hours until dry. The Zr grinding balls were separated from the precursor powder, and 8 g of the powder was placed in an alumina crucible. The powder was then calcined in a tube furnace under an argon atmosphere. The calcination program was 500 °C for 2 hours, followed by a heating at 725 °C at a rate of 5 °C / min for 10 hours. After cooling, the resulting lithium iron phosphate powder was removed from the furnace. The LFP powder was then hand-ground in a mortar and pestle and sieved through a -325 mesh sieve. XRD was used to evaluate phase purity and crystal quality. Phase-pure lithium iron phosphate was produced using lithium carbonate generated by jet milling and refined against standard LFP in the ICSD database (ICSD collection code: 162282). Figure 11 shown in . Specifically, Figure 11 This is an XRD scan of LFP powder produced by jet milling of the sample, with a reference pattern superimposed on it to show all peaks aligned with the LFP reference. The LFP particle size distribution has a D10 of 0.022 μm, a D50 of 0.098 μm, and a D90 of 20 μm.

[0134] Lithium iron phosphate synthesis 2: A portion (3.008 g) of dried Li₂CO₃ sample 23 was weighed together with 15.01 g of FePO₄, 1.064 g of glucose, and 30 mL of isopropanol into a zirconium ball mill. Approximately 20 mL of 0.5 mm Zr balls were added as grinding media, and the wide-mouth bottle was sealed. The mixture was milled in a Retsch PM-100 at 350 rpm for 1.5 hours, with 2-minute intervals and a 30-second pause between each milling. The ball mill was reversed at each interval. The milled slurry was dried at 90 °C for approximately 1 hour until dry. The Zr grinding balls were separated from the precursor powder, and 8 g of the powder was placed in an alumina crucible. The powder was then calcined in a tube furnace under an argon atmosphere. The calcination program was 500 °C for 2 hours, followed by a heating at 725 °C at a rate of 5 °C / min for 10 hours. After cooling, the resulting lithium iron phosphate powder was removed from the furnace. The LFP powder was then hand-ground in a mortar and pestle and sieved through a -325 mesh sieve. XRD was used to assess phase purity and crystal quality. Phase-pure lithium iron phosphate was produced using lithium carbonate generated by jet milling and refined against standard LFP in the ICSD database (ICSD collection code: 162282).

[0135] Lithium iron phosphate synthesis 3 (wet processing method): 14.439 g of 85% H3PO4 solution was mixed with 2.53 g of citric acid and 6.34 g of oxalic acid in a 250 ml three-necked reactor, followed by the addition of 10 g of Fe2O3 powder to the acid mixture. The reactants were maintained at 40 °C for 1 hour. 4.719 g of lithium carbonate sample 27 was slowly added to the above solution over 10 minutes, followed by continuous stirring for 3 hours. The reaction mixture was then spray-dried at inlet and outlet temperatures of 220 °C and 110 °C, respectively. The spray-drying feed rate was 15-18%. The powder was then calcined in a tube furnace under an argon atmosphere. The calcination program was 500 °C for 2 hours, followed by a heating increase at 725 °C at 5 °C / min for 10 hours. After cooling, the resulting lithium iron phosphate powder was removed from the furnace. The LFP powder was then sieved through a -325 mesh sieve. XRD was used to evaluate phase purity and crystal quality.

[0136] Electrochemical Testing: A portion (1.12 g) of the LFP from the above examples was prepared into a slurry having the following components: 90 wt% LFP; 5 wt% PVDF; 5 wt% carbon black; and NMP. The amount of NMP was such that the solid content was approximately 40 wt% of the slurry. The slurry was coated onto an aluminum foil current collector, the coating was dried, and then calendered to 40% porosity to form an electrode. The LFP loading on the electrode was approximately 8 mg / cm². Four coin cells were assembled from each calendered electrode using lithium foil as the counter electrode and 1.2 M LiPF6 (ethylene carbonate: diethyl carbonate = 3:7) and 5% fluoroethylene carbonate as the electrolyte solution. The cells were cycled for 10 cycles at C / 20. The first cycle capacity and coulombic efficiency are summarized in Table 3 below, which shows that the LFP synthesized from the above Li₂CO₃ has battery performance comparable to that of prior art Li₂CO₃.

[0137] Table 3

[0138]

[0139] Concept LiNi x Mn y Co z O2 synthesis: This compound can be produced from the metal-containing precursor Ni using the method disclosed herein. 0.6 Mn 0.2 Co 0.2 (OH)₂ and Li₂CO₃ are synthesized. Specifically, 10 grams of Ni can be used to synthesize Ni. 0.6 Mn 0.2 Co 0.2(OH)₂ and 4.2 g of Li₂CO₃ were introduced into a plastic container at a molar ratio of 1.05 Li to TM for acoustic mixing under gradually increasing forces of 50, 60, and 70 times gravity, each lasting 1 minute. After mixing, the mixture was transferred to an alumina crucible and placed in a tube furnace under a gas flow. Ni 0.6 Mn 0.2 Co 0.2 A mixture of (OH)₂ and Li₂CO₃ was oxidized by heat treatment at 500 °C for 4 hours, followed by calcination at 850 °C for 12 hours, with a heating rate of 5 °C / min. X-ray powder diffraction (XRD) of the resulting powder confirmed that it possessed a layered LiNi structure. 0.6 Mn 0.2 Co 0.2 The formation of O2 (NMC 622).

[0140] definition

[0141] Unless otherwise defined, all technical terms, symbols, and other technical and scientific terms or expressions used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some instances, terms with commonly understood meanings are defined herein for clarity and / or for ease of reference, and the inclusion of such definitions herein should not necessarily be construed as indicating a material difference from the commonly understood meaning in the art.

[0142] The terms “powder” and “granule” are used interchangeably in this document, except that a single powder refers to multiple granules. This disclosure applies to a wide range of granules and powders.

[0143] As used herein, the terms “layer” and “coating layer” are equivalent. Specifically, as with respect to particles, each term “layer” or “coating layer” means that at least a portion of the surface of such particles, substantially all or all of the surface of such particles, is covered by or in contact with a “layer” or “coating layer.” Similarly, the term “coated” with respect to particles means that at least a portion of the surface of such particles, substantially all or all of the surface of such particles, is covered by or in contact with the substance to which such particles are “coated.”

[0144] References to “about” values ​​or parameters in this document include (and descriptions) variations of that value or parameter itself. For example, a description of “about X” includes a description of “X”. Furthermore, references to phrases such as “less than,” “greater than,” “at most,” “at least,” “less than or equal to,” “greater than or equal to,” or other similar phrases followed by a string of values ​​or parameters mean that the phrase is applied to each value or parameter in that string.

[0145] As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context explicitly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and covers any and all possible combinations of one or more of the associated listed items. It should also be understood that, when used herein, the terms “includes” and / or “comprises” specify the presence of the stated feature, integer, step, operation, element, component, and / or unit, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, units, and / or groups thereof.

[0146] This application discloses several numerical ranges in the text and accompanying drawings. The disclosed numerical ranges inherently support any range or value within the disclosed numerical ranges, including endpoints, even if precise range limitations are not stated verbatim in the specification, because this disclosure can be practiced throughout the disclosed numerical ranges.

[0147] The above description is presented to enable those skilled in the art to make and use this disclosure, and it is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Therefore, this disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

1. A method for producing lithium carbonate, the method comprising: A solid lithium precursor containing lithium hydroxide is contacted with a gas containing at least 5% by weight carbon dioxide, thereby converting at least a portion of the solid lithium precursor into lithium carbonate. The lithium carbonate includes micron-sized lithium carbonate particles and nano-sized lithium carbonate particles coated on the micron-sized lithium carbonate particles.

2. The method of claim 1, wherein the solid lithium precursor is ground in a jet mill having an atmosphere containing the gas.

3. The method of claim 1, wherein the solid lithium precursor further comprises an inorganic lithium salt, an organic lithium salt, lithium metal, a lithium alloy, a lithium oxide, or a combination thereof.

4. The method of claim 1, wherein the lithium hydroxide is lithium hydroxide monohydrate.

5. The method of claim 1, wherein the gas comprises at least 25% by weight carbon dioxide.

6. The method of claim 5, wherein the gas comprises at least 50% by weight carbon dioxide.

7. The method of claim 1, wherein at least 75% of the solid lithium precursor is converted into lithium carbonate.

8. The method of claim 1, wherein the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 microns.

9. The method of claim 1, wherein at least a portion of the micron-sized lithium carbonate particles is hollow.

10. The method of claim 1, wherein the lithium carbonate has a concentration of 2 to 12 m 2 Brunol-Emmette-Taylor (BET) specific surface area per g.

11. The method of claim 1, further comprising drying the lithium carbonate in a fluidized bed with or without carbon dioxide gas.

12. A powder, said powder comprising: Micron-sized lithium carbonate particles; and Nanoscale lithium carbonate particles coated on the surface of the micron-sized lithium carbonate particles.

13. The powder of claim 12, wherein at least a portion of the micron-sized lithium carbonate particles is hollow.

14. The powder of claim 12, wherein the micron-sized lithium carbonate particles have a particle size distribution with a D50 of 1 to 10 microns.

15. The powder of claim 12, wherein the lithium carbonate has a concentration of 2 to 12 μm. 2 Brunol-Emmette-Taylor (BET) specific surface area per g.

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