High-energy, long-cycle-life cathode materials and batteries using the same

Abstract

The present invention provides an electrochemically active material, a cathode or electrochemical cell comprising the electrochemically active material, and a method of producing the electrochemically active material. The electrochemically active material as provided herein comprises a first composition of formula Li 1+a MO 2+b (Formula I), wherein -0.3≤a≤1.3 and -0.3≤b≤1.3, and wherein M comprises 30 atomic % to 70 atomic % Mn and 25 atomic % to 70 atomic % Ni, the first composition being formed of a polycrystalline morphology comprising a plurality of crystallites and grain boundaries between adjacent crystallites, the grain boundaries comprising a second composition of formula Li 1+a M’O 2+b (Formula II), wherein -0.1≤a≤1.3 and -0.3≤b≤1.3, wherein the grain boundaries comprise one or more enriching elements in at least a portion thereof, the one or more enriching elements being present in the portion in atomic percent higher than in adjacent crystallites, wherein the one or more enriching elements are Co, Al, or both Co and Al.

Description

[0001] Cross-reference to related applications

[0002] This application relies on and claims priority to the following applications: U.S. Provisional Application No. 63 / 522,514, filed June 22, 2023; U.S. Provisional Application No. 63 / 550,394, filed February 6, 2024; and U.S. Provisional Application No. 63 / 647199, filed May 14, 2024, the entire contents of which are hereby incorporated herein by reference.

[0003] field

[0004] A polycrystalline metal oxide with improved cycle life and excellent specific energy, a method for manufacturing the same, and articles comprising the same are disclosed.

[0005] background

[0006] Most current lithium-ion battery packs include one of two main types of cathode materials. The first is a rhombohedral layered cathode material with the general formula LiMO2 (M = usually a combination of Ni, Co, Mn, and Al). - Layered metal oxides with a NaFeO2-type structure (R-3M space group). To achieve high capacity, these cathodes contain a large percentage of Ni, which is stabilized with Co and small amounts of other elements. Unfortunately, both Ni and Co are expensive, and the latter also presents environmental and supply issues. The second type is olivine-type lithium iron phosphate (LFP) materials. LFP materials have an orthorhombic crystal structure with the Pmma space group (Y. Ikuhara). , N (ano Lett, 2016; 16: 5409-5414). LFP cathodes are much cheaper than LMO2 cathodes; however, they also have much lower capacity (~150 mAh / g, compared to >200 mAh / g for LMO2 cathodes) and below-average discharge voltage (3.4V vs. Li, compared to 3.8V vs. Li for LMO2 cathodes). Importantly, because iron is very detrimental to layered metal oxide cathodes, these two cathode types cannot be produced in the same plant environment, making it difficult for cathode suppliers currently producing LMO2 cathode materials to also produce LFP cathodes without incurring significant costs.

[0007] Therefore, there is a need for new cathode materials that combine high capacity retention with low cost and can be manufactured using existing lithium-ion cathode facilities.

[0008] Overview

[0009] The following overview is provided to facilitate understanding of some of the innovative features unique to this disclosure and is not intended to be an exhaustive description. A full understanding of the various aspects of this disclosure can be obtained by considering the entire specification, claims, drawings, and abstract as a whole.

[0010] Electrochemically active materials are provided, including: Li 1+a MO 2+b A first composition of formula I, wherein -0.3 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3, and wherein M comprises 30 atomic% to 70 atomic% Mn and 25 atomic% to 70 atomic% Ni, the first composition being formed of a polycrystalline morphology comprising a plurality of microcrystals and grain boundaries between adjacent microcrystals; the grain boundaries comprising formula Li 1+a M'O 2+bThe second composition of (Formula II), wherein -0.1 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3; and wherein the grain boundaries comprise one or more enriched elements in at least a portion thereof, the one or more enriched elements being present in said portion at a higher atomic percentage than in adjacent crystallites, wherein said one or more enriched elements comprise or are selected from Co, Al, and both Co and Al. Optionally, M comprises 30 atomic% to 65 atomic% Mn. In some aspects, the second composition has an α-NaFeO2 type structure, a cubic structure, a spinel structure, or a combination thereof. Optionally, the particles have a grain size of about 1 µm to about 25 µm. Optionally, each crystallite independently has a grain size of less than about 1 µm. In any aspect, M optionally comprises Co, optionally at a greater than about 0 atomic% to about 15 atomic%, optionally about 0.01 atomic% to about 10 atomic%. Optionally, M comprises about 30 atomic% to about 70 atomic% of Mn, about 25 atomic% to about 70 atomic% of Ni, greater than 0 to about 15 atomic% of Co and / or 0 to about 5 atomic% of Mg, or any combination thereof. In other aspects, M comprises about 30 atomic% to about 65 atomic% of Mn, about 25 atomic% to about 70 atomic% of Ni, greater than 0 to about 15 atomic% of Co and about 0 atomic% to about 5 atomic% of Mg. In any aspect, the enrichment is optionally Co, Al, or includes both Co and Al. Optionally, Mn in the first composition is present at about 45 atomic% to about 65 atomic% of Mn. Optionally, M comprises less than or equal to 40 atomic% of Ni. In some aspects, M comprises about 25 atomic% to about 70 atomic% of Ni, about 0-15 atomic% of Co, about 30 atomic% to about 65 atomic% of Mn and 0-10 atomic% of additional elements. In any respect, the grain boundaries optionally include an enriched element with an atomic percentage higher than the average atomic percentage of enriched elements in adjacent crystallites. Optionally, M' comprises 30 atomic% to 70 atomic% of Mn relative to total M'. Optionally, M' comprises about 10 atomic% to about 70 atomic% (at%) of Ni relative to total M'. An electrode is also provided, comprising an electrochemically active material as provided herein and a current collector in electrical contact with said electrochemically active material. An electrochemical cell is also provided, comprising a first electrode and a second electrode, the first electrode being an electrode according to any aspect provided herein. Optionally, in said electrochemical cell, the second electrode comprises carbon or lithium titanate, optionally wherein said carbon is or comprises graphite. The electrochemical cell provided herein is optionally characterized in that, when said electrochemical cell comprises a graphite anode, when cycled at an average C rate of >1 from 2.7 – 4.2 V at 45°C (~2 mAh / cm³), 2When the cathode is loaded, the discharge capacity can be maintained at greater than 140 mAh / g after 400 or more cycles, and optionally greater than 160 mAh / g after 400 or more cycles. The electrochemical cell provided herein is optionally characterized in that, when the electrochemical cell contains a graphite anode, it can maintain a discharge capacity of greater than 140 mAh / g when cycled at an average C rate of >1 from 2.7 – 4.6 V at 45°C (~2 mAh / cm³). 2 When cathode-loaded, the discharge capacity remains greater than 140 mAh / g after 400 or more cycles, and optionally greater than 200 mAh / g after 400 or more cycles. In the electrochemical cell, the electrolyte may not include ethylene carbonate. Optionally, the electrolyte comprises lithium salt and dimethyl carbonate, alone or in combination with one or more additives. Optionally, the additives in the electrolyte are fluoroethylene carbonate (FEC), difluoroethylene carbonate (F2EC), tri(trimethylsilyl) malonate (TMSM), tri(trimethylsilyl) phosphite (TMSPi), tri(trimethylsilyl) phosphate (TMSPO4), lithium bis(oxalate)borate (LiDFOB), and the cosolvent 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TFETFPE). In some aspects, the additives optionally include combinations of fluoroethylene carbonate, difluoroethylene carbonate, lithium difluoro(oxalate)borate, or combinations thereof.

[0011] Attached Figure

[0012] The aspects illustrated in the accompanying drawings are illustrative and exemplary and are not intended to limit the subject matter defined by the claims. The following detailed description of exemplary aspects may be understood when read in conjunction with the following drawings:

[0013] Figure 1 The illustration is a schematic diagram of polycrystalline particles with grain boundaries as described in some aspects of this article.

[0014] Figure 2 Figure (A) shows data comparing full-cell cycling between Comparative Example 1 and Example 2. The batteries, using graphite anodes, were cycled at 45°C at 2.7–4.2 V under 1C charge / 1C discharge conditions. Figure (B) shows data comparing full-cell cycling between Comparative Example 2 and Example 2. The batteries, using graphite anodes, were cycled at 45°C at 2.7–4.2 V under 1C charge / 1C discharge conditions.

[0015] Figure 3 The diagram illustrates the XRD diffraction of Comparative Example 3. The peaks are consistent with the rhombohedral LiMO2 structure with the R-3M space group. Inset: Shown in 20... - 27 2 The extended XRD pattern between them shows a Li2MnO3 monoclinic structure consistent with the high Mn cathode;

[0016] Figure 4 The diagram illustrates the cycling of all-button batteries in Comparative Example 4 and Example 4. Figure A – The battery with the graphite anode is formed to 4.65V and cycled at an average 1C discharge at 2.8–4.3V at 45°C in a fast cycling test. Figure B – The battery with the graphite anode is formed to 4.65V and cycled at an average 1C discharge at 2.8–4.6V or 2.8–4.3V at 45°C in a fast cycling test.

[0017] Figure 5 The figure illustrates the data comparing full-cell cycling between Comparative Example 5 and Example 5. The battery with the graphite anode was formed to 4.65V and cycled at an average 1C discharge at 2.8–4.3V at 45°C in a rapid cycling test.

[0018] Figure 6 The figure illustrates the data for a full-cell cycle comparison between Comparative Example 6 and Example 6. The cell with the graphite anode was formed to 4.65V and cycled at an average 1C discharge at 2.8–4.3V in a rapid cycle test.

[0019] Figure 7 The figure illustrates the data for a full-cell cycle comparison between Example 7 and Example 6. The cell with the graphite anode was formed to 4.65V and cycled at an average 1C discharge at 2.8–4.3V in a rapid cycle test.

[0020] Detailed Explanation

[0021] High Mn electrochemically active materials are provided for use as actives in cathodes. It was found that the capacity decay and / or rate capacity problems of existing Mn-rich cathode materials can be solved by enriching grain boundaries with Co and combining this enrichment with a customized amount of Mn, far exceeding the amount typically used in Mn-containing cathode materials. The materials are processable. These grain-bound enriched Mn-containing electrochemically active materials are comparable to currently available LFP cathodes, but have the significant advantage of being able to be fabricated using existing LMO2 electrode fabrication facilities. The Mn-rich materials presented herein have attracted considerable attention due to their relatively low cost (reduced use of Co and Ni), environmental friendliness, and high thermal stability. The materials presented herein exhibit improved rate capacity and / or voltage decay resistance.

[0022] An electrochemical battery, optionally a secondary battery, or any lithium-ion secondary battery, is also provided, comprising an anode, an electrolyte, and a cathode, wherein the cathode comprises an electrochemically active cathode active material comprising multiple particles, the multiple particles comprising multiple microcrystals, each microcrystal comprising a first composition comprising lithium, manganese, and oxygen; and optionally layered structures are present between adjacent microcrystals of the multiple microcrystals. - A second composition of NaFeO2-type structure, cubic structure, spinel structure or combination thereof, with grain boundaries; wherein a customized amount of Mn and a combination of one or more enriched elements enriched at the grain boundaries achieve excellent cycle life and / or rate capacity.

[0023] LiMO-type materials, where M is one or more metals alone or further combined with one or more additional elements, are dense polycrystalline agglomerates in their primary (microcrystalline) form. These LiMO-type materials are typically manufactured using standard solid-state processes at temperatures ranging from 600°C to 900°C, starting with various precursor materials. Precursor materials are typically transition metal hydroxides (represented by the general formula M(OH)₂), lithium precursors (e.g., LiOH or Li₂CO₃), or inorganic precursors with other dopants (e.g., hydroxides, carbonates, nitrates). During the heating process of a precursor mixture including precursor materials with high Mn content, polycrystalline LiMO₂ and Li₂MnO₃ are typically formed, while gases such as H₂O, CO₂, or NO₂ are released.

[0024] The result of sintering under the correct conditions and with the use of appropriate precursors is the formation of one or more secondary particles, which comprise multiple primary crystallites that together form larger secondary particles that can act as electrochemically active materials. It has been previously found that the regions between these primary crystallites, i.e., grain boundaries, can be selectively enriched with Co—as discovered in U.S. Patent No. 9,209,455. In this disclosure, it has been found that significant further improvements can be achieved by replacing some elements in the bulk material with a relatively high but tailored amount of Mn. Unexpectedly, when the Mn levels used in this disclosure are combined with grain boundary enrichment (such as enrichment in Co, Al, or other enriching elements as described herein), cycle life and power capability are improved to address the shortcomings of existing Mn-rich materials. Without being bound by any particular theory, but to be understood, the synergistic relationship between grain boundary enrichment and tailored amounts of Mn is the reason for the unique benefits of materials as presented herein.

[0025] Therefore, this disclosure provides improved electrochemically active materials, such as those suitable for cathodes of Li-ion secondary batteries, which improve cycle life and / or rate capacity compared to existing Mn-rich materials. Various methods for obtaining such cathode active materials and electrochemical cells using such materials in electrodes are also provided.

[0026] As used in this article, “active material” is a material that participates in or is able to participate in the electrochemical charging / discharging reaction of an electrochemical battery, such as by absorbing or desorbing lithium.

[0027] As used in this article, “absorption” can refer to the intercalation, insertion, or alloying reaction of lithium with active materials.

[0028] As used in this article, "desorption" can refer to the de-intercalation, de-insertion, or conversion dealloying reaction of lithium with active materials.

[0029] As used in this article, in the context of lithium-ion batteries, cathode refers to the positive electrode and anode refers to the negative electrode.

[0030] like Figure 1 The diagram discloses a particle comprising microcrystals 10 containing a first composition and grain boundaries 20, 21 containing a second composition, wherein the concentration of one or more enriched elements (optionally Co or Al or both) in the grain boundaries is greater than the concentration of the enriched element in the microcrystals. The particle comprises multiple microcrystals and is referred to as a secondary particle. Optionally, a layer 30 may be disposed on the outer surface of the secondary particles to provide a coated secondary particle.

[0031] The polycrystalline lithium metal oxides presented herein exhibit enhanced electrochemical performance and rate capacity. This composition prevents rapid capacity decay of previously electrochemically cycled Mn-rich materials and exhibits further improved cycle life relative to LFP cathodes, while maintaining other desirable end-use product properties. Such grain-bound enriched high-Mn content materials can be readily manufactured as follows: by calcining a green formulation comprising LiOH and Mn- and Ni-containing hydroxide or carbonate precursors to form particles with well-defined grain boundaries, followed by enriching the grain boundaries with one or more enriching elements, such as Co or a combination of Co and Al (as an illustrative example), so that the resulting particles have more enriching elements at the grain boundaries than before enrichment, and optionally more enriching elements within the microcrystals (whose outer surface is adjacent to the edges of the grain boundaries in secondary particles).

[0032] Therefore, compositions, systems, and methods for manufacturing and using polycrystalline lithiated high-Mn metal oxides with enriched grain boundaries are provided as a means to achieve high initial discharge capacity and low capacity decay during cycling of electrochemical cells using metal oxides as the active component of the cathode, thereby overcoming previous challenges in high-Mn formulations.

[0033] The materials described herein include particles comprising multiple microcrystals, each microcrystal containing a first composition. Particles formed from multiple microcrystals may be referred to as secondary particles. Particles as described herein are uniquely tailored to have grain boundaries between primary microcrystals. After grain boundary formation, selective enrichment of these grain boundaries, for example using Co or Al, produces particles that provide improved performance and cycle life for batteries containing this particle as a cathode component.

[0034] The particles are considered to include grain boundaries formed by or comprising the second composition, wherein, as measured by the atomic percentage of the enriched element relative to the metal in each composition, the concentration of the enriched element, for example, in at least a portion of the grain boundary, is greater than the concentration of the enriched element, for example, in the adjacent primary crystallites. On average, the concentration of the enriched element in the grain boundary containing such an enriched element is optionally greater than the concentration of the enriched element in the adjacent crystallites. The enriched elements in the crystallites of the materials provided herein are optionally relatively homogeneous. Regardless of homogeneity, the concentration of the enriched element in the grain boundary is greater than the average concentration of the enriched element (alone or in combination) in the crystallites adjacent to the grain boundary region. Optionally, the provided first composition includes an additional outer coating that can be disposed on the outer surface of the secondary particles to provide coated secondary particles.

[0035] In some aspects of the particles presented herein, the first composition forming microcrystals (optionally referred to herein as bulk) comprises Li 1+a MO 2+b(Formula I) defines a polycrystalline layered lithium metal oxide structure, and optionally a cell or cell pack formed therefrom, wherein -0.1 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3. In some aspects, a is -0.1, optionally 0, optionally 0.1, optionally 0.2. Optionally, a is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2, or 1.3. In some respects, b is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, optionally 0.3. Optionally, b is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2 or 1.3.

[0036] It should be recognized that, in some respects, the Li in Formula I need not be entirely Li, but may be partially substituted by one or more elements selected from Mg, Sr, Na, K, and Ca. The one or more elements substituting Li may optionally be present in 10 atomic percent or less, optionally 5 atomic percent or less, optionally 3 atomic percent or less, optionally no more than 2 atomic percent, wherein the percentage is relative to the total Li in an otherwise equivalent unsubstituted material.

[0037] In the first composition of Formula I, M comprises a customized concentration of Mn. Mn is optionally present at about 30 atomic% to about 70 atomic% relative to total M, or any value or range therebetween. No benefit of grain boundary enrichment has been observed at Mn concentrations below about 30 atomic%, more directly below about 35 atomic%, or above about 70 atomic%, optionally above about 65 atomic%. Therefore, when Mn is present at about 30 atomic% to about 70 atomic%, and more significantly at about 35 atomic% to about 65 atomic%, combined with grain boundary enrichment of one or more enriching elements (optionally Co or Al) as also provided herein, a significant improvement in cycle life and / or rate performance is achieved relative to non-grain boundary enriched materials. Thus, the materials of Formula I, as provided herein as a first composition or as a second composition further comprising enrichment of one or more enriching elements, optionally comprise 30 atomic% to 70 atomic% of total M in Formula I, optionally 35 atomic% to 65 atomic% of Mn. Optionally, Mn exists in M ​​with an atomic percentage equal to or greater than about 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, or 64 and an atomic percentage equal to or less than about 70, 69, 68, 67, 66, or 65. Optionally, Mn exists in M ​​at approximately equal to or between 45 atomic% and 65 atomic%, 45 atomic% and 64 atomic%, optionally 45 atomic% and 63 atomic%, optionally 45 atomic% and 62 atomic%, optionally 45 atomic% and 61 atomic%, optionally 45 atomic% and 60 atomic%, optionally 40 atomic% and 70 atomic%, 40 atomic% and 65 atomic%, optionally 40 atomic% and 64 atomic%, optionally 40 atomic% and 63 atomic%, optionally 40 atomic% and 62 atomic%, optionally 40 atomic% and 61 atomic%, optionally 40 atomic% and 60 atomic%, optionally 35 atomic% and 65 atomic%, optionally 35 atomic% and 64 atomic%, optionally 35 atomic% and 63 atomic%, optionally 35 atomic% and 62 atomic%, optionally 35 atomic% and 61 atomic%, optionally 35 atomic% and 60 atomic%.

[0038] M in Formula 1 provided in the first composition optionally includes Ni. The amount of Ni in the first composition is optionally from 25 atomic% to 70 atomic% (at%) of the total M. Optionally, the Ni component is equal to or less than 65 atomic%. Optionally, the Ni component is less than or equal to 60 atomic%. Optionally, the Ni component is less than or equal to 40 atomic%. Optionally, the Ni component is less than or equal to 35 atomic%. Optionally, the Ni component of M is less than or equal to 70, 65, 60, 55, 50, 45, 40, 35, 30, or 25 atomic%. In some aspects, Ni is absent.

[0039] The sum of the atomic percentages of Ni and Mn in the first composition, the second composition, or both is optionally equal to or greater than 70 atomic%. Optionally, the sum of the atomic percentages of Ni and Mn in the first composition, the second composition, or both is optionally equal to or greater than about 75 atomic%, optionally 76 atomic%, optionally 77 atomic%, optionally 78 atomic%, optionally 79 atomic%, optionally 80 atomic%, optionally 81 atomic%, optionally 82 atomic%, optionally 83 atomic%, optionally 84 atomic%, optionally 85 atomic%, optionally 86 atomic%, optionally 87 atomic%, optionally 88 atomic%, optionally 89 atomic%, optionally 90 atomic%, optionally 91 atomic%, optionally 92 atomic%, optionally 93 atomic%, optionally 94 atomic%, optionally 95 atomic%, optionally 96 atomic%, optionally 97 atomic%, optionally 99 atomic%, optionally 100 atomic% in the first composition.

[0040] In some aspects, M in the first composition is Mn + Ni or Mn + Ni or Co or both, optionally combined with one or more additional elements, or Mn optionally combined with one or more additional elements. The additional elements are optionally metals. Optionally, the additional elements may include one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In some aspects, the additional elements may include Mg, Co, Al, or combinations thereof. Optionally, the additional elements may be Mg, Al, V, Ti, B, or combinations thereof. Optionally, the additional elements are selected from Mg, Al, V, Ti, or B. Optionally, the additional elements are selected from Co and Al. Optionally, the additional elements are selected from Ca, Co, and Al. Optionally, the additional element is Co.

[0041] The additional element in the first composition may be present in an amount of about 1 atomic% to about 55 atomic% of M in the first composition, specifically about 5 atomic% to about 55 atomic%, more specifically about 10 atomic% to about 55 atomic%. Optionally, the additional element may be present in an amount of about 1 atomic% to about 20 atomic% of M in the first composition, specifically about 2 atomic% to about 18 atomic%, more specifically about 4 atomic% to about 16 atomic%. In some exemplary instances, M is about 25-70 atomic% Ni, about 0-15 atomic% Co, about 30-70 atomic% Mn, and about 0-10 atomic% of the additional element. In an example, M is about 25-70 atomic% Ni, 0-15 atomic% Co, 30-70 atomic% Mn, and 0-10 atomic% of the additional element, wherein the sum of Ni and Mn is equal to or greater than 75 atoms. In some exemplary instances, M is approximately 30-50 atomic% Ni, 0.01-10 atomic% Co, 30-70 atomic% Mn, and 0-10 atomic% additional elements. Optionally, M comprises approximately 30 to approximately 70 atomic% Mn and approximately 25 to approximately 50 atomic% Ni (wherein the sum of Mn and Ni is at least 80 atoms), approximately 0 to approximately 15 atomic% Co, and approximately 0 to approximately 5 atomic% Mg. Optionally, M comprises approximately 30 to approximately 70 atomic% Mn, approximately 25 to approximately 50 atomic% Ni, approximately 0 to approximately 15 atomic% Co, and approximately 0 to approximately 5 atomic% Mg. It should be understood that the total atomic percentage of M is equal to 100.

[0042] In some respects, the first composition portion that partially or wholly forms microcrystals optionally has a layered α-NaFeO2 type structure, a cubic structure, a spinel structure, or a combination thereof.

[0043] In certain respects, the secondary particles have enriched grain boundaries, wherein optionally one or more enriched elements have a higher atomic percentage at the grain boundary than the same element in the crystallite, optionally averaged throughout the crystallite, optionally averaged in adjacent crystallites. Reference Figure 1 As an exemplary illustration, grain boundaries 20, 21 are between adjacent crystallites 10 and include a second composition. The second composition may be as described in U.S. Patent Nos. 9,391,317 and 9,209,455, except that any enriching element as described herein may be enriched independently in the grain boundaries relative to the concentration of that enriching element in the crystallites, and must be combined with a customized amount of Mn as provided herein.

[0044] In some aspects, the second composition that partially or entirely forms the grain boundaries optionally has a layered α-NaFeO2 type structure, a cubic structure, a spinel structure, or a combination thereof. As mentioned above, the concentration of one or more enriching elements in the grain boundaries may be greater than the concentration of the one or more enriching elements in the crystallites. Specifically, one aspect in which the grain boundaries have a layered α-NaFeO2 type structure is mentioned. Another aspect in which the grain boundaries have a defective α-NaFeO2 type structure is mentioned. Yet another aspect in which a portion of the grain boundaries has a cubic or spinel structure is mentioned.

[0045] More specifically, the Mn-rich LiMO materials provided herein optionally conform to the structure of LiMO2 having the R-3M space group. In some aspects, microcrystals, grain boundaries, or both include phase mixtures that also contain a Li2MnO3 monoclinic structure. Therefore, in some aspects, the materials provided herein are optionally heterogeneous mixtures of phase structures. In some aspects, the materials provided herein include...

[0046] Grain boundaries are predominantly LiMO2 structures with the R-3M space group, optionally entirely composed of LiMO2 structures with the R-3M space group. In some aspects, the materials provided herein comprise multiple microcrystals predominantly composed of LiMO2 structures with the R-3M space group, optionally multiple microcrystals entirely composed of LiMO2 structures with the R-3M space group. In some aspects, grain boundaries, microcrystals, or both comprise mixtures of LiMO2 and Li2MO3 structures. Optionally, the Li2MO3 structure is a layered-layered Li2MO3-LiMO2 structure.

[0047] The second composition, which may be partially or wholly present at the grain boundaries, optionally includes components consisting of Li. 1+a M'O 2+bThe lithium metal oxide defined by Formula II, wherein -0.1 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3. Optionally, the second composition is the same as the first composition, except that, relative to the first composition, one or more enriching elements, optionally Co, Al, or both Co and Al, are present or in increased concentration in the second composition. In some aspects of the second composition, a is -0.1, optionally 0, optionally 0.1, optionally 0.2, optionally 0.3, optionally 0.4, optionally 0.5, optionally 0.6, optionally 0.7, optionally 0.8, optionally 0.9, optionally 1.0, optionally 1.1, optionally 1.2, or optionally 1.3. Optionally, a is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2, or 1.3. In some respects, b is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, optionally 0.3, optionally 0.4, optionally 0.5, optionally 0.6, optionally 0.7, optionally 0.8, optionally 0.9, optionally 1.0, optionally 1.1, optionally 1.2, or optionally 1.3.Optionally, b is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2 or 1.3.

[0048] In Formula II, similar to Formula I, M' optionally includes a customized concentration of Mn. Mn optionally exists at 10 atomic% to 70 atomic% relative to total M', or any value or range therebetween. Materials of Formula II as provided herein optionally include 10 atomic% to 70 atomic% of total M' in Formula II, optionally 30 atomic% to 70 atomic% of Mn, and optionally 35 atomic% to 65 atomic% of Mn. Optionally, Mn exists in M' with an atomic percentage equal to or greater than 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, or 64 and an atomic percentage equal to or less than approximately 70, 69, 68, 67, 66, or 65. Optionally, Mn is present in M' at approximately equal to or between 45 atomic% and 65 atomic%, 45 atomic% and 64 atomic%, optionally 45 atomic% and 63 atomic%, optionally 45 atomic% and 62 atomic%, optionally 45 atomic% and 61 atomic%, optionally 45 atomic% and 60 atomic%, optionally 40 atomic% and 70 atomic%, 40 atomic% and 65 atomic%, optionally 40 atomic% and 64 atomic%, optionally 40 atomic% and 63 atomic%, optionally 40 atomic% and 62 atomic%, optionally 40 atomic% and 61 atomic%, optionally 40 atomic% and 60 atomic%, optionally 35 atomic% and 65 atomic%, optionally 35 atomic% and 64 atomic%, optionally 35 atomic% and 63 atomic%, optionally 35 atomic% and 62 atomic%, optionally 35 atomic% and 61 atomic%, optionally 35 atomic% and 60 atomic%. In some respects, Mn is not present in the second composition.

[0049] In Formula II, M' optionally includes Ni. Ni is optionally present in amounts from 10 atomic% to 70 atomic% relative to total M', or any value or range therebetween. Materials of Formula II as provided herein optionally include 10 atomic% to 70 atomic% of total M' in Formula II, optionally 25 atomic% to 70 atomic% of Ni. Optionally, Ni exists in M' with an atomic percentage equal to or greater than 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70. Optionally, Ni is present in M' at an atomic percentage of 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70. Optionally, Ni is not present in the second composition.

[0050] Examples of enriched elements that may be included in M' of Formula II to form secondary particles enriched at grain boundaries include various elements that can substitute for Ni in the structure. For example, elements that can directly substitute for Ni... 3+ The trivalent (3+) ions of the dopants are less readily oxidized than Ni ions during charging, and they will promote the beneficial cycling properties observed in materials as described herein; Ni(III) replaced by Al(III) is one example. If tetravalent (4+) ions replace Ni... 3+ They compensate for the charge through Ni ions in the 2+ state, and their inductive effect increases the potential used to oxidize these Ni ions to the 4+ state; Ni(III) replaced by Mn(IV) is one example. Alternatively, if Ni is replaced by Ni ions in the 2+ state, they compensate for the charge through Ni ions in the 4+ state; Ni(III) replaced by Mg(II) is one example. To replace Ni in the LiM'O2 structure, dopant ions can have a size comparable to Ni ions, and they can increase the local oxidation potential. The relative effect of a given ion on the oxidation potential can generally be determined by its relative to Ni. 3+ The ionization energy is used to estimate. Therefore, the size and Ni 3+Ions with comparable or higher ionization energies may contribute to stabilizing grain boundaries in oxide cathodes. The table below provides examples of ionization energies and six-coordinate (octahedral) ion radii for grain boundaries in high-NiLiMO2 cathode materials that may stabilize charging.

[0051] Table 1: Oxidation potential and ionic radius of elements

[0052]

[0053] Ionization energy

[0054] Therefore, in the second composition, M' further comprises one or more enriched elements selected from the group of elements that oxidize less than nickel when electrochemically charged to 4.3 V or higher relative to the Li metal anode. In one example, M' may comprise Ni and a Co-Mn combination that oxidizes less than nickel when charged to 4.3 V or higher, optionally 4.6 V. In other aspects, M' may comprise Ni, Mn, and one or more elements selected from Cr, Fe, Ti, V, Co, Cu, Zn, Zr, Nb, Sb, W, Sc, Al, Mo, Y, etc., which oxidize less than Ni when charged to 4.3 V relative to lithium metal. Optionally, M' does not include combinations of Ni with Co only, Al only, or a combination of Co and Al, and Co, Al, or both may be present with doping of one or more additional enriched elements as provided herein. In some aspects, M' may comprise elements that do not oxidize when charged to 4.3 V relative to lithium, such as Y, Sc, Ga, In, Tl, Si, Ge, Sn, Pb, etc.

[0055] M' provided in the second composition optionally includes one or more enriching elements, optionally Co, Al, or both, at a higher concentration than that of such elements in the microcrystals as described herein.

[0056] Optionally, the Li in the second composition (grain boundary) need not be entirely Li, but may be partially replaced by one or more Li-enriching elements selected from Mg, Sr, Na, K, and Ca. The one or more Li-enriching elements may optionally be present at 10 atomic percent or less, optionally 5 atomic percent or less, optionally 3 atomic percent or less, optionally no more than 2 atomic percent, where the percentage is relative to the total Li in the material prepared in its original state.

[0057] For any material as provided herein, the nominal or overall formulation of secondary particles (e.g., characterized by elemental mapping from SEM), optionally a first composition or optionally a second composition or both, is defined by the general formula LiMO, where M is Mn and Ni and optionally one or more additional elements, wherein the second composition must include one or more enriched elements. As an example, as determined by elemental mapping, the molar fraction of Co and / or Al (if present) defining the microcrystal composition is lower than the molar fraction of total Co and Al (alone or in combination) in the overall particle composition. The molar fraction of enriched elements (alone or in combination) in the microcrystals may be 0. As measured by elemental mapping, the molar fraction of enriched elements (alone or in combination) at grain boundaries is higher than the molar fraction of enriched elements (alone or in combination) in the overall particles. It should be noted that this is merely an example, as Co, Al, or both may alternatively or additionally be one or more other enriched elements as shown herein.

[0058] The second composition located within the grain boundaries comprises Co or Al or one or more other enriching elements, optionally wherein the concentration of Co or Al or one or more other enriching elements (alone or in combination) at the grain boundaries is greater than the concentration of Co or Al or one or more other enriching elements (alone or in combination) in the microcrystals, optionally wherein the CO concentration at the grain boundaries is greater than the Co concentration in the microcrystals, and optionally wherein the Al concentration at the grain boundaries is greater than the Al concentration in the microcrystals, or the concentration of one or more enriching elements is greater than the concentration of said one or more enriching elements in the microcrystals. As a non-limiting example, it has been found that using a method capable of enriching elements within grain boundaries, 0.01 atomic% to 10 atomic% of Al, optionally 1.5 atomic% or less of Al, can be added to a liquid solution comprising an amount of Co, relative to the total transition metals of the first composition to be enriched, between 0 atomic% and 8 atomic% and optionally between 3 atomic% and 5 atomic% Co, wherein the added Co and Al are incorporated into the grain boundaries of the secondary particles.

[0059] The volume fraction of grain boundaries within a given secondary particle will vary because the primary particle size distribution varies with the overall composition and synthesis conditions. Accordingly, the final concentration of the one or more enriched elements in the grain boundaries will also vary between different secondary particles and within a single secondary particle, while still always being greater than the concentration of the one or more enriched elements in adjacent crystallites or the total crystallites. Therefore, it is most useful to define the amount of enriched elements added to the grain boundaries relative to the formulation of the crystallites. In some aspects, the amount of the one or more enriched elements is similar to the amount of Co described in U.S. Patent No. 11,424,449 or U.S. Patent No. 10,501,335, but in this disclosure, the crystallites and optional grain boundaries further include Mn at or approximately at a customized concentration as otherwise described herein.

[0060] The electrochemically active materials provided herein may be in the form of secondary particles. The particle size of the secondary particles is defined as the size of the secondary particle measured from the outer edge to the opposite outer edge and substantially through the center of the secondary particle. The particle size or average particle size of the first composition (the overall average of all particles of the same composition) is optionally from about 1 µm to about 25 µm, or any value or range therebetween. Optionally, the first composition has a particle size or average particle size of about 1 µm, optionally about 2 µm, optionally 3 µm, optionally about 4 µm, optionally 5 µm, optionally about 6 µm, optionally 7 µm, optionally about 8 µm, optionally 9 µm, optionally about 10 µm, optionally 11 µm, optionally about 12 µm, optionally 13 µm, optionally about 14 µm, optionally 15 µm, optionally about 16 µm, optionally 17 µm, optionally about 18 µm, optionally 19 µm, optionally about 20 µm, optionally 21 µm, optionally about 22 µm, optionally 23 µm, optionally about 24 µm, optionally about 25 µm. Optionally, the particle size or average particle size of the first composition is from about 1 µm to about 15 µm, optionally from about 1 µm to about 10 µm.

[0061] Each crystallite can have any suitable shape, and can be the same or different within each secondary particle. Furthermore, the shapes of individual crystallites can be the same or different in different secondary particles. Due to their crystalline properties, crystallites can be faceted, have multiple planes, and their shapes can approximate geometric shapes. In some aspects, crystallites can be fused with adjacent crystallites having mismatched crystal planes. Crystallites can optionally be polyhedra. Crystallites can have a linear shape and, when viewed in cross-section, a portion or all of the crystallite can be linear. Crystallites can be square, hexagonal, rectangular, triangular, or combinations thereof. The length, width, and thickness of the crystallites can be chosen independently, and each of the length, width, and thickness can be from about 5 to about 1000 nanometers (nm), specifically from about 10 to about 900 nm, and more specifically from about 20 to about 800 nm.

[0062] The materials provided herein can be prepared by synthesizing a green body from at least two components (optionally in powder form). The at least two components may include micronized (or non-micronized) lithium hydroxide or its hydrate, and a precursor hydroxide comprising Mn and optionally one or more other elements, wherein the precursor hydroxide is optionally obtained by co-precipitation. By customizing the conditions for forming the metal hydroxide, electrochemically active materials as provided herein can then be produced.

[0063] In some aspects, the precursor hydroxide may be a mixed metal hydroxide. In some aspects, the mixed metal hydroxide may comprise a metal composition of Mn combined with Ni and optionally Co. Optionally, the mixed metal hydroxide comprises 30-70 atomic% Mn, 25-70 atomic% Ni, 0-15 atomic% Co, and 0-5 atomic% Mg as metal components. Optionally, the mixed metal hydroxide comprises 25-70 atomic% Ni, Co in the range of 0-30 atomic% and Mn in the range of 30-70 atomic%. Optionally, the mixed metal hydroxide comprises 25-70 atomic% Ni, Co in the range of 0-30 atomic%, Al in the range of 0-10 atomic% and Mn in the range of 30-70 atomic%. Optionally, the mixed metal hydroxide comprises 25-70 atomic% Ni, Co in the range of 0-30 atomic%, Al in the range of 0-10 atomic% and Mn in the range of 30-70 atomic%. Optionally, the mixed metal hydroxide comprises 35-65 atomic% Ni, 0-30 atomic% Co, 0-10 atomic% Al, and 35-65 atomic% Mn. Optionally, the metals in the mixed metal hydroxide are approximately 40 atomic% Ni, approximately 56 atomic% Mn, and approximately 4 atomic% Co. Optionally, the metals in the mixed metal hydroxide are approximately 61 atomic% Ni, approximately 35 atomic% Mn, and approximately 4 atomic% Co. Optionally, the metals in the mixed metal hydroxide are approximately 26 atomic% Ni, approximately 70 atomic% Mn, and approximately 4 atomic% Co. Optionally, the metals in the mixed metal hydroxide are approximately 31 atomic% Ni, approximately 65 atomic% Mn, and approximately 4 atomic% Co. Optionally, the metals in the mixed metal hydroxide are approximately 36 atomic% Ni, approximately 60 atomic% Mn, and approximately 4 atomic% Co. For example, precursor hydroxides can be manufactured by precursor suppliers, such as Hunan Brunp Recycling Technology Co. Ltd., using standard methods for preparing nickel hydroxide-based materials.

[0064] Secondary particles can be formed through a multi-step process, thereby forming and calcining primary material particles to establish well-defined grain boundaries, optionally using particles with few or no observable defects. Primary particles with a NaFeO2 structure are then subjected to a liquid process that applies one or more enriching elements, optionally Co, at desired concentration levels, followed by drying and then heat treatment to selectively move enriched element precipitates at the surface into the grain boundaries, thereby forming secondary particles in the grain boundaries, optionally with higher concentrations of Co and / or Al than in the microcrystals. According to a method for producing Ni, Co, and Mn-based secondary particles with high Mn content, as provided as an example herein, formation may include: combining a lithium compound and one or more metal or metalloid hydroxide precursor compounds (e.g., previously generated combined Ni, Co, and Mn, such as by a co-precipitation reaction) to form a mixture; heat-treating the mixture at about 30 to about 200 °C to form a dried mixture; heat-treating the dried mixture at about 200 to about 500 °C for about 0.1 to about 5 hours; and then heat-treating at 600 °C to less than about 1000 °C for about 0.1 to about 10 hours to produce secondary particles. The maximum calcination temperature is relative and specific to the material used in the hydroxide precursor. Optionally, in a single calcination, the maximum temperature may be equal to or less than 950°C, optionally equal to or less than 900°C, optionally equal to or less than 850°C, optionally equal to or less than 800°C, optionally equal to or less than 750°C, optionally equal to or less than 720°C, optionally equal to or less than 715°C, optionally equal to or less than 710°C, optionally equal to or less than 705°C, optionally equal to or less than 700°C. Optionally, the maximum temperature in a single calcination may be approximately 1000°C or lower. Optionally, the maximum temperature may be approximately 950°C or lower. Optionally, the maximum temperature may be approximately 900°C or lower. Optionally, the maximum temperature may be approximately 850°C or lower. Optionally, the maximum temperature may be approximately 800°C or lower. Optionally, the maximum temperature may be approximately 750°C or lower. Optionally, the maximum temperature may be approximately 700°C or lower. Optionally, the maximum temperature may be approximately 660°C or lower. Optionally, the maximum temperature may be approximately 640°C or lower. In other respects, the maximum temperature may be less than approximately 700°C, approximately 695°C, approximately 690°C, approximately 685°C, approximately 680°C, approximately 675°C, approximately 670°C, approximately 665°C, approximately 660°C, approximately 655°C, approximately 650°C, approximately 645°C, or approximately 640°C. The residence time at the maximum temperature may optionally be less than 10 hours. Optionally, the residence time at the maximum temperature may be less than or equal to 8 hours; optionally less than or equal to 7 hours; optionally less than or equal to 6 hours; optionally less than or equal to 5 hours; optionally less than or equal to 4 hours; optionally less than or equal to 3 hours; optionally less than or equal to 2 hours.

[0065] Following calcination, subsequent processing may include pulverizing the calcined material with a mortar and pestle to pass the resulting powder through a desired sieve, optionally a #35 sieve. The powder may then optionally be cannulated in a 1-gallon jar containing 2 cm drum YSZ media for an optional 5 minutes or sufficient time to allow the material to optionally pass through a #270 sieve.

[0066] The product from a single calcination or grinding process can then optionally be processed by a method to produce enriched grain boundaries after a second calcination. The method for enriching grain boundaries within primary particles can be carried out using methods or compositions as shown in U.S. Patent Nos. 9,391,317 and 9,209,455, except that the application process uses a liquid solution comprising a certain amount of enriching element, optionally Co and / or a certain amount of Al. The grain boundary enriching element can optionally be applied by suspending the ground product in an aqueous slurry containing one or more of the enriching elements and a lithium compound at a temperature of approximately 60°C, thereby enriching the element, optionally Co and / or Al, in an aqueous solution at the concentrations described herein. This slurry can then be spray-dried to form a free-flowing powder, which is then subjected to a second calcination, optionally with a heating profile following a two-step ramp / dwell process. The first ramp / dwell temperature profile in the two steps can be from ambient temperature (approximately 25°C) to 450°C and optionally at a rate of 5°C / min, with a dwell time of 1 hour at 450°C. Subsequently, the second ascent / dwelling can be from 450°C to the maximum temperature at a rate of 2°C / minute, and a stay at the maximum temperature for 2 hours. In some respects, the maximum temperature is less than about 725°C, optionally about 700°C. In other respects, the maximum temperature is about 700°C, optionally 750°C.

[0067] By combining a primary calcination at the highest temperature described above with a process of applying grain boundary enrichment elements, followed by a secondary calcination also described above, it was found that the resulting particles with a customized Mn concentration could be used in cathodes to produce significantly improved capacity decay reduction and / or rate performance increase. Such a combination was found to yield additional cycle life to significantly improve the electrochemical performance of the material, while substantially reducing cost relative to existing high-Ni and Co materials. Therefore, it should be recognized that, in some aspects, the particles comprise multiple microcrystals having a composition consisting of Li... 1+a MO 2+bA first composition of a defined polycrystalline layered lithium metal oxide, wherein -0.1 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3. In some aspects, a is -0.1, optionally 0, optionally 0.1, optionally 0.2, optionally 0.3, optionally 0.4, optionally 0.5, optionally 0.6, optionally 0.7, optionally 0.8, optionally 0.9, optionally 1.0, optionally 1.1, optionally 1.2, or optionally 1.3. Optionally, a is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2, or 1.3. In some respects, b is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, optionally 0.3, optionally 0.4, optionally 0.5, optionally 0.6, optionally 0.7, optionally 0.8, optionally 0.9, optionally 1.0, optionally 1.1, optionally 1.2, or optionally 1.3. Optionally, b is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2, or 1.3. The microcrystals have a certain concentration of Mn. Mn is optionally present at 30 atomic% to 70 atomic% relative to total M, or any value or range therebetween.No benefit of grain boundary enrichment was observed at Mn concentrations below 30 atomic%, more directly below 35 atomic%, or above 70 atomic%, optionally above 65 atomic%. The first composition optionally comprises 30 to 70 atomic% of total Mn, optionally 35 to 65 atomic% of Mn. Optionally, Mn is present in M ​​at atomic% or greater than 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, or 64 atomic% and at atomic% or less than 70, 69, 68, 67, 66, or 65 atomic%. Optionally, Mn exists in M ​​in an amount equal to or between 45 atomic% and 65 atomic%, optionally 40 atomic% and 70 atomic%, optionally 35 atomic% and 70 atomic%, optionally 35 atomic% and 65 atomic%, optionally 35 atomic% and 61 atomic%, optionally 35 atomic% and 60 atomic%. The microcrystals have Ni in an amount of 25 atomic% to 70 atomic% (at%) of the M element. The amount of Ni in the first composition is optionally 25 atomic% to 69 atomic% (at%) of the total M. Optionally, the Ni component is equal to or less than 65 atomic%. Optionally, the Ni component is less than or equal to 60 atomic%. Optionally, the Ni component is less than or equal to 40 atomic%. Optionally, the Ni component is less than or equal to 35 atomic%. Optionally, the Ni component of M is less than or equal to 70, 65, 60, 55, 50, 45, 40, 35, 30, or 25 atomic%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, the additional element may include one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In a particular aspect, the additional element may include Mg, Co, Al, or combinations thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or combinations thereof. Optionally, the additional element consists of Mg, Al, V, Ti, and B. The additional element of the first composition may be present in an amount of about 1 to about 90 atomic percent of the first composition, specifically about 5 to about 80 atomic percent, more specifically about 10 to about 70 atomic percent. Optionally, the additional element of the first composition may be present in an amount of about 0 to about 70 atomic percent of M in the first composition, specifically about 5 to about 70 atomic percent, more specifically about 10 to about 70 atomic percent. Optionally, the additional element may be present in an amount of about 1 to about 20 atomic percent of M in the first composition, specifically about 2 to about 18 atomic percent, more specifically about 4 to about 16 atomic percent.In such materials, grain boundaries may be enriched with one or more enriched elements, optionally Co, Al or both, optionally at a concentration 0.1 to 10 atoms higher than that of the one or more enriched elements in the microcrystals.

[0068] The electrochemical batteries provided herein may optionally use the particles provided herein as electrochemical active materials, which may optionally have an initial discharge capacity of 110 mAh / g particles or greater, optionally 120 mAh / g, optionally 130 mAh / g, optionally 140 mAh / g, optionally 150 mAh / g, optionally 160 mAh / g, optionally 170 mAh / g, optionally 180 mAh / g, optionally 190 mAh / g, optionally 200 mAh / g, optionally 210 mAh / g, optionally 220 mAh / g, optionally 230 mAh / g, optionally 240 mAh / g, or optionally 250 mAh / g.

[0069] like Figure 1 The diagram discloses a particle comprising microcrystals 10 containing a first composition and grain boundaries 20, 21 containing a second composition, wherein the concentration of one or more enriched elements (optionally Co or Al or a combination thereof) in the grain boundaries is greater than the concentration of said one or more enriched elements in the microcrystals. The particle comprises multiple microcrystals and is referred to as a secondary particle. Optionally, deposition can be performed on the outer surface of the particle. Figure 1 The outer layer, indicated by 30, may be a passivation layer or a protective layer. The outer layer may completely or partially cover the secondary particles. This layer may be amorphous or crystalline. The layer may contain oxides, phosphates, pyrophosphates, fluorophosphates, carbonates, fluorides, fluoride oxides, or combinations thereof of elements such as Al, Ti, B, Li, or Si, or combinations thereof. In some aspects, the outer layer comprises borates, aluminates, silicates, fluoroaluminates, or combinations thereof. Optionally, the outer layer comprises carbonates. Optionally, the outer layer comprises ZrO2, Al2O3, TiO2, AlPO4, AlF3, B2O3, SiO2, Li2O, Li2CO3, or combinations thereof. Optionally, the outer layer comprises either AlPO4 or Li2CO3. This layer can be deposited by any method or technique that does not adversely affect the desired properties of the particles. Representative methods include, for example, spraying and dip coating.

[0070] Electrodes are also provided that include secondary particles as described herein as a component or sole electrochemical active material. Optional active components as cathodes include secondary particles as described herein. Cathodes may optionally include secondary particles as disclosed above as active materials and may further include conductive agents and / or binders. Conductive agents may include any conductive agent that provides suitable properties and may be amorphous, crystalline, or a combination thereof. Conductive agents may include carbon black, such as acetylene black or lampblack, mesocarbon, graphite, graphene, carbon fibers, carbon nanotubes such as single-walled carbon nanotubes or multi-walled carbon nanotubes, or combinations thereof. The adhesive can be any adhesive that provides suitable properties and may include, for example, polyvinylidene fluoride, copolymers of polyvinylidene fluoride and hexafluoropropylene, poly(vinyl acetate), poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate), poly(methyl methacrylate-co-ethyl acrylate), polyacrylonitrile, polyvinyl chloride-co-vinyl acetate, polyvinyl alcohol, poly(l-vinylpyrrolidone-co-vinyl acetate), cellulose acetate, polyvinylpyrrolidone, polyacrylate, polymethyl methacrylate, polyolefin, polyurethane, polyvinyl ether, acrylonitrile-butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene-styrene, triblock polymers of sulfonated styrene / ethylene-butene / styrene, polyethylene oxide, or combinations thereof.

[0071] A cathode can be manufactured by combining particles, conductive agents (if present), and binders as described herein in suitable ratios, for example, approximately 80 to approximately 98% by weight of active particles, approximately 1 to approximately 20% by weight of conductive agents, and approximately 1 to approximately 10% by weight of binders based on the total weight of the particles, conductive agents, and binders. The particles, conductive agents, and binders can be suspended in a suitable solvent, such as N-methylpyrrolidone, placed on a suitable substrate (such as aluminum foil), and dried in air. It should be noted that the substrate and solvent are given by way of example only. Other suitable substrates and solvents can be used or combined to form the cathode.

[0072] The cathode described herein, when cycled in a 2025 coin cell with an MCMB 10-28 graphite anode, a polyolefin separator, and a 1 M LiPF6 electrolyte in a 1 / 1 / 1 (volume ratio) EC / DMC / EMC containing 1 wt% VC, optionally exhibits significantly reduced capacity decay compared to similar Mn-rich materials without grain boundary enrichment. Capacity measurements plotted against cycle number yield curves with defined slopes. When active particle materials with high Mn content (e.g., 30-70 atomic % Mn) as described herein have grain boundaries enriched with one or more enriched elements, optionally Co and / or Al, as described herein, the capacity slope is lower compared to particles without such grain boundary enrichment. In some respects, the capacity decay of the cell is equal to or less than 10% in the first 200 cycles, and optionally 5% or less after the first 100 cycles.

[0073] Electrochemical cells are also provided, which use electrochemically active cathode materials as described herein as the active material in the cathode and are paired with a suitable anode. The electrochemical cells provided herein optionally use electrochemically active material particles as described herein in the cathode, which optionally have an initial discharge capacity equal to or greater than about 110 mAh / g, optionally about 120 mAh / g, optionally about 130 mAh / g, optionally about 140 mAh / g, optionally about 150 mAh / g, optionally about 160 mAh / g, optionally about 170 mAh / g, optionally about 180 mAh / g, optionally about 190 mAh / g, optionally about 200 mAh / g, optionally about 210 mAh / g, optionally about 220 mAh / g, optionally about 230 mAh / g, optionally about 240 mAh / g, optionally about 250 mAh / g, and optionally exhibit a capacity decay of equal to or less than 10% in the first 200 cycles, and optionally 5% or less after the first 100 cycles. In some respects, the battery capacity degradation is equal to or less than 15% in the first 400 cycles, and optionally 5% or less after the first 200 cycles. Alternatively, the battery capacity degradation is equal to or less than 10% after the first 200 cycles, and optionally less than 9%, optionally less than 8%, optionally less than 7%, optionally less than 6%, optionally less than 5%, optionally less than 4%, optionally less than 3%, or optionally less than 2%. Alternatively, the battery capacity degradation is equal to or less than 15% after the first 300 cycles, and optionally less than 14%, optionally less than 13%, optionally less than 12%, optionally less than 11%, optionally less than 10%, optionally less than 9%, optionally less than 8%, optionally less than 7%, optionally less than 6%, optionally less than 5%, optionally less than 4%, or optionally less than 3%. Optionally, the battery capacity decay is equal to or less than 20% after the first 400 cycles, and optionally less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, less than 11%, less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, or less than 3%.

[0074] The electrochemical cell can be, for example, a lithium-ion battery, a lithium polymer battery, or a lithium battery. The cell may include a cathode, an anode, and a separator between the cathode and the anode. A battery pack may include one cell or two or more cells.

[0075] The diaphragm can be a microporous membrane and may include porous membranes comprising polypropylene, polyethylene, or combinations thereof, or may be woven or nonwoven materials such as glass fiber mat. Certain other diaphragms as known in the art may also be used.

[0076] The anode may include a coating on the current collector. This coating may include suitable carbon, such as graphite, coke, hard carbon, or mesophase carbon, for example, mesophase carbon microspheres. The current collector may be, for example, copper foil.

[0077] In other respects, the anolyte material can be titanium oxide, optionally including nanowires, as described by Armstrong et al. Journal of Power Sources TiO2-B nanowires described in reference 146, no. 1-2 (2005): 501-506. An exemplary example of a titanium oxide is lithium titanium oxide (LTO). Lithium titanium oxide may have a spinel-type structure. The anode may optionally include Li... 4+a Ti5O 12+b (IV) Anodic electrochemically active materials, of which -0.3 ≤ a ≤ 3.3, -0.3 ≤ b ≤ 0.3. In some respects, lithium titanium oxide can be of formula III.

[0078] Li 4+y Ti5O 12 (III)

[0079] Among them 0 < y < 3, 0.1 < y < 2.8 or 0 < y < 2.6.

[0080] Alternatively, lithium titanium oxide can be of formula IV.

[0081] Li 3+z Ti 6-z O 12 (IV)

[0082] In equation IV, 0 < z < 1. Optional, 0 < z < 1, 0.1 < z < 0.8 or 0 < z < 0.5. A combination of anodic electrochemically active materials comprising at least one of the above-mentioned lithium titanium oxides may be used. In some aspects, the anodic electrochemically active material comprises or includes Li4Ti5O.12 .

[0083] The anode or cathode current collector can be formed from materials such as Ti, Al, and Cu. The current collector can be in the form of a foil, perforated foil, wire mesh, or other suitable configuration. The current collector used for the cathode can be in electrical contact with the cathode active material as provided herein. The current collector used for the anode can be in electrical contact with the anode active material provided herein.

[0084] Electrochemical cells also include an electrolyte that can contact the positive electrode (cathode), negative electrode (anode), and membrane. The electrolyte may include organic solvents and lithium salts. Organic solvents can be linear or cyclic carbonates. Representative organic solvents include ethylene carbonate (EC), propylene carbonate, butyl carbonate, and propylene trifluorocarbonate. Butyrolactone, sulfolane, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 3-methyl-1,3-dioxolane, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate (DMC), diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate, methyl propyl carbonate, propanesulfonate lactone, or combinations thereof. In another respect, the electrolyte is a polymeric electrolyte.

[0085] Optionally, the electrolyte does not include ethylene carbonate. Optionally, the electrolyte includes DMC and one or more other additives or co-solvents, and does not include EC. Optionally, the electrolyte includes DMC and two additives, optionally three additives, optionally four additives, optionally five additives. Optionally, the electrolyte includes DMC, LiPF6 and two additional additives, optionally three additional additives, optionally four additional additives, optionally five additional additives.

[0086] Furthermore, the selected additives in the electrolytes used in the battery packs provided herein have lower toxicity than organosulfate and sulfonyl lactone type additives. Exemplary examples of such additives include, but are not limited to, fluoroethylene carbonate (FEC), difluoroethylene carbonate (F2EC), tri(trimethylsilyl) malonate (TMSM), tri(trimethylsilyl) phosphite (TMSPi), tri(trimethylsilyl) phosphate (TMSPO4), lithium bis(oxalate)borate (LiDFOB), and the cosolvent 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TFETFPE). In some aspects, the additives optionally include combinations of fluoroethylene carbonate, difluoroethylene carbonate, and lithium difluoro(oxalate)borate.

[0087] The additive is optionally present in the electrolyte at less than 5% by weight (wt%), depending on the additive. Optionally, the additive is present at less than or equal to 5% by weight, optionally 4.5% by weight, optionally 4% by weight, optionally 3.5% by weight, optionally 3% by weight, optionally 2.5% by weight, optionally 2% by weight, optionally 1.5% by weight, optionally 1% by weight, optionally 0.5% by weight, optionally 0.1% by weight.

[0088] In some respects, the additives in the electrolyte may be present in amounts of greater than 0.1% by weight, optionally 0.5% by weight, optionally greater than 1% by weight, optionally greater than 1.5% by weight, optionally greater than 2% by weight, optionally greater than 2.5% by weight, optionally greater than 3% by weight, optionally greater than 3.5% by weight, optionally greater than 4% by weight, optionally greater than 4.5% by weight, optionally greater than 5% by weight.

[0089] Optionally, the electrolyte includes DMC and FEC, wherein the FEC is present in amounts greater than 0.1 wt%, optionally 0.5 wt%, optionally greater than 1 wt%, optionally greater than 1.5 wt%, optionally greater than 2 wt%, optionally greater than 2.5 wt%, optionally greater than 3 wt%, optionally greater than 3.5 wt%, optionally greater than 4 wt%, optionally greater than 4.5 wt%, optionally greater than 5 wt%, and optionally greater than 6 wt%. In some aspects, the range of FEC is from 1.5 wt% to 6 wt%, optionally from 2 wt% to 5 wt%.

[0090] Optionally, the electrolyte comprises DMC and F2EC, wherein F2EC is present in amounts greater than 0.1 wt%, optionally 0.5 wt%, optionally greater than 1 wt%, optionally greater than 1.5 wt%, optionally greater than 2 wt%, optionally greater than 2.5 wt%, optionally greater than 3 wt%, optionally greater than 3.5 wt%, optionally greater than 4 wt%, optionally greater than 4.5 wt%, and optionally greater than 5 wt%. In some aspects, F2EC ranges from 1.5 wt% to 6 wt%, optionally from 2 wt% to 5 wt%.

[0091] In some aspects, the electrolyte comprises DMC and TMSPO4, wherein TMSPO4 is present in amounts less than 5% by weight (wt%). Optionally, TMSPO4 is present in amounts less than or equal to 5% by weight, optionally 4.5% by weight, optionally 4% by weight, optionally 3.5% by weight, optionally 3% by weight, optionally 2.5% by weight, optionally 2% by weight, optionally 1.5% by weight, optionally 1% by weight, optionally 0.5% by weight, optionally 0.1% by weight. In some aspects, TMSPO4 ranges from 0.1% by weight to 3% by weight, optionally from 0.5% by weight to 2% by weight.

[0092] In some aspects, the electrolyte includes DMC and TMSM, wherein TMSM is present in amounts less than 5% by weight (wt%). Optionally, TMSM is present in amounts less than or equal to 5% by weight, optionally 4.5% by weight, optionally 4% by weight, optionally 3.5% by weight, optionally 3% by weight, optionally 2.5% by weight, optionally 2% by weight, optionally 1.5% by weight, optionally 1% by weight, optionally 0.5% by weight, optionally 0.1% by weight. In some aspects, TMSM ranges from 0.1% by weight to 3% by weight, optionally from 0.5% by weight to 2% by weight.

[0093] In some aspects, the electrolyte includes DMC and TMSPi, wherein TMSPi is present in amounts less than 5% by weight (wt%). Optionally, TMSPi is present in amounts less than or equal to 5% by weight, optionally 4.5% by weight, optionally 4% by weight, optionally 3.5% by weight, optionally 3% by weight, optionally 2.5% by weight, optionally 2% by weight, optionally 1.5% by weight, optionally 1% by weight, optionally 0.5% by weight, optionally 0.1% by weight. In some aspects, TMSPi ranges from 0.1% by weight to 3% by weight, optionally from 0.5% by weight to 2% by weight.

[0094] In some aspects, the electrolyte comprises DMC and the co-solvent TFETFPE, wherein TFETFPE is present in amounts less than 20 wt%, depending on the additives. Optionally, TFETFPE is present in amounts less than or equal to 15 wt%, optionally 10 wt%. In some aspects, TFETFPE is present in amounts from 1 wt% to 20 wt%, or any value or range therebetween, optionally from 2 wt% to 10 wt%.

[0095] Representative lithium salts that can be used in electrolytes include, but are not limited to, LiPF6, LiBF4, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiN(SO2C2F5)2, LiSbF6, LiC(CF3SO2)3, LiC4F9SO3, and LiAlCl4. The lithium salt is optionally present in the electrolyte at a concentration equal to or greater than 0.1 mol (M), optionally 0.5 M, optionally 0.6 M, optionally 0.7 M, optionally 0.8 M, optionally 0.9 M, optionally 1 M, optionally 1.1 M, optionally 1.2 M, optionally 1.3 M, optionally 1.4 M, optionally 1.5 M, optionally 1.6 M, optionally 1.7 M, optionally 1.8 M, optionally 1.9 M, or optionally 2.0 M. The lithium salt is soluble in organic solvents. Combinations containing at least one of the above can be used. The concentration of lithium salt in the electrolyte can be from 0.1 to 2.0 M.

[0096] When present, the concentration of the lithium salt may optionally be equal to or greater than 1.0 M, or optionally equal to or greater than 1.3 M or 2.0 M. For certain additives, such as fluoroethylene carbonate and lithium difluoro(oxalate)borate, higher concentrations of lithium salts, such as 2 M lithium salts, relative to the presence of 1.3 M LiPF6 in the electrolyte, improve cycle life.

[0097] The electrolyte can be a solid ceramic electrolyte.

[0098] When a battery or battery pack including an electrolyte as provided herein is cycled at approximately 2.5 V to approximately 4.3 V, optionally approximately 2.5 V to approximately 4.65 V, optionally greater than approximately 4.3 V, the battery optionally has a capacity retention of approximately 60% or more of its initial capacity after 100 cycles. In some aspects, the capacity retention after 100 cycles is equal to or greater than or equal to 65%, optionally 66%, optionally 67%, optionally 68%, optionally 69%, optionally 70%, optionally 71%, optionally 72%, optionally 73%, optionally 74%, optionally 75%, optionally 76%, optionally 77%, optionally 78%, optionally 79%, optionally 80%, optionally 81%, optionally 82%, optionally 83%, optionally 84%, optionally 85%, optionally 86%, optionally 87%, optionally 88%, optionally 89%, optionally 90%. In any of the foregoing cases, the electrolyte optionally does not undergo a shuttle reaction.

[0099] In some aspects of any of the foregoing cases, the electrochemical cell comprising an anode, cathode, and electrolyte, as provided herein, has a formation voltage (FV) greater than approximately 4.3 V. In some aspects of any of the foregoing cases, the electrochemical cell comprising an anode, cathode, and electrolyte, as provided herein, has a charging voltage (CV) greater than approximately 4.3 V.

[0100] The electrochemical cell can have any suitable configuration or shape, and can be cylindrical or prismatic.

[0101] Various aspects of this disclosure are illustrated by the following non-limiting examples. These examples are for illustrative purposes and not for limiting any practice of the invention. It is to be understood that variations and modifications can be made without departing from the spirit and scope of the invention.

[0102] Example

[0103] Example 1:

[0104] Comparative Example 1:

[0105] Purchase a lithium iron phosphate (LiFePO4) cathode (Targray) and test it as is.

[0106] Example 2:

[0107] Comparative Example 2: High Mn Li 1.2 Ni 0.40 Mn 0.56 Co 0.04 Preparation of O2 cathode

[0108] First, 4.2 kg of NiSO4 6H2O, 449g CoSO4 7H2O and 3.7kg of MnSO4 7H₂O (available from Barentz) was dissolved in 17.2 liters of DI water to form a 2M mixed metal nitrate solution, with the composition being Ni. 0.40 Mn 0.56 Co 0.04 (OH)₂ precursor material. A feed solution containing 1.8 L DI water, 180 g NaSO₄ (Barentz), and 30 ml NH₃OH (14 M) (Barentz) was added to a 3 L reaction vessel and stirred until a temperature of 60 °C was reached. At this point, a metal nitrate solution was added to the reactor along with NH₃OH (14 M, ~0.2 ml / min) and NaOH (10 M, ~2 ml / min) (~4 ml / min). The solution was stirred at 900 rpm using a top-mounted stirrer, and the pH was maintained at ~11.4 and NH₃OH = 0.31 M throughout the reaction. Ni 0.40 Mn 0.56 Co 0.04 The product slurry of (OH)2 was continuously pumped out of the 3L reactor to keep the reactor volume constant. The solution was filtered, placed in an alumina crucible, and dried overnight at 120°C.

[0109] To synthesize high-Mn layered cathode Li 1.2 Ni 0.40 Mn 0.56 Co 0.04 O2, 22.23 g LiOH (dehydrated and ground) and 71.13 g Ni 0.40 Mn 0.56 Co 0.04Add (OH)₂ (in-house manufactured) to a 500 ml container and shake. Place the mixture in an alumina crucible and sinter. Sintering is performed by heating to approximately 450 °C at a rate of approximately 5 °C / min and holding at 450 °C for approximately 2 hours. Then, the temperature is increased to approximately 850 °C at a rate of approximately 2 °C / min and held under oxygen purging for approximately 12 hours. The sample is then allowed to cool naturally. The cooled sample is sieved to provide Li 1.15 Ni 0.40 Mn 0.56 Co 0.04 O2. The resulting sample was sieved and then tested in a button cell.

[0110] Example 2: High Mn Li with grain boundaries enriched in Co and Al 1.2 Ni 0.40 Mn 0.56 Co 0.04 Preparation of O2 cathode

[0111] 2.43 grams (g) of Co(NO3)2 6H2O cobalt nitrate, 0.5g aluminum nitrate Al(NO3)3 9H₂O and 0.83g LiNO₃ were dissolved in 20 ml of methanol heated to 40°C (in a flat-bottomed flask with a magnetic stir bar), and 20g of Li from Comparative Example 2 was added to the solution. 1.2 Ni 0.40 Mn 0.56 Co 0.04 O2. Connect the flask to a rotary evaporator with a water bath at 40°C–50°C. Apply a vacuum to the sample to remove methanol. Place the resulting dried powder in an alumina crucible and heat to approximately 450°C at a rate of 5°C / min and hold at approximately 450°C for approximately 1 hour. Then increase the temperature to approximately 700°C at approximately 2°C / min and hold for approximately 2 hours. Then allow the sample to cool naturally to room temperature to provide an overall composition of Li. 1.2 Ni 0.38 Mn 0.53 Co 0.08 Al 0.01 Materials containing O2.

[0112] Cathode electrodes with a 94:3:3 formulation (active material: AB100:PVDF) of the materials of Examples 2 and Comparative Examples 1 and 2 were assembled in lithium-ion coin cells (size 2025), opposite a graphite carbon anode (MCMB 10-28, MSE Supplies), having a microporous polyolefin separator (Celgard 2325) and a 1 M LiPF6 electrolyte (Kishida Chemical) in a 1 / 1 / 1 (volume ratio) EC / DMC / EMC containing 1 wt% VC. These lithium-ion batteries underwent extended 1C charge / 1C discharge cycling between 4.2 V and 2.7 V at 45°C. Figure 2 The result of this 1C / 1C cycle is shown. For example... Figure 2 As shown in Figure A, the LFP cathode of Comparative Example 1 exhibits rapid energy decay, while the high Mn and Co grain boundary enrichment material of Example 2 exhibits excellent initial cycle energy decay, and the energy decay is less than 10% up to 300 cycles. Figure 2 As shown in B, the Mn-rich material of Comparative Example 2 exhibits relatively rapid capacity decay. However, the high-Mn material with grain boundary enrichment in Example 2 exhibits excellent capacity retention. The discharge capacities of the same electrodes at various rates, electrochemically tested against a Li metal half-cell (cycled between 2.7–4.8 V at room temperature) for the materials of Example 2 and Comparative Example 2, are shown in Table 2.

[0113] Table 2: Half-cell rate capacity test, Comparative Example 2 and Example 2. The battery with the Li anode was cycled between 2.8 and 4.8 V at room temperature. The battery cycles between 2.8 and 4.3V.

[0114]

[0115] Example 3

[0116] Comparative Example 3: Li 1.2 Ni 0.40 Mn 0.56 Co 0.04 O2 preparation

[0117] The total composition of Li was prepared using the same method as provided in Comparative Example 2. 1.2 Ni 0.40 Mn 0.56 Co 0.04 The material is O2, but this sample was calcined at 900℃.

[0118] Example 3: Li with grain boundaries enriched in Co and Al 1.2 Ni 0.40 Mn0.56 Co 0.04 O2 preparation

[0119] The overall composition of Li was prepared in the same manner as in Example 2. 1.2 Ni 0.38 Mn 0.53 Co 0.08 Al 0.01 The material of O2 is simply that this sample was made using the product prepared in Comparative Example 3.

[0120] The material of Example 3 was analyzed by X-ray diffraction (XRD). The results showed... Figure 3 In the middle. For example Figure 3 As shown, the XRD peaks are consistent with the rhombohedral LiMO2 structure with the R-3M space group. (Illustration: shown in 20...) - 27 2 The extended XRD pattern between them shows a monoclinic structure of Li2MnO3 consistent with the high Mn cathode. (Haijun Yu & Haoshen Zhou, J PhysChem Let, 2013; 4:1268-1280).

[0121] Cathode electrodes using the materials of Example 3 and Comparative Example 3 were assembled into Li anode half-cells, which were cycled between 2.8 and 4.8 V at room temperature. The results are shown in Table 3. Full cells with graphite anodes were also constructed.

[0122] Table 3: Half-cell rate capacity test, Comparative Example 3 and Example 3. The battery with the Li anode was cycled between 2.8 and 4.8 V at room temperature.

[0123]

[0124] Example 4

[0125] Comparative Example 4: Li 1.2 Ni 0.40 Mn 0.56 Co 0.04 O2 preparation

[0126] The overall composition of Ni was prepared using the same method as provided in Comparative Example 2. 0.40 Mn 0.56 Co 0.04 The (OH)2 material was prepared by using pH = 10.9 and NH3OH = 0.31 M to increase the solubility of the metal in the supernatant. Therefore, a material similar to Comparative Example 2 but with a higher tap density was formed.

[0127] The total composition of Li was prepared using the same method as provided in Comparative Example 2. 1.2 Ni 0.40 Mn 0.56 Co 0.04 The material is O2, but this sample was calcined at 850°C.

[0128] Example 4: Li with grain boundaries enriched in Co and Al 1.2 Ni 0.40 Mn 0.56 Co 0.04 O2 preparation

[0129] The overall composition of Li was prepared in the same manner as in Example 2. 1.2 Ni 0.38 Mn 0.53 Co 0.08 Al 0.1 The material for O2 is simply 1.52 grams (g) of Co(NO3)2. 6H2O, 0.29g Al(NO3)3 9H2O and 0.23g LiNO3 were mixed with 25g of the product prepared in Comparative Example 4.

[0130] The cathode electrode, having the materials of Comparative Example 4 and Example 4, was used to construct an all-button cell according to Example 2, except that a 1.15 M LiPF6 electrolyte was used in a 3 / 3 / 4 (volume ratio) EC / DEC / DMC. Figure 4 In A, the battery was initially formed to 4.65V and cycled at an average discharge rate of 1C at 2.8-4.3V during rapid cycling tests. The discharge capacity of the Mn-rich material decayed rapidly, while the high-Mn material with grain boundary enrichment exhibited excellent capacity retention. Figure 4 B - The battery was initially formed to 4.65V and cycled at an average 1C discharge rate at 2.8–4.6V or 2.8–4.3V in a rapid cycling test. Compared to the material cycled at 4.3V, the material cycled at 4.6V showed a 20% increase in discharge capacity, while the capacity retention was similar (89% vs 91% after 350 cycles).

[0131] Cathode electrodes using the materials of Example 4 and Comparative Example 4 were assembled into Li anode half-cells, which were cycled between 2.8 and 4.8 V at room temperature. The results are shown in Table 4. Full cells with graphite anodes were also constructed.

[0132] Table 4: Half-cell rate capacity test, Comparative Example 4 and Example 4. The battery with the Li anode cycled between 2.8 and 4.8 V at room temperature.

[0133]

[0134] Example 5

[0135] Comparative Example 5: Li 1.08 Ni 0.56 Mn 0.40 Co 0.04 O2 preparation

[0136] The overall composition of Ni was prepared using the same method as provided in Comparative Example 2. 0.56 Mn 0.40 Co 0.04 The material (OH)2 was modified by changing the Ni / Mn ratio, pH = 11.73 and NH3OH = 0.24 M.

[0137] The total composition of Li was prepared using the same method as provided in Comparative Example 2. 1.08 Ni 0.56 Mn 0.40 Co 0.04 The O2 material simply consisted of 71.16 g of Ni from Comparative Example 5. 0.56 Mn 0.40 Co 0.04 (OH)2 is mixed with 20.41 g of LiOH (dried and ground).

[0138] Example 5: Li with grain boundaries enriched in Co and Al 1.08 Ni 0.56 Mn 0.40 Co 0.04 O2 preparation

[0139] The overall composition of Li was prepared in the same manner as in Example 2. 1.08 Ni 0.54 Mn 0.39 Co 0.06 Al 0.01 The material for O2 is simply 1.51 grams (g) of Co(NO3)2. 6H2O cobalt nitrate, 0.62g aluminum nitrate Al(NO3)3 9H2O and 0.67g LiNO3 were mixed with 25g of the product prepared in Comparative Example 5.

[0140] The cathode electrode prepared with the materials from Comparative Example 5 and Example 5 was evaluated in a full coin cell using the same procedure as in Example 2. The cell was subjected to full-cell cycling in a cell with a graphite anode, constructed as described above and cycled at 2.7–4.2V at 45°C under 1C charge / 1C discharge conditions. The results showed… Figure 5 middle.

[0141] Example 6

[0142] Comparative Example 6. Li 1.03 Ni 0.61 Mn 0.35 Co 0.04 O2 preparation

[0143] The overall composition of Ni was prepared using the same method as provided in Comparative Example 2. 0.61 Mn 0.35 Co 0.04 The material (OH)2 was modified by changing the Ni / Mn ratio, pH=11.94 and NH3OH = 0.2 M.

[0144] The total composition of Li was prepared using the same method as provided in Comparative Example 2. 1.03 Ni 0.61 Mn 0.35 Co 0.04 The O2 material simply consisted of 71.16 g of Ni from Comparative Example 6. 0.61 Mn 0.35 Co 0.04 (OH)2 is mixed with 19.25 g of LiOH (dried and ground).

[0145] Example 6 Li with grain boundaries enriched in Co and Al 1.03 Ni 0.61 Mn 0.35 Co 0.04 O2 preparation

[0146] The overall composition of Li was prepared in the same manner as in Example 2. 1.03 Ni 0.57 Mn 0.34 Co 0.08 Al 0.01 The material of O2 is simply that this sample was made using the product prepared in Comparative Example 6.

[0147] The cathode electrode, having the materials of Comparative Example 6 and Example 6, was used to construct an all-button cell according to Example 2, except that a 1.15 M LiPF6 electrolyte was used in a 3 / 3 / 4 (volume ratio) EC / DEC / DMC. Figure 6 In the experiment, the battery was initially formed to 4.65V and cycled at an average discharge rate of 1C at 2.8-4.3V during rapid cycling tests. The discharge capacity of Mn-rich materials decayed rapidly, while high-Mn materials enriched at grain boundaries exhibited excellent capacity.

[0148] Example 7.

[0149] Comparative Example 7. Li 1.28 Ni 0.36 Mn 0.60 Co 0.04 O2 preparation

[0150] The overall composition of Ni was prepared using the same method as provided in Comparative Example 2. 0.36 Mn 0.60 Co 0.04 The material (OH)2 was modified by simply changing the Ni / Mn ratio, pH = 10.75, and NH3OH = 0.25.

[0151] The total composition of Li was prepared using the same method as provided in Comparative Example 2. 1.28 Ni 0.36 Mn 0.60 Co 0.04 The O2 material simply consisted of 71.13 g of Ni from Comparative Example 7. 0.36 Mn 0.60 Co 0.04 (OH)2 is mixed with 24.53 g of LiOH (dried and ground).

[0152] Example 7 Li with grain boundaries enriched in Co and Al 1.28 Ni 0.36 Mn 0.60 Co 0.04 O2 preparation

[0153] The overall composition of Li was prepared in the same manner as in Example 2. 1.28 Ni 0.35 Mn 0.58 Co 0.06 Al 0.01 The material for O2 is simply 1.51 grams (g) of Co(NO3)2. 6H2O cobalt, 0.62 g Al(NO3)3 9 H2O and 0.67 g LiNO3 were mixed with 25 g of the product prepared in Comparative Example 7.

[0154] The cathode electrode, having the materials of Comparative Example 7 and Example 7, was used to construct an all-button cell according to Example 2, except that a 1.15 M LiPF6 electrolyte was used in a 3 / 3 / 4 (volume ratio) EC / DEC / DMC. Figure 7 In the experiment, the battery was initially formed to 4.65V and cycled at an average discharge rate of 1C at 2.8-4.3V during rapid cycling tests. The discharge capacity of Mn-rich materials decayed rapidly, while high-Mn materials enriched at grain boundaries exhibited excellent capacity.

[0155] Example 8 .

[0156] Table 5: Capacity decay of various samples as provided in Examples 4-7

[0157]

[0158] Additional exemplary aspects

[0159] Aspect 1. An electrochemically active material comprising:

[0160] Formula Li 1+a MO 2+b The first composition of (Formula I), wherein -0.3 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3, and wherein M comprises 30 atomic% to 70 atomic% Mn and 25 atomic% to 70 atomic% Ni, the first composition being formed of a polycrystalline morphology comprising a plurality of microcrystals and grain boundaries between adjacent microcrystals,

[0161] The grain boundary includes the Li 1+a M'O 2+b The second composition of (Formula II), wherein -0.1 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3,

[0162] The grain boundary contains one or more enriched elements in at least a portion thereof, the one or more enriched elements being present in the portion at a higher atomic percentage than in the adjacent microcrystals, wherein the one or more enriched elements are selected from Co, Al, and both Co and Al.

[0163] Aspect 2. The electrochemically active material of aspect 1, wherein M comprises 30 atomic% to 65 atomic% Mn, optionally 35 atomic% to 65 atomic% Mn.

[0164] Aspect 3. An electrochemically active material of aspect 1 or 2, wherein the second composition has an α-NaFeO2 type structure, a cubic structure, a spinel structure, or a combination thereof.

[0165] Aspect 4. Electrochemically active materials of aspects 1-3, wherein the particles have a particle size of about 1 µm to about 25 µm.

[0166] Aspect 5. Electrochemically active materials of aspects 1-4, wherein each of the microcrystals has an independent particle size of less than about 1 µm.

[0167] Aspect 6. Electrochemically active materials of aspects 1-5, wherein the enriched element comprises Co.

[0168] Aspect 7. Electrochemically active materials of aspects 1-6, wherein M further comprises Co.

[0169] Aspect 8. The electrochemically active material of aspect 7, wherein Co is present in an amount greater than about 0 atomic% to about 15 atomic%, optionally from about 0.01 atomic% to about 10 atomic%.

[0170] Aspect 9. Electrochemically active materials of aspect 7 or 8, wherein M comprises about 30 atomic% to about 70 atomic% of Mn, about 25 atomic% to about 70 atomic% of Ni, greater than 0 to about 15 atomic% of Co and / or 0 to about 5 atomic% of Mg, or any combination thereof.

[0171] Aspect 10. An electrochemically active material of any one of Aspects 1-9, wherein M comprises about 30 atomic% to about 65 atomic% Mn, about 25 atomic% to about 70 atomic% Ni, greater than 0 to about 15 atomic% Co and about 0 atomic% to about 5 atomic% Mg.

[0172] Aspect 11. An electrochemically active material of any one of Aspects 1-10, wherein the enriched element is Al, or both Co and Al.

[0173] Aspect 12. An electrochemically active material of any one of Aspects 1-11, wherein M in the first composition is present at about 45 atomic% to about 65 atomic%.

[0174] Aspect 13. An electrochemically active material of any one of Aspects 1-12, wherein M contains less than or equal to 40 atomic percent Ni.

[0175] Aspect 14. An electrochemically active material of any one of Aspects 1-13, wherein M comprises about 25 atomic% to about 70 atomic% Ni, about 0-15 atomic% Co, about 30 atomic% to about 65 atomic% Mn and 0-10 atomic% additional elements.

[0176] Aspect 15. An electrochemically active material of any one of Aspects 1-14, wherein the grain boundaries contain an atomic percentage of the enriched element that is higher than the average atomic percentage of the enriched element in the adjacent microcrystals.

[0177] Aspect 16. An electrochemically active material of any one of Aspects 1-15, wherein M' comprises 30 atomic% to 70 atomic% of Mn relative to total M'.

[0178] Aspect 17. The electrochemically active material of claim 16, wherein M' comprises about 10 atomic% to about 70 atomic% (at%) of Ni in total M'.

[0179] Aspect 18. An electrode comprising an electrochemically active material of any one of Aspects 1-17 and further comprising a current collector in electrical contact with the particles or plurality of particles.

[0180] Aspect 19. An electrochemical cell comprising a first electrode and a second electrode, wherein the first electrode is the electrode of aspect 18.

[0181] Aspect 20. An electrochemical cell of aspect 19, wherein the second electrode comprises carbon or lithium titanate.

[0182] Aspect 21. An electrochemical cell of aspect 20, wherein the carbon comprises graphite.

[0183] Aspect 22. An electrochemical cell according to any one of Aspects 19-21, characterized in that, when said electrochemical cell comprises a graphite anode, when cycled at an average C rate of >1 from 2.7 – 4.2 V at 45°C (~2 mAh / cm³), 2 When cathode loaded, it can maintain a discharge capacity greater than 140 mAh / g after 400 or more cycles, and optionally maintain a discharge capacity greater than 160 mAh / g after 400 or more cycles.

[0184] Aspect 23. An electrochemical cell according to any one of Aspects 19-21, characterized in that, when said electrochemical cell comprises a graphite anode, when cycled at an average C rate of >1 from 2.7 – 4.6 V at 45°C (~2 mAh / cm³), 2 When cathode loaded, it can maintain a discharge capacity greater than 140 mAh / g after 400 or more cycles, and optionally maintain a discharge capacity greater than 200 mAh / g after 400 or more cycles.

[0185] Aspect 24. An electrochemical battery comprising:

[0186] A cathode, an anode, and an electrolyte comprising any one of the electrochemically active materials of aspects 1-17, wherein the electrolyte does not include ethylene carbonate.

[0187] Aspect 25. Electrochemical cell of aspect 24, wherein the anode comprises carbon or lithium titanate.

[0188] Aspect 26. An electrochemical cell of aspect 25, wherein the anode comprises carbon.

[0189] Aspect 26. An electrochemical cell of any one of Aspects 24-26, wherein the electrolyte comprises a lithium salt and dimethyl carbonate alone or in combination with one or more additives.

[0190] Aspect 27. An electrochemical cell of aspect 26, wherein the additive comprises fluoroethylene carbonate (FEC), difluoroethylene carbonate (F2EC), tri(trimethylsilyl) malonate (TMSM), tri(trimethylsilyl) phosphite (TMSPi), tri(trimethylsilyl) phosphate (TMSPO4), lithium bis(oxalate)borate (LiDFOB), and a cosolvent 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TFETFPE). In some aspects, the additive optionally comprises fluoroethylene carbonate, difluoroethylene carbonate, lithium difluoro(oxalate)borate, or combinations thereof.

[0191] Although this disclosure describes exemplary embodiments, those skilled in the art will understand that various changes can be made and its elements can be substituted with equivalents without departing from the scope of the disclosed embodiments. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from its scope. Therefore, this disclosure is not intended to limit itself to the specific embodiments disclosed as the best mode considered for carrying out this disclosure. It should also be understood that the embodiments disclosed herein should be considered in a descriptive sense only and not as limiting. The descriptions of features or aspects of various embodiments should be taken into account for other similar features or aspects of other embodiments.

[0192] It is important to understand that when an element is mentioned "on" another element, it can be directly on the other element or there can be an intermediate element between them. Conversely, when an element is mentioned "directly on" another element, there is no intermediate element.

[0193] It is to be understood that although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or segment from another. Therefore, the “first element,” “component,” “region,” “layer,” or “segment” discussed below may be referred to as a second element, component, region, layer, or segment without departing from the teachings of this document.

[0194] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, as used herein, the singular forms “a” and “the” are intended to include the plural forms, including “at least one”. “Or” means “and / or”. As used herein, the term “and / or” includes any and all combinations of one or more of the related enumerations. It should also be understood that the terms “comprises” and / or “comprising,” or “includes” and / or “including”, when used in this specification, specify the presence of the stated features, regions, integers, steps, operations, elements, and / or components, but do not exclude the presence or inclusion of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof. The term “or a combination thereof” means a combination that includes at least one of the foregoing elements.

[0195] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms, such as those defined in common dictionaries, should be interpreted as having meanings consistent with their meanings in the relevant field and in the context of this disclosure, and not as idealized or overly formal, unless expressly defined herein.

[0196] All atomic % concentrations provided herein are considered to be “approximately” of the enumerated concentrations, whether explicitly stated or not, where “approximately” optionally includes equivalents and / or values ​​within experimental error. In some respects that may be optionally desired, all or some atomic % concentrations are precisely enumerated values ​​or ranges.

[0197] In addition to those shown and described herein, various modifications of the invention will be apparent to those skilled in the art. Such modifications are also intended to fall within the scope of the appended claims.

[0198] It should be recognized that, unless otherwise stated, all reagents are available from sources known in the art. Methods for nucleotide amplification, cell transfection, and protein expression and purification are similarly within the skill level of the art.

[0199] The patents, publications, and applications mentioned in this specification indicate the level of skill of a person skilled in the art to which this invention pertains. These patents, publications, and applications are incorporated herein by reference as if each patent, publication, or application were specifically and individually incorporated herein by reference.

[0200] References

[0201] Y. Ikuhara, “Atomic-scale observations of (010) LiFePO4 surfacebefore and after chemical delithiation” Nano Lett. 2016, 16, 5409-5414

[0202] Haijun Yu & Haoshen Zhou, “High-Energy cathode materials (Li2MnO3-LiMO2) for lithium-ion batteries” J Phys Chem Let 2013, 4, 1268-1280

[0203] He et al., “Challenges and recent advances in high capacity Li-Richcathode materials for high energy density lithium ion batteries” Adv Mater.2021, 33, 2005937

Claims

1. An electrochemically active material comprising: Formula Li 1+a MO 2+b The first composition of (Formula I), wherein -0.3 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3 and wherein M comprises 30 atomic% to 70 atomic% Mn and 25 atomic% to 70 atomic% Ni, the first composition being formed of a polycrystalline morphology comprising a plurality of microcrystals and grain boundaries between adjacent microcrystals; The grain boundary includes the Li 1+a M'O 2+b The second composition of (Formula II), wherein -0.1 ≤ a ≤ 1.3 and -0.3 ≤ b ≤ 1.3; The grain boundary contains one or more enriched elements in at least a portion thereof, the enriched elements being present in the portion at a higher atomic percentage than in the adjacent microcrystals, wherein the enriched elements comprise Co, Al, or both Co and Al.

2. The electrochemically active material according to claim 1, wherein M comprises 30 atomic% to 65 atomic% Mn.

3. The electrochemically active material according to claim 1, wherein the second composition has an α-NaFeO2 type structure, a cubic structure, a spinel structure, or a combination thereof.

4. The electrochemically active material according to claim 1, wherein the electrochemically active material is in the form of secondary particles having a particle size of about 1 µm to about 25 µm.

5. The electrochemically active material according to claim 1, wherein each of the microcrystals independently has a particle size of less than about 1 µm.

6. The electrochemically active material according to claim 1, wherein the enriched element comprises Co.

7. The electrochemically active material according to claim 1, wherein M further comprises Co.

8. The electrochemically active material according to claim 7, wherein Co is present in an amount greater than about 0 atomic% to about 15 atomic%, optionally from about 0.01 atomic% to about 10 atomic%.

9. The electrochemically active material according to claim 7, wherein M comprises about 30 atomic% to about 70 atomic% of Mn, about 25 atomic% to about 70 atomic% of Ni, greater than 0 to about 15 atomic% of Co and / or 0 to about 5 atomic% of Mg, or any combination thereof.

10. The electrochemically active material according to any one of claims 1-9, wherein M comprises about 30 atomic% to about 65 atomic% Mn, about 25 atomic% to about 70 atomic% Ni, greater than 0 to about 15 atomic% Co and about 0 atomic% to about 5 atomic% Mg.

11. The electrochemically active material according to any one of claims 1-9, wherein the enriched element is Al, or both Co and Al.

12. The electrochemically active material according to any one of claims 1-9, wherein M in the first composition is present at about 45 atomic% to about 65 atomic%.

13. The electrochemically active material according to any one of claims 1-9, wherein M contains less than or equal to 40 atomic percent Ni.

14. The electrochemically active material according to any one of claims 1-9, wherein M comprises about 25 atomic% to about 70 atomic% Ni, about 0-15 atomic% Co, about 30 atomic% to about 65 atomic% Mn and 0-10 atomic% additional elements.

15. The electrochemically active material according to any one of claims 1-9, wherein the grain boundary contains an atomic percentage of the enriched element that is higher than the average atomic percentage of the enriched element in the adjacent microcrystals.

16. The electrochemically active material according to claim 1, wherein M' comprises 10 atomic% to 70 atomic% of Mn relative to total M', and optionally 30 atomic% to 65 atomic% of Mn relative to total M'.

17. The electrochemically active material according to claim 15, wherein M' comprises about 10 atomic% to about 70 atomic% (at%) of Ni in total M'.

18. An electrode comprising an electrochemically active material according to any one of claims 1-9 and further comprising a current collector in electrical contact with the electrochemically active material.

19. An electrochemical cell comprising a first electrode and a second electrode, wherein the first electrode is the electrode according to claim 18.

20. The electrochemical cell of claim 19, wherein the second electrode comprises carbon or lithium titanate.

21. The electrochemical cell of claim 20, wherein the carbon comprises graphite.

22. The electrochemical battery according to claim 19, characterized in that, When the electrochemical cell contains a graphite anode, when cycled at an average C rate > 1 from 2.7 – 4.2 V at 45°C (~2 mAh / cm³), 2 When cathode loaded, it can maintain a discharge capacity greater than 140 mAh / g after 400 or more cycles, and optionally maintain a discharge capacity greater than 160 mAh / g after 400 or more cycles.

23. The electrochemical battery according to claim 19, characterized in that, When the electrochemical cell contains a graphite anode, when cycled at an average C rate > 1 from 2.7 – 4.6 V at 45°C (~2 mAh / cm³), 2 When cathode loaded, it can maintain a discharge capacity greater than 140 mAh / g after 400 or more cycles, and optionally maintain a discharge capacity greater than 200 mAh / g after 400 or more cycles.

24. An electrochemical battery comprising: A cathode, an anode, and an electrolyte containing the electrochemically active material according to any one of claims 1-9, wherein the electrolyte does not include ethylene carbonate.

25. The electrochemical cell of claim 24, wherein the anode comprises carbon or lithium titanate.

26. The electrochemical cell of claim 25, wherein the anode comprises carbon.

27. The electrochemical battery of claim 24, wherein the electrolyte comprises a lithium salt and dimethyl carbonate alone or in combination with one or more additives.

28. The electrochemical battery according to claim 27, wherein the additive is fluoroethylene carbonate (FEC), difluoroethylene carbonate (F2EC), tri(trimethylsilyl) malonate (TMSM), tri(trimethylsilyl) phosphite (TMSPi), tri(trimethylsilyl) phosphate (TMSPO4), lithium bis(oxalate)borate (LiDFOB), and the cosolvent 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TFETFPE). In some aspects, the additive optionally includes fluoroethylene carbonate, difluoroethylene carbonate, lithium difluoro(oxalate)borate, or combinations thereof.

29. An electrochemical cell comprising a cathode, an anode, and an electrolyte as described herein, all containing electrochemically active materials as provided herein.

30. Electrochemically active materials, as provided in this article.

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