Spray-dried coating of electroactive particles

Abstract

Systems, methods, and apparatus for producing coated particles of electroactive material are described. The coated electroactive material particles may be produced by a spray drying process comprising atomizing a non-aqueous solution comprising lithium niobium ethoxy and original positive electrode active material particles to produce an atomized solution, passing the atomized solution into a drying chamber, and drying the atomized solution to produce lithium niobium oxide coated positive electrode active material particles. Atomizing is performed via an atomizer. The drying chamber has an airflow to carry the atomized solution therethrough. Drying is performed via airflow within the drying chamber.

Description

Technical Field

[0001] This disclosure relates to the field of electroactive materials for electrochemical batteries, and more specifically, to systems and methods for producing coated electroactive material particles. Background Technology

[0002] High-energy-density electrochemical batteries, such as lithium-ion batteries, are used in a variety of consumer products and vehicles. These include hybrid electric vehicles (HEVs) and electric vehicles (EVs). However, the use of electroactive materials with high specific capacity and energy density (such as some lithium transition metal oxides) is limited by the irreversible capacity loss and reduced cycle stability of these materials.

[0003] Several coatings have been used to modify the capacity and cycling stability of electroactive materials. Deposition techniques such as atomic layer deposition and chemical vapor deposition have been used to provide controlled coating thickness. However, these processes limit the scalability of producing coated electroactive materials and affect certain physical properties of the coated materials. Therefore, there is a need in the art to enhance capacity retention and cycling stability, as well as the production of electroactive materials. Summary of the Invention

[0004] The systems, methods, and apparatus according to this disclosure produce coated electroactive material particles via a spray drying process. Compared to similar electroactive material particles (uncoated particles and particles coated using non-spray drying processes), battery cells incorporating the spray-dried coated electroactive material particles disclosed herein exhibit enhanced specific capacity, capacity retention, and / or efficiency.

[0005] Advantageously, the systems, methods, and apparatuses disclosed herein can provide optimized uniformity of coated particles, for example, by optimizing the morphology, phase uniformity, and / or thickness uniformity of the coating. Furthermore, the systems, methods, and apparatuses disclosed herein can enhance the production of coated electroactive material particles by optimizing the cost of producing the coated electroactive material, increasing the volume of coated electroactive material produced in a given time, and increasing utilization time.

[0006] Advantageously, the coatings formed as disclosed herein possess a uniform phase microstructure throughout the coating (e.g., measured by reducing defect and / or vacancy concentrations). While not bound by theory, this is believed to optimize the performance of the coated particles by providing consistent properties (e.g., ion permeability) throughout the coating. Furthermore, the coating has a macrostructure (e.g., uniform thickness) that matches the macrostructure of the original electroactive material. While not bound by theory, this is believed to optimize the performance of the coated particles by providing consistent flux on the surface of the electroactive material.

[0007] Furthermore, although not bound by theory, the spray drying technique disclosed herein is believed to optimize the performance of battery cells incorporating coated particles by forming a coating with an atomic abundance that is the same as or closer to the desired stoichiometry than coatings formed using deposition processes (e.g., atomic layer deposition), without the use of additional materials or doping processes. For example, a lithium niobate coating formed via spray drying as disclosed herein will have a uniform stoichiometry of LiNbO3 throughout the coating.

[0008] Furthermore, although not bound by theory, it is believed that the spray drying technology disclosed herein can optimize the performance of battery cells incorporating coated particles by optimizing electrolyte interface formation, uniformity, durability, and performance.

[0009] According to an aspect of this disclosure, a method includes: atomizing a non-aqueous solution comprising lithium ethoxylated niobium and virgin cathode active material particles to produce an atomized solution; passing the atomized solution into a drying chamber; and drying the atomized solution to produce lithium niobium oxide-coated cathode active material particles. Atomization is performed via an atomizer. The drying chamber has an airflow to carry the atomized solution through it. Drying is performed via the airflow within the drying chamber.

[0010] According to other aspects of this disclosure, atomization, introduction, and drying are carried out under steady-state conditions.

[0011] According to other aspects of this disclosure, the non-aqueous solution comprises lithium ethoxyniobium in a content of 0.1% to 5% by weight based on the original positive electrode active material.

[0012] According to other aspects of this disclosure, the positive electrode active material is a lithium-rich and manganese-rich material, a nickel-manganese-cobalt material, a lithium nickel-cobalt-aluminum material, a lithium nickel-cobalt-manganese-aluminum material, a lithium iron phosphate material, a lithium iron-manganese-phosphate material, a lithium nickel oxide material, or a combination thereof.

[0013] According to other aspects of this disclosure, the positive electrode active material is a lithium-rich and manganese-rich material.

[0014] According to other aspects of this disclosure, drying in the drying chamber occurs at a temperature of 40°C to 90°C.

[0015] According to other aspects of this disclosure, drying in the drying chamber occurs at a temperature of 70°C.

[0016] According to other aspects of this disclosure, the airflow velocity is 20 L / min.

[0017] According to other aspects of this disclosure, each of the lithium niobium oxide-coated positive electrode active material particles includes a lithium niobium oxide coating defining a homogeneous phase.

[0018] According to other aspects of this disclosure, the lithium niobium oxide coating has a uniform thickness of 0.1 nm to 5 nm, and the lithium niobium oxide coating has the macroscopic structure of the original positive electrode active material particles.

[0019] According to aspects of this disclosure, a lithium niobium oxide-coated positive electrode active material particles are formed by atomizing a non-aqueous solution comprising lithium ethoxylated niobium and original positive electrode active material particles, passing the atomized solution into a drying chamber, and drying the atomized solution. Atomization is performed via an atomizer. The drying chamber has an airflow to carry the atomized solution through it. Drying is performed via the airflow within the drying chamber.

[0020] According to other aspects of this disclosure, atomization, introduction, and drying are carried out under steady-state conditions.

[0021] According to other aspects of this disclosure, the non-aqueous solution comprises lithium ethoxyniobium in a content of 0.1% to 5% by weight based on the original positive electrode active material.

[0022] According to other aspects of this disclosure, the positive electrode active material is a lithium-rich and manganese-rich material, a nickel-manganese-cobalt material, a lithium nickel-cobalt-aluminum material, a lithium nickel-cobalt-manganese-aluminum material, a lithium iron phosphate material, a lithium iron-manganese-phosphate material, a lithium nickel oxide material, or a combination thereof.

[0023] According to other aspects of this disclosure, the positive electrode active material is a lithium-rich and manganese-rich material.

[0024] According to other aspects of this disclosure, drying in the drying chamber occurs at a temperature of 40°C to 90°C.

[0025] According to other aspects of this disclosure, drying in the drying chamber occurs at a temperature of 70°C.

[0026] According to other aspects of this disclosure, the airflow velocity is 20 L / min.

[0027] According to other aspects of this disclosure, each of the lithium niobium oxide-coated positive electrode active material particles includes a lithium niobium oxide coating defining a homogeneous phase.

[0028] According to other aspects of this disclosure, the lithium niobium oxide coating has a uniform thickness of 0.1 nm to 5 nm, and the lithium niobium oxide coating has the macroscopic structure of the original positive electrode active material particles.

[0029] The foregoing features and advantages, as well as other features and advantages, of this disclosure will become apparent when taken in conjunction with the accompanying drawings from the following detailed description of the best mode of implementation of this disclosure. Attached Figure Description

[0030] The accompanying drawings are illustrative and are not intended to limit the scope of the claims. Exemplary aspects are discussed and illustrated in the following detailed description, wherein:

[0031] Figure 1 A schematic battery cell comprising coated electroactive material particles is shown according to aspects of this disclosure;

[0032] Figure 2 A schematic system for producing coated electroactive material particles according to aspects of this disclosure is shown;

[0033] Figure 3 An exemplary spray drying process for producing coated electroactive material particles is shown according to aspects of this disclosure;

[0034] Figure 4 Transmission electron microscope images depicting exemplary atomic layer deposition coated electroactive material particles;

[0035] Figure 5 Transmission electron microscope images depicting exemplary spray-dried coated electroactive material particles produced according to aspects of the present invention;

[0036] Figure 6 A graph depicts the specific capacity and capacity retention of an exemplary battery cell during charge / discharge cycles. Detailed Implementation

[0037] The following detailed descriptions are merely exemplary in nature and are not intended to limit applications and uses. Furthermore, this disclosure is not limited to the explicit or implicit theories presented in the foregoing background, summary of the invention, or accompanying drawings, or in the following detailed descriptions.

[0038] Figure 1 A schematic battery cell 10 (or electrochemical cell) according to aspects of this disclosure is shown. The battery cell 10 can be incorporated into a desired battery architecture, such as a stacked, wound, or cylindrical battery architecture. The battery cell 10 includes a separator 12 disposed between a pair of electrodes (a negative electrode 14 and a positive electrode 16). The separator 12 is configured to electronically isolate the negative electrode 14 and the positive electrode 16. The separator 12 can be a non-conductive porous polymer membrane. The negative electrode 14 is disposed on a first current collector 18 and the positive electrode 16 is disposed on a second current collector 20, each respective current collector being positioned opposite the separator 12.

[0039] The negative electrode 14 is configured to insert ions via a negative electrode active material during battery cell charging and to deintercalate ions during battery cell 10 discharging. The negative electrode active material can be, for example, a lithiated material, a silicon material, a silicon oxide material, a graphite material, or a combination thereof. In some aspects, the lithiated material is a material having the general formula Li... ySiO x The lithium-ion silicon material, wherein y is between 0 and 1 and x is between 0 and 2. In some respects, the lithium-ion material is a lithium-ion silicon-rich oxide, wherein x is less than 1. The electroactive material may have a suitable morphology selected from the group consisting of nanoparticles, nanofibers, nanotubes, micron particles, and combinations thereof.

[0040] A negative electrode 14 is loaded to optimize the operating characteristics of the battery cell 10. The negative electrode may further include carbon materials to enhance the properties of the negative electrode 14. For example, carbon materials may be selected to promote specific morphologies of electroactive materials, enhance ion intercalation and deintercalation, optimize the mechanical properties of the negative electrode 14, and combinations thereof. The carbon materials may be selected from the group consisting of graphite, hard carbon, or soft carbon.

[0041] The positive electrode 16 is configured to insert ions received from the negative electrode 14 via the positive electrode active material during the discharge of the battery cell 10, and to deintercalate ions to the negative electrode 14 during the charging of the battery cell 10. The positive electrode active material cooperates with the negative electrode active material to promote ion and electron flow between the negative electrode 14 and the positive electrode 16.

[0042] The positive electrode active material can be a transition metal electroactive material, such as an electroactive material rich in transition metals. In some aspects, the positive electrode active material is selected from lithium-rich and manganese-rich (“LMR”) materials, nickel-cobalt-manganese (“NCM” ​​or “NMC”) materials, lithium nickel-cobalt-aluminum (“NCA”) materials, lithium nickel-cobalt-manganese-aluminum (“NCMA”) materials, lithium iron phosphate (“LFP”) materials, lithium iron-manganese phosphate (“LMFP”) materials, lithium nickel oxide (“LNO”) materials, and combinations thereof.

[0043] LMR materials can be LMR oxides or LMR layered oxides represented by the formula xLi₂MnO₃(1-x)LiMO₂, where M is one or more transition metals. In some respects, M is selected from the group consisting of manganese, nickel, cobalt, iron, and combinations thereof. NCM materials can be represented by the formula Li[Ni 1-x-y Co x Mn y [O2] represents NCA material, which can be expressed as Li[Ni] 1-x-y Co x Al y O2 represents NCMA material, which can be produced by the formula Li[Ni]. 1-x-y Co x Mn y Al z O2 represents LFP materials. LFP materials can be represented by the formula LiFePO4. LMFP materials can be represented by the formula LiMn. x Fe 1-y PO4 represents LNO material. LNO material can be represented by the formula LiNiO2.

[0044] The first current collector 18 and the second current collector 20 are configured to collect free electrons from adjacent negative electrodes 14 and positive electrodes 16 and distribute them to adjacent negative electrodes 14 and positive electrodes 16. The free electrons move between the first current collector 18 and the second current collector 20 via an external circuit 22. The external circuit 22 may include an external device 24, which may be a load consuming power from the battery cell 10 and / or a power source supplying power to the battery cell 10.

[0045] Each of the negative electrode 14, the positive electrode 16, and the separator 12 may further include an electrolyte 26. For example, the pores of the negative electrode 14, the positive electrode 16, and / or the separator 12 may be filled with electrolyte 26. Electrolyte 26 is formed of an electrolyte solution and promotes ion movement between the negative electrode 14 and the positive electrode 16 during charging and discharging of the electrochemical cell 10.

[0046] Figure 2 A system 200 for producing coated electroactive material particles is shown. The system 200 includes a drying chamber 202 having an input side 204 and an output side 206.

[0047] The input side 204 includes an atomizer 208 and a gas inlet 212. The atomizer 208 is configured to atomize the non-aqueous solution 210 during the introduction of the non-aqueous solution 210 into the drying chamber 202. The non-aqueous solution 210 includes a raw electroactive material 210a and a coating precursor 210b in a non-aqueous solvent.

[0048] The primary electroactive material 210a comprises particles having a predetermined particle size distribution and a predetermined surface morphology. In some aspects, the primary electroactive material is a positive electrode electroactive material selected from the group consisting of LMR materials, NMC materials, NCA materials, NCMA materials, LFP materials, LMFP materials, LNO materials, and combinations thereof. In other aspects, the primary electroactive material is an LMR material. The primary electroactive material 210a can be a layered electroactive material, such as an electroactive material comprising layers of different lithium / metal and / or lithium / transition metal oxides.

[0049] The coating precursor 210b is configured to react under process conditions, which deposits a coating onto the surface of the original electroactive material 210a. In some aspects, the coating precursor 210b is lithium ethoxyniobium. Based on the original electroactive material, lithium ethoxyniobium may be present in an amount of 0.1% to 5% by weight. In some aspects, based on the original electroactive material, lithium ethoxyniobium is present in an amount of 1% by weight.

[0050] Atomizer 208 is selected such that the atomized non-aqueous solution 210 comprises uniformly homogenized original electroactive material 210a particles and coating precursor 210b droplets having a predetermined size distribution.

[0051] Gas inlet 212 is configured to introduce drying gas 214 into the input side 204 of drying chamber 202. In the illustrated embodiment, drying gas 214 is configured to heat and evaporate the atomized solution 210. The flow rate of drying gas 214 is selected to entrain particles, such as raw electroactive material particles and coated electroactive material particles, such that the dried particles are carried out of drying chamber 202 by drying gas 214.

[0052] The drying gas 214 is selected to be inert to or promote the kinetics of the coating reaction. In some respects, the drying gas 214 is air. In other respects, the drying gas 214 is an inert gas, such as nitrogen, argon, carbon dioxide, combinations thereof, etc. The drying gas 214 can be regulated to include a predetermined concentration of water vapor (e.g., regulated air). Alternatively or concurrently, water vapor can be introduced into the drying chamber 202 via a separate input.

[0053] Gas inlet 212 may include heating unit 216 configured to heat dry gas 214 to a desired inlet temperature and / or provide fine temperature control for preheated dry gas 214. In some aspects, heating unit 216 is a heat exchanger with a heating fluid. In some aspects, heating unit 216 is a resistance heater.

[0054] The drying chamber 202 includes a mixing section 218 near the input side 204 and a drying section 220 downstream of the mixing section 218. In the mixing section 218, the drying gas 214 is mixed with the atomized solution 210 to deliver the atomized solution 210 to the drying section 220.

[0055] Gas inlet 212 is positioned relative to atomizer 208 such that atomized solution 210 and dry gas 214 are thoroughly mixed and substantially homogeneous before entering drying section 220. In embodiments with a separate water vapor input, the water vapor input may be positioned to mix water vapor with non-aqueous solution 210 before, simultaneously with, or after mixing solution 210 and dry gas 214, and before the mixture enters drying section 220.

[0056] The dimensions and shape of the drying section 220 are designed to provide a predetermined residence time, such that, under process conditions, each of the pristine positive electrode active material particles is coated with lithium niobate before reaching the output side 206. The coating defines a uniform thickness. In some aspects, the coating defines a thickness from 0.1 nm to 5 nm. In other aspects, the coating defines a thickness of 1 nm.

[0057] The drying section 220 may include components such as a turbulent flow device or other means to control flow properties and optimize the uniformity of the environment experienced by each particle during the drying process.

[0058] Downstream of the drying section 220 includes one or more separators. These separators, such as pre-separator 222 and cyclone separator 224, are configured to separate the coated particles 226 from other components of the stream.

[0059] The pre-separator 222 may be configured to separate residual liquid and / or other components that are too large to be entrained by the drying gas stream. For example, in the illustrated embodiment, the pre-separator 222 is configured to collect residual liquid that has already been collected on components (e.g., walls) of the drying chamber 202 or residual liquid remaining after the mixture leaves the drying section 220. The residual liquid may be, for example, a coating precursor 210b in a solution, solvent, and / or water.

[0060] Cyclone separator 224 is configured to create a vortex with a cutting point in the dry gas flow, separating the dried coating particles 226 from smaller components in the dry gas flow (e.g., dry gas 214 and any unreacted coating precursor solids). The dried coating particles 226 are collected for incorporation into the electrodes of the battery cell, while the dry gas 214 and smaller components exit the system 200 via exhaust outlet 228. The exhaust gas can be treated to recover at least a portion of the dry gas 214 and / or the coating precursor solids therein. The recovered dry gas 214 can be recycled back into the system, for example, via gas inlet 212, and the recovered coating precursor can be recycled to a future non-aqueous solution 210.

[0061] Figure 3 An exemplary spray drying process 300 for producing coated electroactive material particles is shown. The process conditions of the spray drying process 300 are selected to provide a substantially homogeneous reaction environment around each electroactive material particle during the coating process. In some aspects, the process conditions are further selected to produce dried coated particles 226 prior to particle separation or isolation.

[0062] At box 302, a non-aqueous solution is atomized to produce an atomized precursor solution. This atomized precursor solution comprises homogenized primary electroactive material particles and coating precursor droplets. The coating precursor droplets comprise a coating precursor in a solvent. The coating precursor is selected such that the coating precursor droplets are dried to deposit a uniform coating on the primary electroactive material particles. The droplet size is adjusted to optimize the contact between lithium niobium ethanoate and the surface of the homogenized electroactive material particles during drying. In the illustrated embodiment, the primary electroactive material particle 210a is a primary LMR material, the coating precursor 210b is lithium ethoxylated niobium, and the solvent is ethanol.

[0063] At frame 304, an atomized precursor solution is introduced into drying chamber 202. Drying chamber 202 includes an airflow passing through it, which is configured to carry the atomized solution through drying chamber 202 toward an output. The airflow can also be configured to entrain coating particles.

[0064] At box 306, the atomized precursor solution is dried to produce dried coated particles. For example, the coating precursor 210b of lithium ethoxynitride in ethanol can be hydrolyzed during drying to deposit a uniform lithium niobate coating onto the original LMR particles. The process temperature is selected to evaporate the solvent without degrading the kinetics of the coating process and to produce uniformly coated electroactive material particles after the drying process is complete. In some aspects, the process temperature is selected from temperatures in the range of 40°C to 90°C. In some aspects, the process temperature is 70°C.

[0065] At box 308, the dried coated particles are isolated for use, for example, as battery cell electrodes. The isolation of the dried coated particles may include, for example, physical processes, such as cyclone separation. Based on, for example, the size of the dried coated particles, the dried coated particles may be further isolated into multiple portions.

[0066] Advantageously, the spray drying process 300 can be carried out in a steady state to continuously draw in the non-aqueous solution 210 and produce dried coated particles 226 for use in a complete process cycle. The process cycle is not limited by the volume of product or reactants, but only by auxiliary factors such as maintenance of system components.

[0067] As will be understood by those skilled in the art, this disclosure is readily adaptable to various modifications and alternatives, and some representative embodiments have been illustrated in the accompanying drawings and described in detail above. However, it should be understood that the novel aspects of this disclosure are not limited to the specific forms shown in the drawings. Rather, the invention encompasses modifications, equivalents, combinations, sub-combinations, arrangements, groupings, and alternatives that fall within the scope and spirit of this disclosure and are defined by the appended claims.

[0068] As used herein, unless the context clearly indicates otherwise, the words “and” and “or” should be both conjunctions and antonymous conjunctions; unless the context clearly indicates otherwise, the word “all” means “any and all”; the word “any” means “any and all”; the word “including” means “including but not limited to”; the singular forms “a”, “an” and “the” include plural indicators and vice versa.

[0069] Unless otherwise expressly or clearly indicated by the context (including the appended claims), the numerical values ​​of parameters (e.g., quantities or conditions) in this specification should be understood as being modified by the term "about," regardless of whether "about" actually precedes the numerical value. The numerical parameters set forth herein and in the appended claims are approximate values ​​and may vary depending on the desired properties sought to be obtained by this disclosure. At least, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be interpreted at least based on the number of significant figures reported and by applying ordinary rounding techniques.

[0070] For example, approximate terms such as “approximately,” “about,” and “substantially” can be used in this article to mean “within, close to, or almost within,” “within 0-10%,” or “within acceptable manufacturing tolerances,” or logical combinations thereof.

[0071] While the boundaries and limits of the term "about" are readily understood by those skilled in the art, the term "about" implies that the numerical value or property allows for imprecision. If the imprecision provided by "about" is not understood in this ordinary sense in the art, then "about" at least indicates a variation that may be caused by common methods of measuring and using such parameters. For example, unless otherwise understood in the art, the term "about" refers to within 10% (e.g., ±10%) of the value.

[0072] While the boundaries and limits of the term "substantially" are readily understood by those skilled in the art, the term "substantially" implies that some imprecision is permissible for the stated value or property. If the imprecision provided by "substantially" is not understood in this common sense in the art, then "substantially" at least indicates variations that may arise from manufacturing processes and the measurement of such parameters. For example, unless otherwise understood in the art, the term "substantially" means within 5% (e.g., ±5%) of the stated value.

[0073] While the boundaries and limits of the term "essentially" are readily understood by those skilled in the art, the term "essentially" implies that the numerical value or property allows for some slight inaccuracies. If the inaccuracy provided by "essentially" is not understood in this common sense in the art, then "essentially" at least indicates a negligible variation that may not be overcome in the desired parameter. For example, unless otherwise understood in the art, the term "essentially" refers to within 1% (e.g., ±1%) of the value.

[0074] While the boundaries and limits of the term "pure" are readily understood by those skilled in the art, the term "pure" means that a compound may include very trace amounts of other materials. If the imprecision provided by "pure" is not understood in this common sense in the art, then "pure" at least indicates variations that may arise from separation processes and measurements of such parameters. For example, unless otherwise understood in the art, the term "pure" refers to said material at a purity greater than 99.9%.

[0075] It should be understood that the scope provided herein includes the scope, sub-scopes within the scope, and each value within the scope.

[0076] While the best mode for carrying out this disclosure has been described in detail, those skilled in the art to which this disclosure pertains will recognize various alternative designs and embodiments for practicing this disclosure within the scope of the appended claims.

[0077] Example

[0078] Three types of LMR cathode electroactive material samples were prepared. These three categories include pristine LMR particles (“uncoated particles”), LMR particles coated with lithium niobate via atomic layer deposition (“ALD particles”), and LMR particles coated with lithium niobate via a spray drying process (“SD particles”).

[0079] The uncoated LMR particles contain 67% manganese, 17% cobalt and 16% nickel by weight, with an average size of 9 μm.

[0080] ALD particles are formed by coating pristine LMR particles onto a thin film via atomic layer deposition. The film has a thickness of 1 nm and an overall stoichiometry of LiNbO3. Figure 4 A TEM image of an exemplary ALD particle is shown.

[0081] SD particles were formed by coating LMR particles onto a thin film via a spray drying process. The film had a thickness of 1 nm and an overall stoichiometry of LiNbO3. An ethanol solution of lithium ethoxyniobium and LMR particles was prepared. This solution contained 10 g of LMR particles and, based on the LMR particles, 1 wt% lithium ethoxyniobium.

[0082] The drying gas is allowed to flow through the drying chamber until the temperature stabilizes. The flow rate of the drying gas is 20 L / min, and the temperature is 70°C. Once the drying chamber reaches the desired temperature, the solution is introduced into the chamber via an atomizer. The atomizer's volumetric flow rate and pressure are sufficient to provide single, pristine LMR particles and sufficiently small droplets to allow ethoxylated lithium niobium to coat the pristine LMR particles and evaporate the ethanol before leaving the drying chamber. The atomizer nozzle is cleaned as needed to maintain steady-state operation of the process. The atomized solution is passed perpendicularly through the drying chamber in the same direction as the drying gas.

[0083] After the ethanol evaporates, the dry gas and the entrained dry coated particles exit the drying chamber laterally. The entrained particles are separated from the dry gas by a cyclone separator. The dry coated particles are collected and calcined in air at 500°C for 5 hours. Figure 5 A TEM image of an exemplary SD particle is shown.

[0084] Each of these three categories was incorporated into the corresponding battery cell for comparative testing of specific capacity and coulombic efficiency during charge / discharge cycles. Each positive electrode comprises LMR particles, carbon black, and polyvinylidene fluoride in a 94 / 3 / 3 weight ratio to provide 5.5 mAh / cm³. 2 The theoretical capacity is achieved. Each negative electrode comprises 5.5 wt% silicon oxide / graphite to provide the same theoretical capacity as the positive electrode. These battery cells also include 50 μL of electrolyte containing 1.2 M LiPF6 and 1 wt% LiPO2F2, the LiPF6 being in a mixture of fluoroethylene carbonate and dimethyl carbonate in a 1:4 ratio. Each of the full cells undergoes the same formation and life cycle scheme.

[0085] The battery cell formation cycle scheme includes a constant current charging stage, a constant voltage charging stage, and a constant current discharging stage. During the constant current charging stage, a current with a capacitance value of C / 20 is supplied until the voltage reaches 4.6V. After reaching 4.6V, the constant voltage charging stage begins and maintains the voltage at 4.6V until the current reaches a capacitance value of C / 50. During the constant current discharging stage, a current with a capacitance value of C / 20 is drawn until the voltage reaches 2.0V.

[0086] The battery cell's lifecycle includes a constant current charging phase, a constant voltage charging phase, and a constant current discharging phase. During the constant current charging phase, a current with a capacitance value of C / 3 is supplied until the voltage reaches 4.6V. After reaching 4.6V, the constant voltage charging phase begins and maintains the voltage at 4.6V until the current reaches a capacitance value of C / 20. During the constant current discharging phase, a current with a capacitance value of C / 3 is drawn until the voltage reaches 2.0V.

[0087] Figure 6 A graph depicts the specific capacity and capacity retention of an exemplary battery cell during charge / discharge cycles. Lines 602a-c represent the specific capacity of the tested battery cell in mAh / g. Lines 604a-c represent the capacity retention percentage of the tested battery cell.

[0088] Line 602a represents the specific capacity of an exemplary battery incorporating uncoated particles. Line 602b represents the specific capacity of an exemplary battery incorporating ALD particles. Line 602c represents the specific capacity of an exemplary battery incorporating SD particles. It can be seen that uncoated particles initially have the lowest specific capacity, ALD particles have a higher specific capacity than uncoated particles, and SD particles have a higher specific capacity than both uncoated and ALD particles. Furthermore, although the specific capacity decreases with each cycle, the battery cell with SD particles maintains the highest specific capacity of all three categories throughout all test cycles.

[0089] Line 604a represents the capacity retention of an exemplary battery incorporating uncoated particles. Line 604b represents the capacity retention of an exemplary battery incorporating ALD particles. Line 604c represents the capacity retention of an exemplary battery incorporating SD particles. It can be seen that uncoated particles lose capacity retention faster than either ALD or SD particles. While ALD and SD particles exhibit similar trends, after 75 cycles, SD particles consistently maintain a higher capacity retention than ALD particles.

[0090] In addition, each of these three categories was incorporated into the corresponding half-cell for comparative testing of specific capacity and coulombic efficiency during the first cycle. Each of the three categories was incorporated into the corresponding half-cell for comparative testing of specific capacity and coulombic efficiency during charge / discharge cycles. Each positive electrode comprises LMR particles, carbon black, and polyvinylidene fluoride in a 94 / 3 / 3 weight ratio to provide 5.5 mAh / cm³. 2 The theoretical capacity is [not specified]. Each negative electrode is 0.6 mm of pure lithium metal. The half-cell also includes 50 μL of electrolyte containing 1.2 M LiPF6 and 1 wt% LiPO2F2, with the LiPF6 in a 1:4 mixture of fluoroethylene carbonate and dimethyl carbonate. Each half-cell undergoes the same formation and life cycle scheme.

[0091] The half-cell formation cycling scheme includes a constant current charging phase, a constant voltage charging phase, and a constant current discharging phase. During the constant current charging phase, a current with a capacitance value of C / 20 is supplied until the voltage reaches 4.6V. After reaching 4.6V, the constant voltage charging phase begins and maintains the voltage at 4.6V until the current reaches a capacitance value of C / 50. During the constant current discharging phase, a current with a capacitance value of C / 20 is drawn until the voltage reaches 2.0V.

[0092] The half-cell lifecycle scheme includes a constant current charging phase, a constant voltage charging phase, and a constant current discharging phase. During the constant current charging phase, a current with a capacitance value of C / 3 is supplied until the voltage reaches 4.6V. After reaching 4.6V, the constant voltage charging phase begins and maintains the voltage at 4.6V until the current reaches a capacitance value of C / 20. During the constant current discharging phase, a current with a capacitance value of C / 3 is drawn until the voltage reaches 2.0V.

[0093] The initial cycle coulombic efficiency and initial C / 3 discharge specific capacity of each half-cell were tested. The initial C / 3 discharge specific capacity of the uncoated particle half-cell was 225.9 mAh / g, and the initial cycle coulombic efficiency was 82.5%.

[0094] The ALD particle half-cell exhibits lower specific capacity and coulombic efficiency than the uncoated particle half-cell. Specifically, the ALD particle half-cell has an initial C / 3 discharge specific capacity of 219.3 mAh / g and an initial cycle coulombic efficiency of 82.0%.

[0095] The SD particle half-cell exhibits higher specific capacity and coulombic efficiency than the uncoated particle half-cell and the ALD particle half-cell. Specifically, the SD particle half-cell has an initial C / 3 discharge specific capacity of 232.7 mAh / g and an initial cycle coulombic efficiency of 84.9%.

Claims

1. A method comprising: atomizing, via an atomizer, a non-aqueous solution comprising ethoxy lithium niobate and pristine cathode active material particles to produce an atomized solution; passing the atomized solution into a drying chamber having a gas stream to carry the atomized solution through the drying chamber; and drying, via the gas stream within the drying chamber, the atomized solution to produce lithium niobium oxide-coated cathode active material particles. The atomizing, the passing, and the drying are performed at steady state.

2. The method of claim 1, wherein, The non-aqueous solution comprises an ethoxy lithium niobate content of 0.1 wt% to 5 wt% based on the pristine cathode active material.

3. The method of claim 1, wherein, The cathode active material is a lithium-rich and manganese-rich material, a nickel-manganese-cobalt material, a lithium-nickel-cobalt-aluminum material, a lithium-nickel-cobalt-manganese-aluminum material, a lithium iron phosphate material, a lithium iron manganese phosphate material, a lithium nickel oxide material, or a combination thereof.

4. The method of claim 1, wherein, The cathode active material is a lithium-rich and manganese-rich material.

5. The method of claim 1, wherein, The drying within the drying chamber occurs at a temperature of 40 °C to 90 °C.

6. The method of claim 1, wherein, The drying within the drying chamber occurs at a temperature of 70 °C.

7. The method of claim 1, wherein, The gas stream has a flow rate of 20 L / min.

8. The method of claim 1, wherein, Each of the lithium niobium oxide-coated cathode active material particles comprises a lithium niobium oxide coating defining a homogeneous phase.

9. The method of claim 1, wherein, 10. Lithium niobium oxide-coated cathode active material particles formed by: atomizing, via an atomizer, a non-aqueous solution comprising ethoxy lithium niobate and pristine cathode active material particles to produce an atomized solution; passing the atomized solution into a drying chamber having a gas stream to carry the atomized solution through the drying chamber; and drying, via the gas stream within the drying chamber, the atomized solution to produce lithium niobium oxide-coated cathode active material particles. ​

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