Multiphasic cathode material and method of forming it

Abstract

A lithium transition metal oxide powder comprised of interspersed orthorhomic and disordered rocksalt phases therein may be made by mixing a lithium precursor and a Mn precursor and a transition metal precursor comprised of another transition metal in a molar ratio of Mn / other transition metal of at least 1.5 to form a mixture, and heating the mixture for a reaction time (e.g., 15 minutes to 24 hours) and reaction temperature (800 °C to 975 °C) to form the lithium transition metal oxide powder. A powder comprised of a mixture of a disordered rocksalt powder and an orthorhombic powder having an average size ratio (disordered rocksalt powder average / orthorhombic powder average) from 0.2 to 5 is made by comminuting a mixture of these powders.

Description

WCAT-203-A-WOMULTIPHASIC CATHODE MATERIAL AND METHOD OF FORMING ITCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a PCT International Application which claims the benefit of U.S. Provisional Application 63 / 696,098 filed on September 18, 2024. The entire contents of these applications are incorporated herein by reference in their entirety.FIELD

[0002] The present invention is in the field of battery technology.BACKGROUND

[0003] Lithium metal oxides have been used to formulate cathode materials for lithium ion batteries. The cathodes arc derived from a few basic crystallographic structure types, such as spinels, olivines, and layered oxide structures. The layered oxide structures have included lithium- excess type structures, where additional lithium is present in the structure.

[0004] Recently, attention has been focused on disordered rocksalt structures, such as those formed from particular lithium metal oxides. Compounds represented by the formula; xLi3NbO4’(l-x)LiMO2 (1) where M is a divalent or trivalent cation, have been shown to be a promising class of transition metal oxides for use as cathodes in lithium ion batteries. The compounds of formula (1) are considered a disordered rocksalt in which a random atomic arrangement of lithium and transition metal ions are packed in a closely-packed cubic structure. These disordered rocksalt compositions offer the ability to contain up to 3 lithium atoms per formula unit, which is more than the conventional lithium-excess layered materials. Formula (1) can be transformed and represented as LixMyNzOw.

[0005] The disordered rocksalt structure is an attractive cathode material for next generation lithium ion batteries due to a greater specific energy density (e.g., a higher theoretical energy density) than state-of-the-art cathode materials, such as layered lithium metal oxide structures. For example, certain disordered rocksalt structure materials have a theoretical gravimetric energyWCAT-203-A-WO density of about 1120 Wh / kg, while a LiMii2O4 active material has a theoretical gravimetric energy density of about 492 Wh / kg and a LiMm.5Nio.5O4 has a theoretical gravimetric energy density of about 691 Wh / kg. This energy density is especially appealing when lower cost raw materials are used as components in the disordered rocksalt structure, such as manganese, which may be in combination with other transition metals. As such, the disordered rocksalt (DR) materials can achieve relatively high energy density with relatively low material cost. In order to achieve comparable energy density, known cathode materials require higher-cost raw materials, such as cobalt or nickel.

[0006] Unfortunately, these DR materials require the particle size to be in the submicrometer range due to the low Li diffusivity of these materials. This has caused these DR materials to suffer poor capacity and voltage retention issues, largely originating from the poorly controlled, heavily- pulverized nanoparticle morphology introduced upon preparing the DR materials. The pulverized particle morphology of DRs tends to accelerate the electrolyte decomposition and dissolution of Mn, when present, to the electrolyte, leading to shorter cycle life. Also, the pulverized particle morphology may lead to low electrode density decreasing the volumetric energy density of the DR material on a current collector that forms the typical cathode in a battery.

[0007] Disordered rocksalt materials have tended to have a shorter cycle life compared to incumbent lithium ion batteries. Recently, attempts to improve the cycle life of disordered rocksalt batteries has been described by substituting some of the oxygen with fluorine such as described in U.S. Pat. No. 10,280,092. Nevertheless, it would be desirable to provide a battery comprised cathodes comprised of disordered rocksalts having longer life and other desirable attributes such as safer batteries.BRIEF SUMMARY

[0008] Powders having an orthorhombic and disordered rock phase (composite particle “CP”), in the absence of other phases, have been discovered that are useful to form cathodes resulting in batteries having high capacity and longer cycle life. These powders, when cycling, has been surprisingly discovered to form a spinel phase that, without being limiting, contributes to the improved cycle life (i.e., contributes to the intercalation of Li). The presence of the phases in the powder may be determined by X-ray diffraction. Likewise, it has been discovered that certain24861 -9342-9452, v. 2WCAT-203-A-WO physical mixtures of disordered rocksalt and orthorhombic powder (e.g., o-LiMnCh) display similar’ desired characteristics as the composite particles.

[0009] A first illustration is a powder comprised of composite particles having interspersed orthorhombic and disordered rocksalt phases therein. The powder desirably is in the absence of any other phases (i.e., below the detectability of powder X-ray diffraction).

[0010] A second illustration is a powder is comprised of an orthorhombic, spinel and disordered rocksalt phases interspersed therein. The powder desirably is in the absence of any other phases. It has been surprisingly discovered that the first illustration powder preferably forms a spinel phase that contributes to the intercalation of Li allowing for improved capacity retention during battery operation.

[0011] A third illustration is a method to form a lithium transition metal oxide powder comprising, mixing a lithium precursor and a Mn precursor and a transition metal precursor comprised of another transition metal in a molar ratio of Mn / other transition metal of at least 1.5, and heating the mixture for a reaction time and reaction temperature to form the lithium transition metal oxide powder having composite particles comprised of a disordered rocksalt phase and an orthorhombic phase. The powders formed by reacting and forming the interspersed orthorhombic phases are referred to herein as “insitu generated” and “composite particles” as opposed to the powder mixture of the fourth illustration.

[0012] A fourth illustration is a powder mixture comprised of a physical mixture of a disordered rocksalt powder and an orthorhombic powder comprised of LiMnCL having an orthorhombic phase, the orthorhombic powder being present in an amount of 0.5 to 25% by weight of the disordered rocksalt powder and orthorhombic powder.

[0013] A fifth illustration is a method of forming a powder mixture comprised of mixing a disordered rocksalt powder and an orthorhombic powder comprised of LiMnCL having an orthorhombic phase in a weight ratio of the disordered rocksalt powder / orthorhombic powder from 1000 to 1 to form a mixture comminuting the mixture sufficiently to form the powder having an average particle size of less than 10 micrometer and the orthorhombic powder and the rocksalt34861 -9342-9452, v. 2WCAT-203-A-WO powder each have an average particle size and a size ratio of the average particle size of the disordered rocksalt / the average particle size of the orthorhombic powder is from 0.2 to 5.

[0014] The powders may be used in lithium ion batteries. The powder may be used with any suitable battery component to form a lithium ion battery in electrolyte including, for example, a current collector, separator and anode such as those known in the art.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 shows an X-ray diffractogram of a lithium transition metal oxide powder of and not of this invention.

[0016] Figure 2 shows a V v. capacity plots of batteries made with a lithium metal oxide powder of and not of this invention.

[0017] Figure 3 shows a dQ / dV v. V plots of batteries made with a lithium metal oxide powder of and not of this invention.

[0018] Figure 4 shows a V v. capacity plots of batteries made with a lithium transition metal oxide powder of and not of this invention.

[0019] Figure 5 shows a dQ / dV v. V plots of batteries made with a lithium transition metal oxide powder of and not of this invention.

[0020] Figure 6 is an X-ray diffractogram of a lithium transition metal oxide powders of this invention

[0021] Figure 7 shows a V v. capacity plots and capacity v. cycle number plots of batteries made with lithium transition metal oxide powders of this invention.

[0022] Figure 8 is an X-ray diffractogram of lithium transition metal oxide powders of this invention.

[0023] Figure 9 is an scanning transmission electron micrograph (STEM) of a lithium transition metal oxide powder particle of this invention.44861 -9342-9452, v. 2WCAT-203-A-WO

[0024] Figure 10 is an energy dispersive spectroscopy spectra of two regions of a lithium transition metal oxide powder particle (see Figure 9) of this invention.

[0025] Figure 11 shows X-ray diffractograms of powders used to make powder mixtures of this invention.

[0026] Figure 12 shows the capacity of powders and powder mixtures of this invention as function of cycle in batteries made therefrom.

[0027] Figure 13 shows the capacity v. cycle of batteries made with a lithium transition metal oxide powder and physical mixtures of this invention.

[0028] Figure 14 shows the capacity retention v. cycle batteries made with a lithium transition metal oxide powder and physical mixtures of this invention.DETAILED DESCRIPTION

[0029] The following definitions apply to some of the aspects described with respect to some embodiments of the invention. These definitions may likewise be expanded upon herein. Each term is further explained and exemplified throughout the description, figures, and examples. Any interpretation of the terms in this description should take into account the full description, figures, and examples presented herein.

[0030] The singular terms “a,” “an,” and “the” include the plural unless the context clearly dictates otherwise. Thus, for example, reference to an object can include multiple objects unless the context clearly dictates otherwise.

[0031] A rate “C” refers to either (depending on context) the discharge current as a fraction or multiple relative to a “1 C” current value under which a battery (in a substantially fully charged state) would substantially fully discharge in one hour, or the charge current as a fraction or multiple relative to a “1 C” current value under which the battery (in a substantially fully discharged state) would substantially fully charge in one hour.54861 -9342-9452, v. 2WCAT-203-A-WO

[0032] To the extent certain battery characteristics can vary with temperature, such characteristics are specified at ambient ~20 °C to 30 °C, unless the context clearly dictates otherwise.

[0033] Ranges presented herein are inclusive of their endpoints. Thus, for example, the range 1 to 3 includes the values 1 and 3 as well as the intermediate values. When a majority is specified of a component, it means more than 50% by mole or (readily understood from the context used) to essentially all of that component (99% or less). That is, the majority specified constituent of a component is present in an amount greater than 50% to 99%, 90, 80%, 70% or 60% of that component. When a minority of a component is a specified constituent, it is present in an amount less than 50% to about 1% with the balance being the majority specified constituent unless otherwise specified.

[0034] The powder (“composite particles”, “lithium transition metal oxide powder” and “composite particles') is comprised of interspersed orthorhombic and disordered rocksalt phases, which are also referred to as domains. The domains may be any size within the particle dimensions but typically may be less than 1 micrometer, 500, nanometers, 200 nanometers or 100 nanometers (“nanodomains”). These domains are preferably less than 50 or 25 nanometers. The characteristics of the domains and particles may be determined by micrographical techniques as described herein.

[0035] It has been discovered that useful powders comprised of particles having interspersed disordered rocksalt and orthorhombic phases may be formed by mixing and heating a precursor comprised of Li (lithium precursor), a precursor comprised of Mn (Mn precursor) and a precursor comprised of a transition metal other than Mn (TM precursor), where the ratio of Mn / TM is at least 1.5 by moles to form a mixture. The Mn and TM may be contained in separate or the same precursor. Desirably, the Mn / TM molar ratio is at least 1.75, 2 or 2.25 or 2.5 to any practicable such as 20, 15 or 10.

[0036] It has also been discovered that certain powder mixtures of disordered rocksalt (DR) powder mixed and comminuted with an orthorhombic powder comprised of LiMnCh having an orthorhombic phase realizes similar desired characteristics as the in situ generated powder. These powder mixtures are formed by mixing a DR such as those known in the art and desirably one that64861 -9342-9452, v. 2WCAT-203-A-WO is represented by the same formula illustrating the lithium transition metal oxide powder below. The amount of orthorhombic powder in the powder mixture is from 0.1 to 50% by weight, but generally it is desirable for the amount to be from 0.5%, 1% to 10%, 20% or 25%. The powder mixture is desirably comprised of orthorhombic powder and DR powder that are of similar size and size distribution. Illustratively, the orthorhombic powder average size / DR powder average size desirable is 0.2, 0.5 to 5 or 2, with being more desirable for the ratio to be within about 10% or 20% of 1. Likewise, the ratio of the median and D90 and D10 of the orthorhombic powdcr / DR powder is as just described. The size of the powder mixture likewise, is desirably the size described herein for the composite particles (primary particle size). Likewise, the powder mixture may be agglomerated and formed into secondary particles useful for a cathode as described herein.

[0037] The Mn precursor is preferably comprised of Mn in the +3 oxidation state to facilitate the formation of the desired orthorhombic phase concentration and composition. The Mn precursor may be any that is or that forms an oxide upon heating the precursors to the reaction temperature to form the powder. For example, the mixture may be comprised of M112O3 Mii2(CO3)3, MnsCU, or Mn(NC>3)3. The Mn precursor may be a mixed metal precursor (e.g., oxide) where at least a portion of the Mn is in the 3 oxidation state or above. Examples may include YMnCL, M ZnCL, and Mi CdCU. Desirably, at least 25%, 50%, 75%, 90% to essentially all of the Mn by mole or weight present in the mixture has an Mn oxidation state of 3. The Mn precursor present in the mixture may solely be M CL.

[0038] The mixed metal precursor may be formed by mixing a Mn compound with a TM compound that maybe in the same stoichiometric ratio desired in the lithium transition metal oxide powder. The mixture of a Mn compound regardless of oxidation may be mixed with at least one other TM precursor may be mixed as described herein. This mixture without a Li precursor may then be heated to a temperature to form the mixed metal precursor in the absence of lithium and in an atmosphere (e.g., inert atmosphere or oxygen containing) that realizes a mixed metal compound where at least a portion (e.g., 50%, 75%, 90% to all of the Mn has a 3 oxidation state). If desired, the intermediate precursor may be heated in an oxygen containing atmosphere containing no lithium to form a mixed metal precursor (oxide) comprised of Mn having the 3 oxidation state. Any useful temperature and time may be used to form the intermediate precursor. Generally, the forming of the mixed metal precursor may employ temperatures, atmospheres and hold times such74861 -9342-9452, v. 2WCAT-203-A-WO as described for forming the disordered rocksalt, but desirably do substantial amounts of oxygen, (partial pressure of oxygen in air or higher). Higher temperatures may be used if useful, but this may require further or more milling to realize the desired particle size when mixing with the lithium compound.

[0039] The mixture may be formed by any suitable method such as those known in the art with U.S. Pat. Pub. No. 2022 / 0059816 being illustrative and incorporated herein by reference. To form the mixture, metal precursor compounds and lithium compound are mixed based on the desired composition of the disordered rocksalt. One or more of the precursors may be metal compounds comprised of oxygen, fluorine and one or more P, S and N, such as oxides, hydroxides, oxynitrides, nitrides, nitrates, sulfides, sulfates, phosphate, phosphites, fluorides and combinations thereof such as those described in the below desired chemical composition. Illustrative examples of precursors may include TiCh, MirOi, LiOH, Nb Os, LiF, NbFs, and / or the like. The mixture may include one of more compound that may introduce a substitute for the O or F such as ones having S, P, N or combination thereof.

[0040] Desirably, the precursors may be mixed, at the desired amounts to realize the desired powder stoichiometry, in a liquid such as water or organic solvent to make a suspension (one or more of the precursors may be dissolved and precipitated upon removal of the solvent). The milling may be performed by any method useful to realize the desired particle size with examples being a micromedia mill, planetary mill or other comminution method (e.g., stirred, ultrasonic induced or vibratory mills). The particles may have an average particle size that is at most 2 micrometer, 1 micrometer, 400 nanometers (nm), 200 nm, or 100 nm to 5 or 10 nm. An Example of a suitable micro bead mill is a Buhler PML2 mill (Buhler Group). Suitable milling may be performed in commercially available stirred mills such as those available from Buhler Group (Germany) and Nctzsch GmbH (Germany); sonic mills available from Rcsodyn Corporation. (Butte, MT) and planetary mills available from Glen Mills Inc., (Clifton, NJ) and Retsch GmbH (Germany). The size may be determined by any suitable method such as those known in the art including, for example, micrographically or by laser light scattering. The milling time used to comminute to form the precursor mixtures and powder mixtures may be any suitable to realize the desired size, with 5 or 10 minutes to 24, 10, 5, 2 or 1 hours being typical.84861 -9342-9452, v. 2WCAT-203-A-WO

[0041] The milling media may be any useful for milling ceramic particles without causing undo contamination or intended contribution to the composition of the mixture. The milling media may be any useful shape such as spherical, ellipsoidal or cylindrical. Desirably, the milling media is spherical. The milling media may be a ceramic, metal or ceramic metal composite (e.g., WC / Co). The milling media may be any useful for milling the precursors without causing deleterious contamination. Examples of milling media include those comprised of zirconium such as cubic stabilized zirconia (e.g., stabilized with one or more of Mg, Ca, Y, Cc, Al and Hf), zircon, silicon carbide, WC / Co, mixed carbides such as those described in U.S. Pat. No., 5,563,107 and WO 2004 / 110699, incorporated herein by reference. Cubic stabilized zirconia milling media that are suitable may be obtained from Chemco Advanced Material (Suzhou) Co., Ltd., China. Likewise, autogenous milling such as use of a metal oxide desired in the composition may be used as the milling media.

[0042] The suspension of precursor particles may then be dried by any suitable method such as spray drying. Other drying methods involving evaporation, heating, application of vacuum, critical fluid drying or freeze drying may be employed. The spray drying may be performed using any known commercially available spray dryer such as a mini spray dryer, such as the Buchi B- 290 model

[0043] The dried mixture of precursors may then be heated to a reaction time and reaction temperature. The reaction temperature causes the precursors to react and form the lithium transition metal oxide powder comprised of an orthorhombic and disordered rocksalt phase. Desirably, the temperature and time are such that the resulting powder does not fuse into a monolithic fused mass, but retains the dried mixture morphology such as spray dried agglomerates of the precursor particles.

[0044] The reaction temperature and reaction time is any suitable to form the powder having the orthorhombic and disordered rocksalt domains interspersed within the powder particles. Typically, the temperature is from 800 °C to 1000 °C or 975 °C. The reaction temperature may be held for any useful time such as from 10 minutes, 30 minutes, 1, 2, 3, or 5 hours to 12 or 24 hours. The time and temperatures be interrelated (e.g., higher temperatures may more suitable with shorter times). The stoichiometry may more precisely be tailored using differing oxygen containing atmospheres (i.e., partial pressure of oxygen over longer periods of time, which may94861 -9342-9452, v. 2WCAT-203-A-WO be varied during the annealing to form the disordered rocksalt). For example, it may be desirable to heat to a reaction temperature under an inert gas such as noble gas or nitrogen containing atmosphere for a time to form the powder or under an oxygen containing atmosphere such as air, dry air, or oxygen in nitrogen or inert gas at any desirable partial pressure or combinations thereof. In other words, two or more reaction temperatures may be employed to form the powder with the same or differing atmospheres.

[0045] The reaction temperature may be performed under any suitable atmosphere, which may be static or flowing or combination thereof and may be varied depending on the hold temperature employed in the method. The atmosphere may be a noble gas, nitrogen, atmospheric air or dry air and any combination to realize a desired partial pressure of one or more gases. The reaction temperature and time may be selected based on the composition of the precursors employed.

[0046] It has been discovered that the method may form a powder comprising particles having interspersed orthorhombic and disordered rocksalt phases therein. The lithium transition metal oxide powder desirably has a chemical composition represented by:LixM yMnzO2-(a+b)F a Zb where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Mn / M’ > 1.5, Z is one or more of P, N and S. Transition metal is an element falling within the group 3 to group 12 elements of the periodic table. The term 3d transition metal (3dTM) referred to herein means those transition metals having an incomplete filling of the 3d orbital and includes, for example, Sc, Ti, V, Cr, Fe, Co, Ni, Cu and Zn. It is noted that Mn is a 3d transition metal, but since it is separately provided for, is not for the purposes herein included as a 3d TM. The term 4d transition metal (4d TM) referred to herein is a transition metal with incomplete filling of the 4d orbital and includes, for example, Y, Zr, Nb, Mo, Tc, Ru and Rh. The term 5d transition metal (4d TM) referred to herein is a transition metal with incomplete filling of the 4d orbital and includes, for example, Lu, Hf, Ta, W, Re, Os, and Ir.

[0047] It has been discovered M’ is desirably comprised of a 4d TM. The presence of the 4d TM may realize higher capacities and ease of formation of the desired orthorhombic phase with the disordered rocksalt (DR) phase. Illustratively, when a 3d TM and a 4d TM is present, desirably, the amount of 4d TM / (3d TM), by moles, is at least 0.25, 0.5, 0.75 or 1 to essentially all of the TM104861 -9342-9452, v. 2WCAT-203-A-WO present in the lithium transition metal oxide powder other than the Mn is the 4d transition metal (e.g., such as Y, Zr, Nb and Mo). Similarly, the 4d TM to a 3d TM and / or 5d TM present, desirably is present at the same ratios as just described (i.e. , 4d TM / (3d TM+ 5d TM)), where the amount of the 3d TM or 5d TM may be each independently be 0 or some quantity within the ranges for M’. Illustratively, M’ is comprised of Nb and Ti at the ratios just described.

[0048] It has also been discovered that the lithium transition metal oxide powder desirably is comprised of F, which likewise appears to be useful to form the desired orthorhombic phase, which desirably is comprised of LiMnCh. It is understood that LiMnCri may have other metal elements present which typically are present in a trace amount (less than 100, 50 or 10 parts per million by weight “ppm”) or some fraction of the O may be substituted with F, P, S or N so long as the desired phase and electrochemical behavior is realized. That is “b” is desirably greater than 0 and preferably at least 0.05, 0.1 to 0.5 or 0.4 where b > 0. Known methods of trace element analysis such as electron microscopic techniques (e.g., energy dispersive spectroscopy (EDS)) may be used to determine the elemental composition.

[0049] The composition may have any desirable Li of 1 or above, but it may be desirable for Li as represented by x to be at least 1.1, 1.15, 1.2 to 1.65, 1.5 or 1.4.

[0050] The lithium transition metal oxide powder or powder mixture may be any particle size and size distribution useful in a battery. The lithium transition metal oxide powder or powder mixture may desirably have an average primary particle size that is at most 10 micrometers, 5 micrometers, 4 micrometers, 3 micrometers, 2 micrometers, 1 micrometer, 400 nanometers (nm), 200 nm, or 100 nm to 5 or 10 nm. The lithium transition metal oxide powder or powder mixture may have a particle distribution by number or volume of a D90 of at most about 10, 5, 4, 3, 2 or 1.5 micrometers, D50 that is submicromctcr (e.g., less than 1 micrometer to about 0.1 micrometer), and a D10 of at least 0.1 micrometer being particularly useful. The primary particles may be agglomerated to form aggregates (secondary particles such as those arising from spray drying, which may further sintered if desired). Primary particles are discrete unagglomerated particles preferably having the aforementioned particle size distribution. Unagglomerated particles are those that may easily be disrupted by shear (illustratively those bonded at most be van der Waals and hydrogen bonding).114861 -9342-9452, v. 2WCAT-203-A-WO

[0051] The powder mixture of orthorhombic powder and DR powder is formed by mixing said powders, at a weight or volume ratio (DR powder / orthorhombic powder) of 1000, 500, 250, 200, or 100 to 1, 2, 5 or 10 and then comminuting the mixture by milling such as described herein to form the precursors or when forming a cathode mixture (e.g., including other additive such as a carbon and binders). Desirably, the mixture is milled dry in a planetary mill with a carbon such as those described herein. Desirably, the mixture is comprised of orthorhombic (OR) powder and DR powder that have somewhat equivalent size. Illustratively, the size ratio (OR powder average size / DR powder average size) desirably is from 10, 5, or 2 to 0.1, 0.2 or 0.5, with it being desirable for the ration to be at most 20% or 10% from 1. Desirably, the OR an DR powder each have an average primary particle size that is most about 25 micrometer, 15 micrometer or 10 micrometers. The DR and OR powders may be made by the solid state methods described herein.

[0052] Particle size and shape can be measured by any suitable methods known in the ail to measure particle size by diameter (equivalent spherical diameter). In some embodiments, the particle size and shape are determined by laser diffraction as is known in the art. For example, particle size can be determined using a laser diffractometer such as the Microtrac S3500 with static image analysis accessory using PartAnSI software to analyze the captured images of the particles or image analysis of scanning electron micrographs of the particles (e.g., counting of at least 100 particles by image analysis software such as described above).

[0053] Desirably the lithium transition metal oxide powder or powder mixture of the cathode has an average secondary particle size of 1 to 20 micrometers. Each of the secondary particles is an agglomeration of primary particles. The lithium transition metal oxide powder primary particles desirably have an average particle size as described herein and may contain other particles that may be useful such as those useful for increasing the electrical conductivity (e.g., carbon or other inorganic high ionic conductive particles).

[0054] The cathode comprised of the lithium transition metal oxide powder or powder mixture may be used in a rechargeable lithium ion battery cell. The battery cell includes the cathode, an anode, separator and electrolyte. The battery or battery cell may be formed in any suitable atmosphere such as common in the art. For example, a high purity argon atmosphere may be used to limit any undesirable contamination from species present in atmospheric air.124861 -9342-9452, v. 2WCAT-203-A-WO

[0055] The cathode comprised of the lithium transition metal oxide powder or powder mixture desirably is further comprised of an additive such as carbon or carbon forming compound. The lithium transition metal oxide powder may be mixed with other useful additives (e.g., carbon or carbon precursor, binders and the like) by any method with milling as described herein being a suitable method useful. For example, the carbon and other additives may be added via a suspension and spray dried to form spray dried particles. The carbon may include acetylene black, carbon black, carbon fiber, graphite, carbon nano-tubc, KJ600, and / or the like. The carbon may be mixed at a ratio in which the lithium transition metal oxide powder represents a majority and the carbon precursors represent a minority. For example, the lithium transition metal oxide powder and carbon may each be present in an amount such that the amount of lithium transition metal oxide powder / amount of carbon by weight may be a ratio of 100 / 1, 50 / 1 30 / 1, 20 / 1 or 10 / 1 to 5 / 1, 1.5 / or 1 / 1.

[0056] It has been surprisingly discovered that when a sufficient of amount of orthorhombic phase is present in the lithium transition metal oxide powder, cathodes made therefrom may realize improved cycle life of a battery having a pure disordered rocksalt of similar composition. Likewise it has been surprisingly discovered that powder mixtures of DR powder and orthorhombic powder described herein realize improved cycle life of a battery having pure disordered rocksalt (unmixed and comminuted with the orthorhombic powder). Desirably, the amount of the orthorhombic phase or orthorhombic powder present is at least 0.5%, 1%, 2%, or 5% to 75%, 50%, 25%, or 20% by volume or weight. The amount of orthorhombic phase may be determined by X-ray diffraction by any useful method such as those known in the art including, for example, Rietveld refinement. It also has been surprisingly discovered and is believed without being limiting in any way, that the presence of the orthorhombic phase or orthorhombic powder in the lithium transition metal oxide or powder mixture when cycling causes the appearance of a spinel phase that contributes to the intercalation of Li contributing to improved electrochemical behavior.Illustrations

[0057] Illustration 1. A method to form a lithium transition metal oxide powder comprising,134861 -9342-9452, v. 2WCAT-203-A-WO(i) mixing a lithium precursor and a Mn precursor and a transition metal precursor comprised of an other transition metal in a molar ratio of Mn / other transition metal of at least 1.5 to form a mixture, and(ii) heating the mixture for a reaction time and reaction temperature to form the lithium transition metal oxide powder having composite particles comprised of a disordered rocksalt phase and an orthorhombic phase.

[0058] Illustration 2. The method of illustration 1, wherein the molar ratio of Mn / other transition metal is at least 2 to 10.

[0059] Illustration 3. The method of illustration 2, wherein the amount of orthorhombic phase is from about 1% to 60% by weight of the composite particles.

[0060] Illustration 4. The method of illustration 3, wherein the reaction temperature is from 800 °C to 975 °C.

[0061] Illustration 5. The method of illustration 4, wherein the reaction time is from 15 minutes to 24 hours.

[0062] Illustration 6. The method of any one of the preceding illustrations, wherein the heating is performed in an atmosphere comprised of oxygen.

[0063] Illustration 7. The method of illustration 6, wherein the atmosphere has a mole fraction of oxygen of at least 0.1.

[0064] Illustration 8. The method of illustration 6, wherein the Mn precursor is comprised of Mn having a +3 oxidation state.

[0065] Illustration 9. The method of any one of preceding illustrations, wherein the mixing comprises milling.

[0066] Illustration 10. The method of any one of the preceding illustrations, wherein the mixture has an average particle size of at most 2 micrometers equivalent spherical diameter.

[0067] Illustration 11. The method of any one of the preceding illustrations wherein the lithium transition metal oxide powder has a chemical composition represented by:144861 -9342-9452, v. 2WCAT-203-A-WOLixMyMnzO2-(a+b)FaZb where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Mn / M’ > 1.5, Z is one or more of P, N and S.

[0068] Illustration 12. The method of illustration 11, where M’ is comprised of a 4d transition metal.

[0069] Illustration 13. The method of illustration 12, wherein M’ is further comprised of one or more of a 3d transition metal and 5d transition metal.

[0070] Illustration 14. The method of illustration 13, wherein M’ is comprised of the 3d transition metal.

[0071] Illustration 15. The method of illustration 14, wherein the 4d transition metal / 3d transition metal is at least 0.25 by mole.

[0072] Illustration 16. The method of any one of illustration 15, wherein the 4d transition metal / 3d transition metal is at least 1.

[0073] Illustration 17. The method of any one of illustrations 11 to 16, wherein the 3d transition metal is one or more of Ti, V, Cr, Fe, Co, Ni, Cu, and Zn, the 4 transition metal is one or more of Zr, Nb, Y, Mo, Ru LiMnO2, Rh and the 5d transition metal is one or more of La, Hf, Ta, W, Re, Os, and Ir.

[0074] Illustration 18. The method of any one of illustration 11 to 17, wherein the M’ is comprised of Nb and Ti.

[0075] Illustration 19. The method of any one of the preceding illustrations, wherein the orthorhombic phase is comprised of LiMnO2.

[0076] Illustration 20. The method of any one of the preceding illustrations, wherein the lithium transition metal oxide powder is comprised of F.

[0077] Illustration 21. The method of any one of illustrations 11 to 19, wherein 0<(a+b)<0.5.154861 -9342-9452, v. 2WCAT-203-A-WO

[0078] Illustration 22. The method of illustration 21, wherein b-0.

[0079] Illustration 23. A powder comprising composite particles having interspersed orthorhombic and disordered rocksalt phases therein.

[0080] Illustration 24. The powder of illustration 23, wherein the powder has a chemical composition represented by:

[0081] LixM’yMnzO2-(a+b)Fa Zb where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Z is one or more of P, N and S.

[0082] 25. The powder of illustration 24, where M’ is comprised of a 4d transition metal.

[0083] Illustration 26. The powder of illustration 25, wherein M’ is further comprised of one or more of a 3d transition metal and a 5d transition metal.

[0084] Illustration 27. The powder of illustration 26, wherein M’ is comprised of the 3d transition metal.

[0085] Illustration 28. The powder of illustration 27, wherein the 4d transition metal / 3d transition metal is at least 0.25 by mole.

[0086] Illustration 29. The powder of any one of illustration 28, wherein the 4d transition metal / 3d transition metal is at least 1.

[0087] Illustration 30. The powder of any one of illustrations 25 to 30, wherein the 4d transition metal is one or more of Zr, Nb, Y, Mo, Ru, Rh.

[0088] Illustration 31. The powder of any one of illustrations 26 to 30, wherein the 3d transition metal is one or more of Ti, V, Cr, Fe, Co, Ni, Cu, and Zn.

[0089] Illustration 32. The powder of any one of illustrations 26 to 30, wherein the 5d transition metal is one or more of La, Hf, Ta, W, Re, Os, and Ir.164861 -9342-9452, v. 2WCAT-203-A-WO

[0090] Illustration 33. The powder of any one of illustrations 23 to 32, wherein the M’ is comprised of Nb and Ti.

[0091] Illustration 34. The powder of any one of illustrations 23 to 33, wherein the orthorhombic phase is LiMnO2.

[0092] Illustration 35. The powder of any one of illustrations 23 to 34, wherein the powder is comprised of F.

[0093] Illustration 36. The powder of any one of illustrations 23-35, wherein the composite particle is further comprised of a spinel phase.

[0094] Illustration 37. The powder of any one of illustrations 23 to 36, wherein the composite particle’s average particle size of is less than 2 micrometers.

[0095] Illustration 38. The powder of any one of illustrations 23 to 37, wherein the powder further comprises an additive.

[0096] Illustration 39. The powder of illustration 38, wherein the additive is comprised of a carbon or carbon forming compound.

[0097] Illustration 40. The powder of any one of illustrations 24 to 39, wherein Mn / M’ is at least 1.5 by mole.

[0098] Illustration 41. The powder of illustration 40, wherein Mn / M’ is at least 2 by mole.

[0099] Illustration 42. A cathode comprised of the powder of any one of illustrations 23 to41 and carbon.

[0100] Illustration 43. A battery comprised of the cathode of illustration 42.

[0101] Illustration 44. The method of any one of illustrations 1 to 22, wherein Li is removed from the lithium transition metal oxide powder and reinserted to form a lithium transition metal oxide powder having a further spinel phase.174861 -9342-9452, v. 2WCAT-203-A-WO

[0102] Illustration 45. The method of illustration 44, wherein the Li is removed and reinserted electrochemically.

[0103] Illustration 46. A powder mixture comprised of a physical mixture of a disordered rocksalt powder and an orthorhombic powder comprised of LiMnO2 having an orthorhombic phase, the orthorhombic powder being present in an amount of 0.1 to 50% by weight of the disordered rocksalt powder and orthorhombic powder.

[0104] Illustration 47. The powder mixture of illustration 46, wherein the orthorhombic powder and disordered rocksalt powder each have an average particle size and a size ratio of the average particle size of the disordered rocksalt / the average particle size of the orthorhombic powder is from 0.2 to 5.

[0105] Illustration 48. The powder mixture of illustration 47, wherein the ratio is 0.5 to 2.

[0106] Illustration 50. The powder mixture of any one of illustrations 46 to 48, wherein the orthorhombic powder consists essentially of the LiMnO2.

[0107] Illustration 51. The powder mixture of any one of illustrations 46 to 50, wherein the powder has an average particle size of at most 10 micrometers.

[0108] Illustration 52. The powder mixture of illustration 51, wherein the average particle size is at most 1 micrometer.

[0109] Illustration 53. The powder mixture of any one of illustrations 46 to 52, wherein the disordered rocksalt powder has a chemical composition represented by:

[0110] LixM’yMnzO2-(a+b)Fa Zb

[0111] where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Z is one or more of P, N and S.

[0112] Illustration 54. The powder mixture of illustration 53, where M’ is comprised of a 4d transition metal.184861 -9342-9452, v. 2WCAT-203-A-WO

[0113] Illustration 55. The powder mixture of illustration 54, wherein M’ is further comprised of one or more of a 3d transition metal and a 5d transition metal.

[0114] Illustration 56. The powder mixture of illustration 55, wherein M’ is comprised of the 3d transition metal.

[0115] Illustration 57. The powder mixture of illustration 56, wherein the 4d transition metal / 3d transition metal is at least 0.25 by mole.

[0116] Illustration 58. The powder mixture of any one of illustration 57, wherein the 4d transition metal / 3d transition metal is at least 1.

[0117] Illustration 59. The powder mixture of any one of illustrations 53 to 58, wherein the 4d transition metal is one or more of Zr, Nb, Y, Mo, Ru, Rh.

[0118] Illustration 60. The powder mixture of any one of illustrations 54 to 58, wherein the 3d transition metal is one or more of Ti, V, Cr, Fe, Co, Ni, Cu, and Zn.

[0119] Illustration 61. The powder mixture of any one of illustrations 54 to 58, wherein the 5d transition metal is one or more of La, Hf, Ta, W, Re, Os, and Ir.

[0120] Illustration 62. The powder mixture of any one of illustrations 53 to 58, wherein the M’ is comprised of Nb and Ti.

[0121] Illustration 63. The powder mixture of any one of illustrations 46 to 62, wherein the powder further comprises an additive.

[0122] Illustration 64. The powder mixture of illustration 38, wherein the additive is comprised of a carbon or carbon forming compound.

[0123] Illustration 65. A method of forming a powder mixture comprised of mixing a disordered rocksalt powder and an orthorhombic powder comprised of LiMnO2 having an orthorhombic phase in a weight ratio of the disordered rocksalt powder / orthorhombic powder from 1000 to 1 to form a mixture comminuting the mixture sufficiently to form the powder having an average particle size of less than 10 micrometer and the orthorhombic powder and the rocksalt194861 -9342-9452, v. 2WCAT-203-A-WO powder each have an average particle size and a size ratio of the average particle size of the disordered rocksalt / the average particle size of the orthorhombic powder is from 0.2 to 5.

[0124] Illustration 66. The method of illustration 65, wherein the weight ratio is 200 to 2.

[0125] Illustration 67. The method of illustration 66, wherein the weight ratio is 100 to 10.

[0126] Illustration 68. The method of any one of illustrations 65 to 67, wherein the comminuting is performed using one or more of a planetary mill and micromedia mill.

[0127] Illustration 69. The method of any one of illustrations 68, wherein the powder is comprised of an additive.

[0128] Illustration 70. The method of illustration 69, wherein the additive is comprised of carbon.

[0129] Illustration 71. The method of any one of illustrations 65 to 69, wherein the size ratio of the disordered rocksalt powder and an orthorhombic powder prior to comminuting is 10 to 0.1.

[0130] Illustration 72. The method of illustration 71, wherein the size ratio prior to comminuting is 2 to 0.5.

[0131] Illustration 73. The method of illustration 72, wherein the powder mixture has a average size of at most 3 micrometers.Examples

[0132] Lithium transition metal oxide powders (Composite Powder) comprised of DR solely and DR and an orthorhombic phase are made by a solid state reaction as follows. Stoichiometric amounts (see Tables 1 A to IE) of precursors ((LiiCCL, Mn20 , TiCh, NbiOs, and LiF) plus 5 mol% excess Li COa is mixed in deionized water to make a suspension, which was then mixed with a planetary ball mill to decrease the particle size and obtain a homogeneous mixture of precursors. The mixture is dried at 150 °C for 12 h under argon. The dried mixture is heated under argon or nitrogen flow to 800 °C for 4 hours, ground via planetary ball mill and then heated to 900 °C for 12 hours. The amount of orthorhombic phase of the lithium transition metal oxide powder is204861 -9342-9452, v. 2WCAT-203-A-WO determined by X-ray diffraction by fitting the peak profiles and weight % of phases present is determined (this method correlated well with Rietveld refinement).

[0133] Orthorhombic powders comprised of orthorhombic powder comprised of LiMnOi having an orthorhombic phase without a DR phase is made by the same method as forming the DR solely, but using Li2COa and Mu20a plus 5 mol% excess Li2CO3. The phase purity of orthorhombic powder and DR powder solely (DR composition target: Li1.299Mn0.484Ti0.054Nb0.i63O1.783F0.217) is shown in Figure 11.

[0134] The powder (DR, Composite Powder or powder mixture “pure DR blended with orthorhombic powder”) is then dry milled in a planetary ball mill with a conductive carbon additive (acetylene black, carbon black, graphite, carbon nanotubes) in a 96:4 (wt%) ratio to be used as the active material in cathode film preparation. The carbon-coated material is first washed with deionized water and dried at 150 °C for 12 h under vacuum.

[0135] Electrode films is prepared via one of two methods: drop casting or doctor blade drawdown casting. For drop casting, a slurry was prepared by mixing the carbon-coated powder with polyvinylidene difluoride (Sigma Aldrich) and l-methyl-2-pyrrolidinone (Sigma Aldrich). The slurry is then deposited on a roughened stainless steel current collector and dried to form a composite cathode film. For drawdown film casting, the slurry was cast onto an aluminum foil current collector and dried, then electrodes of the appropriate size were punched from the film.

[0136] Battery cells are assembled in a high-purity argon-filled glovebox (M-Braun, 02 and H2O content <0.1 ppm). Half cells were assembled with a thin lithium foil anode, a polypropylene separator, and an electrolyte. The electrolyte used consisted of 1 M lithium hexafluorophosphate in a mixture of ethylene carbonate and ethyl methyl carbonate with an additive. Full cells were assembled the same way but with a graphite anode, which consisted of graphite with carboxymethylcellulose and styrene butadiene rubber as binders, cast on a copper current collector.

[0137] The electrolyte in full cell systems is a locally high concentrated electrolyte developed as described in WO2024 / 145182 (e.g., Electrolyte A4). Half cells were sealed and cycled at 30 °C between 1.8 and 4.5 V at C / 20 formation rate and C / 3 cycling rate, where 1C = 300 mAh / g. Full cells were tested at 30 °C between 1.8 and 4.45 V at C / 20 formation rate and C / 3 cycling rate.214861 -9342-9452, v. 2WCAT-203-A-WONote, in Tables 1A to IE that the Cyl is at the C / 20 rate, Cy2 is at a C / 10 rate and Cy5 is at C / 3 cycling rate.

[0138] From Tables 1A and IB it is apparent that the formation of the desired orthorhombic phase is facilitated by the presence of a 4d transition metal such as Nb. Likewise, the presence of a 3d TM in the absence of a 4d TM tends result in less orthorhombic phase and generally lower capacities even when the Mn / TM ratio is above 1.5. Table 1C shows that the desired orthorhombic phase may be formed over a wide range of input stoichiometries with the Mn / TM ratio being above 2 and in the presence of a 4d TM.

[0139] Tables ID and IE show that the presence of F facilitates the formation of the orthorhombic phase and tends to lead to higher initial capacities while retaining desired capacity retention when made under the same conditions.

[0140] A further composition (Lii.275Mno.525Ti0.o5Nbo.i50i.8Fo.2) is made the same way as described above but is heated to 1000 °C for 12 h and shows no signs of an orthorhombic phase (see Figure 1). This composition is also heated to 900 °C for 12 h shows and has ~6 wt% orthorhombic phase attributed to o-LiMnCh (see Figure 1), indicating the transition temperature to synthesize a phase-pure DR instead of a mixed-phase material is between 900 and 1000 °C.

[0141] The peaks indicating the DR phase are sharp and well resolved. For o-LiMnCh, the most intense reflection, indexed to the (001) plane, is similarly sharp, but several peaks at higher angle, e.g. the (020) at -39° and the (102) at -45°, are broader, and the Kai and Ka2 lines are indistinguishable. The broader peaks may indicate some disorder in the crystalline o-LiMnCb domains, which may be due to intimate mixing with the DR domains on longer length scales. o-LiMnO2 technically adopts a rock salt-type structure distorted by the Jahn-Teller effect acting on the Mn3+ions, which may facilitate some degree of mixing with the disordered rock salt phase.

[0142] Half cell performance is investigated and selected early cycles from galvanostatic tests and the corresponding dQ / dV analysis are shown in Figures 2 and 3. Cycle 1 shows features typical of a Li-rich Mn-based DR material. During charge, a sloping lower voltage feature corresponding to Mn oxidation is observed, after which a flatter feature occurs at high voltage and is assigned to O2' oxidation. Notably, no additional features in the electrochemistry corresponding to o-LiMnCh224861 -9342-9452, v. 2WCAT-203-A-WO are seen on the cycle 1 charge, which may indicate that the DR and o-LiMnCh phases are mixed intimately as a byproduct of being synthesized simultaneously. During discharge, a single sloping feature that represents concomitant Mn and O reduction is observed in addition to a feature (labeled with a star) assigned to a disordered spinel (LixMn’,2O4) phase. This feature is not observed in the phase-pure DR material (annealed at 1000 °C) which is attributed to the lack of the o-LiMnCb secondary phase. Further, the phase-pure DR material shows more accessible Mn oxidation on cycle 1, but the charge passed during O oxidation is notably lower on cycle 1 and essentially inaccessible at faster rates as seen on cycle 5.

[0143] Extended cycling results in more widespread conversion of the o-LiMnCh to the disordered spinel phase as shown in Figures 4 and 5 where electrochemical features of both DR and a spinel-type phase are observed and contribute to maintaining high capacities with cycling. The presence of features from both DR and o-LiMnO corroborates the X-ray diffraction data suggesting that there are bulk crystalline regions of both phases in the as-synthesized material.

[0144] The phase-pure DR is believed to be sufficiently Mn-rich to show signs of spinel-like electrochemical features at later cycles; however, the feature around 4.0 V is broad and less reversible. This may be due to the differences in final structure between DR to spinel conversion and o-LiMnO2 to spinel conversion, highlighting the benefits of having o-LiMnCb regions to direct conversion to spinel that maintains higher reversibility. The multiple high-voltage features in dQ / dV are assigned to ordered filling of the tetrahedral 8a sites, and the lack of resolved features in the initially phase-pure DR material suggests formation of spinel-like domains with a structure that may be deleterious to reversible (de)intercalation of lithium ions.

[0145] The coexistence of spinel features that arise from the o-LiMnCb secondary phase and features from the DR primary phase result in improved performance across nearly all metrics. The mixed-phase material consistently shows higher coulombic efficiency (CE) and lower total resistance than pure DR of the same chemical composition, which is attributed to lesser oxygen redox contributions in the mixed phase material. Oxygen redox, especially during the first charge cycle, contributes additional capacity but can irreversibly produce oxygen gas and / or highly reactive species that react with the electrolyte in ways detrimental to performance. The mixed phase material (lithium transition metal oxide powder of the invention) shows significantly better capacity retention relative to absolute capacity than the pure phases.234861 -9342-9452, v. 2WCAT-203-A-WO

[0146] In full cells, the mixed phase material exhibits lower absolute capacity than the pure DR, but the capacity retention improves at least two-fold, highlighting the stabilizing benefits of the o-LiMnCh phase.

[0147] Figure 6 shows the X-ray diffraction patterns for four different batteries made with lithium transition metal oxide powder of the invention that were synthesized such that there are differing amounts of the secondary o-LiMnCh phase with the same chemical composition. When cycled in half cells, the materials with more o-LiMnCh exhibit slightly less capacity in the voltage region corresponding to Mn redox during charging (up to 4.3 V, approximately); however, all materials show similar discharge capacities within 10 mAh g’1. As shown below, the gap widens by cycle 5 when tested at faster rate and the absolute capacity tracks directly with the amount of o-LiMnCh present in the as synthesized powder. (See Figure 7).

[0148] To further adduce the phase structure lithium transition metal oxide powders are synthesized as described above with the target stoichiometry of Lii.275Mno.525Tio.05Nbo.i50i.8Fo.2 and heated to 800 °C for 4 h followed by 900 °C for either 4 or 12 h. In both cases, o-LiMnCF is observed. A lower amount of o-LiMnCh (i.e. more complete conversion to the DR structure) is seen when the heating time is longer as shown by the X-ray diffraction pattern shown in Figure 8.

[0149] Scanning electron microscopy (SEM) and concomitant energy dispersive spectroscopy (EDX) of particles of varying sizes show evidence of Mn-rich regions (o-LiMnC ) and regions where Ti and Nb are present in greater amounts (DR) as shown in Figures 9 and 10. The SEM image of a particle is only about 200 nm across. EDX spectra from two regions of this particle show a Mn-rich region in Spectrum 57 and one where the Mn to other transition metal ratios are clearly lower (Spectrum 58) as they would be for the DR target composition.

[0150] Half cell performance was tested, and the physically mixed powder was compared to in situ-generated biphasic mixtures of DR and o-LiMnCE (Composite Powder). The composition of materials is based on the stoichiometry of Li1.275Mn0.525Ti0.05Nb0.15O1.85F0.15; where the “in situ- gcncratcd” material has around 8 mol% o-LiMnO2 with none added in the blend, and the “physically mixed” materials consist of the corresponding DR component of composition Li1.299Mno.484Tio o54Nbo.i63O1.783Fo.217 and either no added o-LiMnO2 or 8 wt% added as indicated in Figures 12 to 14 . The physically mixed material shows lower early cycle capacity, especially at fast rate (C / 3) on cycle 5 (Figure 12), indicating the differences in material preparation yield244861 -9342-9452, v. 2WCAT-203-A-WO differences in electrochemical behavior, but similar desirable characteristics compared to DR solely.

[0151] Early cycles from galvanostatic tests and the corresponding dQ / dV analysis shows that all three materials have similar charge profiles, though the pure DR and physical blend show slightly lower O redox capacity than the in situ biphasic material. It becomes clear by cycle 5 that the in situ biphasic material shows faster growth of the spinel-related electrochemical features around 2.8-2.9 V and 3.9-4.0 V, suggesting differences in the o-LiMnCh arc responsible for capacity differences (e.g., microstructural and morphological). It is likely that the separately synthesized o-LiMnCh is more crystalline and ordered than that generated in situ during DR formation of the composite particles having the orthorhombic phase dispersed therein.

[0152] These trends hold upon extended cycling (Figures 13 and 14) , where widespread conversion of the o-LiMnCh to what is likely a disordered spinel phase is observed. The pure DR phase with no added o-LiMnCh shows the typical behavior of faster capacity fade in early cycles, caused by initial high contributions to capacity from O redox quickly falling due to a significant proportion of such oxidation reactions being irreversible. The DR and o-LiMnCE cathode blend has lower initial capacity than the in situ-generated biphasic mixture due to the o-LiMnCE being less active in early cycles (i.e. requiring more cycles for full “activation”). Nevertheless, the retention behavior of the two o-LiMnCh-containing materials is nearly identical, with improvements over the pure DR control.

[0153] Film-cast electrodes were produced. The trends observed in drop-cast half cells extend to the full cell format and become more apparent. Cells were tested with various voltage windows to explore the effects on o-LiMnCh activation and retention behavior. As seen in the half cells, cells made with the physical cathode blend have slightly lower capacities (4-10 mAh / g) than their in situ counterparts. Increasing the lower voltage cutoff (LVC) leads to a decrease in capacity, indicating redox processes are still taking place and the material is not polarizing quickly, while increasing the upper voltage cutoff (UVC) leads to a corresponding increase in capacity as more delithiation is achieved upon charging.

[0154] Galvanostatic cycling experiments show similar behavior to the half cell experiments where spinel-like features arise with cycling. The lower capacity of physically mixed materials appears to come from lower O redox capacity, and likely smaller contributions from the added o- LiMnCh than the native o-LiMnCF in the in .s / ' / M-powdcr. Again, the in situ-generated material254861 -9342-9452, v. 2WCAT-203-A-WO shows faster growth of the spinel-related features around 2.7 V, which indicates differences in the o-LiMnCh phase and transformation in early cycles relative to the physically mixed material. This may indicate that the in situ o-LiMnCh phase is more disordered and interspersed with the DR phase, leading to more Li accessibility in early cycles leading to faster phase transformation in early cycles. The trends here are continued throughout to 100 cycles. Long-term cycling again shows that absolute capacity is marginally lower for the physical cathode blends, but in most cases retention is cither nearly identical or improved relative to the in .sdu-gcncratcd mixture (Figures 13 and 14). This suggests that while differences cause changes in the early cycle electrochemistry, it is not imperative to generate the biphasic mixture in situ, and similar results can be achieved with physical mixtures such as those described herein, which are displayed in Table A.Table A:264861 -9342-9452, v. 2WCAT-203-A-WOTable 1A• = No Ti present.WCAT-203-A-WOTable IB284861-9342-9452, v 2WCAT-203-A-WOTable 1C# detected, not quantified.WCAT-203-A-WOTable ID304861-9342-9452, v 2WCAT-203-A-WOTable IE314861-9342-9452, v 2

Claims

1. WCAT-203-A-WOWHAT IS CLAIMED IS:

1. A method to form a lithium transition metal oxide powder comprising,(i) mixing a lithium precursor and a Mn precursor and a transition metal precursor comprised of an other transition metal in a molar ratio of Mn / other transition metal of at least 1.5 to form a mixture, and(ii) heating the mixture for a reaction time and reaction temperature to form the lithium transition metal oxide powder having composite particles comprised of a disordered rocksalt phase and an orthorhombic phase.

2. The method of claim 1, wherein the molar ratio of Mn / other transition metal is at least 2 to 10.

3. The method of claim 2, wherein the orthorhombic phase is present in an amount from about 1% to 60% by weight of the composite particles.

4. The method of claim 3, wherein the reaction temperature is from 800 °C to 975 °C.

5. The method of claim 4, wherein the reaction time is from 15 minutes to 24 hours.

6. The method of claim 5, wherein the heating is performed in an atmosphere comprised of oxygen.

7. The method of claim 6, wherein the atmosphere has a mole fraction of oxygen of at least 0.1.

8. The method of claim 6, wherein the Mn precursor is comprised of Mn having a +3 oxidation state.

9. The method of claim 1, wherein the mixing comprises milling.

10. The method of claim 9, wherein the mixture has an average particle size of at most 2 micrometers equivalent spherical diameter.WCAT-203-A-WO11. The method of claim 1 wherein the lithium transition metal oxide powder has a chemical composition represented by:LixM yMnzO2-(a+b)Fa Zb where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Mn / M’ > 1.5, Z is one or more of P, N and S.

12. The method of claim 11, where M’ is comprised of a 4d transition metal.

13. The method of claim 12, wherein M’ is further comprised of one or more of a 3d transition metal and 5d transition metal.

14. The method of claim 13, wherein M’ is comprised of the 3d transition metal.

15. The method of claim 14, wherein the 4d transition metal and 3d transition metal are present in a molar ratio (4d transition metal / 3d transition metal) that is at least 0.25 by mole.

16. The method of any one of claim 15, wherein the 4d transition metal / 3d transition metal is at least 1.

17. The method of claim 16, wherein the 3d transition metal is one or more of Ti, V, Cr, Fe, Co, Ni, Cu, and Zn, the 4 transition metal is one or more of Zr, Nb, Y, Mo, Ru LiMnCh, Rh and the 5d transition metal is one or more of La, Hf, Ta, W, Re, Os, and Ir.

18. The method of any one of claim 17, wherein the M’ is comprised of Nb and Ti.

19. The method of any one of claims 1 to 18, wherein the orthorhombic phase is comprised of LiMnO2.

20. The method of claim 11, wherein the lithium transition metal oxide powder is comprised of F.21 . The method of claim 11 , wherein 0<(a+b)<0.5.

22. The method of claim 21, wherein b=0.334861 -9342-9452, v. 2WCAT-203-A-WO23. A powder comprising composite particles having interspersed orthorhombic and disordered rocksalt phases therein.

24. The powder of claim 23, wherein the powder has a chemical composition represented by:LixM’yMnz02-(a+b)Fa Zb where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Z is one or more of P, N and S.

25. The powder of claim 24, where M’ is comprised of a 4d transition metal.

26. The powder of claim 25, wherein M’ is further comprised of one or more of a 3d transition metal and a 5d transition metal.

27. The powder of claim 26, wherein M’ is comprised of the 3d transition metal.

28. The powder of claim 27, wherein the 4d transition metal and 3d transition metal are present in a molar ratio (4d transition metal / 3d transition metal) that is at least 0.25 by mole.

29. The powder of any one of claim 28, wherein the 4d transition metal / 3d transition metal is at least 1.

30. The powder of claim 25, wherein the 4d transition metal is one or more of Zr, Nb, Y, Mo, Ru, Rh.

31. The powder of claim 30, wherein the 3d transition metal is one or more of Ti, V, Cr, Fe, Co, Ni, Cu, and Zn.

32. The powder of claim 31, wherein M’ is comprised of a 5d transition metal that is one or more of La, Hf, Ta, W, Re, Os, and Ir.

33. The powder of any one of claims 23 to 32, wherein M’ is comprised of Nb and Ti.

34. The powder of claim 23, wherein the orthorhombic phase is LiMnO2.

35. The powder of claim 23, wherein the powder is comprised of F.344861 -9342-9452, v. 2WCAT-203-A-WO36. The powder of claim 23, wherein the composite particle is further comprised of a spinel phase.

37. The powder of claim 23, wherein the composite particle has an average particle size of less than 2 micrometers.

38. The powder of claim 23, wherein the powder further comprises an additive.

39. The powder of claim 38, wherein the additive is comprised of a carbon or carbon forming compound.

40. The powder of claim 24, wherein Mn / M’ is at least 1.5 by mole.41 . The powder of claim 40, wherein Mn / M’ is at least 2 by mole.

42. A cathode comprised of the powder of any one of claims 23 to 41 and carbon.

43. A battery comprised of the cathode of claim 42.

44. The method of claim 1, wherein Li is removed from the lithium transition metal oxide powder and reinserted to form a lithium transition metal oxide powder having a further spinel phase.

45. The method of claim 44, wherein the Li is removed and reinserted electrochemically.

46. A powder mixture comprised of a physical mixture of a disordered rocksalt powder and an orthorhombic powder comprised of LiMnCL having an orthorhombic phase, the orthorhombic powder being present in an amount of 0.5 to 25% by weight of the disordered rocksalt powder and orthorhombic powder.

47. The powder mixture of claim 46, wherein the orthorhombic powder and disordered rocksalt powder each have an average particle size and a size ratio of the average particle size of the disordered rocksalt / the average particle size of the orthorhombic powder is from 0.2 to 5.

48. The powder mixture of claim 47, wherein the ratio is 0.5 to 2.354861 -9342-9452, v. 2WCAT-203-A-WO49. The powder mixture of claim 48, wherein the ratio is within 20% of 1.

50. The powder mixture of claim 46, wherein the orthorhombic powder consists essentially of the LiMnCh.

51. The powder mixture of claim 46, wherein the powder has an average particle size of at most 10 micrometers.

52. The powder mixture of claim 51, wherein the average particle size is at most 1 micrometer.

53. The powder mixture of claim 46, wherein the disordered rocksalt powder has a chemical composition represented by:LixM yMnzO2-(a+b)Fa Zb where 1.0<x<1.75; 0<y<0.55; 0.2<z<0.8; 0<(a+b)<0.7; (b>0), M’ is one or more transition metal other than Mn; Z is one or more of P, N and S.

54. The powder mixture of claim 53, where M’ is comprised of a 4d transition metal.

55. The powder mixture of claim 54, wherein M’ is further comprised of one or more of a 3d transition metal and a 5d transition metal.

56. The powder mixture of claim 55, wherein M’ is comprised of the 3d transition metal.

57. The powder mixture of claim 56, wherein the 4d transition metal and 3d transition metal are present in a molar ratio (4d transition metal / 3d transition metal) that is at least 0.25 by mole.

58. The powder mixture of claim 57, wherein the 4d transition metal / 3d transition metal is at least 1.

59. The powder mixture of claim 58, wherein the 4d transition metal is one or more of Zr, Nb, Y, Mo, Ru, Rh.364861 -9342-9452, v. 2WCAT-203-A-WO60. The powder mixture of claim 58, wherein the 3d transition metal is one or more of Ti, V, Cr, Fe, Co, Ni, Cu, and Zn.

61. The powder mixture of claim 54, wherein M’ is comprised of a 5d transition metal that is one or more of La, Hf, Ta, W, Re, Os, and Ir.

62. The powder mixture of claim 53, wherein the M’ is comprised of Nb and Ti.

63. The powder mixture of claim 46, wherein the powder further comprises an additive.

64. The powder mixture of claim 63, wherein the additive is comprised of a carbon or carbon forming compound.

65. A method of forming a powder mixture comprised of mixing a disordered rocksalt powder and an orthorhombic powder comprised of LiMnCh having an orthorhombic phase in a weight ratio of the disordered rocksalt powder and orthorhombic powder (disordered rocksalt powder / orthorhombic powder) from 1000 to 1 to form a mixture comminuting the mixture sufficiently to form the powder having an average particle size of less than 10 micrometer and the orthorhombic powder and the rocksalt powder each have an average particle size and a size ratio of the average particle size of the disordered rocksalt / the average particle size of the orthorhombic powder is from 0.2 to 5.

66. The method of claim 65, wherein the weight ratio is 200 to 2.

67. The method of claim 66, wherein the weight ratio is 100 to 10.

68. The method of claim 65, wherein the comminuting is performed using one or more of a planetary mill and micromedia mill.

69. The method of claim 68, wherein the powder is comprised of an additive.

70. The method of claim 69, wherein the additive is comprised of carbon.

71. The method of claim 65, wherein the size ratio of the disordered rocksalt powder and an orthorhombic powder prior to comminuting is 10 to 0.1.374861 -9342-9452, v. 2WCAT-203-A-WO72. The method of claim 71, wherein the size ratio prior to comminuting is 2 to 0.5.

73. The method of claim 72, wherein the powder mixture has a average size of at most 3 micrometers.384861 -9342-9452, v. 2

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