Electrode materials comprising Fe-doped tunnel oxides of sodium, lithium, manganese and metals, electrodes comprising same and their use in electrochemistry - Patents.com

Abstract

This technology uses the formula Na a Li b Fe c Mn d M e O 2 (wherein a is 0

Description

[Technical field]

[0001] Related Applications This application claims priority under applicable law to U.S. Provisional Patent Application No. 63 / 362.616, filed April 7, 2022, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] Technical Field This application generally relates to the field of electrochemically active materials and their use in electrochemical applications. More specifically, this application relates to electrode materials comprising tunnel oxides of at least one metal partially substituted with sodium, magnesium, and lithium as electrochemically active materials, electrodes comprising them, methods for their manufacture, and their use in electrochemical cells. [Background technology]

[0003] background LiCoO2, LiNi 0.33 Mn 0.33 Co 0.33 O2 (NMC 111), LiNi 0.6 Mn 0.2 Co 0.2 O2 (NMC 622) and LiNi 0.8 Mn 0.1 Co 0.1One of the main drawbacks of cathode materials currently commercially used in lithium-ion batteries (LIBs) and so-called solid-state batteries, such as O2 (NMC 811), is their high production cost. The raw materials used to produce the cathode materials are becoming increasingly important in the total cost of the battery, which could be problematic for the expansion of the market share of LIBs and so-called solid-state batteries. For example, the weighted average price of cobalt could limit the future applications of LIBs and solid-state batteries. Therefore, cathode materials with reduced amounts of cobalt and cobalt-free cathode materials have attracted great attention, especially in large-scale, high-energy density energy storage systems. For example, lithium iron phosphate (LiFePO4 or LFP) has attracted great interest due to the cost-effectiveness of its materials. However, the energy density of LFP batteries has not improved enough to meet the demands of the electric vehicle market.

[0004] Therefore, there remains a need for the development of new electrode materials that eliminate one or more of the shortcomings of conventional commercially available cathode materials, such as new low-cost, high-capacity, high-voltage cathode materials for LIBs and so-called all-solid-state batteries. Summary of the Invention [Means for solving the problem]

[0005] overview According to one aspect, the present technology provides a compound of formula Na a Li b Fe c Mn d M eO2 (where a is a number such that 0 < a < 0.22, b is a number such that 0.18 < b < 0.40, a + b is such that 0.38 < a + b < 0.62, c is a number such that 0 < c ≤ 0.40, d is a number such that 0.44 ≤ d < 1, e is a number such that c + d + e = 1, and M is selected from manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), tin (Sn), ruthenium (Ru), other similar metals, and combinations of at least two of them) relates to an electrochemical active material containing sodium, manganese, and a lithium-substituted iron-doped tunnel-type oxide of at least one metal element.

[0006] According to one example, M is selected from manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), ruthenium (Ru), other similar metals, and combinations of at least two of them. According to an example of interest, M is titanium (Ti).

[0007] According to another example, a is a number such that 0.01 < a < 0.22, or 0.02 < a < 0.22, or 0.03 < a < 0.22, or 0.04 < a < 0.22, or 0.05 < a < 0.22, or 0.06 < a < 0.22, or 0.07 < a < 0.22, or 0.08 ≤ a ≤ 0.21, etc. According to an example of interest, a is a number such that 0.08 ≤ a ≤ 0.21.

[0008] According to another example, b is a number such that 0.19 < b < 0.40, or 0.20 ≤ b < 0.40, or 0.20 ≤ b < 0.39, or 0.20 ≤ b ≤ 0.38. According to an example of interest, b is a number such that 0.20 ≤ b ≤ 0.38.

[0009] According to another example, c is a number such as 0.05 < c ≤ 0.40, or 0.10 < c ≤ 0.40, or 0.15 < c ≤ 0.40, or 0.20 < c ≤ 0.40, or 0.25 < c ≤ 0.40, or 0.30 ≤ c ≤ 0.40. According to the desired example, c is a number such that 0.30 ≤ c ≤ 0.40.

[0010] According to another example, d is a number such that 0.44 ≤ d < 1, or 0.44 ≤ d < 0.95, or 0.44 ≤ d < 0.90, or 0.44 ≤ d < 0.85, or 0.44 ≤ d < 0.80, or 0.44 ≤ d < 0.75, or 0.44 ≤ d < 0.70, or 0.44 ≤ d < 0.65, or 0.44 ≤ d < 0.60, or 0.44 ≤ d ≤ 0.55. According to the desired example, d is a number such that 0.44 ≤ d ≤ 0.55.

[0011] According to another example, the sodium, manganese, and lithium-substituted iron-doped tunnel-type oxide of at least one metal is selected from the group consisting of Na 0.10 Li 0.33 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.08 Li 0.38 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.20 Li 0.24 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.21 Li 0.20 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.10 Li 0.40 Fe 0.08 Mn 0.81 Ti 0.11 O2 and Na 0.10 Li 0.40 Fe 0.11 Mn 0.78 Ti 0.11 selected from the group consisting of O2.

[0012] According to another aspect, the present technology relates to an electrode material comprising an electrochemically active material as defined herein.

[0013] According to one embodiment, the electrode material further comprises an electronically conductive material. According to one example, the electronically conductive material is selected from the group consisting of carbon black, acetylene black, graphite, graphene, carbon fiber, carbon nanofiber, carbon nanotube, and a combination of at least two thereof. According to an example of interest, the electronically conductive material comprises carbon black. For example, the carbon black is Super P™ carbon or Ketjen™ carbon. According to another example of interest, the electronically conductive material comprises carbon fiber. For example, the carbon fiber is vapor grown carbon fiber (VGCF).

[0014] According to another embodiment, the electrode material further comprises a binder. According to one example, the binder is selected from the group consisting of polyether-type polymer binders, fluorinated polymers, and water-soluble binders. According to an example of interest, the binder is a fluorinated polymer. For example, the fluoropolymer is polyvinylidene fluoride (PVDF).

[0015] According to another embodiment, the electrode material further comprises an additive, according to one example, the additive is selected from the group consisting of ion conductors, inorganic particles, glass particles, ceramic particles, salts, and other similar additives.

[0016] According to another aspect, the present technology relates to an electrode comprising an electrode material as defined herein on a current collector.

[0017] According to one embodiment, the electrode is a positive electrode.

[0018] According to another aspect, the present technology relates to an electrochemical cell including a negative electrode, a positive electrode, and an electrolyte, wherein the positive electrode is as defined herein.

[0019] According to one embodiment, the negative electrode comprises an alkali metal, an alloy containing an alkali metal, or a pre-lithiated electrochemically active material. According to one example, the negative electrode comprises metallic lithium or an alloy containing metallic lithium. According to one example, the negative electrode comprises metallic lithium.

[0020] According to another embodiment, the electrolyte is a glass or ceramic electrolyte.

[0021] According to another embodiment, the electrolyte is a liquid electrolyte comprising a salt in a solvent.

[0022] According to another embodiment, the electrolyte is a gel electrolyte comprising a salt in a solvent and, optionally, a solvating polymer.

[0023] According to another embodiment, the electrolyte is a solid polymer electrolyte comprising a salt in a solvating polymer.

[0024] According to one example, the salt is a lithium salt. For example, the lithium salt may be lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride (Li Cl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkylphosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate[B(CO2)2] (LiBBB), and combinations of at least two of these. According to an example of interest, the lithium salt is lithium hexafluorophosphate (LiPF6).

[0025] According to another aspect, the present technology relates to a battery comprising at least one electrochemical cell as defined herein.

[0026] According to one embodiment, the battery is selected from the group consisting of a lithium battery, a lithium ion battery, a sodium battery, a sodium ion battery, a potassium battery, a potassium ion battery, a magnesium battery, and a magnesium ion battery. According to one example, the battery is a lithium battery or a lithium ion battery. [Brief description of the drawings]

[0027] [Figure 1]FIG. 1 is an X-ray diffraction pattern of the tunnel-type sodium, lithium, and manganese oxide powder of formula Na0.08Li0.36MnO2 described in Example 1(d).

[0028] [Diagram 2] FIG. 2 is an X-ray diffraction pattern of the tunnel-type sodium, lithium, iron, manganese, and titanium oxide powder of the formula NaLiFeMnTiO as described in Example 1(d).

[0029] [Diagram 3] FIG. 3 is an X-ray diffraction pattern of the tunnel-type sodium, lithium, iron, manganese, and titanium oxide powder of the formula NaLiFeMnTiO as described in Example 1(d).

[0030] [Figure 4] FIG. 4 is an X-ray diffraction pattern of the tunnel-type sodium, lithium, iron, manganese, and titanium oxide powder of the formula NaLiFeMnTiO as described in Example 1(d).

[0031] [Diagram 5] FIG. 5 is an X-ray diffraction pattern of the tunnel-type sodium, lithium, iron, manganese, and titanium oxide powder of the formula NaLiFeMnTiO as described in Example 1(d).

[0032] [Figure 6] 6 shows charge-discharge profiles obtained for cell 1, as described in Example 2(b), recorded at (1) 2.0 V to 4.8 V vs. Li+ / Li at a cycling rate of 0.1 C and (2) 2.0 V to 4.6 V vs. Li+ / Li. Results are shown for the second charge-discharge cycle.

[0033] [Figure 7]7 shows the charge-discharge profile obtained for cell 2, as described in Example 2(b), recorded from 2.0 V to 4.6 V vs. Li+ / Li at a cycling rate of 0.1 C. Results are shown for the second charge-discharge cycle.

[0034] [Figure 8] 8 shows the charge-discharge profile obtained for cell 3, as described in Example 2(b), recorded from 2.0 V to 4.6 V vs. Li+ / Li at a cycling rate of 0.1 C. Results are shown for the second charge-discharge cycle.

[0035] [Figure 9] 9 shows the charge-discharge profile obtained for Cell 4, as described in Example 2(b), recorded from 2.0 V to 4.8 V vs. Li+ / Li at a cycle rate of 0.1 C. Results are shown for the second (1) and fifth (2) charge-discharge cycles.

[0036] [Figure 10] 10 shows the charge-discharge profile obtained for cell 5, as described in Example 2(b), recorded from 2.5 V to 4.8 V vs. Li+ / Li at a cycling rate of 0.1 C. Results are shown for the second charge-discharge cycle.

[0037] [Figure 11] FIG. 11 shows (a) the charge-discharge profile recorded at a cycle rate of 0.1 C from 2.0 V to 4.8 V vs. Li+ / Li, and (b) a graph representing the capacity as a function of cycle number obtained for Cell 6, as described in Example 2(b).

[0038] [Figure 12] FIG. 12 shows (a) the charge-discharge profile recorded at a cycle rate of 0.1 C from 2.0 V to 4.8 V vs. Li+ / Li, as described in Example 2(b), and (b) a graph depicting the capacity as a function of cycle number obtained for cell 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Detailed Description All technical and scientific terms and expressions used herein have the same definitions as commonly understood by those skilled in the art. Nevertheless, definitions of some of the terms and expressions used are provided below.

[0040] When the term "about" is used herein, it means approximately, within the region, or in the vicinity.For example, when the term "about" is used in relation to a numerical value, the term modifies the numerical value up or down with a variation of 10% compared to the nominal value.This term can also take into account, for example, experimental error or rounding of measuring device.

[0041] Whenever an interval of values ​​is referred to in this application, the lower and upper limits of the interval are always included in the definition, unless otherwise specified. Whenever an interval of values ​​is referred to in this application, not only the individual values ​​included in the interval of values, but also all intermediate intervals and subintervals are included in the definition.

[0042] In this application, when the article "a" is used to introduce an element, it has the meaning of "one or more," not "only one." Of course, when the description states that a particular step, component, element, or feature "may" be included or "can be" included, that particular step, component, element, or feature need not be included in every embodiment.

[0043] The present technology generally relates to electrochemically active materials, their methods of manufacture, and their use in electrochemical cells. More specifically, the present technology relates to electrochemically active materials comprising lithium-substituted iron-doped tunnel oxides of sodium, manganese, and at least one metallic element.

[0044] According to one example, the metal element of the lithium-substituted iron-doped tunnel-type oxide of sodium, manganese, and at least one metal element may be a transition metal, a post-transition metal, a metalloid, an alkali metal other than lithium or sodium, an alkaline earth metal, or a combination thereof if suitable. For example, the metal may be a transition or post-transition metal selected from the group consisting of manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), tin (Sn), ruthenium (Ru), and other similar metal elements, or a combination thereof if suitable.

[0045] According to another example, the electrochemically active material has the formula Na a Li b Fe c Mn d M e O2 (where a is a number such that 0 < a < 0.22, b is a number such that 0.18 < b < 0.40, a + b is such that 0.38 < a + b < 0.62, c is a number such that 0 < c ≤ 0.40, d is a number such that 0.44 ≤ d < 1, e is a number such that c + d + e = 1, and M is selected from the group consisting of manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), tin (Sn), ruthenium (Ru), and other similar metal elements, or a combination thereof if suitable) and includes a lithium-substituted iron-doped tunnel-type oxide of sodium, manganese, and at least one metal element.

[0046] It is understood that when the metal element (M) is manganese (Mn), the lithium-substituted iron-doped tunnel-type oxide of sodium, manganese, and at least one metal element contains manganese in at least two different oxidation states.

[0047] According to some examples, the metal element (M) is a transition metal selected from the group consisting of manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), ruthenium (Ru), and other similar transition metals, or a combination thereof if suitable. According to some examples of purposes, the metal element is titanium (Ti).

[0048] According to some examples, a is a number such that 0.01 < a < 0.22, or 0.02 < a < 0.22, or 0.03 < a < 0.22, or 0.04 < a < 0.22, or 0.05 < a < 0.22, or 0.06 < a < 0.22, or 0.07 < a < 0.22, or 0.08 ≤ a ≤ 0.21. According to some examples of purposes, a is a number such that 0.08 ≤ a ≤ 0.21.

[0049] According to some examples, b is a number such that a + b satisfies 0.38 < a + b < 0.61, or 0.38 < a + b < 0.60, or 0.38 < a + b < 0.59, or 0.38 < a + b < 0.58, or 0.38 < a + b < 0.57, or 0.38 < a + b < 0.56, or 0.38 < a + b < 0.55, or 0.38 < a + b < 0.54, or 0.38 < a + b < 0.53, or 0.38 < a + b < 0.52, or 0.38 < a + b < 0.51, or 0.38 < a + b < 0.50, or 0.38 < a + b < 0.49, or 0.38 < a + b < 0.48, or 0.38 < a + b < 0.47, or 0.39 < a + b < 0.47, or 0.40 < a + b < 0.47. According to some examples of purposes, b is a number such that a + b satisfies 0.40 < a + b < 0.47. For example, b may be a number such that 0.19 < b < 0.40, or 0.20 ≤ b < 0.40, or 0.20 ≤ b < 0.39, or 0.20 ≤ b ≤ 0.38. According to some examples of purposes, b is a number such that 0.20 ≤ b ≤ 0.38.

[0050] According to some examples, c is a number such that 0.05 < c ≤ 0.40, or 0.10 < c ≤ 0.40, or 0.15 < c ≤ 0.40, or 0.20 < c ≤ 0.40, or 0.25 < c ≤ 0.40, or 0.30 ≤ c ≤ 0.40. According to some example purposes, c is a number such that 0.30 ≤ c ≤ 0.40.

[0051] According to some examples, d is a number such that 0.44 ≤ d < 1, or 0.44 ≤ d < 0.95, or 0.44 ≤ d < 0.90, or 0.44 ≤ d < 0.85, or 0.44 ≤ d < 0.80, or 0.44 ≤ d < 0.75, or 0.44 ≤ d < 0.70, or 0.44 ≤ d < 0.65, or 0.44 ≤ d < 0.60, or 0.44 ≤ d ≤ 0.55. According to some example purposes, d is a number such that 0.44 ≤ d ≤ 0.55.

[0052] Non-limiting examples of lithium-substituted iron-doped tunnel-type oxides of sodium, manganese, and at least one metal element are Na 0.10 Li 0.33 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.08 Li 0.38 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.20 Li 0.24 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.21 Li 0.20 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.10 Li 0.40 Fe 0.08 Mn 0.81 Ti 0.11 O2, and Na 0.10 Li 0.40 Fe 0.11 Mn 0.78 Ti 0.11 contain O2.

[0053] According to another example, the electrochemically active material may further comprise at least one doping element, which may be included in a smaller amount, for example, to adjust or optimize its electrochemical properties. For example, the electrochemically active material may be doped by partial substitution of a metal element with at least one other element. For example, the electrochemically active material may be lightly doped with at least one doping element selected from transition metals (e.g., iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn), titanium (Ti), chromium (Cr), copper (Cu), vanadium (V), zinc (Zn), and / or yttrium (Y)), post-transition metals (e.g., Al), alkaline earth metals (e.g., Mg), and / or metalloids (e.g., Sb).

[0054] According to another example, the electrochemically active material may be in the form of particles (e.g., microparticles or nanoparticles) that may be freshly formed and may further include a coating material, which may be an electronically conductive material, such as a carbon coating.

[0055] For example, partial substitution of sodium ions with lithium ions can significantly improve the electrochemical performance of electrochemical cells containing the electrochemically active materials of the present invention.

[0056] According to some examples, partial substitution of sodium ions with lithium ions in the lithium-substituted iron-doped tunnel oxide of sodium, manganese, and at least one metal element can substantially improve the electrochemical properties of the electrochemically active material. Without wishing to be bound by theory, partial substitution of sodium ions with lithium ions can stabilize the structure of the electrochemically active material based on the iron-doped tunnel oxide of sodium, manganese, and at least one metal element, and thus substantially improve its electrochemical performance. For example, the electrochemical properties of the electrochemically active material can be adjusted by changing the degree of lithium substitution.

[0057] According to some examples, doping of sodium, manganese, and lithium-substituted tunnel oxides of at least one metal element with iron ions can also substantially improve the electrochemical properties of the electrochemically active material. For example, partial substitution of manganese with iron ions can significantly increase the average operating voltage of the electrochemically active material. For example, the electrochemical properties of the electrochemically active material can be adjusted by varying the degree of iron substitution.

[0058] According to some examples, the electrochemical properties of the electrochemically active material can also be substantially improved by cation doping the lithium-substituted iron-doped tunnel oxides of sodium, manganese, and at least one metal element with transition metals or post-transition metals such as those mentioned above. For example, partial substitution of manganese with titanium can substantially improve the electrochemical properties of the electrochemically active material. For example, the composition of the transition metals or post-transition metals in the lithium-substituted iron-doped tunnel oxides of sodium, manganese, and at least one metal element can be changed to adjust the electrochemical properties of the electrochemically active material.

[0059] The present technology also relates to a method for producing an electrochemically active material as defined herein, comprising the steps of: (i) preparing an iron-doped tunnel oxide of sodium, manganese, and at least one metallic element; and (ii) partially replacing the sodium ions of the sodium, manganese, and iron doped tunnel oxides of at least one metallic element with lithium ions to obtain an electrochemically active material. The present invention relates to a method comprising the steps of:

[0060] According to one example, the sodium, manganese and iron doped tunnel oxide of at least one metallic element prepared in step (i) has the formula Na a Fe c Mn d M eO2 (where a is a number such that 0.38 < a < 0.62, c is a number such that 0 < c ≤ 0.40, d is a number such that 0.44 ≤ d < 1, e is a number such that c + d + e = 1, and M is selected from the group consisting of manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), tin (Sn), ruthenium (Ru), and other similar metals, or combinations thereof when suitable).

[0061] According to some examples, the metal element (M) is a transition metal selected from the group consisting of manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), ruthenium (Ru), and other similar transition metals, or combinations thereof when suitable. According to some examples for certain purposes, the metal element is titanium (Ti).

[0062] According to some examples, a is a number such that 0.38 < a < 0.62, or 0.38 < a < 0.60, or 0.38 < a < 0.58, or 0.38 < a < 0.56, or 0.38 < a < 0.54, or 0.38 < a < 0.52, or 0.38 < a < 0.50, or 0.38 < a < 0.48, or 0.38 < a ≤ 0.46, or 0.40 < a ≤ 0.46, or 0.41 ≤ a ≤ 0.46. According to some examples for certain purposes, a is a number such that 0.41 ≤ a ≤ 0.46.

[0063] Non-limiting examples of sodium, manganese, and iron-doped tunnel-type oxides of at least one metal element are Na 0.44 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.43 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.44 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na0.46 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.44 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.44 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.41 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.50 Fe 0.08 Mn 0.81 Ti 0.11 O2, and Na 0.50 Fe 0.11 Mn 0.78 Ti 0.11 Contains O2.

[0064] According to one example, the sodium, manganese, and iron doped tunnel oxides of at least one metal element may be prepared by a solid-state synthesis technique or a wet synthesis technique, for example, the wet synthesis technique may be a sol-gel process.

[0065] According to some examples, the iron-doped tunnel oxides of sodium, manganese, and at least one metal element may be prepared by a solid-state synthesis process. The solid-state synthesis process may include mixing and grinding selected amounts of appropriate precursors (metal oxides or metal carbonates) to obtain the iron-doped tunnel oxides of sodium, manganese, and at least one metal element having a desired stoichiometry. The mixing and grinding steps may be performed sequentially, simultaneously, or partially overlapping with each other in time.

[0066] According to some examples, the mixing and grinding steps are performed simultaneously. All suitable mixing and grinding methods are contemplated. For example, the solid precursor may be mixed and ground manually or by any suitable mechanical method, such as mechanical grinding. The solid-state synthesis process may also include heating the mixed and ground precursor to obtain the desired iron-doped tunnel oxide of sodium, manganese, and at least one metal element. The heating step may be performed at a temperature and for a period sufficient to obtain a powder of iron-doped tunnel oxide of sodium, manganese, and at least one metal element. The heating step may be performed, for example, in a furnace at a temperature of about 800° C. to about 1000° C., inclusive. The heating step may be performed, for example, for a period ranging from about 3 hours to about 24 hours, inclusive. The heating step may be performed under any suitable conditions to obtain the desired powder of iron-doped tunnel oxide of sodium, manganese, and at least one metal element. For example, the heating step may be performed under an air or oxygen atmosphere, although any other suitable atmosphere is contemplated.

[0067] According to some examples, the sodium, manganese, and iron doped tunnel oxides of at least one metal element may be prepared by a wet chemical synthesis process, such as a sol-gel process. The sol-gel process may be carried out in an aqueous medium using an inorganic salt precursor and a chelating agent. For example, the inorganic salt precursor may be a metal carbonate, acetate, oxalate, or alkoxide precursor, and the chelating agent may be an organic acid, such as citric acid. The sol-gel process may consist of dissolving an appropriate amount of inorganic salt precursor in water and dissolving a molar ratio of (Na+Mn):chelating agent of about 10. For example, the dissolving step may be carried out with stirring. The solution thus obtained may then be heated with stirring to a temperature sufficient to form a sol-gel precursor for a sufficient period of time. For example, the solution may then be heated to a temperature of about 80° C. until a sol-gel precursor is formed. The sol-gel precursor thus obtained may then be calcined at a temperature sufficient to decompose the organic and inorganic contents for a sufficient period of time. For example, the sol-gel precursor may then be calcined in a furnace at a temperature of about 400° C. for about 6 hours. The powder thus obtained may then be ground and calcined at a sufficient temperature and for a sufficient time to obtain the desired powder of iron-doped tunnel oxides of sodium, manganese, and at least one metal element. For example, the calcination step may be carried out in a furnace at a temperature of about 900° C. for about 9 hours. The calcination step may be carried out under any suitable conditions to obtain the desired powder of iron-doped tunnel oxides of sodium, manganese, and at least one metal element. For example, the calcination step may be carried out under an air or oxygen atmosphere, although any other suitable atmosphere is contemplated.

[0068] According to some examples, partial replacement of sodium ions with lithium ions may be performed by a one-step or two-step ion exchange process. The ion exchange reaction may be performed by mixing the powder of the iron-doped tunnel oxide of sodium, manganese, and at least one metal element prepared in step (i) with an excess of a lithium salt or lithium salt composition. The lithium salt composition may be a mixture of lithium nitrate (LiNO3) and lithium chloride (LiCl) or lithium hydroxide (LiOH), for example, in a molar ratio of LiNO3:LiCl or LiOH of about 2:1. For example, the powder prepared in step (i) may be mixed with up to a 20-fold molar excess of a lithium salt or lithium salt composition. The mixture may then be heated at a temperature and for a period sufficient to obtain the electrochemically active material, i.e., the lithium-substituted iron-doped tunnel oxide of sodium, manganese, and at least one metal element of the desired stoichiometry. For example, the mixture may be heated to a temperature of about 240° C. to about 400° C. either once for about 4 hours to about 15 hours, or twice for about 2 hours to about 10 hours.

[0069] The present technology also relates to an electrode material comprising an electrochemically active material as defined herein, or prepared by the method as defined herein.

[0070] According to an example, the electrode material defined herein may further comprise an electronically conductive material.Non-limiting examples of electronically conductive materials include carbon sources such as carbon black (e.g., Ketjen™ carbon and Super P™ carbon), acetylene black (e.g., Shawinigan carbon and Denka™ carbon black), graphite, graphene, carbon fiber (e.g., vapor grown carbon fiber (VGCF)), carbon nanofiber, carbon nanotube (CNT), and combinations of at least two thereof.According to a variant of interest, the electronically conductive material is selected from Ketjen™ carbon, Super P™ carbon, VGCF, and combinations of at least two thereof.According to a variant of interest, the electronically conductive material is a mixture of VGCF and carbon black.

[0071] According to another example, the electrode material defined herein may further include a binder. For example, the binder may be selected for compatibility with various elements of the electrochemical cell. Any known compatible binder is contemplated. For example, the binder may be a polyether type polymer binder, a fluorinated polymer, and a water-soluble binder. According to one example, the binder is a fluorinated polymer such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE). According to another example, the binder is a water-soluble binder such as styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), hydrogenated NBR (HNBR), epichlorohydrin rubber (CHR), or acrylate rubber (ACM), optionally including a thickener such as carboxymethyl cellulose (CMC), or an acidic polymer such as polyacrylic acid (PAA), poly(methyl methacrylate) (PMMA), or a combination thereof. According to another example, the binder is an optionally crosslinked polymeric binder of the polyether type. For example, the polymeric binder of the polyether type binder is linear, branched and / or crosslinked and based on poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO) or a combination of the two (or as an EO / PO copolymer), and optionally comprises crosslinkable units. According to a variant of interest, the binder is polyvinylidene fluoride (PVDF).

[0072] According to another example, the electrode material defined herein may further optionally include at least one additional additive, such as an ion conductor, inorganic particles, glass or ceramic particles, nanoceramics (e.g., aluminum oxide (Al2O3), titanium dioxide (TiO2), silicon dioxide (SiO2), and other similar compounds), salts (e.g., lithium salts), and other similar additives. For example, the additional additive may be an ion conductor selected from the group consisting of NASICON, LISICON, thio-LiSICON, garnets, sulfides, sulfur halides, phosphates, thio-phosphates, and combinations of at least two thereof, in crystalline and / or amorphous form.

[0073] According to another aspect, the present technology relates to an electrode comprising the electrode material defined herein on a current collector (e.g., aluminum or copper foil). The electrode may also be a free-standing electrode. According to an example of interest, the electrode is a positive electrode.

[0074] According to another aspect, the present technology relates to an electrochemical cell including a negative electrode, a positive electrode, and an electrolyte, wherein the positive electrode is as defined herein.

[0075] According to one example, the negative electrode (counter electrode) comprises an electrochemically active material selected from all known compatible electrochemically active materials. For example, the electrochemically active material of the negative electrode may be selected for its electrochemical compatibility with various elements of the electrochemical cell defined herein. Non-limiting examples of electrochemically active negative electrode materials include alkali metals, alkali metal alloys, and pre-lithiated electrochemically active materials. According to an example of interest, the electrochemically active material of the negative electrode may be a metallic lithium film or an alloy containing metallic lithium.

[0076] According to another example, the electrolyte may be selected for its compatibility with the various elements of the electrochemical cell. Any type of compatible electrolyte is contemplated. For example, the electrolyte may be a liquid electrolyte comprising a salt in a solvent. The electrolyte may also be a gel electrolyte comprising a salt in a solvent and, optionally, a solvating polymer. The electrolyte may also be a solid polymer electrolyte comprising a salt in a solvating polymer. The electrolyte may also be a glass or ceramic electrolyte.

[0077] The salt, when present in the electrolyte, may be an ionic salt, such as a lithium salt. Non-limiting examples of lithium salts include lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride, and the like. Lithium salts include lithium (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkylphosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate[B(CO2)2] (LiBBB), and combinations of at least two of these. According to an example of interest, the lithium salt is lithium hexafluorophosphate (LiPF6).

[0078] The solvent, when present in the electrolyte, is preferably a non-aqueous solvent. Non-limiting examples of non-aqueous solvents include cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and vinylene carbonate (VC); acyclic carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dipropyl carbonate (DPC); lactones such as γ-butyrolactone (γ-BL) and γ-valerolactone (γ-VL); 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), ethoxymethoxyethane ( acyclic ethers such as tetraethylene glycol dimethyl ether (TEGDME), trimethoxymethane, tetraethylene glycol dimethyl ether or tetraglyme (TEGDME), and ethyl monoglyme; cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, and dioxolane derivatives; and other solvents such as dimethyl sulfoxide, formamide, acetamide, dimethylformamide, acetonitrile, propylnitrile, nitromethane, phosphoric acid triesters, sulfolane, methylsulfolane, propylene carbonate derivatives, and mixtures thereof. According to some examples of interest, the non-aqueous solvent is a mixture of at least two carbonates, such as a mixture of ethylene carbonate and ethyl methyl carbonate (EC / EMC). According to examples of interest, the electrolyte is a liquid electrolyte and includes LiPF6 in an EC / EMC mixture ([3:7] by volume) containing 5% fluoroethylene carbonate (FEC).

[0079] According to some examples, the electrolyte is a liquid electrolyte and the electrode material comprises an electrochemically active material as defined herein or prepared by a method as defined herein, PVDF as a binder, and an electronically conductive material selected from the group consisting of Ketjen™ carbon, Super P™ carbon, and VGCF.

[0080] According to some examples, the electrolyte is a gel electrolyte or a gel polymer electrolyte. The gel polymer electrolyte may, for example, comprise a polymer precursor, a salt (e.g., a salt as defined above), a solvent (e.g., a solvent as defined above), and, if necessary, a polymerization and / or cross-linking initiator. Non-limiting examples of gel electrolytes include, but are not limited to, the gel electrolytes described in PCT patent applications published in WO2009 / 111860 (Zaghib et al.) and WO2004 / 068610 (Zaghib et al.).

[0081] According to some examples, the liquid or gel electrolyte as defined above may also impregnate a separator, examples of which include, but are not limited to, separators such as Whatman™ glass fiber GF filters.

[0082] According to some examples, the electrolyte is a solid polymer electrolyte comprising a salt in a solvent polymer. For example, the solid polymer electrolyte may be selected from all known solid polymer electrolytes and may be selected for its compatibility with various elements of an electrochemical cell. For example, the solid polymer electrolyte is selected for its compatibility with lithium. The solid polymer electrolyte may generally comprise one or more solid polar polymers, optionally crosslinked, and a salt (e.g., a salt as defined above). Polyether-type polymers, such as those based on PEO, may be used, although several other suitable polymers are known and contemplated for the preparation of solid polymer electrolytes. The polymer may be crosslinked. Examples of such polymers include branched polymers, such as star or comb polymers, such as those described in the U.S. patent published in U.S. Pat. No. 7,897,674 B2 (Zaghib et al.) (US'674).

[0083] According to some examples, the solid polymer electrolyte may include a block copolymer comprised of at least one lithium ion solvation segment and, optionally, at least one crosslinkable segment. Preferably, the lithium ion solvation segment is represented by Formula I: [ka] (In the formula, R is a hydrogen atom, C1-C 10 Alkyl group, or -(CH2-OR a R b ) group, R a is (CH2-CH2-O) y and R b is a hydrogen atom and C1-C 10 alkyl groups, x is an integer selected from the range of 10 to 200,000; and y is an integer selected from the range of 0 to 10. The repeat unit is selected from homopolymers or copolymers having the following repeat units:

[0084] According to another example, the crosslinkable segment may be a polymer segment that includes at least one functional group that is multi-dimensionally crosslinkable by irradiation or heat treatment.

[0085] According to some examples, the electrolyte is a solid polymer electrolyte comprising LiPF6 and a solvating polymer based on PEO. According to some examples, the electrolyte is a solid polymer electrolyte as defined above, and the electrode material comprises an electrochemically active material as defined herein or an electrochemically active material prepared by a method as defined herein, and an electronically conductive material selected from the group consisting of Ketjen™ carbon, Super P™ carbon, and VGCF.

[0086] In examples where the electrolyte is a solid polymer electrolyte, the electrode material may include, for example, about 80 wt.% to about 90 wt.% electrochemically active material, about 1 wt.% to about 5 wt.% electronically conductive material, and about 5 wt.% to about 19 wt.% solid polymer electrolyte.

[0087] According to some examples, the electrolyte is a glass or ceramic electrolyte. For example, the glass or ceramic electrolyte may include a crystalline ion-conducting ceramic or an amorphous ion-conducting ceramic, an amorphous ion-conducting glass, or an ion-conducting glass ceramic. Non-limiting examples of glass or ceramic electrolytes include site-deficient perovskite-type electrolytes, garnet-type electrolytes, NASICON-type glass-ceramic electrolytes, LISICON-type electrolytes, lithium stabilized sodium ion (Na + ) conductive aluminum oxide (Al2O3), and other similar glass or ceramic electrolytes.

[0088] According to some examples, the electrolyte may also optionally include at least one additional additive, such as an ion-conducting material, inorganic particles, glass or ceramic particles, e.g., nanoceramics (e.g., aluminum oxide (Al2O3), titanium dioxide (TiO2), silicon dioxide (SiO2), and similar compounds), and other such additives. For example, the additional additive may be selected from NASICON, LISICON, thio-LISICON, garnets, sulfides, sulfur halides, phosphates, thio-phosphates, and combinations thereof, in crystalline and / or amorphous form. According to one example, the additional additive may be substantially dispersed in the electrolyte. The additional additive may also be present in a separate layer.

[0089] The present technology also relates to a battery comprising at least one electrochemical cell as defined herein. For example, the battery may be a lithium or lithium-ion battery, a sodium or sodium-ion battery, a magnesium or magnesium-ion battery, or a potassium or potassium-ion battery. According to a variant of the object, the battery is a lithium or lithium-ion battery. According to another variant of the object, the battery is a sodium or sodium-ion battery. EXAMPLES

[0090] The following examples are for illustrative purposes only and should not be construed as further limiting the scope of the contemplated invention. These examples are better understood with reference to the accompanying figures.

[0091] Unless otherwise specified, all numerical values ​​expressing amounts of ingredients, preparation conditions, concentrations, properties, and the like used herein are understood to be modified in all cases by the term "about". At the very least, each numerical parameter should be interpreted in light of the number of reported significant digits and by applying common rounding techniques. Thus, unless otherwise specified, the numerical parameters set forth herein are approximations that may vary depending on the desired properties. Notwithstanding the fact that the parameters defining the numerical ranges and scope of the embodiments are approximations, the numerical values ​​set forth in the following examples are reported as precisely as possible. However, any numerical value inherently contains some errors resulting from variations in experiments, testing measurements, statistical analyses, and the like.

[0092] Example 1 Synthesis of electrochemically active materials

[0093] a) Solid-state synthesis of sodium, manganese, and iron-doped tunnel oxides of at least one metallic element Formula Na 0.44 Mn 0.55 Ti 0.10 O2, Na 0.43 Fe 0.34 Mn 0.44Ti 0.22 O2, Na 0.46 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.44 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.41 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.50 Fe 0.08 Mn 0.81 Ti 0.11 O2, and Na 0.50 Fe 0.11 Mn 0.78 Ti 0.11 Sodium, manganese, and iron-doped tunnel oxides of at least one metallic element of O2 were synthesized by simple solid-state reactions. The respective precursors, sodium carbonate (Na2CO3), manganese(III) oxide (Mn2O3), iron(III) oxide (Fe2O3), and titanium dioxide (TiO2), were weighed to obtain the desired stoichiometry. Samples were prepared by grinding and mixing the precursor powders. The ground and mixed precursor powders were then placed in a furnace and heated to temperatures of about 700 °C to about 1000 °C under air or oxygen atmosphere for 2 to 24 hours.

[0094] b) Wet chemical synthesis of sodium, manganese, and iron-doped tunnel oxides of at least one metallic element. Alternatively, the formula Na 0.44 Mn 0.55 Ti 0.10 O2, Na 0.43 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.46 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.44 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.41 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.50Fe 0.08 Mn 0.81 Ti 0.11 O2 and Na 0.50 Fe 0.11 Mn 0.78 Ti 0.11 Sodium, manganese, and iron-doped tunnel oxides of at least one metallic element of O2 were also prepared using the sol-gel process. The sol-gel powders were synthesized using citric acid (C6H8O7) as a chelating agent. The respective precursors sodium carbonate (Na2CO3), manganese(II) acetate ((CH3CO2)2Mn), iron(II) oxalate, and titanium tetrabutoxide (C 16 H 36 O4Ti) (all from Sigma-Aldrich, ≥99.99%) was weighed to obtain the desired stoichiometry and dissolved in distilled water under magnetic stirring with C6H8O7 in a molar ratio of (Na+Mn) / C6H8O7 = 10. The solution thus obtained was then heated to a temperature of about 80°C with stirring until a transparent sol-gel precursor was obtained.

[0095] The sol-gel precursor thus obtained was then calcined in a furnace at a temperature of about 400° C. for about 6 hours to decompose the organic and inorganic contents (including anionic salts and C6H8O7).

[0096] Finally, the powder thus obtained is ground in a mortar and sintered in a furnace at a temperature of about 900° C. for about 9 hours in air or oxygen atmosphere to obtain the final sol-gel powder Na 0.44 Mn 0.55 Ti 0.10 O2, Na 0.43 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.46 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.44 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.41 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.50Fe 0.08 Mn 0.81 Ti 0.11 O2 and Na 0.50 Fe 0.11 Mn 0.78 Ti 0.11 Got O2.

[0097] c) Synthesis of iron-doped tunnel oxides of sodium, lithium, manganese, and at least one metallic element. Formula Na 0.10 Li 0.33 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.08 Li 0.38 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.20 Li 0.24 Fe 0.34 Mn 0.55 Ti 0.11 O2, Na 0.21 Li 0.20 Fe 0.40 Mn 0.50 Ti 0.10 O2, Na 0.10 Li 0.40 Fe 0.08 Mn 0.81 Ti 0.11 O2 and Na 0.10 Li 0.40 Fe 0.11 Mn 0.78 Ti 0.11 Sodium, lithium, manganese, and iron-doped tunnel oxides of at least one metallic element of O2 were prepared using a one- or two-step ion-exchange process to partially replace sodium ions with lithium ions.

[0098] The ion exchange reaction was carried out by mixing the powders prepared in Examples 1(a) and 1(b) with a 20-fold molar excess of a lithium eutectic salt composition of lithium nitrate (LiNO3) and lithium chloride (LiCl) or lithium hydroxide (LiOH) (1:1 molar ratio of LiNO3:LiCl or LiOH). The mixture was then heated to a temperature of about 120°C to about 400°C either once for about 0.5 hours to about 10 hours or twice for about 0.25 hours to about 5 hours to obtain the desired stoichiometry.

[0099] Finally, for comparison purposes, the formula Na 0.08 Li 0.36 Tunnel oxides of sodium, lithium, manganese and at least one metal element of MnO2 were also prepared. This material has the formula Na 0.44 The tunnel-type sodium and manganese oxides of MnO2 were used to obtain the ion exchange reaction in this example.

[0100] d) X-ray diffraction (XRD) on powder The atomic and molecular structures of the electrochemically active materials were studied by X-ray diffraction on the powders of the iron-doped tunnel oxides of sodium, lithium, manganese, and at least one metal element prepared in Example 1(c). 0.08 Li 0.36 MnO2, Na 0.10 Li 0.33 Fe 0.34 Mn 0.44 Ti 0.22 O2, Na 0.08 Li 0.38 Fe 0.30 Mn 0.55 Ti 0.15 O2, Na 0.20 Li 0.24 Fe 0.34 Mn 0.55 Ti 0.11 O2 and Na 0.21 Li 0.20 Fe 0.40 Mn 0.50 Ti0.10 The X-ray diffraction patterns of O2 powder are shown.

[0101] Example 2 Electrochemical properties

[0102] a) Electrochemical cell configuration The electrochemical properties of the electrochemically active material prepared in Example 1(c) were investigated. All cells were assembled in a 2032-type coin cell case with the components shown in Table 1, and a negative electrode comprising a metallic lithium film on an aluminum current collector. All cells were assembled with a Whatman™ glass fiber GF paper filter separator impregnated with a 1 M solution of LiPF6 in a non-aqueous solvent mixture of EC / EMC ([3:7] by volume) and 5% FEC as the liquid electrolyte. The electronic conductive material was a mixture of Ketjen™ carbon and Super P™ carbon ([1:1] by weight). [Table 1]

[0103] b) Electrochemical behavior This example illustrates the electrochemical behavior of the electrochemical cell described in Example 2(a).

[0104] FIG. 6 shows the charge-discharge profiles of two comparative cells (cell 1). In (1), the charge-discharge voltage was about 2.0 V to about 4.8 V vs. Li + At a cycle rate of 0.1C for / Li, (2) is about 2.0V to about 4.6V vs. Li + / Li. Charge and discharge were carried out at a temperature of about 25° C. Results are shown for the second charge-discharge cycle.

[0105] FIG. 7 shows the second charge-discharge profile of cell 2. The charge-discharge was performed from about 2.0 V to about 4.8 V vs. Li + The cycle was performed at 25°C for 1000mA / Li at a cycle rate of 0.1 C. Charge and discharge were performed at a temperature of approximately 25°C.

[0106] FIG. 8 shows the charge / discharge profile of cell 3. The charge / discharge was performed from about 2.0 V to about 4.8 V vs. Li + The cycles were performed at a rate of 0.1 C with 100 / Li. The charge / discharge cycles were performed at a temperature of about 25° C. Results are shown for the second charge / discharge cycle.

[0107] FIG. 9 shows the charge / discharge profile of cell 4. The charge / discharge was performed from about 2.0 V to about 4.8 V vs. Li + The cycling was carried out at a cycle rate of 0.1 C with 1000 mA / Li. The charging and discharging was carried out at a temperature of about 25° C. Results are shown for the second (1) and fifth (2) charge-discharge cycles.

[0108] FIG. 10 shows the charge / discharge profile of cell 5. The charge / discharge profile is from about 2.0 V to about 4.8 V vs. Li + The cycles were performed at a rate of 0.1 C with 100 / Li. The charge / discharge cycles were performed at a temperature of about 25° C. Results are shown for the second charge / discharge cycle.

[0109] FIG. 11(a) shows the charge / discharge profile of cell 6. The charge / discharge was performed from about 2.0 V to about 4.8 V vs. Li + The cycles were performed at a cycle rate of 0.1 C with 100 / Li. The charge / discharge cycles were performed at a temperature of about 25° C. FIG. 11(b) is a graph showing the capacity as a function of cycle number obtained for Cell 6.

[0110] FIG. 12(a) shows the charge / discharge profile of the cell 7. The charge / discharge was performed from about 2.0 V to about 4.8 V vs. Li + The cycles were performed at a cycle rate of 0.1 C with 100 / Li. The charge / discharge cycles were performed at a temperature of about 25° C. FIG. 12(b) is a graph showing the capacity as a function of cycle number obtained for Cell 7.

[0111] The capacity, voltage, and specific energy delivered by cells 1-5 are shown in Table 2. [Table 2]

[0112] As can be observed in Table 2, the presence of iron ions substantially increases the average working potential of the electrochemically active material. Table 2 also shows that partial replacement of sodium ions with lithium ions and / or partial replacement of manganese ions with titanium ions can substantially improve the electrochemical properties of the electrochemically active material.

[0113] Numerous modifications can be made to any of the above-described embodiments without departing from the contemplated scope of the invention. All references, patents or scientific literature documents mentioned in this application are incorporated herein by reference in their entirety for all purposes.

Claims

1. Formula Na ａ Li ｂ Fe ｃ Mn ｄ M ｅ O ２ An electrochemical active material comprising sodium, manganese, and lithium-substituted iron-doped tunnel-type oxide of at least one metallic element (wherein a is a number such that 0 < a < 0.22, b is a number such that 0.18 < b < 0.40, a + b is such that 0.38 < a + b < 0.62, c is a number such that 0 < c ≤ 0.40, d is a number such that 0.44 ≤ d < 1, e is a number such that c + d + e = 1, and M is selected from manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), tin (Sn), ruthenium (Ru), other similar metals, and at least two combinations thereof).

2. The electrochemical active material according to claim 1, wherein M is selected from manganese (Mn), titanium (Ti), vanadium (V), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), zirconium (Zr), ruthenium (Ru), other similar metals, and at least two combinations thereof, preferably M is titanium (Ti).

3. The electrochemical active material according to claim 1, wherein a is a number such that 0.01 < a < 0.22, or 0.02 < a < 0.22, or 0.03 < a < 0.22, or 0.04 < a < 0.22, or 0.05 < a < 0.22, or 0.06 < a < 0.22, or 0.07 < a < 0.22, or 0.08 ≤ a ≤ 0.21, preferably a is a number such that 0.08 ≤ a ≤ 0.

21.

4. The electrochemical active material according to claim 1, wherein b is a number such that 0.19 < b < 0.40, or 0.20 ≤ b < 0.40, or 0.20 ≤ b < 0.39, or 0.20 ≤ b ≤ 0.38, and preferably b is a number such that 0.20 ≤ b ≤ 0.

38.

5. The electrochemical active material according to claim 1, wherein c is a number such that 0.05 < c ≤ 0.40, or 0.10 < c ≤ 0.40, or 0.15 < c ≤ 0.40, or 0.20 < c ≤ 0.40, or 0.25 < c ≤ 0.40, or 0.30 ≤ c ≤ 0.40, and preferably c is a number such that 0.30 ≤ c ≤ 0.

40.

6. The electrochemical active material according to claim 1, wherein d is a number such that 0.44 ≤ d < 1, or 0.44 ≤ d < 0.95, or 0.44 ≤ d < 0.90, or 0.44 ≤ d < 0.85, or 0.44 ≤ d < 0.80, or 0.44 ≤ d < 0.75, or 0.44 ≤ d < 0.70, or 0.44 ≤ d < 0.65, or 0.44 ≤ d < 0.60, or 0.44 ≤ d ≤ 0.55, and preferably d is a number such that 0.44 ≤ d ≤ 0.

55.

7. The lithium-substituted iron-doped tunnel-type oxide of sodium, manganese, and at least one metal element is Na ０．１０ Li ０．３３ Fe ０．３４ Mn ０．４４ Ti ０．２２ O ２ 、Na ０．０８ Li ０．３８ Fe ０．３０ Mn ０．５５ Ti ０．１５ O ２ 、Na ０．２０ Li ０．２４ Fe ０．３４ Mn ０．５５ Ti ０．１１ O ２ 、Na ０．２１ Li ０．２０ Fe ０．４０ Mn ０．５０ Ti ０．１０ O ２ 、Na ０．１０ Li ０．４０ Fe ０．０８ Mn ０．８１ Ti ０．１１ O ２ and Na ０．１０ Li ０．４０ Fe ０．１１ Mn ０．７８ Ti ０．１１ O ２ The electrochemical active material according to claim 1, selected from the group consisting of

8. An electrode material comprising an electrochemical active material as defined in any one of claims 1 to 7.

9. The electrode material according to claim 8, further comprising an electronically conductive material preferably selected from the group consisting of carbon black, acetylene black, graphite, graphene, carbon fiber, carbon nanofiber, carbon nanotube, and at least two combinations thereof.

10. The electrode material according to claim 9, wherein the electronically conductive material contains carbon black, and preferably the carbon black is Super P® carbon or Ketjen® carbon.

11. The electrode material according to claim 9, wherein the electronically conductive material includes carbon fibers, and preferably the carbon fibers are vapor-processed carbon fibers (VGCF).

12. The electrode material according to claim 8, further comprising a binder preferably selected from the group consisting of polyether-type polymers, fluoropolymers, and water-soluble binders.

13. The electrode material according to claim 12, wherein the binder is a fluoropolymer, and preferably the fluoropolymer is polyvinylidene fluoride (PVDF).

14. The electrode material according to claim 8, further comprising an additive preferably selected from the group consisting of ion conductors, inorganic particles, glass particles, ceramic particles, salts, and other similar additives.

15. An electrode comprising an electrode material defined in claim 8 on a current collector.

16. An electrochemical cell comprising a negative electrode, a positive electrode, and an electrolyte, wherein the positive electrode is as defined in claim 15.

17. The electrochemical cell according to claim 16, wherein the negative electrode comprises an alkali metal, an alloy containing an alkali metal, or a pre-lithified electrochemical active material, preferably the negative electrode comprises metallic lithium or an alloy containing metallic lithium, and more preferably the negative electrode comprises metallic lithium.

18. The electrochemical cell according to claim 16, wherein the electrolyte is a glass or ceramic electrolyte.

19. The electrochemical cell according to claim 16, wherein the electrolyte is (i) a liquid electrolyte containing a salt in a solvent, (ii) a gel electrolyte containing a salt in a solvent and optionally a solvating polymer, or (iii) a solid polymer electrolyte containing a salt in a solvating polymer.

20. The aforementioned salt is lithium hexafluorophosphate (LiPF ６ ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF ４ ), lithium bis(oxalato) borate (LiBOB), lithium nitrate (LiNO) ３ ), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO2) ４ ), lithium hexafluoroarsenate (LiAsF ６ ), lithium trifluoromethanesulfonate (LiSO4) ３ CF ３ ) (LiTf), Lithium fluoroalkyl phosphate [PF ３ (CF ２ CF ３ ) ３ ] (LiFAP), Lithium tetrakis(trifluoroacetoxy) borate Li[B(OCOCF ３ ) ４ ](LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate[B(C ６ O ２ ) ２ The electrochemical cell according to claim 19, wherein the lithium salt is preferably selected from the group consisting of ] (LiBBB) and at least two combinations thereof, and preferably the lithium salt is lithium hexafluorophosphate (LiPF6).

21. A battery comprising at least one electrochemical cell as defined in claim 16, wherein the battery is preferably selected from the group consisting of lithium batteries, lithium-ion batteries, sodium batteries, sodium-ion batteries, potassium batteries, potassium-ion batteries, magnesium batteries, and magnesium-ion batteries, and more preferably the battery is a lithium battery or a lithium-ion battery.

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