Method for manufacturing cathode material for rechargeable lithium-ion batteries

Abstract

To provide a method for manufacturing a high capacity positive electrode material for use in a rechargeable lithium battery.SOLUTION: A method uses mixed metals as feedstocks for wet chemical reactions to create high quality precursors that can be used to prepare high quality cathode materials after lithiation. An important feature is that in the precursor preparation method, most of the aqueous solutions used in the wet chemical reactions are recycled back to the reactor, such that the overall method produces little or no emissions during the production of the cathode precursor material.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims priority to U.S. Provisional Application No. 62 / 899,677, filed on 12 September 2019, which is incorporated herein by reference in its entirety for all purposes.

[0002] This invention relates to a method for producing a cathode material for rechargeable lithium (Li) batteries, and to a cathode material produced by this method. In particular, the method provided relates to the production of such cathode materials with relatively few emissions compared to current industrial methods. [Background technology]

[0003] (Description of prior art) Rechargeable lithium-ion batteries have been used as energy storage elements in several different types of devices. These devices include mobile phones, portable computers, wireless power tools, and hybrid and electric vehicles. In recent years, the demand for high-power lithium-ion batteries has increased dramatically, particularly with the rapid market growth of electric vehicles. The main components of a lithium-ion battery include the negative electrode, positive electrode, and electrolyte. During the charge-discharge cycle, lithium ions move between the negative electrode active material and the positive electrode active material via the electrolyte. Due to its limited specific capacity and high manufacturing and raw material costs, the positive electrode active material is usually the most expensive component in a lithium-ion battery. Therefore, the selection of the positive electrode active material is a crucial process for improving the performance and reducing the cost of a lithium-ion battery.

[0004] Currently, lithium mixed metal oxides, mostly containing nickel, cobalt, manganese, and / or aluminum along with other necessary dopants, are the main components used in the manufacture of high-performance cathode active materials. The demand for and manufacture of such materials continues to increase significantly.

[0005] Current industrial methods for producing these high-performance cathode materials, such as lithium mixed metal oxides, involve two main steps. The first step is the precursor manufacturing step, and the second step is the lithiation step. The precursor step begins with the use of mixed metal sulfates dissolved in water to form an aqueous solution. However, these methods can release undesirable emissions. [Overview of the project]

[0006] The advantages described above, as well as other purposes and objectives inherent thereto, are provided at least partially or completely by the methods of the present invention, as set forth below herein.

[0007] One embodiment of the present invention is a method for producing a cathode material for batteries such as lithium-ion batteries, the method reducing the amount of toxic or hazardous emissions from currently known methods for producing lithium mixed metal oxides. Therefore, it would be desirable to provide a preferred method that generates little to no emissions. In one embodiment, the method provides a system in which the entire essentially liquid portion derived from the reaction is completely reused, or can be reused, into the reaction system without significant treatment. Furthermore, the method may require little to no need to evaporate water and / or decompose organic matter or nitrates during the final high-temperature treatment / calcination method.

[0008] One embodiment is a method for producing a positive electrode active material. This method is as follows: To provide an aqueous solution having a pH greater than 7; The process involves adding a first metal to an aqueous solution to form a reaction solution, wherein the first metal is selected from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, and combinations thereof; The process involves forming a product solution comprising the step of adding an oxidizing agent and a second metal to a reaction solution, wherein the second metal is selected from at least two elements from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, zirconium, yttrium, titanium, vanadium, molybdenum, and combinations thereof, and the product solution comprises a positive electrode active material precursor, and the positive electrode active material precursor product comprises a first metal and a second metal, wherein the first metal and the second metal are not the same; This includes isolating the cathode active material precursor from at least a portion of the product solution and thereby forming a filtrate.

[0009] Another embodiment provides a chemical method for producing a lithium mixed metal oxide as a cathode active material for use in rechargeable lithium batteries. This method comprises two main steps: a wet chemical method for producing a precursor and a solid-state reaction called "lithiation" for producing the final cathode material.

[0010] One embodiment of the present invention provides a method for producing a lithium mixed metal oxide as a positive electrode active material for use in the manufacture of lithium-ion batteries, using two main steps: a precursor preparation step and a lithiation step.

[0011] (A) In the precursor preparation step, the selected metals in their metallic forms are added to a stirred reaction system containing a mixture of solid metal particles and mixed metal hydroxide particles in an aqueous solution, along with one or more selected oxidizing agents, a selected metal nitrate, and nitic acid, which are also introduced into a reactor to oxidize the metal particles under alkaline conditions. The overall oxidation reaction is represented by the following equation: xMe+yMe'(NO3) n +zHNO3+(0.25xm-2yn-2z)O2+(0.5xm+2yn+z)H2O→Me x Me' y (OH) (xm+yn) +(yn+z)NH3 In the formula, Me represents at least one metal in metallic form selected from the group consisting of nickel, manganese, cobalt, aluminum, and magnesium; Me' represents at least one metal in its ionic form selected from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, zirconium, yttrium, titanium, vanadium, and molybdenum; Me x Me' y (OH) (xm+yn) Here, x represents the precursor product; x and y are the mole fractions of metals Me and Me', respectively, m is the molar-weighted average chemical value of the mixed metal Me in the precursor product, n is the molar-weighted average chemical value of the mixed metal Me' in ionic form in the reactants, and z is the mole fraction of HNO3 introduced into the reaction system; xm ≥ 8yn + 8z, x + y = 1, 1 ≥ x > 0, y ≥ 0, z ≥ 0. Here, the slurry obtained from the oxidation reaction is removed from the reactor, unreacted raw material metals are removed from the slurry, and it is reused in the reaction system with or without reactivation treatment using nitric acid and / or a combination of nitric acid and ammonia / ammonium, after which solid-liquid separation is performed, where the recovered solid material is used as the precursor product and the liquid material is reused directly in the reaction system without any treatment.

[0012] (B) In the lithiation process, the recovered precursor product is mixed with a lithium-containing compound and optionally other dopants to produce a final mixture, which is then calcined to obtain a positive electrode active material.

[0013] In one embodiment, raw materials, which may be mostly in metallic form, are introduced into the reaction system. The reaction system typically comprises at least one agitated mixing tank and a reactor, the reactor of which may be equipped with a magnetic separation device for removing and reusing unreacted raw materials. A reactivation step may be provided before reusing unreacted raw materials to keep the raw materials active during the reaction. An oxidizing agent such as oxygen and / or nitrate is introduced into the reaction system to oxidize the metal. After the reaction, a solid-liquid separation operation is performed. The liquid portion may be reused in the reaction system, and the solid portion is recovered as a precursor material. An artificial solution having essentially the same or similar composition as the filtrate may be prepared and used to initiate the reaction until a suitable filtrate is produced from the filtration system and then reused in the reaction system.

[0014] In the lithiation stage, the precursor material produced above is mixed with a lithium-containing compound and optionally other dopants, followed by a calcination treatment, and then additional surface treatment as needed to obtain the final cathode active material.

[0015] Accordingly, embodiments of the present invention provide a system and method for producing lithium mixed metal oxides with little or no waste generation. That is, the system may allow the entire essentially liquid portion from the reaction to be completely reused in the reaction system without any processing.

[0016] An additional feature is that while the method of the present invention can be carried out in batch processing, it can also be carried out in essentially continuous processing, as described below.

[0017] In another embodiment, the present invention also provides cathode material precursor products, where suitable cathode material precursors are produced, and these precursors are produced in a stable, continuous manner in a one-step reaction system in the manner described herein. This embodiment also includes a final cathode active material and a cathode produced therefrom, as produced by the method described herein with respect to the present invention.

[0018] In a third aspect, the present invention also provides a battery, where the positive electrode of the battery is manufactured by the chemical method described above with respect to the embodiments of the present invention.

Brief Description of the Drawings

[0019] Here, the following non-limiting examples are used and the accompanying drawings are referred to in order to demonstrate the embodiments.

[0020] [Figure 1] SEM image of the sample recovered from Example 1, using nitrate and acetate as anions in the reaction system.

[0021] [Figure 2] SEM image of the sample recovered from Example 2, using only nitrate as an anion in the reaction system.

[0022] [Figure 3] Graph of the oxidation-reduction potential (ORP) as a function of time for the results of Example 3. This graph shows the oxidation-reduction potential (ORP) as a function of time after introducing the metal powder into the filtrate. Curve 1 shows the ORP for an inert metal powder, and curve 2 shows the reactivation treatment of the same metal powder as curve 1 but using ammonium nitrate.

[0023] However, it should be clearly understood that the examples and the drawings are for illustrative purposes only and do not necessarily limit the scope of the present invention.

Modes for Carrying Out the Invention

[0024] Embodiments relate to a method for the manufacture of a positive electrode material for an energy storage device, particularly a lithium ion battery, where the method typically improves and / or solves the problem of emissions associated with the fabrication of lithium metal oxides. Thus, the described method produces little or no emissions, and essentially the entire liquid portion from the reaction may be recycled completely into the reaction system without any significant treatment. Such a system is further advantageous because it requires little or no need to evaporate water during the final high temperature treatment / firing method, and / or to decompose organic substances or nitrates.

[0025] It is well known that metal oxides or metal hydroxides can be formed from corrosion methods, for example, metal oxidation in an aqueous solution or in a hydrated state. This principle may be used in a first step to produce a precursor material from a pure metal, where the metal corrosion / oxidation reaction and the coprecipitation reaction occur simultaneously in the same reactor. The overall reaction is shown by the following formula: xMe + yMe´(NO3) n + zHNO3 + (0.25xm - 2yn - 2z)O2 + (0.5xm + 2yn + z)H2O → Me x Me´ y (OH) (xm+yn) + (yn + z)NH3 where Me represents at least one metal selected from the group consisting of nickel, manganese, cobalt, aluminum, and magnesium, preferably in metallic form; Me´ represents at least one metal selected from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, zirconium, yttrium, titanium, vanadium, and molybdenum, preferably in their ionic form; Me x Me´ y (OH) (xm+yn)∫ represents the precursor product; x and y are the mole fractions of metals Me and Me', respectively, where m is the molar weighted average value of mixed metal Me in the precursor product, n is the molar weighted average value of mixed metal Me' in ionic form in the reactants, and z is the mole fraction of HNO3 introduced into the reaction system. In the equation, xm ≥ 8yn + 8z, x + y = 1, 1 ≥ x > 0, y ≥ 0, and z ≥ 0.

[0026] Oxygen can be used as an oxidizing agent because, when used, it typically does not produce any significant by-products during the reaction. Oxygen can be supplied either as a pure oxygen source or as oxygen contained in other gases, such as oxygen in the air.

[0027] Some metal nitrates may be included for use with elements that do not readily react with oxygen, or for elements that are not readily handled during processing operations such as stirring for homogeneous mixing or magnetic separation of their metallic forms.

[0028] Nitric acid can be used as an additional oxidizing agent to slow down the coprecipitation reaction of metal nitrates and for baffling purposes. Nitrates or their combination with ammonia can also be used to reactivate recycled raw materials. Ammonia is the only by-product when nitrates and nitric acid are used. However, the ammonia produced is in gaseous form and does not remain in the reaction system during the operation. Therefore, in the above wet chemical method for preparing precursors, no additional or new chemicals are added to the liquid after solid-liquid separation occurs. Thus, the liquid can be directly reused in the reaction system by at least up to 75%, more preferably at least up to 90%, and even more preferably up to 100%, without any adverse effect on the overall reaction.

[0029] The generated ammonia gas can be recovered as a useful chemical or chemical precursor for other industries, such as the fertilizer industry.

[0030] To obtain high-quality products with consistent properties, the reactions described herein may be operated in continuous mode until the reaction reaches steady-state conditions. This provides better control over the resulting chemical composition. In one approach, the same liquids as in the reaction system may be used. An artificial solution with a similar composition is prepared and used to initiate the reaction. This artificial solution is used until the liquid produced from the solid-liquid separation operation is similar to the artificial solution.

[0031] The pH of the reaction slurry may be in the range of 7.5 to 13, or alternatively, in the range of 8 to 12. The pH of the solution can be adjusted by adding an acid selected from sulfuric acid, nitric acid, or acetic acid, and / or by adding an alkaline substance selected from lithium hydroxide or lithium oxide, sodium hydroxide or sodium oxide, potassium hydroxide or potassium oxide, and ammonia. pH adjustment may be performed by adding an acid such as sulfuric acid or nitric acid, and / or by adding an alkaline substance such as lithium hydroxide or sodium hydroxide to the reaction mixture. Note that lower pH values ​​may degrade the quality of the co-precipitate product, while higher pH values ​​may cause metal passivation during the corrosion reaction.

[0032] The reaction temperature may range from 20°C to the boiling point of the reaction slurry, including 20°C to 100°C.

[0033] Maintaining acceptable conductivity of the reaction system may also be important for controlling the corrosion reaction. Therefore, the reaction slurry may also contain dissolved salts to form an electrolyte for conductivity. The salts may include salts such as sulfates, acetates, nitrates, and chlorates, and cations selected from sodium, lithium, potassium, and ammonium. The salts may be reusable in the recycled liquid recovered after separation of the liquid and solid.

[0034] To produce a final lithium material with good performance, such as high capacity, the precursor material may have small primary particles within each secondary particle, i.e., a high BET (Brunauer-Emmett-Teller) surface area. When nitrates are used as oxidizing agents and / or doping elements are required, nitrates should generally be present in the reaction system. Therefore, chemical reactions involving the dissolution and precipitation of metals should proceed well using only nitrates as anions in the reaction system. However, the BET surface area of ​​the precursor material is usually very low with only nitrates in the reaction system. To increase the BET surface area, at least one additional selected anion and / or additive can be applied to the reaction system, which can alter the pattern of precursor particle growth. These additional anions may be selected from borates, bromides, iodides, chlorides, sulfates, formates, or acetates, etc. Considering that the level of impurities in the final product may increase if more anions and / or additives are introduced into the reaction system, i chemicals that can be decomposed during the high-temperature lithiation process, such as acetates, may be selected.

[0035] Ammonium must generally be present in the reaction system as a cation. However, other cations can also be introduced into the reaction system to adjust the pH and conductivity. Considering that introducing more cations into the reaction system may increase the level of impurities in the final product, lithium ions may be selected as the primary cation in the final product. The aqueous solution may contain at least one additional cation besides ammonium, such as sodium, potassium, and lithium. Lithium ions may be selected as the primary cation in the final product.

[0036] The reaction slurry may also typically contain dissolved complexing agents, such as a mixture of ammonia and ammonium, which can chelate metal ions in aqueous solution. The overall function of these complexing or chelating agents is to control the properties of the coprecipitation product and the corrosion reaction of the metal. The goal is to activate the response.

[0037] A method for producing a cathode material may also include a step in which unreacted raw material metals recovered from the slurry, for example by a magnetic separation step, are reactivated by grinding and / or washing, for example, with a nitrate acid or a combination thereof.

[0038] Furthermore, the method may also include a step in which solid particles having the same or similar composition as the precursor product but with a smaller particle size than the precursor product are introduced into the reaction system at the start of the reaction and / or during the reaction.

[0039] Embodiments of the method described herein can therefore be used to produce compositionally similar particles of cathode material precursor having a uniform elemental distribution within each particle, where the metal is added in a stable, continuous manner in a single-step reaction system. However, the method can also be applied to produce particles having a heterogeneous elemental distribution within each particle, such as a compositional gradient or layered particles of cathode material precursor in a multi-step reaction system, by adding different metals at different times or stages. In such a multi-step system, each stage can deposit layers of material having various compositions for different functions. For example, the core region of the cathode material particle may be nickel-rich for higher capacity, while the surface area may be manganese, cobalt, magnesium, tungsten, or aluminum-rich for a stable interface with the electrolyte found in lithium-ion batteries.

[0040] Accordingly, the embodiment of the method provides a system in which, in order to produce a precursor having a heterogeneous elemental distribution within each particle, a metal is continuously added at the same ratio at all times to produce a precursor having a uniform elemental distribution within each particle, or the metal is continuously added at different ratios over time.

[0041] Next, the final cathode active material produced in the present invention can be obtained by mixing the precursor compound with a lithium-containing compound and carrying out a calcination reaction, which can then be optionally surface-treated if necessary. This method is commonly called lithiation, and this lithiation method is typically carried out as a solid-phase reaction at a temperature of 600°C to 1100°C, depending on the chemical composition of the final material. In the lithiation reaction step, oxidation conditions may also be required as part of the method. Air, oxygen, and nitrates may be used as oxidizing agents.

[0042] For most applications, lithium hydroxide and lithium carbonate may be used as lithium sources, with or without crystallization water.

[0043] After lithiation, slight crushing / grinding may be required in a size reduction operation to break up loose agglomerates formed during the lithiation process. Subsequently, optional surface treatments may be required or desired to stabilize the surface of the material, such as washing to remove excess lithium hydroxide / lithium carbonate and other impurities, as well as any coatings.

[0044] In this way, the positive electrode material can undergo further processing after firing, which includes washing to remove excess lithium and other unwanted impurities, and coating the positive electrode material for better performance of the positive electrode material in battery manufacturing and / or battery applications. [Examples]

[0045] (Example 1) According to the manufacturing method described above, an aqueous solution of approximately 2.2 L was prepared and transferred to a 3 L reaction vessel equipped with a stirring and heating system. The aqueous solution contained approximately 1.0 M sodium acetate, 0.2 M sodium nitrate, and 0.1 M ammonium nitrate. The solution was heated to a temperature of approximately 60°C while stirring at a stirring speed of approximately 800 rpm. The pH was adjusted to approximately 10 by adding 28% ammonia solution and sodium hydroxide. Approximately 100 grams of metallic nickel was added to the reaction vessel. After approximately 30 minutes, approximately 50 grams of ball-milled metal hydroxide powder was added to the reaction vessel as a seed. The metal hydroxide powder, with a D50 size of less than 1 μm, contained mostly nickel, with small amounts of cobalt and manganese.

[0046] 68% nitric acid was continuously introduced into the reaction vessel using a peristaltic pump, and 11 grams of metal powder with a Ni:Co:Mn ratio of 90:5:5 was manually introduced into the reaction vessel every hour. The pumping rate of the nitric acid pump was approximately 2.8 mL / hour. This pumping rate was about 10% lower than the theoretical value required to react all the metals. This was because oxygen was drawn into the reaction system by the agitator during the reaction, and this oxygen also participated in the reaction as another oxidizing agent.

[0047] Every four hours, approximately 200 mL of slurry was collected from the reaction vessel, and the collected slurry was magnetically separated. The separated magnetic portion was returned to the reaction vessel. The non-magnetic solid portion was filtered and then washed with water. All the filtrate, along with the washing water, was returned to the reaction vessel.

[0048] The above procedure was repeated for three consecutive days. The final solid portion of the filtration process was dried at approximately 120°C for at least 5 hours as the precursor of the present invention. This solid sample was sent for scanning electron microscopy (SEM) and BET surface area testing. Figure 1 shows an SEM image of the sample recovered on the precursor particles from the above reaction. The particles are smooth and spherical with fine secondary particles. The BET surface area is approximately 17 m². 2 It was / g.

[0049] (Example 2 (Comparison)) For comparison, a second experiment was conducted. The reaction conditions were the same as those described in Example 1. The only significant difference was that the aqueous solution contained only nitrates as anions in the reaction system, namely sodium nitrate at a concentration of approximately 1.2 M and ammonium nitrate at a concentration of 0.1 M. Figure 2 shows an SEM image of the precursor particles of the sample recovered from this example. The particles are spike-like with very coarse secondary particles. The BET surface area is only 3.3 m². 2 The value was / g. Such products are generally considered unsuitable as precursors for producing lithium metal oxide cathode materials.

[0050] (Example 3 (Reactivation)) Approximately 300 g of unreacted, wet metal powder was collected after magnetic separation and exposed to air for 3 days. Approximately 100 g of the exposed metal powder was directly introduced into a 3 L container while stirring. The container contained approximately 2.5 L of filtrate recovered from the solid-liquid separation step of the method. The oxidation-reduction potential (ORP) was measured at a different time than the introduction of the metal powder. Typically, an ORP below -300 mV indicates that the metal is active, and the test results are shown as curve 1 in Figure 3. The ORP was stable at approximately -120 mV, which indicates that the metal powder was inactive.

[0051] In another test, approximately 100 g of the same exposed metal powder was introduced into 200 mL of 0.1 M NH4NO3 solution, whose pH was adjusted to approximately 10.5 by adding ammonia. After stirring for several minutes, the metal powder was transferred to a 3 L container while stirring. Again, the container was used in the method. The sample contained approximately 2.5 L of filtrate recovered from the solid-liquid separation process. ORP was measured at a different time than the transfer of the metal powder. The test results are shown as curve 2 in Figure 3. ORP rapidly decreased to -400 mV within 10 minutes, indicating that the inert metal powder was activated.

[0052] Therefore, it is clear that the present invention provides methods, products, and batteries that fully satisfy the above-mentioned objectives, subjects, and advantages. Thus, although specific embodiments of the present invention have been described, it will be understood that alternative forms, modifications, and variations can be suggested to those skilled in the art, and that this specification is intended to encompass all such alternative forms, modifications, and variations that fall within the scope of the appended claims.

Claims

1. A method for producing a positive electrode active material precursor, A step of providing an aqueous solution having a pH greater than 7, A step of forming a reaction solution by adding a first metal to the aqueous solution, wherein the first metal is selected from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, and combinations thereof. A step of forming a product solution comprising the step of adding an oxidizing agent and a second metal to the reaction solution, wherein the second metal is selected from at least two elements from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, zirconium, yttrium, titanium, vanadium, molybdenum, and combinations thereof, and the product solution comprises a positive electrode active material precursor, wherein the positive electrode active material precursor comprises the first metal and the second metal, wherein the first metal and the second metal are not the same, A step of isolating the positive electrode active material precursor from at least a portion of the product solution, thereby forming a filtrate, A step of isolating unreacted metals, including the first and second metals, from the filtrate, A step of reusing the unreacted metal in the aqueous solution and the reaction solution, A step of recombining the filtered liquid with the product solution, Methods that include...

2. The method according to claim 1, further comprising the step of adding a mixed metal hydroxide to the aqueous solution.

3. The method according to claim 1 or 2, wherein the aqueous solution has a pH of 7.5 to 13.

4. The method according to claim 1 or 2, wherein the aqueous solution further comprises an acid selected from the group consisting of sulfuric acid, nitric acid, acetic acid, or a combination thereof.

5. The method according to claim 1 or 2, wherein the aqueous solution further comprises an alkaline substance selected from the group consisting of lithium hydroxide, lithium oxide, sodium hydroxide, sodium oxide, potassium hydroxide, potassium oxide, and ammonia.

6. The method according to claim 1 or 2, wherein the aqueous solution further comprises a conductive salt.

7. The method according to claim 6, wherein the conductive salt is selected from the group consisting of sulfates, acetates, nitrates, chlorates, and combinations thereof.

8. The method according to claim 6, wherein the conductive salt comprises a cation selected from the group consisting of sodium, lithium, potassium, ammonium, and combinations thereof.

9. The method according to claim 1 or 2, wherein the aqueous solution further comprises an additional anion.

10. The method according to claim 9, wherein the additional anion is selected from the group consisting of borates, bromides, iodides, chlorides, sulfates, formates, acetates, and combinations thereof.

11. The method according to claim 1 or 2, wherein the aqueous solution contains a cation.

12. The method according to claim 11, wherein the cation is selected from the group consisting of sodium, potassium, lithium, and combinations thereof.

13. The method according to claim 1 or 2, wherein the aqueous solution further comprises a complexing agent.

14. The method according to claim 13, wherein the complexing agent comprises ammonia and ammonium.

15. The method according to claim 1 or 2, wherein the step of forming the product solution further includes stirring the reaction solution.

16. The method according to claim 1 or 2, wherein the product solution is formed continuously under substantially steady-state conditions.

17. The method according to claim 1 or 2, wherein the step of forming the product solution further comprises adding positive electrode active material precursor particles to the reaction solution.

18. The method according to claim 1 or 2, wherein at least 90% of the liquid in the filtrate is recombined with the product solution.

19. The method according to claim 1 or 2, wherein the filtrate is directly recombined with the product solution.

20. The method according to claim 1 or 2, wherein the oxidizing agent is selected from the group consisting of oxygen, nitric acid, and combinations thereof.

21. The method according to claim 1 or 2, wherein the aqueous solution comprises nitric acid and at least one of ammonia and ammonium.

22. The method according to claim 1 or 2, further comprising the step of treating the unreacted metal with an acid.

23. The method according to claim 22, wherein the acid is selected from the group consisting of nitric acid, ammonia, ammonium, and combinations thereof.

24. The method according to claim 22, further comprising a step of further processing the unreacted metal, wherein the additional processing is selected from the group consisting of grinding, washing, and combinations thereof.

25. The method according to claim 1 or 2, wherein the positive electrode active material precursor comprises precursor particles having a substantially uniform distribution of metal elements within each particle.

26. The method according to claim 1 or 2, wherein the positive electrode active material precursor comprises precursor particles having a substantially non-uniform distribution of metal elements within each particle.

27. The method according to claim 26, wherein the substantially heterogeneous distribution of metal elements within each particle is selected from the group consisting of gradient distribution, layered distribution, and combinations thereof.

28. A step of forming a final mixture containing the isolated positive electrode active material precursor and a lithium-containing compound, The method according to claim 1 or 2, further comprising the step of calcining the final mixture to form a calcined final mixture containing a positive electrode active material.

29. The method according to claim 28, wherein the final mixture further comprises a dopant.

30. The method according to claim 28, wherein the lithium-containing compound is selected from the group consisting of lithium hydroxide, lithium carbonate, and combinations thereof.

31. The method according to claim 28, wherein the firing is performed at a temperature of 600°C to 1100°C.

32. The method according to claim 28, further comprising the step of processing the positive electrode active material, wherein the processing is selected from the group consisting of washing, coating, and combinations thereof.

33. A method for forming an energy storage device, A step of forming a positive electrode, wherein the positive electrode formation includes depositing the positive electrode active material described in claim 28 onto a current collector, A method comprising the step of inserting the positive electrode, the negative electrode, and the separator into a housing, wherein the separator is positioned between the negative electrode and the positive electrode.

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