Blended cathode active material containing iron phosphate-based material and nickel oxide-based material and method thereof

Abstract

Blended cathode active materials, including iron phosphate-based and nickel oxide-based active materials, and methods for their manufacture are described. Blended cathode active materials enable energy storage devices with improved performance, including improved capacity retention and cycle life, but are not limited to these.

Description

[Technical Field]

[0001] [Cross-reference of related applications] All applications in which foreign or national priority claims are identified in the application datasheet or PCT request filed with this application are incorporated herein by reference under 37 CFR 1.57 and Rules 4.18 and 20.6. This application claims the interests of U.S. Provisional Patent Application No. 63 / 499,655, filed 2 May 2023, titled “BLENDED CATHODE ACTIVE MATERIAL INCLUDING IRON PHOSPHATE BASED AND NICKEL OXIDE BASED MATERIALS, AND METHODS THEREOF,” which is incorporated herein by reference in its entirety for any purpose.

[0002] This disclosure relates in general to energy storage devices, and more specifically to cathode active materials for lithium-ion batteries and processes for forming them. [Background technology]

[0003] Energy storage devices are widely used to power electronic, electromechanical, electrochemical, and other useful devices. Such batteries include primary chemical batteries, secondary (rechargeable) batteries, fuel cells, and various types of capacitors, including ultracapacitors. Increasing the operating voltage and temperature limits of electrochemical energy storage devices can lead to increased energy density, increased power capacity, and a wider range of real-world use cases.

[0004] Some cathode electrodes in lithium-ion batteries are manufactured from first-row transition metal oxides. Examples of such cathode active materials include lithium cobalt oxide (LCO), lithium nickel manganese cobalt oxide (NMC), and lithium manganese oxide (LMO). Some other cathode electrodes in lithium-ion batteries contain transition metal phosphates such as lithium iron phosphate (LFP). However, the performance of the cathode active material used in lithium-ion batteries can lead to poor quality and undesirable battery performance, including loss of charge storage capacity during repeated charge-discharge cycles. [Overview of the Initiative]

[0005] For the purpose of summarizing the advantages achieved beyond the present invention and the prior art, specific purposes and advantages of the present invention are described herein. Not all such purposes or advantages can be achieved in any particular embodiment of the present invention. Therefore, for example, those skilled in the art will recognize that the present invention may be embodied or implemented to achieve or optimize one advantage or set of advantages taught herein, without necessarily achieving other purposes or advantages that may be taught or suggested herein.

[0006] In one embodiment, a blended cathode active material is described. The blended cathode active material comprises an iron phosphate-based active material; and a nickel oxide-based active material comprising at least one lithium nickel manganese cobalt oxide or lithium nickel cobalt aluminum oxide. In some examples, the iron phosphate-based active material is selected from the group consisting of lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), and combinations thereof. In some examples, the nickel oxide-based active material is selected from the group consisting of lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum oxide (NCA), and combinations thereof. In some examples, the NMC is selected from the group consisting of NMC550, NMC640, NMC631, NMC730, NMC75:25:0, NMC532, NMC111, NMC811, NMC622, NMC Ni83, NMC Ni91, and combinations thereof.

[0007] In some cases, the blended cathode active material contains iron phosphate-based active material at a concentration of approximately 90–99% by weight. In some cases, the blended cathode active material contains nickel oxide-based active material at a concentration of approximately 0.1–15% by weight. In some cases, the blended cathode active material contains nickel oxide-based active material at a concentration of approximately 0.1–3% by weight. In some cases, the nickel oxide-based active material contains at least approximately 4 m 2 It has a specific surface area of ​​ / g. In some examples, the nickel oxide-based active material contains less than about 3 wt% lithium-containing impurities. In some examples, the lithium-containing impurities are selected from the group consisting of LiOH, Li2CO3, and combinations thereof. In some examples, the nickel oxide-based active material contains less than about 0.5 wt% LiOH. In some examples, the nickel oxide-based active material contains less than about 1 wt% Li2CO3.

[0008] In another embodiment, an energy storage device is described. The energy storage device comprises a cathode electrode containing a blended cathode active material; a separator; an anode electrode; an electrolyte; and a housing, the cathode electrode, separator, and anode electrode being located within the housing. In some embodiments, the anode electrode contains a graphite active material.

[0009] In another embodiment, a process for forming a blended cathode active material is described. The method comprises combining an iron phosphate-based active material with a nickel oxide-based active material to form a blended cathode active material mixture, wherein the nickel oxide-based active material comprises at least one of lithium nickel manganese cobalt oxide and lithium nickel cobalt aluminum oxide.

[0010] In some examples, the process further includes surface treatment of the nickel oxide-based active material before combination. In some examples, the surface treatment of the nickel oxide-based active material includes grinding. In some examples, the surface treatment of the nickel oxide-based active material is carried out in an atmosphere free of water and CO2. In some examples, the surface treatment of the nickel oxide-based active material is carried out in ambient air. In some examples, the process further includes heating the nickel oxide-based active material before combining it with the iron phosphate-based active material. In some examples, the heating is carried out at a temperature of 650°C to 800°C.

[0011] In another embodiment, a method for forming a blended cathode active material is described. The method includes surface-machining a nickel oxide-based active material to form a processed nickel oxide-based active material; heating the processed nickel oxide-based active material at a temperature of 650°C to 800°C to form a treated nickel oxide-based active material; and combining an iron phosphate-based active material with the treated nickel oxide-based active material to form a blended cathode active material mixture. In some examples, the nickel oxide-based active material comprises at least one of lithium nickel manganese cobalt oxide and lithium nickel cobalt aluminum oxide. In some examples, the specific surface area of ​​the treated nickel oxide-based active material is greater than the specific surface area of ​​the nickel oxide-based active material. In some examples, the blended cathode active material mixture contains the treated nickel oxide-based active material in an amount of about 0.1 to 3% by weight. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows a process for forming a blended cathode active material according to several embodiments.

[0013] [Figure 2] The following describes a process for processing nickel oxide-based active materials according to several embodiments.

[0014] [Figure 3A] SEM images and XRD spectra of raw NMC powder according to several embodiments are shown.

[0015] [Figure 3B] SEM images and XRD spectra of NMC powder processed according to several embodiments are shown.

[0016] [Figure 3C] SEM images of NMC powder processed according to several embodiments are shown.

[0017] [Figure 4A]The bar graphs show the amounts of LiOH and Li2CO3 in raw NMC powder and treated NMC powder formed according to several embodiments.

[0018] [Figure 4B] The graphs show the specific surface area of ​​raw NMC powder and processed and treated NMC powder formed according to several embodiments.

[0019] [Figure 5A] This plot shows the first charge-discharge voltage-capacity curves of batteries containing blended cathode active materials, including LFP and NMC640, according to several embodiments, compared to a baseline battery.

[0020] [Figure 5B] This plot shows the first charge-discharge voltage-capacity curves of batteries containing blended cathode active materials including LFP and NMC Ni83 in several embodiments, compared to a baseline battery.

[0021] [Figure 5C] This plot shows the voltage against normalized charge capacity of batteries containing blended cathode active materials, including LFP and NMC640, according to several embodiments, compared to a baseline battery.

[0022] [Figure 5D] This plot shows the first charge-discharge voltage-capacity curves of batteries containing LMFP and blended cathode active materials including NMC640 or NMC Ni83, according to several embodiments, compared to a baseline battery.

[0023] [Figure 6A] This plot shows the discharge capacity as a function of time at a 40°C cycle for batteries containing various cathode active materials according to several embodiments.

[0024] [Figure 6B]This plot shows the normalized discharge capacity as a function of time at a 40°C cycle for batteries containing various cathode active materials according to several embodiments.

[0025] [Figure 6C] This plot shows the internal resistance (by normalized delta V(dV)) as a function of time at a 40°C cycle for batteries containing various cathode active materials according to several embodiments.

[0026] [Figure 7A] This plot shows the actual discharge capacity as a function of time at a 55°C cycle for batteries containing various cathode active materials according to several embodiments.

[0027] [Figure 7B] This plot shows the normalized discharge capacity as a function of time at a 55°C cycle for batteries containing various cathode active materials according to several embodiments.

[0028] [Figure 7C] This plot shows the internal resistance (by normalized delta V(dV)) as a function of time at a 55°C cycle for batteries containing various cathode active materials according to several embodiments.

[0029] [Figure 8A] This plot shows the actual discharge capacity as a function of time at a 70°C cycle for batteries containing various cathode active materials according to several embodiments.

[0030] [Figure 8B] This plot shows the normalized discharge capacity as a function of time at a 70°C cycle for batteries containing various cathode active materials according to several embodiments.

[0031] [Figure 8C]This plot shows the internal resistance (by normalized delta V(dV)) as a function of time at a 70°C cycle for batteries containing various cathode active materials according to several embodiments.

[0032] [Figure 9] This plot shows the normalized discharge capacity as a function of time over various electrochemical charging ranges of batteries containing various cathode active materials according to several embodiments.

[0033] [Figure 10A] This plot shows the discharge capacity as a function of time at a 70°C cycle for pouch-type batteries containing various cathode active materials according to several embodiments.

[0034] [Figure 10B] This plot shows the normalized discharge capacity as a function of time at a 70°C cycle for pouch-type batteries containing various cathode active materials according to several embodiments.

[0035] [Figure 10C] This plot shows the internal resistance (by normalized delta V(dV)) as a function of time at a 70°C cycle for pouch-type batteries containing various cathode active materials according to several embodiments.

[0036] [Figure 11A] This bar graph shows the area loading of iron deposited on the anode electrode of batteries containing various cathode active materials according to several embodiments, after 7,000 hours of cycling at 40°C.

[0037] [Figure 11B] This bar graph shows the area loading of iron deposited on the anode electrode of batteries containing various cathode active materials according to several embodiments, after 3,400 hours of cycling at 55°C.

[0038] [Figure 11C]This bar graph shows the area loading of iron deposited on the anode electrode of batteries containing various cathode active materials according to several embodiments, after 4,400 hours of cycling at 70°C.

[0039] [Figure 11D] This plot shows the area load of iron deposited on the anode electrode of batteries containing various cathode active materials after being held at various temperatures according to several embodiments, as a function of normalized discharge capacity loss.

[0040] [Figure 12A] This bar graph shows the area-ratio charge transfer resistance of batteries containing various cathode active materials according to several embodiments, after storage at 60°C, compared to a baseline battery.

[0041] [Figure 12B] This bar graph shows the irreversible and reversible capacity losses of batteries containing various cathode active materials according to several embodiments, after storage at 60°C for 500 hours, compared to a baseline battery.

[0042] [Figure 12C] This bar graph shows the irreversible and reversible capacity losses of batteries containing various cathode active materials according to several embodiments, after 1,000 hours of storage at 60°C, compared to a baseline battery.

[0043] [Figure 13A] This plot shows the actual discharge capacity of LFP / NMC622 half-cells as a function of cycles in several embodiments.

[0044] [Figure 13B] This plot shows the normalized discharge capacity as a function of cycles for LFP / NMC622 half-cells in several embodiments.

[0045] [Figure 14A-B]Figure 14A shows voltage-time curves of total capacitance at C / 20 for several embodiments.

[0046] Figure 14B is an enlarged view showing the circled region of the voltage curve in Figure 14A.

[0047] [Figure 15A] This plot shows the actual discharge capacity of LFP / NMC622 and LFP single-layer pouch batteries as a function of cycles in several embodiments.

[0048] [Figure 15B] The normalized discharge capacity of LFP / NMC622 and LFP single-layer pouch batteries in several embodiments is shown as a function of cycles.

[0049] [Figure 15C] The internal resistance (with normalized delta V(dV)) with respect to cycle time of LFP / NMC622 and LFP single-layer pouch batteries in several embodiments is shown. [Modes for carrying out the invention]

[0050] This disclosure can be understood by referring to the following detailed description. For clarity, please note that certain elements in the various drawings may not be drawn to scale, may be represented schematically or conceptually, and may not otherwise precisely correspond to the specific physical configuration of the embodiment.

[0051] Various embodiments of blended cathode active materials with improved energy density and capacity retention, as well as methods for preparing such blended cathode active materials, are provided herein. Such blended cathode active materials can enable improvements in energy storage device performance, such as electrode capacity, and improvements in battery cycles, while minimizing the use of expensive elements (e.g., nickel, cobalt).

[0052] In some embodiments, the blended cathode active material can include an iron phosphate-based active material and a nickel oxide-based active material. In some embodiments, the iron phosphate-based active material can include lithium iron phosphate (i.e., LiFePO4 or "LFP"), lithium manganese iron phosphate (e.g., LiMn 0.6 Fe 0.4 PO4 or "LMFP"), and combinations thereof. In some embodiments, the iron phosphate-based active material includes LFP. In some embodiments, the iron phosphate-based active material includes LMFP. In some embodiments, the iron phosphate-based active material includes LFP and LMFP.

[0053] In some embodiments, the blended cathode active material includes the iron phosphate-based active material at a concentration of 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 98.5 wt%, 99 wt%, 99.5 wt%, 99.8 wt% or 99.9 wt%, or approximately these values, or at least these values, or at least approximately these values, or at a concentration within any range between these values. For example, in some embodiments, the amount of the iron phosphate-based active material in the blended cathode active material is any one of 85-99.9 wt%, 90-99.9 wt%, 85-95 wt%, 95-99.9 wt%, 98-99.9 wt%, or 85-99 wt%, or approximately any one of these ranges.

[0054] In some embodiments, the nickel oxide-based active material includes lithium nickel manganese cobalt oxide (i.e., LiNi x Mn y Co 1-x-y O2 or "NMC"), lithium nickel cobalt aluminum oxide (i.e., LiNi x Co y Al zThis includes O2 (or "NCA") and combinations thereof. In some embodiments, the nickel oxide active material includes lithium NMC. In some embodiments, the nickel oxide active material includes NCA. In some embodiments, the nickel oxide active material includes NMC and NCA. In some embodiments, NMC is selected from the group consisting of NMC550, NMC640, NMC631, NMC730, NMC75:25:0, NMC532, NMC111, NMC811, NMC622, NMC Ni83, NMC Ni91, and combinations thereof. In some embodiments, NMC includes NMC550. In some embodiments, NMC includes NMC640. In some embodiments, NMC includes NMC631. In some embodiments, NMC includes NMC730. In some embodiments, NMC includes NMC75:25:0. In some embodiments, NMC includes NMC532. In some embodiments, NMC includes NMC111. In some embodiments, the NMC includes NMC811. In some embodiments, the NMC includes NMC622. In some embodiments, the NMC includes NMC Ni83. In some embodiments, the NMC includes NMC Ni91. In some embodiments, the NMC includes NMC640 and NMC Ni83.

[0055] In some embodiments, the blended cathode active material contains nickel oxide-based active material at concentrations of 0.1% by weight, 0.2% by weight, 0.5% by weight, 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, or 15% by weight, or approximately these values, or at least these values, or at least approximately these values, or any range between these values. For example, in some embodiments, the amount of nickel oxide-based active material in the blended cathode active material is one of the following values: 0.1–15% by weight, 1–15% by weight, 0.1–10% by weight, 1–10% by weight, 5–10% by weight, 1–9% by weight, 10–15% by weight, 9–11% by weight, 5–9% by weight, 1–3% by weight, 0.1–3% by weight, 1–2.5% by weight, 0.1–2.5% by weight, or 0.1–3% by weight, or approximately one of these values.

[0056] In some embodiments, the specific surface area of ​​the nickel oxide-based active material is 1 m². 2 / g, 2m 2 / g, 2.5m 2 / g, 3m 2 / g, 3.5m 2 / g, 3.75m 2 / g, 4m 2 / g, 4.25m 2 / g, 4.5m 2 / g, 4.75m 2 / g, 5m 2 / g, 5.25m 2 / g, 5.5m 2 / g, 5.75m 2 / g, 6m 2 / g, 6.25m 2 / g, 6.5m 2 / g, 7m 2 / g, 8m 2 / g, 9m 2 / g, 10m 2 / g, 11m 2 / g, 12m 2 / g, 13m 2 / g, 14m 2 / g, 15m 2The specific surface area is either / g, approximately these values, at least these values, at least approximately these values, or any range between these values. In some embodiments, the specific surface area is measured by the Brunauer-Emmett-Teller (BET) method.

[0057] In some embodiments, the nickel oxide-based active material contains lithium-containing impurities. In some embodiments, the lithium-containing impurities include LiOH, Li2CO3, or a combination thereof. In some embodiments, the nickel oxide-based active material contains lithium-containing impurities in amounts of 0.1% by weight, 0.5% by weight, 1.0% by weight, 1.5% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, or approximately these values, or at most these values, or at most approximately these values, or in any range between these values. In some embodiments, the nickel oxide-based active material contains LiOH in amounts of 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1.0% by weight, 1.1% by weight, 1.2% by weight, 1.3% by weight, 1.4% by weight, 1.5% by weight, 2% by weight, 3% by weight, or approximately these values, or at most these values, or at most approximately these values, or any range between these values. In some embodiments, the nickel oxide-based active material contains Li2CO3 in amounts of 0.2 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.4 wt%, 1.5 wt%, 2 wt%, or approximately these values, or at most these values, or at most approximately these values, or any range between these values. In some embodiments, the concentration of impurities such as LiOH or Li2CO3 is determined by titration.

[0058] In some embodiments, the blended cathode active material includes additional active materials, such as lithium manganese oxide ("LMO"), lithium nickel manganese oxide ("LNMO"), lithium cobalt oxide ("LCO"), lithium titanate ("LTO"), or combinations thereof. In some embodiments, the blended cathode active material includes at least two of LFP, LMFP, NMC, NCA, LMO, LNMO, LCO, LTO, and combinations thereof.

[0059] • Formation process of blend cathode active material Blended cathode active materials can be formed through various processes. Figure 1 shows an exemplary process 100 for producing a blended cathode active material. Process 100 includes a first step 110 in which an iron phosphate-based active material and a nickel oxide-based active material are combined to form a blended cathode active material mixture. In some embodiments, the combination is performed at room temperature. In some embodiments, the combination is performed at ambient temperature to form the blended cathode active material mixture. In some embodiments, the combination of the iron phosphate-based active material and the nickel oxide-based active material includes mixing the iron phosphate-based active material with the nickel oxide-based active material. In some embodiments, the mixing includes steps selected from grinding, blending, and combinations thereof. In some embodiments, the iron phosphate-based active material and the nickel oxide-based active material are mixed in a ratio intended for the electrode film. In certain embodiments, the blended cathode active material mixture is combined (e.g., mixed) with a lithium source to form an active material mixture.

[0060] Continuing to refer to Figure 1, in some embodiments, the manufacturing process 100 includes an optional step 120 of heating the blended cathode active mixture to form the blended cathode active. In some embodiments, the blended cathode active is used to form an electrode film. In some embodiments, the blended cathode active mixture is heated to temperatures of 650°C, 660°C, 670°C, 680°C, 690°C, 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, temperatures approximately these values, temperatures at least these values, temperatures at least approximately these values, temperatures up to these values, temperatures up to approximately these values, or any range of temperatures between these values. In some embodiments, the blended cathode active mixture is not heated before being used to form an electrode film. In some embodiments, the process of forming a blended cathode active material includes mixing an iron phosphate-based active material with a nickel oxide-based active material to form a blended cathode active material.

[0061] In some embodiments, process 100 further includes increasing the specific surface area of ​​the blend cathode active material mixture. In some embodiments, increasing the specific surface area of ​​the blend cathode active material mixture includes steps selected from crushing, grinding, and combinations thereof. In some embodiments, process 100 further includes processing the blend cathode active material mixture. In some embodiments, the processing includes steps selected from sieving, washing, filtering, drying, coating, and combinations thereof.

[0062] In some embodiments, the nickel oxide-based active material is processed before being combined with the iron phosphate-based active material. Figure 2 shows an exemplary process 200 for processing the nickel oxide-based active material before being combined with the iron phosphate-based active material. Process 200 includes a step 210 to surface-process the raw nickel oxide-based active material to form a processed nickel oxide-based active material. In some embodiments, surface-processing increases the specific surface area of ​​the nickel oxide-based active material. In some embodiments, surface-processing reduces particle size, modifies and / or textures the surface of the particles, and / or breaks down particle aggregates. In some embodiments, surface-processing of the nickel oxide-based active material includes crushing, grinding, and combinations thereof. In some embodiments, surface-processing of the nickel oxide-based active material includes surface roughening. In some embodiments, surface-processing of the nickel oxide-based active material includes destroying the structure of the nickel oxide-based active material. In some embodiments, grinding is selected from the group consisting of planetary ball mills, Spex mills, high-shear high-energy mills, attritor mills, and vibratory mills, or combinations thereof. In some embodiments, surface area processing of the nickel oxide-based active material includes ball mill grinding.

[0063] In some embodiments, the surface area processing of the nickel oxide-based active material is carried out over a period of time of 10 hours, 20 hours, 30 hours, 40 hours, 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, 100 hours, 110 hours, 120 hours, 130 hours, 140 hours, 150 hours, 160 hours, 170 hours, 180 hours, 190 hours, 200 hours, 250 hours, 300 hours, approximately these times, at least these times, at least approximately these times, or any range of times between these values. In some embodiments, the specific surface area of ​​the processed nickel oxide-based active material is 10 m². 2 / g, 11m 2 / g, 12m 2 / g, 13m 2 / g, 14m 2 / g, 15m 2 / g, 16m 2 / g, 17m 2 / g, 18m 2 / g, 19m 2 / g, 20m 2 / g, 21m 2 / g, 22m 2 / g, 23m 2 / g, 24m 2 / g, 25m 2 / g, 25m 2 / g, 26m 2 / g, 27m 2 / g, 28m 2 / g, 29m 2 / g, 30m 2 / g, 35m 2 / g, 40m 2 / g, 45m 2 / g, 50m 2 The specific surface area is either / g, approximately these values, at least these values, at least approximately these values, or any range between these values. In some embodiments, the specific surface area is measured by the Brunauer-Emmett-Teller (BET) method.

[0064] Continuing to refer to Figure 2, process 200 may include step 220, in which the processed nickel oxide active material is heated to form a treated nickel oxide active material. In some embodiments, such as in process 100, the treated nickel oxide active material is combined with an iron phosphate active material to form a blended cathode active material mixture. In some embodiments, the heating is performed at temperatures of 650°C, 660°C, 670°C, 680°C, 690°C, 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, temperatures approximately these values, temperatures at least these values, temperatures at least approximately these values, temperatures up to these values, temperatures up to approximately these values, or any range of temperatures between these values. For example, heating may be carried out at temperatures ranging from approximately 650°C to approximately 800°C, 660°C to approximately 800°C, 670°C to approximately 800°C, 670°C to approximately 780°C, 670°C to approximately 750°C, 690°C to approximately 750°C, or any range between these values. In some embodiments, heating is carried out for 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, approximately these times, at least these times, at least approximately these times, or any range between these values. In some embodiments, heating is carried out in the presence of oxygen. In some embodiments, heating is carried out in an oxygen atmosphere. In some embodiments, the treated nickel oxide active material has a specific surface area greater than that of the untreated nickel oxide active material. In some embodiments, the amount of impurities in the nickel oxide active material can be reduced by heating for a certain amount of time and at a certain temperature, but the treated nickel oxide active material still retains a larger specific surface area than the untreated nickel oxide active material.

[0065] In some embodiments, instead of or in addition to heating, the processed nickel oxide active material is washed with an aqueous solution to form a treated nickel oxide active material. In some embodiments, the aqueous solution has an initial pH of about 9 to about 11.

[0066] In some embodiments, raw nickel oxide active material is treated without heating to form treated nickel oxide active material. In some embodiments, raw nickel oxide active material is treated in a one-step process to form treated nickel oxide active material. In some embodiments, the one-step process includes surface area processing of the nickel oxide active material in an atmosphere with no or substantially no air, for example, in a glove box. In some embodiments, the one-step process includes surface area processing of the raw nickel oxide active material in an atmosphere with no or substantially no CO2 and water.

[0067] In some embodiments, nickel oxide-based active materials are synthesized to achieve similar properties to those of treated nickel oxide-based active materials. In some embodiments, the synthesis involves spray pyrolysis of a solution containing nickel, cobalt, manganese, and lithium nitrate. In some embodiments, the synthesis involves co-precipitating an NMC(OH)2 precursor, followed by heating the co-precipitated product with a lithium source. In some embodiments, the D50 particle size of the synthesized nickel oxide-based active material includes 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, approximately these values, at most these values, at least these values, or any range between these values, for example, about 1 to 2 μm.

[0068] In some embodiments, the specific surface area of ​​the treated nickel oxide-based active material is 1 m². 2 / g, 2m 2 / g, 2.5m 2 / g, 3m 2 / g, 3.5m 2 / g, 3.75m 2 / g, 4m 2 / g, 4.25m 2 / g, 4.5m 2 / g, 4.75m 2 / g, 5m 2 / g, 5.25m 2 / g, 5.5m 2 / g, 5.75m 2 / g, 6m 2 / g, 6.25m 2 / g, 6.5m 2 / g, 7m 2 / g, 8m 2 / g, 9m 2 / g, 10m 2 / g, 15m 2 The specific surface area is either / g, approximately these values, at least these values, at least approximately these values, or any range between these values. In some embodiments, the specific surface area is measured by the Brunauer-Emmett-Teller (BET) method. In some embodiments, the specific surface area of ​​the treated nickel oxide active material is about 1.5, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 times that of the untreated nickel oxide active material, or approximately these values, at least these values, at least approximately these values, or any range between these values.

[0069] In some embodiments, the treated nickel oxide active material contains a reduced amount of lithium-containing impurities compared to the processed nickel oxide active material. In some embodiments, the lithium-containing impurities include LiOH, Li2CO3, or a combination thereof. In some embodiments, the treated nickel oxide active material contains lithium-containing impurities in amounts of 0.1% by weight, 0.5% by weight, 1.0% by weight, 1.5% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, approximately these values, at most these values, or at most approximately these values, or in any range between these values. In some embodiments, the treated nickel oxide-based active material contains LiOH in amounts of 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1.0% by weight, 1.1% by weight, 1.2% by weight, 1.3% by weight, 1.4% by weight, 1.5% by weight, 2% by weight, 3% by weight, approximately these values, at most these values, or amounts at most approximately these values, or any range between these values. In some embodiments, the treated nickel oxide active material contains Li2CO3 in amounts of 0.2 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.4 wt%, 1.5 wt%, 2 wt%, approximately these values, at most these values, or at most approximately these values, or any range between these values. In some embodiments, the amount of lithium-containing impurities in the treated nickel oxide active material is 5, 4, 3, 2, 1, or 0.5 times the amount of lithium-containing impurities in the untreated nickel oxide active material, or approximately these values, less than these values, or any range between these values.

[0070] In some embodiments, the treated nickel oxide active material has a larger specific surface area than the untreated nickel oxide active material, but the amount of impurities in the treated nickel oxide active material is the same as or less than that in the untreated nickel oxide active material. Therefore, the use of the treated nickel oxide active material can significantly reduce the amount of nickel oxide active material required to form the blended cathode active material for electrodes in energy storage devices, while the energy storage device can still achieve improved performance.

[0071] ·Electrode film Blended cathode active materials can be used to prepare electrode films and / or electrodes for energy storage devices. In some embodiments, the electrode film (e.g., a cathode electrode film) comprises a blended cathode active material. In some embodiments, the electrode comprises a current collector and an electrode film. In some embodiments, the electrode is a cathode electrode. In some embodiments, the electrode film and / or electrode comprises a blended cathode active material. In some embodiments, the electrode film contains a blended cathode active material in amounts of 70% by weight, 75% by weight, 80% by weight, 81% by weight, 82% by weight, 83% by weight, 84% by weight, 85% by weight, 86% by weight, 87% by weight, 88% by weight, 89% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight, 98% by weight, 99% by weight, 100% by weight, approximately these values, at least these values, or amounts of at least approximately these values, or any range between these values.

[0072] In some embodiments, the second electrode film is an anode electrode film. In some embodiments, the anode electrode film includes an anode active material. In some embodiments, the anode active material may include, for example, insert materials (such as carbon, graphite, and / or graphene), alloying / dealloying materials (such as silicon, silicon oxide, tin, and / or tin oxide), metallic alloys or compounds (such as Si-Al and / or Si-Sn), and / or conversion materials (such as manganese oxide, molybdenum oxide, nickel oxide, and / or copper oxide). The anode active material may be used alone or mixed together to form a multiphase material (such as Si-C, Sn-C, SiOx-C, SnOx-C, Si-Sn, Si-SiOx, Sn-SnOx, Si-SiOx-C, Sn-SnOx-C, Si-Sn-C, SiOx-SnOx-C, Si-SiOx-Sn, Sn-SiOx-SnOx, etc.). Anode active materials include common natural graphite, synthetic or artificial graphite, surface-modified graphite, spherical graphite, flake graphite, and blends or combinations of these types of graphite, metallic elements and their compounds, as well as metal-C composites for anodes.

[0073] In some embodiments, the electrode film includes a carbon material configured to reversibly intercalate lithium ions. In some embodiments, the electrode film includes the carbon material in amounts of 20% by weight, 15% by weight, 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, approximately these values, up to these values, or the total amount of up to approximately these values, or the total amount of any range between these values. In some embodiments, the lithium intercalation carbon is selected from graphite carbon, graphite, hard carbon, soft carbon, and combinations thereof. For example, the electrode film of an electrode may include a binder material, one or more of graphite carbon, graphite, graphene-containing carbon, hard carbon, and soft carbon, as well as a conductivity-enhancing material. In some embodiments, the electrode is mixed with lithium metal and / or lithium ions.

[0074] In some embodiments, the electrode film includes a conductive additive. In some embodiments, the conductive additive may include a conductive carbon additive. In some embodiments, the conductive carbon additive includes carbon black, carbon nanotubes, such as single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). In some embodiments, the electrode film contains the conductive additive in amounts of 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.25% by weight, 0.1% by weight, approximately these values, up to these values, or the total amount of up to approximately these values, or the total amount of any range between these values. In some embodiments, each of the conductive additives is present in amounts of 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.25% by weight, 0.1% by weight, approximately these values, up to these values, or up to approximately these values, or any range between these values. In some embodiments, the conductive additive is carbon black.

[0075] In some embodiments, the electrode film includes a binder. In some embodiments, the binder may include polytetrafluoroethylene (PTFE), polyolefins, polyalkylenes, polyethers, styrene-butadiene, polysiloxanes and polysiloxane copolymers, branched polyethers, polyvinyl ethers, carboxymethylcellulose (CMC), copolymers thereof, and / or combinations thereof. In some embodiments, the polyolefin may include polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVDF), copolymers thereof, and / or combinations thereof. For example, the binder may include polyvinyl chloride, poly(phenylene oxide) (PPO), polyethylene-block-poly(ethylene glycol), poly(ethylene oxide) (PEO), poly(phenylene oxide) (PPO), polyethylene-block-poly(ethylene glycol), polydimethylsiloxane (PDMS), polydimethylsiloxane-coalkylmethylsiloxane, copolymers thereof, and / or combinations thereof. In some embodiments, the binder may comprise a thermoplastic material. In some embodiments, the binder comprises a fibrillable polymer and / or a fibrillated polymer. In certain embodiments, the binder comprises, essentially comprises, or comprises a single fibrillable binder and / or a fibrillated binder, such as PTFE. In some embodiments, the binder comprises, essentially comprises, or comprises PVDF. In some embodiments, the electrode film contains a binder in amounts of 20% by weight, 19% by weight, 18% by weight, 17% by weight, 16% by weight, 15% by weight, 14% by weight, 13% by weight, 12% by weight, 11% by weight, 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.25% by weight, 0.1% by weight, approximately these values, up to these values, or up to approximately these values, or any range of these values.

[0076] In some embodiments, the electrode film includes a thickness of 1000μm, 900μm, 800μm, 700μm, 600μm, 500μm, 400μm, 300μm, 250μm, 200μm, 150μm, 100μm, 90μm, 80μm, 70μm, 60μm, 50μm, 40μm, 30μm, 20μm, 15μm, 10μm, approximately these values, up to these values, or up to approximately these values, or a thickness within any range between these values. In some embodiments, the electrode film has an active material loading (which can be expressed as the mass of the electrode film per unit area of the electrode film or the current collector) of 3mg / cm 2 2, 4mg / cm 2 2, 5mg / cm 2 2, 10mg / cm 2 2, 15mg / cm 2 2, 20mg / cm 2 2, 30mg / cm 2 2, 40mg / cm 2 2, 50mg / cm 2 2, 100mg / cm 2 2, and is provided in approximately these values, at least these values, or at least approximately these values, or within any range between these values.

[0077] The electrode film thickness can be selected to correspond to a desired areal capacity, specific capacity, areal energy density, energy density, or specific energy density. In some embodiments, the electrode film has an areal capacity (which can be expressed as the capacity per unit area of the electrode film or the current collector) of 1mAh / cm 2 2, 1.5mAh / cm 2 2, 1.7mAh / cm 2 2, 1.9mAh / cm 2 2, 2.0mAh / cm 2 2, 2.5mAh / cm 2 2, 3mAh / cm 2 2, 3.5mAh / cm 2 2, 4mAh / cm 2 [[ID=4​2]]2, 4.5mAh / cm 2 2, 5mAh / cm 2 2, 5.5mAh / cm 2 2, 6mAh / cm 2 2, 6.5mAh / cm 2 2, 7mAh / cm2 7.5mAh / cm² 2 , 8mAh / cm 2 9mAh / cm² 2 , 10mAh / cm 2 , 11mAh / cm 2 , 12mAh / cm 2 , 13mAh / cm 2 , 14mAh / cm 2 , 15mAh / cm 2 , 20mAh / cm 2 , 25mAh / cm 2 These values ​​can be provided as approximately these values, at least these values, or at least approximately these values, or any range between these values.

[0078] In some embodiments, the electrode film is placed on a current collector. In some embodiments, the current collector may include a metallic material, such as aluminum, nickel, copper, or a combination thereof. In some embodiments, the current collector may include a pure metal. In some embodiments, the current collector may include a metallized polymer film or a metal-coated polymer film. In some embodiments, the polymer may include polyethylene terephthalate (PET), biaxially oriented polypropylene (BOPP), or a combination thereof. In some embodiments, the metal coating may include aluminum. In some embodiments, coating the final electrode film mixture may involve forming a uniform electrode film mixture coating. In some embodiments, the current collector may include thicknesses of 200 μm, 100 μm, 50 μm, 40 μm, 30 μm, 20 μm, 15 μm, 10 μm, 5 μm, approximately these values, up to these values, or up to approximately these values, or any range of thicknesses between these values.

[0079] In some embodiments, the electrode film may be a wet-processed electrode film. In some embodiments, the electrode film is prepared by a wet or slurry-based electrode manufacturing process. In some embodiments, the electrode film of this disclosure may be a dry-processed electrode film. In some embodiments, the electrode film is prepared by a dry electrode manufacturing process. As used herein, a dry electrode manufacturing process may refer to a process for forming a dry electrode film that does not use or substantially does not use a solvent. For example, the components of an active layer or electrode film, including a carbon material and a binder, may include, consist of, or essentially consist of dry particles. A combination of dry particles for forming an active layer or electrode film can be provided to provide a dry particle active layer mixture. In some embodiments, the active layer or electrode film may be formed from a dry particle active layer mixture such that the weight percentages of the components of the active layer or electrode film and the weight percentages of the components of the dry particle active layer mixture are substantially the same. In some embodiments, an active layer or electrode film formed from a dry particle active layer mixture using a dry manufacturing process may not contain, or substantially contain, any processing additives, such as solvents and the resulting solvent residues. In some embodiments, the resulting active layer or electrode film is a self-supporting film formed from a dry particle mixture using a dry process. In some embodiments, the resulting active layer or electrode film is a self-supporting film formed from a dry particle mixture using a dry process. The process for forming the active layer or electrode film may include fibrillating a binder component so that the film contains a fibrillating binder. In further embodiments, the self-supporting active layer or self-supporting electrode film may be formed in the absence of a current collector. In further embodiments, the active layer or electrode film may include a fibrillated polymer matrix so that the film is self-supporting. It is conceivable that a matrix, lattice, or web of fibrils can be formed to provide a mechanical structure to the electrode film.

[0080] • Energy storage devices In some embodiments, the energy storage device includes a separator, an anode electrode, a cathode electrode, an electrolyte, and a housing, wherein the electrolyte, separator, anode electrode, and cathode electrode are arranged within the housing, and the separator is positioned between the anode and cathode electrodes. In some embodiments, the cathode includes a blended cathode active material as described herein. In some embodiments, the energy storage device is formed by arranging the electrolyte, separator, anode electrode, and cathode electrode as described herein within the housing, with the separator positioned between the anode and cathode electrodes. In some embodiments, the energy storage device is a battery. In some embodiments, the energy storage device is a lithium-ion battery. In some embodiments, the energy storage device includes an anode electrode positioned between two cathode electrodes.

[0081] In some embodiments, the energy storage device is filled with a suitable lithium-containing electrolyte. For example, the energy storage device may include a lithium salt and a solvent, such as a non-aqueous solvent or an organic solvent. Generally, the lithium salt contains an anion that is stable to oxidation and reduction. In some embodiments, the anion may be monovalent. In some embodiments, the lithium salt may be selected from lithium hexafluoride phosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiFSI), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium bis(trifluoromethanesulfonyl)imide (LiN(SO2CF3)2), lithium trifluoromethanesulfonate (LiSO3CF3), lithium bis(oxalate)borate (LiB(C2O4)2), lithium bis(fluorosulfonyl)imide (LiN(SO2F)2), lithium difluoro(oxalate)borate (LiC2BF2O4), and combinations thereof. In some embodiments, the electrolyte may include a quaternary ammonium cation and an anion selected from the group consisting of hexafluorophosphate, tetrafluoroborate, and iodide. In some embodiments, the salt concentration may be about 0.1 mol / L(M) to about 5 M, about 0.2 M to about 3 M, or about 0.3 M to about 2 M. In further embodiments, the salt concentration of the electrolyte may be about 0.7 M to about 2 M. In certain embodiments, the salt concentration of the electrolyte may be about 0.2 M, about 0.3 M, about 0.4 M, about 0.5 M, about 0.6 M, about 0.7 M, about 0.8 M, about 0.9 M, about 1 M, about 1.1 M, about 1.2 M, 1.3 M, 1.4 M, 1.5 M, or values ​​in between.

[0082] In some embodiments, the energy storage device may contain a liquid solvent. The solvent does not need to dissolve all components of the electrolyte, nor does it need to completely dissolve any component. In further embodiments, the solvent may be an organic solvent. In some embodiments, the solvent may contain one or more functional groups selected from dioxathiolane (e.g., 1,3,2-dioxathiolane-2,2-dioxide (i.e., "DTD")), carbonates, ethers and / or esters. In some embodiments, the solvent may contain a carbonate. In further embodiments, the carbonate may be selected from cyclic carbonates, e.g., ethylene carbonate (EC), propylene carbonate (PC), vinylethylene carbonate (VEC), vinylene carbonate (VC), fluoroethylene carbonate (FEC) and combinations thereof, or acyclic carbonates, e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) and combinations thereof. In some embodiments, one or more solvents may be used in concentrations of 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, or 90% by weight, approximately these values, at least these values, or concentrations of at least these values, or any range between these values. In some embodiments, the solvent is used as an additive in the electrolyte system and can be used at concentrations of approximately 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1% by weight, 1.1% by weight, 1.2% by weight, 1.3% by weight, 1.4% by weight, 1.5% by weight, 1.6% by weight, 1.7% by weight, 1.8% by weight, 1.9% by weight, 2% by weight, 2.1% by weight, 2.2% by weight, 2.3% by weight, 2.4% by weight, 2.5% by weight, 2.6% by weight, 2.7% by weight, 2.8% by weight, 2.9% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, or 10% by weight, up to these values, or up to approximately these values, or any range of concentrations between these values.For example, in some embodiments, the amount of additive in the electrolyte is within the following ranges: 0.1–10% by weight, 1–6% by weight, 2–5% by weight, 0.1–6% by weight, 2–8% by weight, 2–3% by weight, or 1–4% by weight, or approximately one of these values.

[0083] In some embodiments, an energy storage device comprising a blended cathode active material may be characterized by improved performance, such as improved electrode capacity, improved battery cycle performance, reduced capacity loss over the device's lifespan, improved storage stability, improved power delivery, reduced electrode degradation, and / or reduced capacity fade.

[0084] In some embodiments, the cathode of the energy storage device has an initial specific capacity of 100 mAh / g, 120 mAh / g, 140 mAh / g, 150 mAh / g, 160 mAh / g, 170 mAh / g, 180 mAh / g, 190 mAh / g, 200 mAh / g, 250 mAh / g, 300 mAh / g, approximately these values, at least these values, or at least approximately these values, or any range between these values. In some embodiments, the capacity retention rate after 2000 cycles is 75%, 80%, 85%, or 90% of the original capacity, approximately these values, at least these values, or at least approximately these values, or any range between these values. In some embodiments, the capacity at C-rate 2 is 75%, 80%, 85%, or 90% of the capacity at C-rate 0.1, approximately these values, at least these values, or at least approximately these values, or any range between these values. In some embodiments, the capacity retention rate is 80%, 85%, 90%, or 95% of the original capacity or the fifth cycle capacity after a cycle of 3000 hours, approximately these values, at least these values, or at least approximately these values, or any range between these values. In some embodiments, the capacity retention rate is 90%, 91%, 92%, 93%, 94%, or 95% of the original capacity or the fifth cycle capacity after a cycle of 7000 hours, approximately these values, at least these values, or at least approximately these values, or any range between these values. In some embodiments, the capacity retention rate is 90%, 95%, 96%, or 97% of the original capacity or the fifth cycle capacity after a cycle of 4500 hours, approximately these values, at least these values, or at least approximately these values, or any range between these values. In some embodiments, the irreversible capacity loss after 500 hours of storage is 8%, 7%, 6%, 5%, 4%, or 3%, approximately these values, up to these values, or up to approximately these values, or any range between these values.In some embodiments, the irreversible capacity loss is 3%, 2%, or 1%, approximately these values, up to these values, or up to approximately these values, or any range between these values, after 1,000 hours of storage.

[0085] In some embodiments, energy storage devices containing a blended cathode active material reduce the decomposition of iron into electrolytes that may deposit on the anode. In some embodiments, the area load of iron deposited on the anode electrode after 7,000 hours of cycling at 40°C is 0.8 μg / cm². 2 , 0.7 μg / cm³ 2 , 0.6 μg / cm³ 2 Or 0.5 μg / cm³ 2 , approximately these values, up to these values, or up to approximately these values, or any range between these values. In some embodiments, the area loading of iron deposited on the anode electrode after 3,400 hours of cycling at 55°C is 1.8 μg / cm² 2 , 1.6 μg / cm³ 2 , 1.4 μg / cm³ 2 , 1.2 μg / cm³ 2 , or 1.1 μg / cm³ 2 , approximately these values, at most these values, or at most approximately these values, or any range between these values. In some embodiments, the area loading of iron deposited on the anode electrode after 4,400 hours of cycling at 70°C is 6 μg / cm². 2 5.5 μg / cm³ 2 5 μg / cm³ 2 4.5 μg / cm³ 2 4 μg / cm³ 2 3.5 μg / cm³ 2 , or 3 μg / cm³ 2 , approximately these values, at most these values, or at most approximately these values, or any range between these values. [Examples]

[0086] Exemplary embodiments of the present disclosure, including processes, materials, and / or products obtained, are described in the following examples.

[0087] • Example 1 - Preparation of processed and treated nickel oxide-based active materials Raw LiNi 1-x-y Mn x Co y O2(NMC) powder was ball-milled for approximately 5 days to form processed NMC powder. Raw NMC powder was milled using a ceramic mill jar and zirconia mill beads. 1 kg of raw NMC powder was loaded into a mill jar in a dry room, then airtightly sealed and milled. Milling was performed in air using a roller mill.

[0088] Next, the processed NMC powder was heated in an O2 atmosphere for approximately 5 hours at 650°C, 700°C, and 800°C, respectively, to form treated NMC powder.

[0089] Figure 3A shows the SEM image and XRD spectrum of the unprocessed NMC powder. As shown in Figure 3A, the unprocessed NMC has a relatively smooth surface. Figure 3B shows the SEM image and XRD spectrum of the processed NMC powder. Figure 3C shows the SEM image of the processed NMC powder heated at 700°C.

[0090] Figure 4A shows the amount of impurities in raw and treated NMC powders formed under different conditions. As shown in Figure 4A, the raw NMC powder ("parent") contains relatively small amounts of LiOH and Li2CO3. In contrast, the processed NMC powder ("child") contains relatively large amounts of LiOH and Li2CO3. The amounts of LiOH and Li2CO3 in the processed NMC powder after heating at 650°C ("child 650C"), 700°C ("child 700C"), and 800°C ("child 800C") gradually decrease compared to the unheated processed NMC powder, respectively.

[0091] Figure 4B shows the specific surface areas of unprocessed NMC powder, processed NMC powder, and treated NMC powder formed under different conditions. As shown in Figure 4B, the specific surface area of ​​unprocessed NMC powder (parent) is relatively low, the specific surface area of ​​processed NMC powder ("child") is relatively high, and the specific surface area of ​​treated NMC powder heated at 650°C ("child_650C"), 700°C ("child_700C"), and 800°C ("child_800C") gradually decreases compared to processed NMC powder without heating.

[0092] • Example 2 - Preparation of Blend Cathode LiFePO4 (LFP) and unprocessed or processed LiNi 1-x-y Mn x Co y A blended cathode active material mixture was formed by blending O2(NMC) powder with LFP in a mass ratio of 9:1 or 9.8:0.2. The resulting LFP / NMC mixture, carbon black, polyvinylidene fluoride (PVDF), and N-methyl-2-pyrrolidone (NMP) were blended into a slurry. The mass ratio of LFP / NMC mixture:carbon black:PVDF was 96:2:2 or 92:4:4. The resulting slurry was coated onto aluminum foil using a slurry coater. The coated electrodes were then calcined in a furnace at over 120°C to remove all NMP solvent.

[0093] • Example 3 - LFP / Unprocessed NMC Pouch Type Battery Structure Three types of pouch-type batteries were prepared using unprocessed NMC powder. Two types of NMC were tested and blended with LFP in the cathode: LiNi 0.6 Mn 0.4 O2 (NMC640) and LiNi 0.83 Mn 0.06 Co 0.11 O2 (Ni83 or NMC Ni83). The mass ratio of the LFP / NMC mixture:carbon black:PVDF was 96:2:2. All anodes in the battery were graphite. Table 1 summarizes the prepared LFP / NMC battery structures. [Table 1] "Balanced voltage" is the voltage at which the battery is designed to have a cathode-to-anode area capacity ratio of 115:100 (this is the "N / P ratio") and a capacity of 220mAh. • "Positive electrode area" refers to the area of ​​the electrode coating on the positive electrode side (cathode).

[0094] • Example 4 - Electrochemical performance of LFP / raw NMC The electrochemical performance of the batteries prepared in Example 3 was tested. Figure 5A is a plot showing the first charge-discharge voltage-capacity curve of a battery containing a blended cathode active material with 90% LFP and 10% raw NMC640, compared to a baseline battery containing 100% LFP. Figure 5B is a plot showing the first charge-discharge voltage-capacity curve of a battery containing a blended cathode active material with 90% LFP and 10% raw NMC Ni83, compared to a baseline battery containing 100% LFP.

[0095] As shown in Figures 5A and 5B, the LFP battery was charged with a constant current to 3.8V and then discharged with a constant current to 2.5V at C / 20, where 5C is equivalent to 220mAh. Since the capacity did not significantly increase when the battery was charged to a voltage higher than 3.5V, the entire capacity of the LFP was stored between 2.5V and 3.5V.

[0096] LFP / raw NMC640 batteries and LFP / raw Ni83 batteries were charged and discharged using a two-step procedure (also known as "Blended 3.8V 2-Step"). The LFP / raw NMC640 batteries and LFP / raw Ni83 batteries were (1) charged with constant current constant voltage (CCCV) at C / 3 to 3.5V (based on LFP capacity), (2) charged with constant current at C / 3 to 3.8V (based on NMC capacity), (3) discharged with constant current at C / 3 to 3.5V (based on NMC capacity), and (4) discharged with constant current at C / 3 to 2.5V (based on LFP capacity). Thus, in the blended batteries, all of the LFP capacity from 2.5V to 3.5V was provided by the LFP, and all of the capacity from 3.5V to 3.8V was provided by the NMC, as shown as an additional gradient in Figures 5A and 5B.

[0097] Figure 5C shows the voltage versus normalized charge capacity curves of an LFP / raw NMC640 battery compared to a baseline battery containing 100% LFP and another battery containing 100% raw NMC532. The batteries were equilibrated to charge to 3.8V, and the experiment was performed at 70°C with a cycle rate of C / 3. The voltage capacity profile of the LFP / raw NMC640 battery could be distinguished from the 100% LFP battery and the 100% raw NMC532 battery because the material detached lithium in a completely separate voltage range. Furthermore, it was observed that a 10 wt% addition of raw NMC640 to the LFP / raw NMC640 battery accounted for approximately 20% of the capacity when charging was limited to 3.8V.

[0098] • Example 5 - LMFP / Unprocessed NMC Pouch-Type Battery Structure Three pouch-type batteries were prepared, two types of raw NMC were tested, and LiMn was used in the cathode. 0.8 Fe 0.2 Blended with PO4 (LMFP): LiNi 0.6 Mn 0.4 O2 (NMC640) and LiNi 0.83 Mn 0.06 Co 0.11 O2 (Ni83 or NMC Ni83). All anodes in the battery were graphite. Table 2 summarizes the prepared LMFP / raw NMC battery structures. [Table 2]

[0099] • Example 6 - Electrochemical performance of LMFP / raw NMC The electrochemical performance of the batteries prepared in Example 5 was tested. Figure 5D is a plot showing the first charge-discharge voltage-capacity curves of batteries containing blended cathode active materials including LMFP / raw NMC640 and LMFP / raw Ni83, compared to a baseline battery containing 100% LMFP.

[0100] Since the voltage ranges of LMFP and NMC overlap, a single-step charge / discharge procedure was used. As shown in Figure 5D, all batteries were charged with a constant current to 4.2V, and then discharged with a constant current to 2.5V at C / 20, where 5C is equivalent to 220mAh. Similar to Figures 5A and 5B, an additional gradient was observed in the LMFP / raw NMC640 battery and the LMFP / raw Ni83 battery compared to the LMFP battery.

[0101] • Example 7 - Cycling performance of LFP / raw NMC640 at 40°C The cycle performance of LFP / raw NMC640 batteries (i.e., “blended” or “blended batteries”) was tested at 40°C compared to a baseline battery containing 100% LFP (i.e., “LFP” or “LFP batteries”). The batteries contained an electrolyte containing 1.5 M lithium bis(fluorosulfonyl)imide (LiFSI) salt dissolved in ethylene carbonate (EC) and dimethyl carbonate (DMC) solvents (EC:DMC volume ratio was 3:7), with 2 wt% vinylene carbonate (VC) as an additive. The test procedures for LFP / raw NMC640 batteries and LFP batteries were as follows: (a) "LFP_3.5V" - Charge the LFP battery to 3.5V using C / 3 and then discharge it to 2.5V using constant current with C / 3; (b) "Blend_3.5V_no_acti" - Charge the blend battery to 3.5V with C / 3 CCCV (1) and discharge it to 2.5V with constant current with C / 3 (2) (c) "Blend_3.5V_one_acti" - In the first cycle, the Blend battery is (1) charged to 3.8V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3, and in the remaining cycles, (1) charged to 3.5V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3; (d) "Blend 9 3.5V 1 3.8V" - Charge the blend battery to CCCV at (1) C / 3 to 3.5V over 1.9 cycles, (2) constant current discharge at C / 3 to 2.5V, charge at CCCV at C / 3 to 3.5V over 2.1 cycles, (2) constant current charge at C / 3 to 3.8V, (3) constant current discharge at C / 3 to 3.5V, (4) constant current discharge at C / 3 to 2.5V, and loop back to step 1; (e) "LFP_3.8V" - Charge the LFP battery to 3.8V with C / 3 and discharge it with constant current to 2.5V with C / 3; (f) "Blend 3.8V 1 step" - Charge the blend battery to CCCV (1) C / 3 to 3.8V, and (2) discharge it to 2.5V with constant current using C / 3; (g) "Blend 3.8V 2-step process" - Charge the blend battery (1) with C / 3 to 3.5V using CCCV, (2) with C / 3 constant current charge to 3.8V, (3) with C / 3 constant current discharge to 3.5V, and (4) with C / 3 constant current discharge to 2.5V; (h) "Blend 3.7V 2-step process" - Charge the blend battery to CCCV (1) 3.5V (based on LFP capacity) using C / 3, (2) charge with constant current using C / 3 to 3.7V, (3) discharge with constant current using C / 3 to 3.5V, and (4) discharge with constant current using C / 3 to 2.5V.

[0102] Figure 6A shows the actual battery discharge capacity versus cycle time for the described LFP / raw NMC640 battery and LFP battery, and Figure 6B shows the battery discharge capacity of Figure 6A normalized for the fifth cycle. Figures 6A and 6B demonstrate that the LFP / raw NMC640 battery showed a 2x improvement in overall capacity retention compared to a baseline battery containing 100% LFP. Figures 6A and 6B also show an improvement in NMC capacity activation, as the LFP / raw NMC640 battery provided superior overall capacity retention.

[0103] Figure 6C shows the internal resistance versus cycle time (by normalized delta V (dV)) of the described LFP / raw NMC640 battery and LFP battery. Delta V is the difference between the average charge voltage and the average discharge voltage and represents the occurrence of battery tension over cycle time. Blended batteries and pure LFP batteries were observed to have stable battery tension throughout the entire cycle. It was further observed that blending NMC with LFP did not increase tension during cycling at 40°C.

[0104] • Example 8 - Cycling performance of LFP / raw NMC640 at 55°C The cycle performance of LFP / raw NMC640 batteries (i.e., “blended” or “blended batteries”) was tested at 55°C compared to a baseline battery containing 100% LFP (i.e., “LFP” or “LFP batteries”). The batteries contained the same electrolyte as in Example 7. The test procedures for LFP / raw NMC640 batteries and LFP batteries were as follows: (a) "LFP_3.5V" - Charge the LFP battery to 3.5V using C / 3 and then discharge it to 2.5V using constant current with C / 3; (b) "LFP_3.8V" - Charge the LFP battery to 3.8V using C / 3 and discharge it to 2.5V using constant current with C / 3; (c) "Blend_3.5V_one_acti" - In the first cycle, the Blend battery is (1) charged to 3.8V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3, and in the remaining cycles, (1) charged to 3.5V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3; (d) "Blend 3.8V 2-step process" - Charge the blend battery to CCCV (1) 3.5V with C / 3, (2) constant current charge to 3.8V with C / 3, (3) constant current discharge to 3.5V with C / 3, and (4) constant current discharge to 2.5V with C / 3.

[0105] Figure 7A shows the actual battery discharge capacity versus cycle time for the described LFP / raw NMC640 battery and LFP battery, and Figure 7B shows the normalized battery discharge capacity of Figure 7A for the fifth cycle. Figures 7A and 7B demonstrate a similar improvement in capacity retention rate in the blended LFP / raw NMC640 battery at 55°C compared to the LFP battery. Figure 7C shows the internal resistance versus cycle time (by normalized delta V (dV)) for the described LFP / raw NMC640 battery and LFP battery, demonstrating that the blend of NMC and LFP did not increase the tension during cycling at 55°C.

[0106] • Example 9 - Cycling performance of LFP / raw NMC640 at 70°C The cycle performance of LFP / raw NMC640 batteries (i.e., “blended” or “blended batteries”) was tested at 70°C compared to a baseline battery containing 100% LFP (i.e., “LFP” or “LFP batteries”). The batteries contained the same electrolyte as in Example 7. The test procedures for LFP / raw NMC640 batteries and LFP batteries were as follows: (a) "LFP_3.5V" - Charge the LFP battery to 3.5V using C / 3 and then discharge it to 2.5V using constant current with C / 3; (b) "Blend_3.5V_no_acti" - Charge the blend battery to 3.5V with C / 3 CCCV (1) and discharge it to 2.5V with constant current with C / 3 (2) (c) "Blend_3.5V_one_acti" - In the first cycle, the Blend battery is (1) charged to 3.8V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3, and in the remaining cycles, (1) charged to 3.5V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3; (d) "Blend 9 3.5V 1 3.8V" - Charge the blend battery to CCCV at (1) C / 3 to 3.5V over 1.9 cycles, (2) constant current discharge at C / 3 to 2.5V, charge at CCCV at C / 3 to 3.5V over 2.1 cycles, (2) constant current charge at C / 3 to 3.8V, (3) constant current discharge at C / 3 to 3.5V, (4) constant current discharge at C / 3 to 2.5V, and loop back to step 1; (e) "LFP_3.8V" - Charge the LFP battery to 3.8V with C / 3 and discharge it with constant current to 2.5V with C / 3; (f) "Blend 3.8V 1 step" - Charge the blend battery to CCCV (1) C / 3 to 3.8V, and (2) discharge it to 2.5V with constant current using C / 3; (g) "Blend 3.8V 2-step process" - Charge the blend battery (1) with C / 3 to 3.5V using CCCV, (2) with C / 3 constant current charge to 3.8V, (3) with C / 3 constant current discharge to 3.5V, and (4) with C / 3 constant current discharge to 2.5V; (h) "Blend 3.7V 2-step process" - Charge the blend battery to CCCV (1) 3.5V with C / 3, (2) constant current charge to 3.7V with C / 3, (3) constant current discharge to 3.5V with C / 3, and (4) constant current discharge to 2.5V with C / 3.

[0107] Figure 8A shows the actual battery discharge capacity versus cycle time for the described LFP / raw NMC640 battery and LFP battery, and Figure 8B shows the normalized battery discharge capacity for the fifth cycle. Figures 8A and 8B demonstrate that the LFP / raw NMC640 battery exhibits improved overall capacity retention at higher voltages. Figure 8C shows the internal resistance versus cycle time (by normalized delta V (dV)) for the described LFP / raw NMC640 battery and LFP battery, demonstrating that the blend of NMC and LFP did not increase puncture during cycling at 70°C.

[0108] • Example 10 - Full cycle performance of LFP / raw NMC640 at 70°C The full electrochemical cycle performance of LFP / raw NMC640 batteries (i.e., “Blend”, “Blend Battery”, or “NMC+LFP”) was tested at 70°C compared to a baseline battery containing 100% LFP (i.e., “LFP”, or “LFP Battery”) or 100% NMC532 (i.e., “NMC”, or “NMC Battery”). The battery types, electrolytes, and test procedures for LFP / raw NMC640, NMC, and LFP batteries were as follows: (a) Charge an NMC532 battery containing an electrolyte containing lithium hexafluoride phosphate (LiPF6) salt dissolved in a blended solvent with an EC to DMC ratio of 3:7 and containing 2 wt% VC to 3.8V at C / 3; (b) Charge an NMC532 battery containing an electrolyte containing a LiFSI salt dissolved in a blended solvent with an EC to DMC ratio of 3:7 and containing 2 wt% VC to 3.8V at C / 3; (c) Charge an LFP battery containing an electrolyte containing a LiPF6 salt dissolved in a blended solvent with an EC to DMC ratio of 3:7 and containing 2 wt% VC to 3.65V at C / 3; (d) Charge an LFP battery containing an electrolyte containing a LiFSI salt dissolved in a blended solvent with an EC to DMC ratio of 3:7 and containing 2 wt% VC to 3.65V at C / 3; (e) Charge an LFP / NMC640 battery containing an electrolyte containing a LiPF6 salt dissolved in a blended solvent with an EC to DMC ratio of 3:7 and containing 2 wt% VC to 3.8V at C / 3; (f) Charge an LFP / NMC640 battery containing an electrolyte with LiFSI salt dissolved in a blended solvent containing 2 wt% VC and an EC to DMC ratio of 3:7 to "NMC+LFP w / LiFSI(3.80V)" to 3.8V at C / 3.

[0109] Plot (a) in Figure 9 shows the discharge capacity as a function of time over the full electrochemical cycle window for the described LFP / raw NMC640, LFP, and NMC batteries. The rate of capacity loss was fastest for the LFP battery, followed by the NMC532 battery containing LiPF6. The LFP / raw NMC640 battery containing LiPF6 showed improved capacity retention compared to the NMC532 battery. Surprisingly, the LFP / raw NMC640 battery, in which the majority of the positive electrode is composed of LFP, yielded superior capacity retention at 70°C compared to the battery with an NMC positive electrode using a LiPF6 electrolyte. Furthermore, the LFP / raw NMC640 battery containing a LiFSI electrolyte showed improved capacity retention compared to the LFP / raw NMC640 battery containing a LiPF6 electrolyte.

[0110] Plots (b) and (c) in Figure 9 show the discharge capacities classified by contributions above 3.5V (i.e., 3.5–3.8V) and below 3.5V (i.e., 2.5–3.5V), respectively. Discharge capacities above 3.5V can represent capacities attributable to NMC, and discharge capacities below 3.5V represent capacities attributable to LFP. As observed in plot (b) of Figure 9, the LFP / raw NMC640 battery showed a very low rate of capacity fade after 1,000 hours. Furthermore, plot (c) of Figure 9 shows that including raw NMC640 in the blended cathode battery results in a reversible cycle improvement, including a slight reduction in fade, compared to the LFP battery. The LFP / raw NMC640 battery also shows superior performance when using LiPF6. Thus, as observed in Figure 9, the inclusion of NMC in the LFP battery resulted in an improvement in cycle life.

[0111] • Example 11 - Cycling performance of LFP / raw Ni83 at 70°C The cycle performance of LFP / raw Ni83 batteries (i.e., "blended" or "blended batteries") was tested at 70°C compared to a baseline battery containing 100% LFP (i.e., "LFP" or "LFP batteries"). The batteries contained an electrolyte containing 1.5 M LiFSI salt dissolved in a blended solvent with 2 wt% VC and an EC to DMC ratio of 3:7. The test procedures for LFP / Ni83 and LFP batteries were as follows: (a) "LFP_3.5V" - Charge the LFP battery to 3.5V using C / 3 and then discharge it to 2.5V using constant current with C / 3; (b) "Blend_3.5V_no_acti" - Charge the blend battery to 3.5V with C / 3 CCCV (1) and discharge it to 2.5V with constant current with C / 3 (2) (c) "Blend_3.5V_one_acti" - In the first cycle, the Blend battery is (1) charged to 3.8V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3, and in the remaining cycles, (1) charged to 3.5V with C / 3 CCCV and (2) discharged with constant current to 2.5V with C / 3; (d) "LFP_3.8V" - Charge the LFP battery to 3.8V using C / 3 and discharge it to 2.5V using a constant current with C / 3; (e) "Blend 3.8V 1 step" - (1) Charge the blend battery to 3.8V with C / 3 using CCCV, and (2) discharge it to 2.5V with constant current using C / 3; (f) "Blend 3.8V 2-step process" - Charge the blend battery to CCCV (1) 3.5V with C / 3, (2) constant current charge to 3.8V with C / 3, (3) constant current discharge to 3.5V with C / 3, and (4) constant current discharge to 2.5V with C / 3.

[0112] Figure 10A shows the actual battery discharge capacity versus cycle time for the LFP / raw Ni83 battery and LFP battery described herein, and Figure 10B shows the normalized battery discharge capacity for the fifth cycle. Figures 10A and 10B demonstrate that blending 10% Ni83 with LFP improved the overall capacity retention of the battery. Figure 10C shows the internal resistance versus cycle time (by normalized delta V (dV)) for the LFP / raw Ni83 battery and LFP battery, demonstrating that the blend of NMC and LFP did not increase the tension during cycling at 70°C.

[0113] • Example 12 - Cycle performance of LMFP / raw NMC640 and LMFP / raw Ni83 The cycle performance of LMFP / raw NMC640 batteries and LMFP / raw Ni83 batteries at 40°C, 55°C, and 70°C was tested compared to a baseline battery containing 100% LMFP (i.e., "LMFP" or "LMFP battery"). The batteries contained an electrolyte containing 1.5 M LiPF6 salt dissolved in a blended solvent with an EC to DMC ratio of 3:7, containing 2 wt% VC and 1 wt% 1,3,2-dioxathiolane-2,2-dioxide (DTD). The LMFP / raw NMC640 batteries, LMFP / raw Ni83 batteries, and LMFP batteries were charged and discharged at a constant current to CCCV at a rate of C / 3 in the voltage range of 4.2V to 2.5V.

[0114] LMFP / raw NMC640 batteries and LMFP / raw Ni83 batteries delivered similar cycle performance compared to baseline 100% LMFP batteries.

[0115] • Example 13 - Anode Iron Deposition To verify whether blending NMC with LFP reduces Fe dissolution from LFP, X-ray fluorescence (XRF) spectroscopy was used to measure the area loading (μg / cm²) of Fe deposited on the graphite anode of LFP / raw NMC640 batteries and pure LFP batteries. 2 The amount of iron deposited on the anode electrode was quantified. Figure 11A is a bar graph showing the area loading of iron deposited on the anode electrode after 7,000 hours of cycling at 40°C. For example, Figure 11A shows that the amount of iron deposited on the anode electrode in a pure LFP battery is approximately 0.8 μg / cm³ after 7,000 hours of cycling at 40°C. 2 In contrast, the iron deposition on the anode electrode of the LFP / raw NMC640 battery was approximately 0.6 μg / cm³. 2 The following was observed. Figure 11B is a bar graph showing the area loading of iron deposited on the anode electrode after 3,400 hours of cycling at 55°C. For example, Figure 11B shows that the amount of iron deposited on the anode electrode in a pure LFP battery was approximately 1.9 μg / cm³ after 3,400 hours of cycling at 55°C. 2 In contrast, the iron deposit on the anode electrode of the LFP / raw NMC640 battery was approximately 1.2 μg / cm³. 2 This indicates that the amount was less than [amount missing]. Figure 11C is a bar graph showing the area loading of iron deposited on the anode electrode after 4,400 hours of cycling at 70°C. For example, Figure 11C shows that the amount of iron deposited on the anode electrode in a pure LFP battery was approximately 6 μg / cm³ after 4,400 hours of cycling at 70°C. 2 In contrast, the iron deposit on the anode electrode of LFP / raw NMC640 batteries was approximately 5 μg / cm³ at most. 2 It is approximately 3.5 μg / cm³ 2This indicates that the level was low. As shown in Figures 11A, 11B, and 11C, batteries containing LFP / raw NMC640 showed less Fe dissolution from the cathode and deposition on the anode compared to baseline batteries containing 100% LFP.

[0116] Figure 11D is a plot showing the area load of iron deposited on the anode electrode of batteries after being held at various temperatures, as a function of normalized discharge capacity loss. In other words, Figure 11D shows the normalized discharge capacity loss in these long-cycled batteries as a function of the area load of Fe (μg / cm²) on their graphite anodes. 2 The results are shown for the following: At each temperature, the LFP / raw NMC640 battery cycled at a maximum of 3.8V had the least Fe deposition and the lowest capacity loss. Furthermore, the battery containing 100% LFP had the most Fe deposition and the highest capacity loss. In addition, normalized capacity loss and Fe area loading showed a linear correlation at each temperature, and battery capacity loss and Fe dissolution from the cathode electrode were positively correlated, indicating that these can be reduced by blending raw NMC with LFP.

[0117] • Example 14 - Storage test of LFP / raw NMC640 battery at 60°C Electrochemical impedance spectroscopy (EIS) was used to measure the charge transfer resistance (Rct) of batteries containing various cathode active materials after 500 and 1,000 hours of storage. By comparing the Rct before and after storage, the increase in the battery's resistance to charge transfer during the storage period can be determined. Here, LFP / raw NMC640 batteries and pure LFP batteries were filled with an electrolyte containing either 1.5 M LiFSI salt or 1.5 M LiPF6 salt dissolved in a blended solvent with a 3:7 ratio of EC to DMC, containing 2 wt% VC. The batteries were charged to 3.8 V at C / 20 and then stored under open-circuit conditions at 60°C without charging or discharging by an external circuit. The capacity loss and impedance of the batteries were measured after 500 and 1,000 hours.

[0118] Figure 12A is a bar graph showing the area-to-area charge transfer resistance of batteries containing various cathode active materials and electrolyte salts, compared to a baseline battery, after storage at 60°C. As demonstrated by Figure 12A, batteries with LiPF6 salts showed a much larger increase in Rct. However, using the same electrolyte solution, LFP / raw NMC640 batteries showed a similar Rct to pure LFP batteries.

[0119] Figures 12B and 12C show capacity loss during storage at 60°C. Irreversible loss refers to the portion of capacity loss that cannot be recovered in subsequent cycles. Reversible loss refers to the portion of capacity loss that can be recovered in subsequent cycles. In both storage periods of 0–500 hours and 500–1,000 hours at 60°C, the LFP / raw NMC640 battery showed less irreversible loss than the pure LFP battery. Furthermore, the reversible loss of the LFP / NMC640 battery was similar to that of the pure LFP battery.

[0120] • Example 15 - Manufacturing and Cycle Performance of NMC622 Half-Battery Half-cells were manufactured using cathode electrodes containing unprocessed NMC622 powder, processed NMC622 powder, or treated NMC622 powder as the cathode active material. A slurry was formed by mixing the unprocessed NMC622 powder, processed NMC622 powder, or treated NMC622 powder, carbon black, and PVDF in a ratio of 92:4:4 in NMP. The resulting slurry was coated onto aluminum foil using a slurry coater. The coated electrodes were then fired in a furnace exceeding 120°C to remove the NMP solvent and form a cathode. The formed cathode was assembled into a half-cell. The half-cell contained an electrolyte having 1M LiPF6 salt dissolved in fluoroethylene carbonate (FEC) and dimethyl carbonate (DMC) solvents (the volume ratio of FEC:DMC was 1:4).

[0121] The half-cell was manufactured by arranging the cathode electrode, separator, and lithium foil within the half-cell housing. The half-cell cycle performance of the NMC622 cell was tested at 30°C. The test procedure for the NMC622 half-cell was as follows: charge to 4.3V with C / 5 in CCCV; discharge to 3V with constant current in C / 5.

[0122] Figure 13A shows the cycle performance of NMC622 half-cells including raw NMC622 powder ("parent"), processed NMC622 powder ("child"), treated NMC622 powder heated at 650°C ("child_650_reheated"), and treated NMC622 powder heated at 700°C ("child_700_reheated"). Figure 13B shows the normalized cycle performance of the NMC622 half-cells. As shown in Figure 13A, all half-cells have similar initial capacities. As shown in Figures 13A and 13B, half-cells containing raw NMC622 powder, as well as half-cells containing treated NMC622 powder heated at 650°C and 700°C, have a capacity retention rate of over 90% after 50 cycles, and the capacity retention rate of the treated NMC622 powder heated at 700°C is similar to that of the raw NMC622 powder.

[0123] • Example 16 - Cycling performance of LFP / NMC622 at 55°C Three single-layer pouch (SLP) type batteries were prepared using the same raw or processed NMC powder as in Example 3. 0.6 Mn 0.2 Co 0.2 O2(NMC 622)NMC 622 was used. Raw NMC622 powder was ground for approximately 5 days, and then heated at 700°C to form processed NMC powder. Raw or processed NMC powder was mixed with LFP in the intended ratio to form an LFP / NMC mixture. The mass ratio of LFP / NMC mixture:carbon black:PVDF was 92:4:4. All anodes in the battery were graphite. Table 3 summarizes the prepared LFP / NMC battery structures. [Table 3]

[0124] The batteries were tested at 55°C. The batteries contained the same electrolyte as those in Example 7. The test procedure for the LFP / NMC622 batteries and LFP batteries was as follows: (1) Charge to 3.8V with C / 3 in CCCV; (2) Discharge to 2.5V with constant current in C / 3.

[0125] Figure 14A shows the voltage-to-time curve of total capacity at C / 20. Figure 14B is a magnified view showing the circled region of the voltage curve in Figure 14A. Figure 15A shows the actual battery discharge capacity versus cycle time plot for the described LFP / NMC622 and LFP batteries, and Figure 15B shows the normalized discharge capacity of Figure 15A. Figures 15A and 15B demonstrate that batteries using 2 wt% processed NMC622 powder have similar performance and capacity retention to batteries using 10 wt% raw NMC622 powder, and improved capacity retention compared to batteries using 2 wt% raw NMC622 powder. Furthermore, all batteries using NMC622 powder blended with LFP powder have improved capacity retention compared to batteries using LFP powder alone. Figure 15C shows the internal resistance versus cycle time (by normalized delta V (dV)) for the described LFP / NMC622 and LFP batteries.

[0126] While specific embodiments have been described, these embodiments are presented as examples only and are not intended to limit the scope of this disclosure. In fact, the novel methods and systems described herein can be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the systems and methods described herein without departing from the spirit of this disclosure. The appended claims and their equivalents are intended to encompass forms or modifications that fall within the scope and spirit of this disclosure.

[0127] Features, materials, properties, or groups described in relation to a particular aspect, embodiment, or example should be understood to be applicable to any other aspect, embodiment, or example described in this section or elsewhere in this specification, unless incompatible therewith. All features disclosed herein (including the accompanying claims, abstract, and drawings) and / or all steps of any method or process disclosed herein may be combined in any combination, except for any combination in which at least some of such features and / or steps are mutually exclusive. The protection is not limited to any details of any of the aforementioned embodiments. The protection extends to any novel features or any novel combination of features disclosed herein (including the accompanying claims, abstract, and drawings), or to any novel steps of any method or process disclosed herein.

[0128] Furthermore, certain features described in this disclosure in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may be implemented separately in multiple embodiments or in any suitable subcombination. Furthermore, although features may be described above as acting in a particular combination, one or more features from a claimed combination may, in some cases, be removed from the combination, and the combination may be claimed as a subcombination or a variation of a subcombination.

[0129] Furthermore, while operations may be shown in the drawings or described herein in a specific order, such operations do not need to be performed in the specific order shown or in a sequential order, or not all operations need to be performed, in order to achieve the desired result. Other operations not shown or described may be incorporated into the exemplary methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or in between any of the described operations. Furthermore, operations may be rearranged or rearranged in other embodiments. Those skilled in the art will understand that in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the drawings. Depending on the embodiment, some of the steps described above may be omitted and others added. Furthermore, features and attributes of the particular embodiments disclosed above can be combined in various ways to form further embodiments, all of which fall within the scope of this disclosure. Also, the separation of various system components in the above embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described components and systems can generally be integrated into a single product or packaged into multiple products. For example, any of the components of the energy storage system described herein can be provided separately or integrated (e.g., packaged together or combined together) to form an energy storage system.

[0130] For the purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not all such advantages can necessarily be achieved according to any particular embodiment. Therefore, for example, a person skilled in the art will recognize that this disclosure may be embodied or implemented to achieve one advantage or group of advantages taught herein without necessarily achieving other advantages that can be taught or suggested herein.

[0131] Conditional language such as “can,” “could,” “might,” or “may,” unless otherwise specified or understood to have a different meaning in the context in which they are used, is generally intended to convey that a particular embodiment includes certain features, elements, and / or processes, but other embodiments do not. Therefore, such conditional language does not generally imply that features, elements, and / or processes are required in any way in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether these features, elements, and / or processes should be included in or performed in any particular embodiment, with or without user input or prompting.

[0132] Conjunctions such as the phrase "at least one of X, Y, and Z" are generally understood in contexts where they are used to convey that an item, term, etc., could be any of X, Y, or Z, unless otherwise specified. Therefore, such conjunctions are not generally intended to imply that a particular embodiment requires the presence of at least one X, at least one Y, and at least one Z.

[0133] The terms "approximately," "about," "generally," and "substantially" as used herein represent values, quantities, or characteristics close to the stated values, quantities, or characteristics that still perform the desired function or achieve the desired result. For example, the terms "approximately," "about," "generally," and "substantially" may refer to quantities within 10%, 5%, 1%, 0.1%, and 0.01% of the stated quantity, depending on the desired function or desired result.

[0134] The scope of this disclosure is not intended to be limited by any specific disclosure of preferred embodiments in this section or elsewhere in this specification, but may be defined by the claims, as presented in this section or elsewhere in this specification, or as to be presented in the future. The language of the claims should be interpreted broadly on the basis of the language used in the claims, and should be construed as non-exclusive, not limited to the embodiments described herein or under examination of the application.

[0135] If any, headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein.

Claims

1. Iron phosphate-based active material, A nickel oxide-based active material comprising at least one lithium nickel manganese cobalt oxide or lithium nickel cobalt aluminum oxide, A blend of cathode active materials, including a blend of cathode active materials.

2. The blended cathode active material according to claim 1, wherein the iron phosphate-based active material is selected from the group consisting of lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), and combinations thereof.

3. The blended cathode active material according to claim 1 or 2, wherein the nickel oxide-based active material is selected from the group consisting of lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum oxide (NCA), and combinations thereof.

4. The blended cathode active material according to claim 3, wherein the NMC is selected from the group consisting of NMC550, NMC640, NMC631, NMC730, NMC75:25:0, NMC532, NMC111, NMC811, NMC622, NMC Ni83, NMC Ni91, and combinations thereof.

5. A blended cathode active material according to any one of claims 1 to 4, comprising the iron phosphate-based active material in a concentration of approximately 90 to 99% by weight.

6. A blended cathode active material according to any one of claims 1 to 5, comprising the nickel oxide-based active material in a concentration of about 0.1 to 15% by weight.

7. A blended cathode active material according to any one of claims 1 to 6, comprising the nickel oxide-based active material in a concentration of about 0.1 to 3% by weight.

8. The nickel oxide-based active material is at least about 4 m ２ A blend cathode active material according to any one of claims 1 to 7, having a specific surface area of ​​1 / g.

9. The blended cathode active material according to any one of claims 1 to 8, wherein the nickel oxide-based active material contains less than about 3% by weight of lithium-containing impurities.

10. The lithium-containing impurity is LiOH, Li ２ CO ３ A blend cathode active material according to claim 9, selected from the group consisting of the following, and combinations thereof.

11. The blended cathode active material according to any one of claims 1 to 10, wherein the nickel oxide-based active material contains less than about 0.5% by weight of LiOH.

12. The nickel oxide-based active material contains less than 1% by weight of Li ２ CO ３ A blend cathode active material according to any one of claims 1 to 11, comprising:

13. An energy storage device, A cathode electrode comprising a blended cathode active material according to any one of claims 1 to 12, Separator and, Anode electrode and Electrolytes, Housing and Equipped with, An energy storage device in which the cathode electrode, the separator, and the anode electrode are arranged within the housing.

14. The energy storage device according to claim 13, wherein the anode electrode contains a graphite active material.

15. A process for forming a blend cathode active material, The step of combining an iron phosphate-based active material with a nickel oxide-based active material to form a blended cathode active material mixture includes: A process wherein the nickel oxide-based active material comprises at least one of lithium nickel manganese cobalt oxide and lithium nickel cobalt aluminum oxide.

16. The process according to claim 15, further comprising the step of surface-machining the nickel oxide-based active material before the combining step.

17. The process according to claim 15 or 16, wherein the step of surface-processing the nickel oxide-based active material includes grinding.

18. The step of surface-processing the nickel oxide-based active material involves water and CO ２ The process according to any one of claims 15 to 17, carried out in an atmosphere of non-existence of the following.

19. The process according to any one of claims 15 to 17, wherein the step of surface-processing the nickel oxide-based active material is performed in ambient air.

20. The process according to any one of claims 15 to 19, further comprising the step of heating the nickel oxide-based active material before combining the iron phosphate-based active material with the nickel oxide-based active material.

21. The process according to claim 20, wherein the heating is carried out at a temperature of 650°C to 800°C.

22. A method for forming a blended cathode active material, The steps include: surface processing of a nickel oxide-based active material to form a processed nickel oxide-based active material; The process involves heating the processed nickel oxide-based active material at a temperature of 650°C to 800°C to form a treated nickel oxide-based active material. The steps include combining an iron phosphate-based active material with the treated nickel oxide-based active material to form a blend cathode active material mixture, Methods that include...

23. The method according to claim 22, wherein the nickel oxide-based active material comprises at least one of lithium nickel manganese cobalt oxide and lithium nickel cobalt aluminum oxide.

24. The method according to claim 22 or 23, wherein the specific surface area of ​​the treated nickel oxide-based active material is greater than the specific surface area of ​​the nickel oxide-based active material.

25. The method according to any one of claims 22 to 24, wherein the blend cathode active material mixture contains the treated nickel oxide-based active material in an amount of about 0.1 to 3% by weight.

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