WO2020047213A1

WO2020047213A1 - Attritor-mixed positive electrode active materials

Info

Publication number: WO2020047213A1
Application number: PCT/US2019/048745
Authority: WO
Inventors: Dongqiang LIU; Amélie FORAND; Myunghun CHO; Karim Zaghib; Jan L. Allen; Samuel A. Delp III; T. Richard Jow
Original assignee: HYDRO-QUéBEC; Government Of The United States Of America, As Represented By The Secretary Of The Army
Priority date: 2018-08-30
Filing date: 2019-08-29
Publication date: 2020-03-05

Abstract

The disclosure provides a method of manufacturing an active material having the general chemical formula A_xM_yE_z(XO₄)_q, wherein A is an alkali metal or an alkaline earth metal, M is an electrochemically active metal, E is a non-electrochemically active metal, a boron group element, or silicon or any alloys or combinations thereof, X is phosphorus or sulfur or a combination thereof, 0<x≤1, y>0, z ≥0, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced. The method includes attritor-mixing precursors of the active material to form precursor particles having an average size and heating the stoichiometric amounts of the precursors to at least a temperature for at least a heating duration of time to form the active material.

Description

ATTRITOR-MIXED POSITIVE ELECTRODE ACTIVE MATERIALS

PRIORITY CLAIM

The present application claims priority under 35 U.S.C. §H9(e) to U.S. Provisional Patent Application Ser. No. 62/725,045, filed August 30, 2018, titled “ATTRITOR-MIXED POSITIVE ELECTRODE ACTIVE MATERIALS,” which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to methods of manufacturing positive electrode active materials using attritor-mixing.

BACKGROUND

Batteries contain electrochemically active materials in their electrodes. These electrochemically active materials are often simply referred to as active materials.

Active materials are typically manufactured from precursor materials. However, many common manufacturing techniques are not suitable for active material manufacturing. For example, lithium metal phosphate active materials are often very sensitive to water or humidity during manufacturing, resulting in low yields, poor-quality product, or the inability to use some manufacturing methods entirely. In addition, many methods suitable for the production of very small batches, such as high-energy ball milling, often performed using a SPEX® mixer (SPEX Sample Prep, New Jersey), are not scalable to larger batches and commercial production.

SUMMARY

The present disclosure provides a method of manufacturing an active material having the general chemical formula A_xM_yE_z(X04)q and a crystal structure, wherein A is an alkali metal or an alkaline earth metal, M is an electrochemically active metal, E is located in the same structural location as A in the crystal structure and is a non- electrochemically active metal, a boron group element, or silicon (Si) or any alloys or combinations thereof, X is phosphorus (P), sulfur (S) or silicon (S), or a combination thereof, 0<x<l, y>0, z >0, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced. The method includes attritor-mixing precursors of the active material to form precursor particles having an average size and heating the stoichiometric amounts of the precursors to at least a temperature for at least a heating duration of time to form the active material.

The present disclosure further provides an active material having the general chemical formula AxMyEz(X0₄)q and a crystal structure, wherein A is an alkali metal, M is an electrochemically active metal, E is located in the same structural location as A in the crystal structure and is a non-electrochemically active metal, a boron group element, or silicon (Si) or any alloys or combinations thereof, X is phosphorus (P) or sulfur (S) or a combination thereof, 0<x<l, y>0, z >0, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced. The active material is prepared according to above method.

The present disclosure further includes a battery including a negative electrode, an electrolyte, and a positive electrode including the above active material.

The above method, active material and battery may be further characterized by one or more of the following additional features, which may be combined with one another or any other portion of the description in this specification, including specific examples, unless clearly mutually exclusive:

i) A may be lithium (Li), sodium (Na) or potassium (K);

i-a) A may be Li;

i-b) A may be Na;

ii) M may be a transition metal, or an alloy or any combinations thereof;

ii-a) M may be iron (Fe), chromium (Cr), manganese (Mn), nickel (Ni), cobalt (Co), vanadium (V), or titanium (Ti), or an alloy or any combinations thereof;

ii-b) M may be Co or an alloy thereof;

ii-c) M may be a combination of Co and Fe;

ii-d) M may be a combination of Co and Cr;

ii-e) M may be a combination of Co, Fe, and Cr;

iii) z may be greater than 0;

iii-a) E may be Si;

iii-b) E may be a non-electrochemically active metal;

iii-b-l) the non-electrochemically active metal may be magnesium (Mg), calcium (Ca), strontium (Sr), zinc (Zn), scandium (Sc), or lanthanum (La), or any alloys or combinations thereof; iii-c) E may be a boron group element;

iii-c-l) the boron group element may be aluminum (Al) or gallium (Ga) or a combination thereof;

iv) X may be P;

v) X may be S;

vi) X may be Si;

vii) the precursors may include at least one hydroxide, alkali metal phosphate, non-metal phosphate, metal oxide, acetate, oxalate, or carbonate;

vii-a) the hydroxide may include at least one of Li OH, Co(OH)₂ Al(OH)₃; vii-b) the alkali metal phosphate may include at least one of L1H2PO4 or L12HPO4;

vii-c) the non-metal phosphate may include at least one of NH4H2PO4 or (NH₄)2HP0₄;

vii-d) the metal oxide may include at least one of Cn03, CaO, MgO, SrO, AI2O3, Ga₂0₃, T1O2, ZnO, SC2O3, La₂0₃ or Zr0₂;

vii-e) the acetate may include Si(OOCCH₃)4;

vii-f) the oxalate may include FeC204,NiC204 or C0C2O4;

vii-g) the carbonate may include L12CO3, MnC0₃, C0CO3 or N1CO3;

viii) attritor-mixing may include placing balls and the precursors in an attritor in a set w:w ratio;

ix) attritor-mixing may include placing a total volume of balls and precursors in an attritor container that is no more than 75% of a total volume of the attritor container;

x) attritor-mixing may occur for a mixing duration of time until a particle size plateau is reached;

xi) attritor-mixing may occur for no more than 10% longer than a mixing duration of time at which the particle size plateau is reached;

xii) attritor-mixing may occur for a mixing duration of time sufficient to result in a yield in an active material yield plateau;

xiii) attritor-mixing may occur for no more than 10% longer than a mixing duration of time sufficient to result in a yield in an active material yield plateau; xiv) attritor-mixing may occur for a mixing duration of time sufficient to result in an active material capacity plateau;

xvi) attritor-mixing may occur for no more than 10% longer than a mixing duration of time sufficient to result in an active material capacity plateau;

xvii) attritor-mixing may occur for a mixing duration of time between and including 10 hours and 12 hours;

xviii) the precursor particles may have an average particle size of between and including 1 pm and 700pm;

xix) the precursor particles may be filtered to remove particles over a set size; xx) A may be Li, M may be Co or a Co alloy or combination, and X may be P, and the temperature may be between and including 600°C and 800 °C;

xxi) heating may occur for a heating duration of time between and including 6 hours and 24 hours;

xxii) the method may have a yield of between least 95% and 99.9%;

xxiiii) the active material may have has a purity of between 95% and 99.9%.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention may be further understood through reference to the attached figures. The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 is an X-ray diffraction (XRD) profile of a multiple-substituted lithium cobalt phosphate ( LiCoo.82Feo.o976Cro.o488Sio.oo976P04) active material. Typical XRD patterns of the final product with trace of impurity are marked by *.

FIG. 2 is a representative energy-dispersive X-ray spectroscopy (EDX) analysis of an iron (Fe), silicon (Si) and chromium (Cr)-containing active material showing trace Si and Cr agglomeration. The scale bar in all images is 10 pm.

FIG. 3 is a representative cross-sectional energy-dispersive X-ray spectroscopy (EDX) analysis of a Fe, Cr and Si-containing active material showing trace Cr impurities. The scale bar in the leftmost image is 10 um. The scale bars in all other images is 5 pm. FIG. 4A and FIG. 4B are a pair of representative scanning electron microscope (SEM) image of particles of active material. The scale bar in FIG. 4A is 20 um. The scale bar in FIG. 4B image is 5 pm.

FIG. 5 is a flow chart of a method of attritor-mixing precursors and heating to form an active material.

FIG. 6 is a schematic partially cross-sectional elevation drawing of an attritor suitable for use in the present disclosure.

FIG. 7 is a graph showing the effect of balfprecursor w:w ratio during attritor mixing on capacity of active material formed from the attritor-mixed precursors.

FIG. 8A is a graph showing particle size distribution after attritor-mixing for 6 hours with an 8: 1 balfprecursor w:w ratio.

FIG. 8B is a graph showing the particle size distribution of the same precursor mixture as in FIG. 8 A after attritor-mixing for 12 hours with an 8:1 balfprecursor w:w ratio.

FIG. 9 is a battery including an active material according to the present disclosure.

FIG. 10 is an XRD profile of a LiCoo.82Feo.o97₆Cro.o488Sio.oo97₆P04 active material after 6 hours or 12 hours of attritor-mixing with a 6: 1 balfprecursor w:w ratio.

FIG. 11 is an XRD profile of a LiCoo.82Feo.o97₆Cro.o488Sio.oo97₆P04 active material after 12 hours of attritor-mixing with an 8: 1 balfprecursor w:w ratio.

FIG. 12 is an XRD profile of a LiCoo.82Feo.o97₆Cro.o488Sio.oo97₆P04 active material after 12 hours of attritor-mixing a with a 10: 1 balfprecursor w:w ratio.

FIG. 13 is an XRD profile of a LiCoo.82Feo.o97₆Cro.o488Sio.oo97₆P04 active material after 12 hours of attritor-mixing a with a 12: 1 balfprecursor w:w ratio.

FIG. 14 is an XRD profile of a LiCoo.82Feo.o97₆Cro.o488Sio.oo97₆P04 active material after 12 hours of attritor-mixing a with a 14: 1 balfprecursor w:w ratio.

DETAILED DESCRIPTION

The present disclosure relates to methods of manufacturing alkali metal active materials using attritor-mixing. The method is usable to produce commercial -level quantities of active material with no or low levels of impurities. Active Materials

Methods of the present disclosure may be used to produce positive electrode active materials having a crystal structure and including an alkali metal or an alkaline earth metal, an electrochemically active metal, and a tetraoxide polyanion, such as phosphate. These active materials are most commonly used as the cathode active material in a battery.

In particular, the positive electrode active materials may have a general chemical formula AxMyEz(X0₄)q and a crystal structure. A may be an alkali metal or an alkaline earth metal. M may be an electrochemically active metal. E may be located in the same structural location as A in the crystal structure and be a non- electrochemically active metal, a boron group element, or silicon (Si) or any alloys or combinations thereof. X may be part of the tetraoxide polyanion and may be phosphorus (P), sulfur (S) or silicon (S), or a combination thereof. 0<x<l, y>0, z >0, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced.

The alkali metal (Group 1, Group I metal) in the active material may be lithium (Li) sodium (Na), or potassium (K). The alkaline earth metal (Group 2, Group IIA metal) may be magnesium (Mg) or calcium (Ca). The alkali metal or alkaline earth metal may be present as a mobile cation or able to form a mobile cation, such as lithium ion (Li⁺), sodium ion (Na⁺), potassium ion (K⁺), magnesium ion (Mg²⁺), or calcium ion (Ca²⁺).

The metal in the active material may be any electrochemically active metal, most commonly a transition metal, such as a Group 4-12 (also referred to as Groups IVB-VIII, IB and IIB) metal. Particularly useful transition metals include those that readily exist in more than one valence state. Examples include iron (Fe), chromium (Cr), manganese (Mn), nickel (Ni), cobalt (Co), vanadium (V), or titanium (Ti). The active material may include any electrochemically active combinations or alloys of these metals.

In addition, the active material may contain, in the place of M in the crystal structure, non-electrochemically active metals or a boron group element (Group 13, Group III), or silicon (Si), or any combinations or alloys thereof, which otherwise affect the electrical or electrochemical properties of the active material For example, non-electrochemically active metals or boron group element or silicon (Si) may change the operating voltage of the active material, or increase the electronic conductivity of active material particles, or improve the cycle life or coulombic efficiency of a battery containing the active material. Suitable non-electrochemically active metals include alkaline earth metals (Group 2, Group II metals) such as magnesium (Mg), calcium (Ca) or strontium (Sr), or zinc (Zn), scandium (Sc), or lanthanum (La), or any alloys or combinations thereof. Suitable boron group elements include aluminum (Al) or gallium (Ga) and combinations thereof.

The tetraoxide polyanion may be phosphate (P0₄). Some active materials may contain other tetraoxide polyanions, such as sulfate (S0₄) or silicate (Si0₄) in place of or in combination with phosphate.

The alkali metal, electrochemically active metal, non-electrochemically active metal or boron group element or silicon (Si), and tetraoxide polyanion are present in relative amounts so that the overall active material compound or mixture of compounds is charge balanced. The active material compound or mixture of compounds are primarily present in a crystalline, as opposed to an amorphous form, which may be confirmed via XRD. If the active material contains a mixture of compounds or a compound that may assume multiple crystal structures, the active material may exhibit more than one phase, with each phase having a different crystal structures. Common crystal structures for active materials produced using the methods described herein include olivine, NASICON, and orthorhombic structures. The presence of a given crystal structure as well as the identity of the active material compound producing that structure may be confirmed using XRD and reference XRD patterns correlating to known crystal structures. An example of such confirmation for Fe, Cr and Si-substituted LiCoPCri is provided in FIG. 1.

The active material may have the general chemical formula AxM_yE_z(X0₄)q, in which A is the alkali metal, M is the electrochemically active metal, E is the non- electrochemically active metal or boron group element or Si or any alloys or combinations thereof, and X is phosphorus (P) or sulfur (S) or a combination thereof, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced. In more specific examples, the active material may be a simple phosphate, such a lithium metal phosphate LiMP0₄, in which M is the electrochemically active metal. In particular, it may be LiFePCri, LiMnP0₄ or LiCoPC The active material may also be a more complex material, such as Li_xM_yE_zP0₄, where 0<x<l, y>0, and z>0, M is the electrochemically active metal and e E is a non-electrochemically active metal or a boron group element (Group 13, Group III), or Si. For example, the active material may be LiCoo.9Feo.iP0₄, Lio.95Coo.85Feo.iCro.o5P0₄,

Lio.93Coo.8₄Feo.iCro.o5Sio.oiP0₄, and LiCoo.82Feo.o97₆Cro.o₄₈₈Sio.oo97₆P0_4.

Active materials produced using the methods of the present disclosure may also have an integrally formed coating, such as a carbon coating or polymer coating. This integrally formed coating may be covalently bonded to the active material. Chemical formulas listed herein do not include coatings, even for active materials that are typically coated.

Active materials produced using the methods of the present disclosure may have a purity of at least 95%, at least 98%, at least 99%, or a purity in a range between and including any combinations of these values, as measured by XRD refinement, an example of which is provided in FIG. 1. Impurities are typically in the form of unreacted precursors or precursors that have reacted to form compounds other than the active material and crystalline impurities in amounts of 1% or greater of a given crystalline impurity compound may be detected using XRD. Non-crystalline impurities and impurities in amounts of less than 1% may be detected using EDX, examples of which are provided in FIG. 2 and FIG. 3.

Active materials formed using the methods disclosed herein, when used in a battery, may exhibit stable capacity, with a capacity fade of 50% or less, 40% or less, 20% or less, 10% or less, 5% or less, 1% or less, or a range between and including any combinations of these values over 110 cycles at C/2 as compared to the capacity at the tenth cycle at C/2.

Active materials formed using the methods disclosed herein may be in the form of particles that are, on average over the batch of particles, excluding agglomerates, no longer than 1 nm, 10 nm, 50 nm, 100 nm, 500 nm, or 999 nm, or any range between and including any combination of these values. Such particles are referred to as nanoparticles. Active materials formed using the methods disclosed herein may be in the form of particles that are, on average over the batch of particles excluding agglomerates, no longer than 1 pm, 10 pm, 50 pm, 100 pm, 500 pm, or 999 pm, or any range between and including any combination of these values. Such particles are referred to as microparticles.

Active materials particle may form agglomerates, in which case any agglomerate is excluded from the average particle size discussed above. However, the agglomerate may itself be a nanoparticle or a microparticle. For example, the agglomerate may be a microparticle composed of nanoparticles of active material.

Particle and agglomerate size may be assessed using scanning electron microscopy (SEM), an example of which is shown in FIGs. 4A and 4B.

Precursors

Suitable precursors for use in manufacturing the active material will depend on the specific active material to be produced. Typically the precursors are in solid form, as the methods disclosed herein are solid state manufacturing methods. Wet precursors or those available as hydrates or containing substantial humidity may be dried prior to use in the methods of the present disclosure. Common precursors include metal hydroxides, such as LiOH, Co(OH)₂ and Al(OH)₃, alkali metal or alkaline earth metal phosphates, such as L1H2PO4 or LriHPCri, non-metal phosphates, such as NH4H2PO4, (NH₄)₂HP04, metal oxides, such as CnCh, CaO, MgO, SrO, AI2O3, Ga₂03, T1O2, ZnO, SC2O3, La₂03 or ZrCk, acetates, such as Si(OOCCH3)4, oxalates, such as FeCiCri, N1C2O4 or C0C2O4 (which are often stored as a hydrate, which may be dried before use in the present methods), and carbonates, such as U2CO3, MnCCh, C0CO3 or NiCCh.

For active materials that have a coating, such as a carbon coating, coating precursors may also be included in the methods described herein. Suitable coating precursors include elemental carbon or carbon-containing materials, such as polymers, that are broken down to form a carbon coating. Suitable coating precursors may also include coating polymers, or monomers or oligomers that form larger coating polymers.

Methods of Manufacturing Active Materials

The present disclosure provides methods of manufacturing active materials, including those described above, from precursors, including those described above. The methods are solid-state methods that generally include attritor-mixing of at least non-coating precursors, followed by heating the mixture.

Methods disclosed herein may be used to form at least 1 kg, at least 2 kg, at least 3kg, at least 5 kg, at least 10 kg, at least 25 kg, at least 50 kg, at least 100 kg active material, or an amount between and including any two of these recited amounts (e.g. between and including 1 kg and 2 kg, between and including 1 kg and 3 kg, between and including 1 kg and 5 kg, between and including 1 kg and lOkg, between 1 kg and 50 kg, between and including 1 kg and 50 kg, between and including 1 kg and 100 kg, between 25 kg and 50 kg) per batch.

Methods disclosed herein, prior to particle size filtering, may have a yield of at least 80%, at least 85%, or at least 90%, at least 95%, or at least 99%, at least 99.9% or an amount between and including any two of these recited amounts per batch. Yield is measured prior to particle size filtering to exclude effects directly to the particle size selected, rather than the active-particle forming reaction and method.

For coated active materials, the coating precursor may be added prior to attritor-mixing, after attritor-mixing, but before heating, or after heating, depending largely on the coating to be formed. For example, carbon coating precursors will typically be added prior to attritor-mixing. Polymer coating precursors will typically be added after heating. For simplicity, the method as described below does not include a description of coating precursors or when they are added to the process, nor does it include details of how the coating is formed. One of ordinary skill in the art, using the teachings of the present disclosure and, optionally, through conducting a series of simple experiments in which coating materials are added at different stages of the methods, also optionally in different relative amounts, will be able to readily determine how to incorporate coating steps into the methods disclosed herein.

Referring now to FIG. 5, the present disclosure provides a method 110 for manufacturing an active material. In step 120, wet or hydrate precursors are dried. In step 130, precursors that are too large to fit in the attritor chamber or to be milled by the attritor are cut to a sufficiently small size. Steps 120 and 130 may be performed in any order.

In step 140, stoichiometric amounts of precursors that will be attritor-mixed are placed in the chamber of the attritor and attritor-mixed to form precursor particles. Although, typically, all active material precursors will be attritor-mixed, some precursors may be added after attritor-mixing.

The attritor used in step 140 may be any suitable attritor. An attritor is a mixing apparatus having a container, an arm extending from the exterior of the container through a lid of the container and into the interior of the container, and at least one and typically a plurality of paddles in the interior of the container coupled to the arm so that when the arm rotates in response to a rotational force applied outside of the container, the paddles rotate within the container. If a material is in the container, then it will be impacted by the paddles and its size will be reduced by a combination of friction and impact with the paddles or other materials in the container.

An example attritor 200 suitable for use in methods of the present disclosure is depicted in FIG. 6. Attritor 200 includes a container 210, which has a lid 220. Attritor 200 also includes couple 230, which attaches to an external source of rotational force, such as a motor. Couple 230 is located at a first end of an arm 240, which is located exterior to the container 210. The arm 240 passes through a guide 250 mounted on the lid 220 and through the lid 220 into the interior of the container 210. At least one and, as depicted, typically a plurality of paddles 260 are located in the interior of the container 210 and are coupled to a portion of the arm 240 also in the interior of the container 210.

The attritor 200 also includes a plurality of balls 270 (depicted as only two balls for simplicity).

During operation of the attritor, the balls are also impacted by the paddles and/or the material and help reduce the size of the precursors.

Balls used in step 140 may be of any size suitable to reduce the precursors to a set particle size within a set time. 19 mm diameter balls may work particularly well, and 12.7 mm diameter balls may also be suitable.

The balls may be made of any materials that do not react with the precursors to a degree that reduces yield below 80% or produces impurities in an amount of more than 5% total impurities. Suitable materials for the balls include steel, zirconium, or tungsten. The balls may have an interior made of a different material with an exterior coating of a suitable material. Although the balls contribute to reduction of precursor size, they also occupy volume in the attritor chamber that might otherwise be occupied by precursors. Accordingly, the proportion of balls to total precursors (w:w) may be limited to the smallest ratio that still allows an active material having the selected particle size or other set property to result from the overall method 110. For example, FIG. 7 shows a comparison of capacity and ball dotal precursors (w:w) such as might be used to select the proportion.

The particle size of precursors after attritor-mixing is typically 10 pm or less, 50 pm or less, 100 pm or less, 500 pm or less, 600 pm or less, or 750 pm or less and any ranges between and including and combinations of these values, ( e.g . between and including 1 pm and 10 pm, between and including 1 pm and 50pm, between and including 10 pm and 50 pm, between and including 1 pm and 600 pm). An appropriate w:w ratio may vary depending on the precursors used, the size of the precursors prior to attritor mixing, the size of the balls, and the attritor used, but one of ordinary skill in the art, using the teachings of this disclosure, may readily determine the appropriate balkprecursor ratio by simply varying these parameters until an acceptable precursor particle size or other set property such as capacity is obtained.

The total volume of balls and precursors in the attritor should not have a volume exceeding that specified by the attritor manufacturer. Typically, the total volume of balls and precursors is no more than 75% of the total volume of the attritor container, to allow sufficient room for the balls and precursors to move during mixing.

For any given set of precursors (at a selected pre-attritor-mixing size), balkprecursor ratio, ball size, and attritor, there will be a reduction of average precursor particle size over time during attritor-mixing until a particle size plateau is reached. Once the particle size plateau is reached, any additional duration of attritor- mixing will not further reduce the average precursor particle size by more than 10%, as compared to the average precursor particle size at the duration of time when the particle size plateau is reached. The plateau may also readily be determined by one of ordinary skill in the art, using the teachings of this disclosure. Although attritor- mixing in step 140 may be continued after the particle size plateau is reached, typically step 140 will last only until the particle size plateau is reached, no more than 10% longer than the duration at which the particle size plateau is reached, or a duration between and including these two times. Common mixing times to reach plateau include 10-12 hours. Examples particle size distributions based on mixing duration that may be used to determine when plateau is reached are provided in FIG. 8A and FIG. 8B

Properties, such as yield or active material capacity, determined at least in part by particle size may also exhibit a plateau with respect to attritor-mixing duration and attritor-mixing duration may be set based on such an alternative plateau such that the attritor-mixing duration is only until the plateau is reached, no more than 10% longer than the duration at which the plateau is reached, or a duration between and including these two times.

In some methods, it may be useful to control the temperature within the attritor during attritor-mixing. For example, some precursors may be temperature-sensitive, or it may be useful to limit reaction of the precursors to for the active material during attritor-mixing. If useful, the attritor may further contain a cooling system, such as an exterior cooling system or a cooling system located within the container, lid, arm, paddles, or any combinations of these. The cooling system may keep the temperature below a set temperature during step 140. Alternatively, or in addition, the precursors may be cooled prior to attritor-mixing in step 140. Also alternatively, or in addition, the attritor may include a thermometer to allow a ready determination of whether the precursors exceeded a set temperature during step 140, in which case they may be discarded or subjected to a quality control process.

After attritor-mixing in step 140, a stoichiometric amount of any precursors not subjected to attritor-mixing is added to the attritor-mixed precursor particles.

Next, in step 150, the attritor-mixed precursor particles are filtered to exclude particles above a set size, typically lOpm, 50 pm, or 100 pm.

The filtered precursors are then heated in step 160 for a duration of time to undergo a chemical reaction and form the active material. The temperature to which the precursors are heated may vary depending on the precursors and active material. The heating in step 50 may be a simple heating process, in which the precursors are heated to a set temperature and maintained at that temperature for the duration of time. The heating in step 160 may also be a more complicated, stepped process, in which the precursors are heated to one or more temperatures for one or more times. The rate at which heating in step 160 occurs may also be controlled to occur at a particular degrees per minute and step 160 may even include cooling followed by heating in the overall heating process.

For active materials containing lithium, cobalt, and phosphate, the maximum temperature in heating step 50 may be at least 600 °C, particularly between and including 600 °C and 800 °C, and may be attained through temperature increases of between 1 °C/min and 10 °C/min. The heating step may last for at least 6 hours, at least 8 hours, at least 10 hours, or at least 12 hours, at least 18 hours, least 24 hours and ranges between and including and combinations of these values particularly between and including 6 hours and 24 hours. Heating may occur under a reducing or inert atmosphere, such as a nitrogen (N2) atmosphere. Heating may be preceded by a purge at room temperature (25 °C) under a reducing or inert atmosphere, such as a nitrogen atmosphere, for 1-4 hours, typically 3 hours.

After heating, in step 170 the material is cooled. Cooling may be a simple, passive cooling process, an active cooling process, or a stepped process. The material may be maintained a particular temperatures for a duration of time. The rate at which cooling occurs may also be controlled to occur at a particular degrees per minute and step 170 may even include heating followed by cooling in the overall cooling process.

The active material is present by the end of the cooling process 170. Depending on the precursors and active material, the active material may often be present even at the end of heating in step 160. In some methods 110, the heating process 510 and the cooling process 170 may overlap to form one continuous heating/cooling process.

Finally, in step 180, the active material is filtered to exclude particles above a set size. For example, 25 pm, 35 pm, 38 pm, 40 pm, 50pm, or 100 pm.

It will be understood that methods of the present disclosure may practice only steps 140 and 160 (or step 160/170 in place of step 160 if heating and cooling form one continuous heating/cooling process). The other steps described in connection with method 110 are each independently omittable. All or part of the steps of method 110 may be carried out in conditions that limit humidity. For example, all or part of the steps of method 110 may be carried out in a dry room or in a water-exclusive atmosphere, such as an inert, hydrogen, or nitrogen atmosphere (although, for most active materials, this degree of precaution is not needed), or at ambient humidity of less than 25% or less than 10%.

Active materials produced using the above method may be used in the positive electrodes of batteries, such as the battery 300 illustrated in FIG. 9. The battery 300 includes negative electrode (anode) 310, positive electrode (cathode) 320, and electrolyte 330. The electrolyte may include a mobile lithium ion (Li⁺), sodium ion (Na⁺), or potassium ion (K⁺) corresponding to the alkali metal in the active material, or a mobile magnesium ion (Mg⁺) or calcium ion (Ca⁺) corresponding to the alkaline earth metal in the active material . If the electrolyte is a liquid or gel electrolyte, the battery 300 may further include a separator. The negative electrode 310 may include the alkali metal or alkaline earth metal in the active material or a compound thereof, such as a titanate or niobiate, or carbon, such as graphite. The negative electrode 310 may also include a separate current collector. The positive electrode 320 may further include a separate current collector, binder, conductive additive, or combinations thereof.

Batteries such as battery 300 can be used, for example, in standard cell format batteries, portable electronics, medical devices, automobiles, aircraft, and grid supply/storage applications.

EXAMPLES

The following examples are provided solely to illustrate certain principles associated with the invention. They are not intended to nor should they be interpreted as disclosing or encompassing the entire breath of the invention or any embodiments thereof.

Example 1: Attritor-Mixed LiCoo.82Feo.o976Cro.o488Sio.oo976P04 ( 6:1 ratio)

930 g of UH2PO4, 675 g of CO(OH)₂, 160 g of FeCiCU 2H₂0, 28.5 g of Cr₂0₃, 23 g of Cr(OOCCH₃)3, and 76.3 g of acetylene black having dimensions of less than 500 pm were pre-dried at l20°C overnight under vacuum and then placed in an attritor having container volume of 9.5 L, 11.3 kg of steel balls (6: 1 ball precursor w:w ratio) with diameter of 19 mm were added. The attritor was operated at 400 rpm for 6-12 hours. Attri tor-mixed precursors were transferred to an oven then heated to 700 °C for 12 hours under N2 and naturally cooled in the oven. After heat treatment, about 1.4 kg of final product was obtained and then filtered through a 38 pm sieve. XRD analysis of the resulting material is presented in FIG. 10. The XRD data confirm that active material having the same structure as LiCoPCri was produced even after only 6 hours of mixing.

Example 2: Attritor-Mixed LiCoo.82Feo.o976Cro.o488Sio.oo976PO 4 (8: 1 ratio)

723 g of L1H2PO4, 525 g of CO(OH)₂, 122 g of FeC₂0₄ 2H₂0, 22.2 g of Cr₂0₃, 17.9 g of Cr(OOCCH₃)3, and 59.4 g of acetylene black having dimensions of less than 500 pm were firstly pre-dried at l20°C overnight under vacuum and then placed in an attritor having container volume of 9.5 L, 11.8 kg of steel balls (8: 1 ball precursor w:w ratio) with diameter of 19 mm were added. The attritor was operated at 400 rpm for 12 hours. Attri tor-mixed precursors were transferred to an oven then heated to 700 °C for 12 hours under N2 and naturally cooled in the oven. After heat treatment, about 1.1 kg of final product was obtained and then filtered through a 38 pm sieve. XRD analysis of the resulting material is presented in FIG. 11. The XRD data confirm that active material having the same structure as LiCoPCri was produced. Example 3: Attritor-Mixed LiCoo.82Feo.o976Cro.o488Sio.oo976P04 (10: 1 ratio)

578 g of L1H2PO4, 420 g of CO(OH)₂, 97.6 g of FeC₂C>4 2H₂0, 17.7 g of CnCb, 14.3 g of Cr(OOCCIT₃)₃, and 47.5 g of acetylene black having dimensions of less than 500 pm were firstly pre-dried at l20°C overnight under vacuum and then placed in an attritor having container volume of 9.5 L, 11.8 kg of steel balls (10: 1 ball precursor w:w ratio) with diameter of 19 mm were added. The attritor was operated at 400 rpm for 12 hours. Attritor-mixed precursors were transferred to an oven then heated to 700 °C for 12 hours under N2 and naturally cooled in the oven. After heat treatment, about 0.9 kg of final product was obtained and then filtered through a 38 pm sieve. XRD analysis of the resulting material is presented in FIG. 12. The XRD data confirm that active material having the same structure as LiCoPCri produced.

Example 4: Attritor-Mixed LiCoo.82Feo.o976Cro.o488Sio.oo976P04 (12: 1 ratio)

483 g of L1H2PO4, 351 g of CO(OH)₂, 81.5 g of FeC₂C>4 2H₂0, 14.8 g of CnCb, 12.0 g of Cr(OOCCH₃)₃, and 39.8 g of acetylene black having dimensions of less than 500 mih were firstly pre-dried at l20°C overnight under vacuum and then placed in an attritor having container volume of 9.5 L, 11.8 kg of steel balls (12: 1 balkprecursor w:w ratio) with diameter of 19 mm were added. The attritor was operated at 400 rpm for 12 hours. Attritor-mixed precursors were transferred to an oven then heated to 700 °C for 12 hours under N2 and naturally cooled in the oven. After heat treatment, about 0.73 kg of final product was obtained and then filtered through a 38 pm sieve. XRD analysis of the resulting material is presented in FIG. 13. The XRD data confirm that active material having the same structure as LiCoPCri was produced.

Example 5: Attritor-Mixed LiCoo.82Feo.o976Cro.o488Sio.oo976PO 4 (14: 1 ratio)

413 g of L1H2PO4, 301 g of CO(OH)₂, 70 g of FeC₂C>4 2H₂0, 12.7 g of Cr₂0₃, 10.3 g of Cr(OOCCH₃)3, and 34 g of acetylene black having dimensions of less than 500 pm were firstly pre-dried at l20°C overnight under vacuum and then placed in an attritor having container volume of 9.5 L, 11.8 kg of steel balls (14: 1 balkprecursor w:w ratio) with diameter of 19 mm were added. The attritor was operated at 400 rpm for 12 hours. Attritor-mixed precursors were transferred to an oven then heated to 700 °C for 12 hours under N2 and naturally cooled in the oven. After heat treatment, about 0.62 kg of final product was obtained and then filtered through a 38 pm sieve. XRD analysis of the resulting material is presented in FIG. 14. The XRD data confirm that active material having the same structure of LiCoPCri was produced.

The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Claims

1. A method of manufacturing an active material having the general chemical formula AxMyEz(X0₄)q and a crystal structure, wherein A is an alkali metal or alkaline earth metal, M is an electrochemically active metal, E is located in the same structural location as A in the crystal structure and is a non-electrochemically active metal, a boron group element, or silicon (Si) or any alloys or combinations thereof, X is phosphorus (P) or sulfur (S) or a combination thereof, 0<x<l, y>0, z >0, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced, the method comprising:

attritor-mixing precursors of the active material to form precursor particles having an average size; and

heating the stoichiometric amounts of the precursors to at least a temperature for at least a duration of time to form the active material.

2. The method of claim 1, wherein A is lithium (Li), sodium (Na) or potassium (K).

3. The method of claim 2, wherein A is Li.

4. The method of claim 2, wherein A is Na.

5. The method of claim 1, wherein M is a transition metal, or an alloy or any combinations thereof.

6. The method of claim 4, wherein M is iron (Fe), chromium (Cr), manganese (Mn), nickel (Ni), cobalt (Co), vanadium (V), or titanium (Ti), or an alloy or any combinations thereof.

7. The method of claim 5, wherein M is Co or an alloy thereof.

8. The method of claim 5, wherein M is a combination of Co and Fe.

9. The method of claim 5, wherein M is a combination of Co and Cr.

10. The method of claim 5, wherein M is a combination of Co, Fe, and Cr.

11. The method of claim 1, wherein z>0.

12. The method of claim 11, wherein E is Si.

13. The method of claim 11, wherein E is a non-electrochemically active metal.

14. The method of claim 13, wherein the non-electrochemically active metal is magnesium (Mg), calcium (Ca), strontium (Sr), zinc (Zn), scandium (Sc), or lanthanum (La), or any alloys or combinations thereof.

15. The method of claim 11, wherein E is a boron group element.

16. The method of claim 15, wherein the boron group element is aluminum (Al) or gallium (Ga) or a combination thereof.

17. The method of claim 1, wherein X is P.

18. The method of claim 1, wherein X is S.

19. The method of claim 1, wherein X is Si.

19. The method of claim 1, wherein the precursors comprise at least one hydroxide, alkali metal phosphate, alkaline earth metal phosphate, non-metal phosphate, metal oxide, acetate, oxalate, or carbonate.

20. The method of claim 19, wherein the hydroxide comprises at least one of Li OH, Co(OH)₂ Al(OH)₃.

21. The method of claim 19, wherein the alkali metal phosphate comprises at least one of LiThPCri or LriHPCri.

22. The method of claim 19, wherein the non-metal phosphate comprises at least one of NH4H2PO4 or (NTri^HPCri.

23. The method of claim 19, wherein the metal oxide comprises at least one of CnCb, CaO, MgO, SrO, AI2O3, Ga2Cb, T1O2, ZnO, SC2O3, La2Cb or ZrCk.

24. The method of claim 19, wherein the acetate comprises Si(OOCCH₃)4.

25. The method of claim 19, wherein the oxalate comprises FeC204, N1C2O4 or C0C2O4.

26. The method of claim 19, wherein the carbonate comprises L12CO3, MnCCb, C0CO3 or NiCCb.

27. The method of claim 1, wherein attritor-mixing comprises placing balls and the precursors in an attritor in a set w:w ratio.

28. The method of claim 1, wherein attritor-mixing comprising placing a total volume of balls and precursors in an attritor container that is no more than 75% of a total volume of the attritor container.

29. The method of claim 1, wherein attritor-mixing occurs until a particle size plateau is reached.

30. The method of claim 1, wherein attritor-mixing occurs for no more than 10% longer than the duration at which the particle size plateau is reached.

31. The method of claim 1, wherein attritor-mixing occurs for a duration of time sufficient to result in a yield in an active material yield plateau.

32. The method of claim 1, wherein attritor-mixing occurs for no more than 10% longer than a duration of time sufficient to result in a yield in an active material yield plateau.

33. The method of claim 1, wherein attritor-mixing occurs for a duration of time sufficient to result in an active material capacity plateau.

34. The method of claim 1, wherein attritor-mixing occurs for no more than 10% longer than a duration of time sufficient to result in an active material capacity plateau.

35. The method of claim 1, wherein attritor-mixing occurs for a mixing duration of time between and including 10 hours and 12 hours.

36. The method of claim 1, wherein the precursor particles have an average particle size of between and including 1 pm and 700pm.

37. The method of claim 1, further comprising filtering the precursor particles to remove particles over a set size.

38. The method of claim 1, wherein A is Li, M is Co or a Co alloy or combination, and X is P, and the temperature is between and including 600°C and 800 °C.

39. The method of claim 1, wherein heating occurs for a heating duration of time between and including 6 hours and 24 hours.

40. The method of claim 1, wherein the method has a yield of between least 95% and 99.9%.

41. The method of claim 1, wherein the active material has a purity of between 95% and 99.9%.

42. An active material having the general chemical formula AxMyEz(X0₄)q and a crystal structure wherein A is an alkali metal or an alkaline earth metal, M is an electrochemically active metal, E is located in the same structural location as A in the crystal structure and is a non-electrochemically active metal, a boron group element, or silicon (Si) or any alloys or combinations thereof, X is phosphorus (P) or sulfur (S) or a combination thereof, 0<x<l, y>0, z >0, q>0, and the relative values of x, y, z, and q are such that the general chemical formula is charge balanced, wherein the active material is prepared according to any of the above claims.

43. A battery comprising:

a negative electrode,

an electrolyte, and

a positive electrode comprising the active material of Claim 42.