Process for delithiation of transition metal oxides

Abstract

To obtain a delithified electrochemically active material that can be directly combined with electrodes, a chemical process for removing lithium from an electrochemically active composition is provided. [Solution] The process is li x The present invention provides an electrochemically active composition defined by the formula MO2, wherein M comprises Ni, and M optionally further comprises one or more other metals, transition metals, rare earth metals, or combinations thereof, and x is a first Li / M atomic ratio of 0.8 to 1.3; and provides the electrochemically active composition to be combined with a strong oxidizing agent for a lithium removal time to obtain a delithiated electrochemically active material, wherein more than 50% of the initial nickel in the electrochemically active composition is present in the delithiated electrochemically active composition after the lithium removal time.

Description

Technical Field

[0001] The present disclosure relates to the formation of electrochemically active compositions suitable for use in primary or secondary applications, and more specifically to the initial removal of lithium from synthesized or previously treated lithiated transition metal oxides.

Background Art

[0002] The formation of electrochemically active compositions for use in batteries typically involves two primary steps. First, a precursor is formed by a coprecipitation reaction or the like, whereby transition metals are intermingled in the form of hydroxides or carbonates to form a precursor powder. The precursor is then mixed with a lithium compound and fired at a high temperature to form an electrochemically active composition.

[0003] In some cases, it is beneficial to precharge the cathode material before use in a battery. During the formation of the charged state of the cathode material by conventional processes, the material is subjected to pickling, whereby lithium is removed while maintaining the crystal arrangement of other elements in the material. This enables the resulting delithiated material to be incorporated into a "charged" electrochemical cell as the electrochemically active composition of the cathode.

[0004] Conventional methods for achieving this delithiation of electrochemically active compositions have suffered from several drawbacks such as relatively high cost and low yield of materials (about 50% yield). Therefore, an improved process for the oxidation of lithiated electrochemically active compositions for use in electrochemical cells is needed.

Summary of the Invention

[0005] The following summary is provided to facilitate an understanding of some of the innovative features unique to the present disclosure and is not intended as a complete description. The various aspects of the present disclosure can be fully understood by taking the entire specification, claims, drawings, and summary together.

[0006] According to some embodiments of this disclosure, a process for removing lithium from an electrochemically active composition may include providing an electrochemically active composition and combining the electrochemically active composition with a strong oxidizing agent for a lithium removal time. The electrochemically active composition may include Li, Ni, and O. The electrochemically active composition may optionally have an initial Li / Ni at% ratio of 0.9 to 1.15.

[0007] According to some embodiments of the present disclosure, the lithium removal time is such that the second Li / Ni at% ratio after the lithium removal time is 0.6 or less, thereby forming a delithiated electrochemically active composition. [Brief explanation of the drawing]

[0008] The embodiments shown in the drawings are essentially descriptive and illustrative, and are not intended to limit the subject matter defined by the claims. The following detailed description of the descriptive embodiments can be understood in conjunction with the following drawings.

[0009] [Figure 1] Schematic diagrams illustrating the process of forming the delithiated electrochemically active compositions provided herein are illustrated in several embodiments.

[0010] It should be understood that, as used in the attached drawings, dashed lines may indicate optional components or process steps, while solid lines may indicate required components or process steps according to some embodiments of the process described herein and presented for illustrative purposes only. [Modes for carrying out the invention]

[0011] This disclosure relates to a novel process for forming delithiated electrochemically active compositions. Optionally, these delithiated electrochemically active compositions may be suitable for use in electrochemical cells such as primary or secondary batteries. A cost-effective method is provided for forming delithiated metal oxides, such as delithiated nickel oxide. The process provided herein not only uses low-cost reactants but also produces the formed material in higher yields than conventional methods.

[0012] As used herein, the term “transition metal precursor” refers to a transition metal in the form of a hydroxide, oxide, oxyhydroxide, carbonate, or nitrate.

[0013] As used herein, the term “lithium compound” refers to lithium-containing compositions in the form of lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium acetate, lithium peroxide, lithium bicarbonate, or lithium halide.

[0014] As used herein, the term “active material precursor” refers to a mixed product of a lithium compound, a transition metal precursor, and, in some embodiments, a processing additive.

[0015] As used herein, the term "calcination" is understood as a heat treatment in the presence of an oxidizing atmosphere to cause a chemical transformation of the material.

[0016] As used herein, the term “electrochemically active composition” refers to a calcined active material precursor.

[0017] As used herein, the term “desitisized electrochemically active composition” refers to an electrochemically active composition that has undergone a delithiation process. A “desitisization process” is a process that reduces the lithium atomic percentage (at%) in a metal base. Generally, delithiation processes operate by oxidation of the cathode material.

[0018] The temperatures provided herein are, optionally, absolute numbers as described, or approximate temperatures defined as ±10°C from absolute numbers as described.

[0019] A process is provided for forming an electrochemically active composition suitable for inserting Li. Examples of electrochemically active compositions of transition metal oxides include, but are not limited to, LiNiMO-based chemicals, where M is optionally present in the material and may be any transition metal, rare earth element, or combination thereof. Much of this disclosure concerns delithified electrochemically active compositions, such as those that are atomically predominantly Ni, but it is understood that the processes for forming these materials in a charged state may similarly be attributable to other electrochemically active compositions.

[0020] Referring here to Figure 1, the process 100 for removing lithium from an electrochemically active composition may include providing an electrochemically active composition 110 and combining the electrochemically active composition with a strong oxidizing agent for a lithium removal time 120, thereby forming a delithiated electrochemically active composition. Optionally, the process may include forming the delithiated electrochemically active composition in a lithium-ion battery cathode 130. Optionally, the process may include recycling the lithium removed from the delithiated electrochemically active composition 140.

[0021] The electrochemically active composition before undergoing the process described herein is of formula Li xThe composition may include elements corresponding to MO2, where x is the atomic ratio of Li to M, typically 0.8 to 1.3, and M is one or more of Co, Ni, Mn, Al, Mg, Ti, Zr, Nb, Hf, V, Cr, Sn, Cu, Mo, W, Fe, Si, Zn, B, other transition metals, rare earth elements, or combinations thereof. In some embodiments, M is one, two, three, four, five, or more elements from the aforementioned list. Optionally, the composition may include Li, Ni, and O alone or, further optionally, with one or more additional elements. Optionally, the composition may include Li, Ni, Co, and O alone or in combination with one or more elements. In some embodiments, the composition may include Li, Ni, Co, Mg or Mn, and O alone or in combination with one or more other elements. Optionally, the composition may include Li, Ti, and O alone or in combination with one or more other elements. Any electrochemically active composition suitable for use as a cathode active material in a primary or secondary electrochemical cell may be used in the delithiation process according to this disclosure.

[0022] Regardless of the presence or absence of other elements, the electrochemically active composition can have an initial stoichiometric Li / M atomic percent (at%) ratio of 0.8 to 1.3, optionally 0.9 to 1.15, or any value or range therebetween. For example, the initial at% ratio of Li to nickel can be 0.9 to 1.1, or 0.95 to 1.15, or 0.95 to 1.05. The stoichiometric ratio of Li to M can be measured by any method known in the art. As an example, optionally, inductively coupled plasma atomic emission spectroscopy (ICP) or atomic absorption spectroscopy using standard methods described by J.R. Dean (Practical Inductively Coupled Plasma Spectroscopy, Chichester, England: Wiley, 2005, 65 - 87), and Welz and Sperling (Atomic Absorption Spectrometry, 3rd ed., Weinheim, Germany: Wiley VCH, 1999, 221 - 294). As an example, the chemical composition of each sample can be examined by a Varian Liberty 100 inductively coupled plasma (ICP) system.

[0023] The electrochemically active composition can further include Li, Ni, O, and one or more additives. Optionally, the electrochemically active composition includes one, two, three, four, five, six, or more additives. The one or more additives are optionally Co, Mn, Al, Mg, Ti, Zr, Nb, Hf, V, Cr, Sn, Cu, Mo, W, Fe, Si, Zn, B, other transition metals, rare earth elements, or combinations thereof. The rare earth element can be one or more of La, Nd, Y, or any other element traditionally defined as a rare earth element. The one or more additives can include elements other than transition metals, such as processing aids like potassium. In some embodiments, the electrochemically active composition includes Li, Ni, and Mg. In other embodiments, the electrochemically active composition includes Li, Ni, and Mn.

[0024] In some embodiments, the electrochemically active composition comprises Ni and optionally one or more additives. In such embodiments, the delithiated electrochemically active composition may comprise 10 at% or more, optionally 20 at% or more, optionally 30 at% or more, optionally 40 at% or more, optionally 50 at% or more, optionally 60 at% or more, optionally 70 at% or more, optionally 80 at% or more, optionally 90 at% or more, optionally 95 at% or more, optionally 96 at% or more, optionally 97 at% or more, optionally 98 at% or more, optionally 99 at% or more, optionally 100 at% Ni, based on the atomic percentage (at%) with respect to the total metal in the electrochemically active composition. Optionally, the atomic percentage of Ni is 70 at% to 99 at% or more. Optionally, the atomic percentage of Ni is 80 at% to 99 at% or more. Optionally, the atomic percentage of Ni is 90 at% to 99 at% or more. Optionally, Ni is the only transition metal designed in or present in the material such that Ni is present substantially at 100 at%.

[0025] Optionally, the electrochemically active composition comprises Ni and one or more other transition metals. One or more other transition metals (other than Ni) are optionally present, each independently, at 0 at% to 90 at%, optionally 1 at% to 90 at%. Optionally, one or more other transition metals are each independently present at 0 at% to 50 at%, optionally 1 at% to 50 at%. Optionally, one or more other transition metals are each independently present at 1 at% to 30 at%, optionally 1 at% to 20 at%, optionally 1 at% to 10 at%, 1 at% to 7 at%, 1 at% to 5 at%, 2 at% to 20 at%, 5 at% to 20 at%, 10 at% to 20 at%. Optionally, one, two, three or more other transition metals other than Ni are present in the electrochemically active composition.

[0026] Electrochemically active compositions have particle size. Particle size is defined as D50, which is the diameter of particles such that 50% of the sample mass is less than D50 and 50% of the sample mass is greater than D50. Optionally, particle size is 1–20 μm, or any value or range in between. Optionally, particle size is 1–15 μm, optionally, 1–10 μm, optionally, 1–7 μm, optionally, 4–7 μm, optionally, 4–6 μm. Particle size can be measured by techniques known in the art, optionally, by laser diffraction.

[0027] The process provided herein comprises combining an electrochemically active composition with a strong oxidizing agent.120 The combining step may occur at a pH of 1.0 or higher, and optionally at a pH of 3.0 or higher. The strong oxidizing agent and the electrochemically active composition are combined for a lithium removal time. Optionally, the electrochemically active composition and the strong oxidizing agent are Ni 2+ Some transition metals, such as , increase in solubility in acidic solutions and are therefore combined with high pH values. For example, the pH can be above 3.0, or above 4.0, or above 5.0, or above 6.0, or above 7.0, or above 8.0, or above 9.0, or above 10.0, or above 11.0, or above 12.0, or even above 13.0, or any combination thereof.

[0028] It should be understood that step 120, which combines an electrochemically active composition with a strong oxidizing agent, is a chemical oxidation process, not an electrochemical oxidation process. Therefore, according to some embodiments of this disclosure, step 120 can be carried out in a chemical reactor such as a beaker, flask, fluidized bed reactor, CSTR, batch reactor, or any other suitable chemical reactor, rather than an electrochemical reactor.

[0029] The strong oxidizing agent can be any oxidizing agent that can promote the delithiation of the LiNiO2 material. For example, the strong oxidizing agent can be one or more of hypochlorite, chlorite, chlorate, perchlorate, hydrogen peroxide, chlorine, molecular oxygen, or ozone. In embodiments where the strong oxidizing agent is ozone, the ozone can be bubbled through a solution containing an electrochemically active material. According to some exemplary embodiments, the strong oxidizing agent is hypochlorite (ClO2). - ) is or may contain a salt. Optionally, the oxidizing agent may contain or may contain other oxidation intermediates such as HOCl, OCl, or other species.

[0030] A strong oxidizing agent can be any oxidizing agent having a standard potential greater than 0.7 volts (V vs SHE) relative to a standard hydrogen electrode, and optionally greater than 1 (V vs SHE). Table 1 below shows some useful oxidizing agents and their standard potentials. For example, a strong oxidizing agent may optionally have a standard potential greater than 0.7 (V vs SHE), or optionally greater than 0.8 (V vs SHE), or optionally greater than 0.9 (V vs SHE), or optionally greater than 1.0 (V vs SHE), or optionally greater than 1.1 (V vs SHE), or optionally greater than 1.2 (V vs SHE), or optionally greater than 1.3 (V vs SHE), or optionally greater than 1.4 (V vs SHE), or optionally greater than 1.5 (V vs SHE), or optionally The oxidizing agent may have a standard potential greater than 1.6 (V vs. SHE), or optionally greater than 1.7 (V vs. SHE), or optionally greater than 1.8 (V vs. SHE), or optionally greater than 1.9 (V vs. SHE), or optionally greater than 2.0 (V vs. SHE), or optionally greater than 2.1 (V vs. SHE), or optionally greater than 2.2 (V vs. SHE), or optionally greater than 2.3 (V vs. SHE), or even greater than 2.3, or any combination thereof. [Table 1]

[0031] The cations of the salt (e.g., hypochlorite, chlorite, chlorate, perchlorate) can be NH4, Na, Ca, K, or combinations thereof. The salt is hypochlorite (ClO - This refers to a cation having an anion of a chlorite, chlorate, or perchlorate. For example, hypochlorite may be NaClO, Ca(ClO)2, KClO, or a combination thereof.

[0032] Optionally, strong oxidizing agents contain chlorine. For example, sodium hypochlorite contains chlorine. When strong oxidizing agents such as hypochlorites are used, the pH is optionally below 9.0 and above 1.5, optionally below 9.0 and above 4.0, and optionally below 9.0 and above 4.5.

[0033] When the strong oxidizing agent does not contain hypochlorite, the pH may be any of the following: 1.0 to 9.0, optionally 2.0 to 9.0, optionally 3.0 to 9.0, optionally 4.0 to 9.0, or optionally 5.0 to 9.0.

[0034] According to some embodiments of this disclosure, the strong oxidizing agent is not a persulfate such as sodium persulfate. Avoiding the use of persulfates may be preferable for both economic and technical reasons. Persulfate-based strong oxidizing agents can reduce the yield of delithiated electrochemically active materials by forming acids and consequently solubilizing nickel.

[0035] Optionally, the process may include recycling or reusing lithium removed from electrochemically active compositions. Lithium recycling presents the separation challenge of removing lithium from strong oxidizing agents and, optionally, removing salts of strong oxidizing agents. While not bound by theory, it is conceivable that the separation of lithium from calcium may be easier than the separation of lithium from sodium. Furthermore, a 1:2 Ca:ClO -The ratio reduces the amount and concentration of calcium that may need to be removed. Therefore, in some embodiments where lithium recycling is used, it may be preferable to use calcium hypochlorite rather than sodium hypochlorite. In some embodiments, Li may be recycled by a process substantially described in U.S. Patent Application No. 62 / 754,739.

[0036] The molar ratio of the strong oxidizing agent to the electrochemically active composition during the delithiation time may be 0.1 or greater. Optionally, the molar ratio of the strong oxidizing agent to the electrochemically active composition during the delithiation process may be 10 or less. For example, the molar ratio may be 0.1 or greater, 0.2 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater, or any combination thereof. Optionally, the molar ratio of the strong oxidizing agent to the electrochemically active composition may be 9 or less, and optionally, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less. Optionally, the molar ratio of the strong oxidizing agent to the electrochemically active composition may be 1 to 10 or any value or range in that range, optionally 1 to 8, optionally 2 to 8, optionally 1 to 5, optionally 2 to 5, optionally 1 to 4, optionally 2 to 4, or optionally 2 to 3.

[0037] The lithium removal time is the time such that the second Li / Ni at% ratio after lithium removal is 0.6 or less, thereby forming a delithiated electrochemically active composition. The second Li / Ni at% ratio is obtained after lithium removal but before placement in the electrochemical cell. According to some embodiments of the present disclosure, the second Li / Ni at% ratio after lithium removal may be less than 0.6, less than 0.5, less than 0.35, less than 0.3, less than 0.2, less than 0.1, less than 0.05, less than 0.03, or any combination thereof.

[0038] The lithium removal time may be 0.5 hours or longer. It should be understood that the lithium removal time is the amount of time the electrochemically active composition is in contact with the strong oxidizing agent. For example, the lithium removal time may be 0.5 hours or longer, 1 hour or longer, 1.5 hours or longer, 2 hours or longer, 3 hours or longer, 4 hours or longer, 5 hours or longer, 6 hours or longer, 7 hours or longer, 8 hours or longer, 9 hours or longer, or even 10 hours or longer, or any combination thereof.

[0039] According to some embodiments of this disclosure, the process may be carried out in the absence of a strong acid. A strong acid refers to an acid that is completely ionized in solution, such as an acid with a pKa of less than about -1. 2+ Since it can dissolve in an acidic environment, the absence of strong acids can be beneficial. This solubility results in the loss of up to 50% of nickel in the electrochemically active material during delithiation. For example, the process may be carried out in the absence of sulfuric acid.

[0040] Optionally, the process may be carried out in the presence of a strong acid, for example, HCl, but not limited to this example. While not bound by theory, it is thought that the presence of a strong acid may act to reduce the nickel yield, while the oxidizing effect of a strong oxidizing agent may offset this reduction in yield. Ni 2+ It may be soluble in acid, but Ni 4+ It is considered insoluble even in acids. By oxidizing nickel from a 2+ oxidation state to a 4+ oxidation state, a larger amount of solid nickel-containing material can be preserved.

[0041] Nickel yield may exceed 5%. As used herein, nickel yield refers to the ratio of the total weight of nickel in the delithified electrochemically active material after lithium removal time (at the time of the second Li / Ni at% ratio) to the total weight of nickel in the electrochemically active material (at the time of the second Li / Ni at% ratio) compared to the total weight of nickel in the electrochemically active material (at the time of the second Li / Ni at% ratio). Optionally, the nickel yield may be 5% or more, optionally, 10% or more, optionally, 15% or more, optionally, 20% or more, optionally, 25% or more, optionally, 30% or more, optionally, 35% or more, optionally, 40% or more, optionally, 45% or more, optionally, 50% or more, optionally, 60% or more, optionally, 70% or more, optionally, 80% or more, optionally, 90% or more, optionally, 95% or more, optionally, 98% or more, or even optionally, 99% or more, of the weight of the initial nickel in the electrochemically active material in the delithified electrochemically active material after the lithium removal time.

[0042] The initial capacity of the delithiated electrochemically active composition may be 250 mAh / g or higher. The initial capacity is optionally measured using a sintered counter electrode containing mainly Ni in an aqueous electrolyte. The initial capacity refers to the capacity of the delithiated electrochemically active composition during the first cycle of electrochemical discharge. For example, the initial capacity may be 250 mAh / g or higher, 300 mAh / g or higher, 400 mAh / g or higher, 500 mAh / g or higher, 600 mAh / g or higher, 700 mAh / g or higher, 800 mAh / g or higher, 900 mAh / g or higher, or even 1000 mAh / g or higher, or any combination thereof.

[0043] Various aspects of the present invention are illustrated by the following non-limiting examples. These examples are for illustrative purposes only and do not limit any implementation of the present invention. It will be understood that modifications and alterations can be made without departing from the spirit and scope of the present invention. [Examples]

[0044] In the following examples, unless otherwise indicated, a 12.5 wt percent (%) aqueous sodium hypochlorite solution was combined with LiNiO at various volumes and pH values. The reactants were combined in a reactor with stirring and temperature control. The reactor was mixed at a rate sufficient to keep the LiNiO in suspension and maintained at 25°C ± 2°C.

[0045] Example 1: In Example 1, the generalized example described above was carried out at pH 13.2 with various volume (of 12.5% ​​NaOCl) / weight LiNiO ratios. Table 2 below shows the dependence of the average Ni oxidation state, final Li / Ni atomic ratio, and volume based on V / weight or mol / mol at pH 13.2. [Table 2]

[0046] Example 2: In Example 2, the generalized example described above was carried out at pH 7 with various volume (of 12.5% ​​NaOCl) / weight LiNiO ratios. Table 3 below shows the dependence of the average Ni oxidation state and volume on V / weight and mol / mol at pH 7. [Table 3]

[0047] Example 3: In Example 3, the generalized example described above was carried out in the range of 7 to 13.2 or pH value. The delithiation time was 6 hours, and an average particle size of 4.73 micrometers was used. Table 4 below shows the dependence of the average Ni oxidation state, Li / Ni atomic ratio, and volume on pH. [Table 4]

[0048] Example 4: In Example 4, the generalized example described above was carried out with a pH of 7, a NaOCl / LiNiO V / w of 25, a NaOCl / LiNiO mol / mol of 5.90, and an oxidation time of 5 hours (hrs). Example 4 produced an average volume of 391 mAh / g and an average Ni oxidation state of 3.5.

[0049] Example 5: In Example 5, the generalized example described above was carried out with a pH of 6, a NaOCl / LiNiO V / w of 25, a NaOCl / LiNiO mol / mol of 5.90, and an oxidation time of 5 hours (hrs). Example 5 produced an average volume of 417 mAh / g and an average Ni oxidation state of 3.53.

[0050] Example 6: In Example 6, the generalized example described above was carried out with a pH of 6, a NaOCl / LiNiO V / w of 25, a NaOCl / LiNiO mol / mol of 5.90, and an oxidation time of 8 hours (hrs). Example 5 produced an average volume of 402 mAh / g and an average Ni oxidation state of 3.55.

[0051] Example 7: In Example 7, the generalized example described above was carried out with a pH of 5, a NaOCl / LiNiO V / w of 25, a NaOCl / LiNiO mol / mol of 5.90, and an oxidation time of 5 hours (hrs). Example 5 produced an average volume of 399 mAh / g and an average Ni oxidation state of 3.52.

[0052] Example 8: In Example 8, the generalized example described above was carried out at pH 5, NaOCl / LiNiO V / w of 16.7, NaOCl / LiNiO mol / mol of 3.93, and an oxidation time of 5 hours (hrs). Example 5 produced an average volume of 399 mAh / g and an average Ni oxidation state of 3.49.

[0053] Example 9: In Example 9, the generalized example described above was carried out at pH 13.2, a temperature of 35°C, and with NaOCl / LiNiO V / w and NaOCl / LiNiO mol / mol. Table 5 below shows the dependence of the average Ni oxidation state, Li / Ni atomic ratio, and average volume at various delithiation times. [Table 5]

[0054] Example 10 In Example 10, the generalized example described above was carried out at pH 13.2 and V(NaOCl) / w(particles) of 100. Table 6 below shows the dependence of the average Ni oxidation state, Li / Ni atomic ratio, and average volume on both delithiation time and NaCIO concentration. [Table 6]

[0055] Example 11 In Example 11, the generalized examples described above were carried out at pH 6 and pH 7, and temperatures of 25°C and 35°C. Table 7 below shows the dependence of volume on temperature and pH. [Table 7]

[0056] The foregoing descriptions of specific embodiments are essentially illustrative and are not intended in any way to limit the invention, its uses, or the scope of use, and are naturally subject to change. This disclosure is provided in relation to the non-limiting definitions and terminology contained herein. These definitions and terminology are not designed to function as limitations on the scope or practice of the invention, but are presented for illustrative and descriptive purposes only. Processes or compositions are described as a sequence of individual steps or using specific materials, but the steps or materials may be interchangeable so that the description of the invention may include multiple parts or steps arranged in many ways that are readily understood by those skilled in the art.

[0057] The terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or sections, but it will be understood that these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used solely to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, the “first element,” “component,” “region,” “layer,” or “section” considered below may be referred to as the second (or other) element, component, region, layer, or section without deviating from the teachings herein.

[0058] The technical terms used herein are intended to describe only specific embodiments and are not intended to limit them. Where used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form, which includes “at least one,” unless the content explicitly indicates otherwise. “Or” means “and / or.” Where used herein, the term “and / or” includes any and all combinations of one or more of the enumerated items relating to the subject. Where used herein, the terms “comprises” and / or “comprising,” or “includes” and / or “including” indicate the presence of the described features, regions, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof. The term “or combination thereof” means a combination that includes at least one of the aforementioned elements.

[0059] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art in which this disclosure pertains. Terms as defined in commonly used dictionaries should be construed to have the meaning consistent with their meanings in the context of the relevant art and this disclosure, and should not be construed in an ideal or overly formal sense unless expressly defined herein.

[0060] In addition to those shown and described herein, various modifications of the present invention will be apparent to those skilled in the art. Such modifications are also intended to fall within the scope of the appended claims.

[0061] The patents, publications, and applications referenced herein indicate the level of skill of those skilled in the art to which the present invention relates. These patents, publications, and applications are incorporated herein by reference to the same extent as if each patent, publication, or application were incorporated herein by reference specifically and individually.

[0062] The foregoing description illustrates specific aspects of the present invention, but does not mean to limit their implementation.

Claims

1. A chemical process for removing lithium from an electrochemically active composition, Li ｘ MO ２ To provide an electrochemically active composition defined by the formula, wherein M is optionally one or more metals, transition metals, rare earth metals, or combinations thereof, and x is a first Li / M at% ratio of 0.8 to 1.

3. The method includes combining the electrochemically active composition with a strong oxidizing agent during the lithium removal time, A process wherein the lithium removal time is such that the second Li / M at% ratio after the lithium removal time is 0.6 or less, thereby forming a delithiated electrochemically active composition.

2. The process according to claim 1, carried out in the absence of a strong acid.

3. The process according to claim 1, carried out in the absence of sulfuric acid.

4. The process according to claim 1, 2, or 3, wherein the strong oxidizing agent is one or more of hypochlorite, chlorite, chlorate, perchlorate, hydrogen peroxide, chlorine, hypochlorous acid, or ozone.

5. The process according to claim 1, 2, or 3, wherein the strong oxidizing agent is not a persulfate.

6. The cation of the salt is NH ４ The process according to claim 4, wherein the element is Na, Ca, K, or a combination thereof.

7. The process according to any one of claims 1 to 6, wherein the pH in the combining step is 3.0 or higher.

8. The process according to any one of claims 1 to 6, wherein the pH in the combining step is 4.0 or higher.

9. The process according to any one of claims 1 to 6, wherein the pH in the combining step is 5.0 or higher.

10. The process according to any one of claims 1 to 6, wherein the pH in the combining step is 7.0 or higher.

11. The process according to any one of claims 1 or 4 to 10, wherein the combining step is performed in the presence of a strong acid.

12. The process according to claim 11, wherein the strong acid is HCl.

13. The process according to any one of claims 1 to 12, wherein the lithium removal time is 0.5 hours or more.

14. The process according to any one of claims 1 to 12, wherein the lithium removal time is 4 hours or more.

15. The process according to any one of claims 1 to 13, wherein the lithium removal time is 5 hours or more.

16. The process according to any one of claims 1 to 14, wherein the second Li / Ni at% ratio is less than 0.

5.

17. The process according to claim 16, wherein the second Li / Ni at% ratio is less than 0.

35.

18. The process according to claim 16, wherein the second Li / Ni at% ratio is less than 0.

3.

19. The process according to any one of claims 1 to 18, wherein the molar ratio of the strong oxidizing agent to the electrochemically active composition is 0.5 or greater.

20. The process according to claim 19, wherein the molar ratio is 1 or greater.

21. The process according to claim 19, wherein the molar ratio is 5 or more.

22. The process according to any one of claims 1 to 21, wherein the initial volume of the delithiated electrochemically active composition is 250 mAh / g or more.

23. The process according to claim 22, wherein the initial capacity is 400 mAh / g or more.

24. The process according to any one of claims 1 to 23, wherein the electrochemically active composition comprises Li, Ni, O, and one or more additives.

25. The process according to claim 24, wherein one or more additives are selected from the group consisting of Co, Mn, Al, Mg, Ti, Zr, Nb, Hf, V, Cr, Sn, Cu, Mo, W, Fe, Si, Zn, B, other transition metals, rare earth elements, or combinations thereof.

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