Metal oxide and mixed metal oxide coatings on cathode active materials using isopropanolate precursors

Abstract

The present invention provides a method for manufacturing a cathode electrode comprising a) dissolving one or more first organic isopropanolate precursors in a first solvent to form a mixture; b) adding cathode active material particles to the mixture; c) heating and stirring the mixture to a first predetermined temperature and for a first predetermined period of time to form a first metal oxide coating on the cathode active material particles; d) filtering out the cathode active material particles from the mixture; and e) calcining the cathode active material particles at a second predetermined temperature for a second predetermined period of time.

Description

Technical Field

[0001] The present disclosure relates to battery cells of a battery pack, and more particularly to a method of forming a single metal oxide, double metal oxide, or multi-metal oxide coating on cathode active material particles using one or more organic isopropoxide precursors. Background Art

[0002] The information provided in this section is intended to generally introduce the background of the present disclosure. To the extent that the work currently attributed to the inventors is described in this section and aspects of the specification that may not otherwise be determined to be prior art as of the filing date are not to be construed as being admitted as prior art against the present disclosure, either expressly or implicitly.

[0003] The present disclosure relates to battery cells of a battery pack, and more particularly to a method of forming a single metal oxide, double metal oxide, or multi-metal oxide coating on cathode active material particles using one or more organic isopropoxide precursors.

[0004] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid vehicles, and / or fuel cell vehicles, include one or more electric motors and a battery pack system including one or more battery cells, modules, and / or battery packs. A power control system is used to control the charging and / or discharging of the battery pack system during charging and / or driving.

[0005] A battery cell includes a cathode electrode, an anode electrode, and a separator. The cathode electrode includes a cathode active material layer disposed on a cathode current collector. The anode electrode includes an anode active material layer disposed on an anode current collector. Summary of the Invention

[0006] A method for manufacturing a cathode electrode includes a) dissolving one or more first organic isopropoxide precursors in a first solvent to form a mixture; b) adding cathode active material particles to the mixture; c) heating and stirring the mixture to a first predetermined temperature for a first predetermined period of time to form a first metal oxide coating on the particles of the cathode active material; d) filtering the cathode active material particles from the mixture; and e) calcining the cathode active material particles at a second predetermined temperature for a second predetermined period of time.

[0007] In other examples, the first predetermined temperature is from 80°C to 250°C. The second predetermined temperature is from 300°C to 550°C.

[0008] In other examples, one or more first organoalkoxide precursors are selected from aluminum (Al), titanium (Ti), niobium (Nb), zirconium (Zr), strontium (Sr), tin (Sn), barium (Ba), lithium (Li), antimony (Sb), lanthanum (La), samarium (Sm), germanium (Ge), gadolinium (Gd), yttrium (Y), scandium (Sc), boron (B), and cerium (Ce). The cathode active material is selected from lithium-rich manganese materials (LMR), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium nickel cobalt manganese aluminum (NCMA), lithium nickel manganese cobalt (NMC), lithium nickel oxide (LNO), lithium manganese oxide (LMO), and combinations thereof.

[0009] In other examples, one or more first organoalkoxide precursors comprise a single organoalkoxide precursor, and the first metal oxide coating on the cathode active material particles comprises a single metal oxide coating.

[0010] In other examples, one or more first organoalkoxide precursors comprise N organoalkoxide precursors, and the first metal oxide coating on the cathode active material particles comprises an N-metal oxide coating, where N is an integer greater than 1.

[0011] In other examples, the first metal oxide coating on the cathode active material particles has a thickness of 2 nm to 50 nm.

[0012] In other examples, the first metal oxide coating on the cathode active material particles has a thickness of 5 nm to 20 nm.

[0013] In other features, after d) and before e), f) rinsing the cathode active material particles comprising the first metal oxide coating; g) generating a mixture by adding one or more second organoalkoxide precursors to a second solvent; h) stirring the mixture until the one or more second organoalkoxide precursors are dissolved; i) adding the cathode active material particles comprising the first metal oxide coating to the mixture; j) heating the mixture to a first predetermined temperature and for a first predetermined period of time to form a second metal oxide coating on the cathode active material particles; and k) filtering the cathode active material particles from the mixture.

[0014] In other features, the method comprises washing the cathode active material particles and drying the cathode active material particles after d) and before e). The first metal oxide coating comprises a single metal oxide selected from Al, Ce, Ti, Sr, and Ge. The first metal oxide coating comprises a double metal oxide selected from Li-Ce, Li-Zr, Ce-Al, Gd-Al, Gd-Ce, Sb-Al, Sb-Ce, Ge-Al, and Ge-Ce.

[0015] Among other features, the conductivity of the metal in the first metal oxide coating is lower than the conductivity of the metal oxide in the second metal oxide coating. The first metal oxide in the first metal oxide coating is selected from Ce, Al, and Zr, and the second metal oxide in the second metal oxide coating is selected from Li, Gd, Sb, and Ge.

[0016] A method of manufacturing a cathode electrode, comprising: a) dissolving one or more organic isopropoxide precursors in a solvent to form a mixture, wherein the one or more organic isopropoxide precursors are selected from aluminum (Al), titanium (Ti), niobium (Nb), zirconium (Zr), strontium (Sr), tin (Sn), barium (Ba), lithium (Li), antimony (Sb), lanthanum (La), samarium (Sm), germanium (Ge), gadolinium (Gd), yttrium (Y), scandium (Sc), boron (B), and cerium (Ce); b) adding cathode active material particles to the mixture, wherein the cathode active material is selected from lithium-rich manganese materials (LMR), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium nickel cobalt manganese aluminum (NCMA), lithium nickel manganese cobalt (NMC), lithium nickel oxide (LNO), lithium manganese oxide (LMO), and combinations thereof; c) heating the mixture to a first predetermined temperature of 80°C to 250°C and for a first predetermined period of time to form a metal oxide coating on the cathode active material particles; d) filtering out the cathode active material particles from the mixture; and e) calcining the cathode active material particles at a second predetermined temperature of 300°C to 550°C for a second predetermined period of time.

[0017] Among other features, the one or more organic isopropoxide precursors comprise aluminum (Al) and titanium (Ti). The metal oxide coating has a thickness of 2 nm to 50 nm. The metal oxide coating has a thickness of 5 nm to 20 nm.

[0018] The present invention discloses the following solutions:

[0019] Solution 1. A method of manufacturing a cathode electrode, comprising:

[0020] a) dissolving one or more first organic isopropoxide precursors in a first solvent to form a mixture;

[0021] b) adding cathode active material particles to the mixture;

[0022] c) heating and stirring the mixture to a first predetermined temperature and for a first predetermined period of time to form a first metal oxide coating on the cathode active material particles;

[0023] d) filtering out the cathode active material particles from the mixture; and

[0024] e) calcining the cathode active material particles at a second predetermined temperature for a second predetermined period of time.

[0025] Solution 2. The method according to Solution 1, wherein the first predetermined temperature is 80°C to 250°C.

[0026] Solution 3. The method according to Solution 1, wherein the second predetermined temperature is 300°C to 550°C.

[0027] Solution 4. The method according to Solution 1, wherein:

[0028] the one or more first organic isopropoxide precursors are selected from isopropoxides of aluminum (Al), titanium (Ti), niobium (Nb), zirconium (Zr), strontium (Sr), tin (Sn), barium (Ba), lithium (Li), antimony (Sb), lanthanum (La), samarium (Sm), germanium (Ge), gadolinium (Gd), yttrium (Y), scandium (Sc), boron (B), and cerium (Ce); and

[0029] the cathode active material is selected from lithium-rich manganese layered oxides (LMR), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium nickel cobalt manganese aluminum oxides (NCMA), lithium nickel manganese cobalt oxides (NMC), lithium nickel oxides (LNO), lithium manganese oxides (LMO), and combinations thereof.

[0030] Solution 5. The method according to Solution 1, wherein the one or more first organic isopropoxide precursors comprise a single organic isopropoxide precursor, and the first metal oxide coating on the cathode active material particles comprises a single metal oxide coating.

[0031] Solution 6. The method according to Solution 1, wherein the one or more first organic isopropoxide precursors comprise N organic isopropoxide precursors, and the first metal oxide coating on the cathode active material particles comprises an N-metal oxide coating, where N is an integer greater than 1.

[0032] Solution 7. The method according to Solution 1, wherein the first metal oxide coating on the cathode active material particles has a thickness of 2 nm to 50 nm.

[0033] Solution 8. The method according to Solution 1, wherein the first metal oxide coating on the cathode active material particles has a thickness of 5 nm to 20 nm.

[0034] Solution 9. The method according to Solution 1, further comprising, after d) and before e):

[0035] f) rinsing the cathode active material particles comprising the first metal oxide coating;

[0036] g) generating a mixture by adding one or more second organic isopropoxide precursors to a second solvent;

[0037] h) Stir the mixture until the one or more second metal isopropoxide precursors are dissolved;

[0038] i) Add the cathode active material particles comprising the first metal oxide coating to the mixture;

[0039] j) Heat the mixture to a first predetermined temperature for a first predetermined period of time to form a second metal oxide coating on the cathode active material particles; and

[0040] k) Filter out the cathode active material particles from the mixture.

[0041] Aspect 10. The method according to Aspect 1, further comprising washing the cathode active material particles and drying the cathode active material particles after d) and before e).

[0042] Aspect 11. The method according to Aspect 1, wherein the first metal oxide coating comprises a single metal oxide selected from Al, Ce, Ti, Sr, and Ge.

[0043] Aspect 12. The method according to Aspect 1, wherein the first metal oxide coating comprises a double metal oxide selected from Li-Ce, Li-Zr, Ce-Al, Gd-Al, Gd-Ce, Sb-Al, Sb-Ce, Ge-Al, and Ge-Ce.

[0044] Aspect 13. The method according to Aspect 9, wherein the conductivity of the metal oxide in the first metal oxide coating is lower than the conductivity of the metal oxide in the second metal oxide coating.

[0045] Aspect 14. The method according to Aspect 9, wherein the first metal oxide in the first metal oxide coating is selected from oxides of Ce, Al, and Zr, and the second metal oxide in the second metal oxide coating is selected from oxides of Li, Gd, Sb, and Ge.

[0046] Aspect 15. A method of manufacturing a cathode electrode, comprising:

[0047] a) Dissolve one or more metal isopropoxide precursors in a solvent to form a mixture, wherein the one or more metal isopropoxide precursors are selected from isopropoxides of aluminum (Al), titanium (Ti), niobium (Nb), zirconium (Zr), strontium (Sr), tin (Sn), barium (Ba), lithium (Li), antimony (Sb), lanthanum (La), samarium (Sm), germanium (Ge), gadolinium (Gd), yttrium (Y), scandium (Sc), boron (B), and cerium (Ce);

[0048] b) Add cathode active material particles to the mixture, where the cathode active material is selected from lithium-rich manganese layered oxides (LMR), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium nickel cobalt manganese aluminum oxide (NCMA), lithium nickel manganese cobalt oxide (NMC), lithium nickel oxide (LNO), lithium manganese oxide (LMO), and combinations thereof;

[0049] c) Heat the mixture to a first predetermined temperature of 80 °C to 250 °C for a first predetermined period of time to form a metal oxide coating on the cathode active material particles;

[0050] d) Filter out the cathode active material particles from the mixture; and

[0051] e) Calcinate the cathode active material particles at a second predetermined temperature of 300 °C to 550 °C for a second predetermined period of time.

[0052] Aspect 16. The method according to Aspect 15, wherein the one or more organoalkoxide precursors comprise isopropoxides of aluminum (Al) and titanium (Ti).

[0053] Aspect 17. The method according to Aspect 15, wherein the metal oxide coating has a thickness of 2 nm to 50 nm.

[0054] Aspect 18. The method according to Aspect 15, wherein the metal oxide coating has a thickness of 5 nm to 20 nm.

[0055] From the detailed description, the claims, and the drawings, further applicable fields of the present disclosure will become apparent. The detailed description and specific examples are only intended to illustrate and are not intended to limit the scope of the present disclosure. Brief Description of the Drawings

[0056] The present disclosure will be more fully understood through the detailed description and the drawings, wherein:

[0057] Figure 1 is a side cross-sectional view of an example of a battery cell of a battery pack including a cathode electrode, an anode electrode, and a separator according to the present disclosure;

[0058] Figure 2 is a side cross-sectional view of an example of a cathode electrode having cathode active material coated with one or more organoalkoxide precursors to form a single metal oxide, double metal oxide, or multi-metal oxide coating according to the present disclosure;

[0059] Figure 3A is an enlarged view of an example of cathode active material having a single metal oxide, double metal oxide, or multi-metal oxide coating according to the present disclosure;

[0060] Figure 3B is an enlarged view of an example of a cathode active material having first and second single metal oxides, double metal oxides, or multi-metal oxide coatings according to the present disclosure;

[0061] Figure 4 is a flow chart of an example of a method of coating a cathode active material with one or more organoalkoxide precursors to form a single metal oxide, double metal oxide, or multi-metal oxide coating according to the present disclosure; and

[0062] Figure 5 is a graph illustrating an example of the discharge capacity and percentage of discharge capacity retention of coated and uncoated cathode active materials according to the present disclosure.

[0063] In the drawings, reference numerals may be reused to identify like and / or identical elements. Detailed Description

[0064] Although the battery cells according to the present disclosure are shown in the context of an electric vehicle, the battery cells may be used in stationary applications and / or other applications.

[0065] Lithium-rich manganese layered oxides (LMRs) exhibit higher specific capacities than commercial LFP and NMC-based cathode materials. However, detrimental reactions at the cathode-electrolyte interface reduce the cycling stability of LMR cathode electrodes. Constructing an artificial barrier to mitigate these adverse interactions can improve the cycle life of LMR cathode materials.

[0066] The present disclosure relates to a method of using one or more organometallic oxide precursors to produce a single metal oxide, double metal oxide, or multi-metal oxide coating (e.g., Al-TiO x ) on particles of a cathode active material. In some examples, the metal oxide coating comprises a single coating having one or more metal oxides. In other examples, the metal oxide coating comprises two or more coatings, each coating having one or more metal oxides.

[0067] For example, the metal oxide coating comprises a single coating having two metal oxide species (e.g., Al-TiO x )). For example, it is believed that a first metal ion (e.g., an aluminum ion (Al 3+ )) penetrates the surface of the cathode active material, while a second metal ion (e.g., a titanium ion (Ti 4+ )) remains on the surface of the cathode active material. In the absence of water / alcohol, the organoalkoxide precursors remain intact and prevent the nucleation of unbound / free metal oxide nanoparticles in solution. Unlike nanoparticles or colloidal solutions, two or more molecular metal precursors mixed in solution facilitate the uniform deposition of these metals over the metal oxide coating.

[0068] The method according to the present disclosure enables a simple method for single-metal oxide, double-metal oxide, or multi-metal oxide coatings of cathode active material particles. The thickness of the metal oxide coating can be adjusted by creating surface terminations (e.g., hydroxide (-OH)), allowing further reaction with the alkoxide precursor.

[0069] In some instances, one or more organic alkoxide precursors are selected from alkoxides of aluminum (Al), titanium (Ti), niobium (Nb), zirconium (Zr), strontium (Sr), tin (Sn), barium (Ba), lithium (Li), antimony (Sb), lanthanum (La), samarium (Sm), germanium (Ge), gadolinium (Gd), yttrium (Y), scandium (Sc), boron (B), and cerium (Ce). The method can be used to produce one or more single-metal or mixed-metal coatings with any of the above metal precursors.

[0070] In some instances, the metal oxide coating thickness is from 2 nm to 50 nm. In other instances, the metal oxide coating thickness is from 5 nm to 20 nm. In some instances, the metal weight loading is from 0.01 wt% to 2 wt% of the cathode active material. Large-scale coating can be carried out using solution batch synthesis and / or continuous stirred tank reactors.

[0071] In some instances, the cathode active material is selected from lithium-rich manganese layered oxides (LMR), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium nickel cobalt manganese aluminum oxide (NCMA), lithium nickel manganese cobalt oxide (NMC), lithium nickel oxide (LNO), lithium manganese oxide (LMO), and combinations thereof.

[0072] In some instances, modifications to the metal oxide coating method can include sequential deposition of metal precursors. In some instances, the coated material is washed (e.g., with water or a solvent), and the process is repeated with the same or different organic alkoxide precursors to increase the coating thickness and / or produce a multi-metal oxide coating.

[0073] In some instances, the metal oxide coating comprises a single-metal oxide selected from Al, Ce, Ti, Sr, and Ge. In some instances, the metal oxide coating comprises a double-metal coating selected from Li-Ce, Li-Zr, Ce-Al, Gd-Al, Gd-Ce, Sb-Al, Sb-Ce, Ge-Al, and Ge-Ce.

[0074] In some instances, two consecutive coatings with different compositions are used. In some instances, a solution of a first metal precursor and a cathode active material is heated and stirred. After a predetermined period of time, the solution is filtered and rinsed with a solvent such as acetone and / or ethanol. The coated cathode active material is air-dried at a predetermined temperature for a predetermined period of time. In some instances, the predetermined temperature is from 70 °C to 150 °C (e.g., 80 °C), and the predetermined period of time is from 12 hours to 24 hours. The dried coated cathode active material is added to a second metal precursor solution and the process continues as described above.

[0075] In some instances, the conductivity of the metal oxide in the first metal oxide coating is lower than the conductivity of the metal oxide in the second metal oxide coating. In some instances, the first metal in the first metal oxide coating is selected from Ce, Al, Zr, and the second metal in the second metal oxide coating is selected from Li, Gd, Sb, Ge.

[0076] Now referring Figure 1 , battery cell 10 of the battery pack includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 arranged in a battery cell stack 12 in a predetermined order, where C, S, and A are integers greater than zero. The battery cell stack 12 is arranged in a housing 50. The C cathode electrodes 20-1, 20-2, …, and 20-C include cathode active material layers 24 on one or both sides of a cathode current collector 26. The A anode electrodes 40-1, 40-2, ..., and 40-A include anode active material layers 42 arranged on one or both sides of an anode current collector 46.

[0077] In some instances, the cathode active material layer 24 and / or the anode active material layer 42 includes a coating applied to the current collector, the coating including one or more active materials, one or more conductive additives, and / or one or more binder materials. In some instances, the A anode electrodes 40 and the C cathode electrodes 20 exchange lithium ions during charge / discharge. The cathode active material layer 24 includes a cathode active material coated with one or more metal oxide coatings as described herein.

[0078] In some instances, the cathode current collector 26 and / or the anode current collector 46 includes a metal foil, a metal mesh, a perforated metal, a three-dimensional (3D) metal foam, and / or an expanded metal. In some instances, the current collector is made of one or more materials selected from copper, stainless steel, brass, bronze, zinc, aluminum, and / or their alloys. External tabs 28 and 48 are respectively connected to the current collectors of the cathode electrode and the anode electrode, and may be arranged on the same side or different sides of the battery cell stack 12. The external tabs 28 and 48 are connected to the terminals of the battery pack.

[0079] Now referring to Figure 2 , one of the C cathode electrodes 20 is shown in more detail. The cathode active material layer 24 of one of the C cathode electrodes 20 includes a coated cathode active material 62, an optional conductive additive 64, and an optional binder 66. In some examples, the cathode active material 62 is coated with one or more organometallic isopropoxide precursors to form one or more single-metal oxide, double-metal oxide, or multi-metal oxide coatings on the particles of the cathode active material.

[0080] In some examples, the cathode active material 62 is selected from lithium-rich manganese layered oxides (LMR), lithium nickel manganese cobalt oxides (NMC), nickel cobalt manganese aluminum oxides (NCMA), lithium iron phosphate (LFP), lithium nickel oxides (LNO), lithium manganese iron phosphate (LMFP), lithium manganese oxides (LMO), and combinations thereof.

[0081] In Figure 3A , the cathode active material 62 is coated with a first metal oxide coating 70 including one or more metal oxides. One or more organometallic isopropoxide precursors are used to form a single-metal oxide, double-metal oxide, or multi-metal oxide coating on the particles of the cathode active material 62 to produce the first metal oxide coating 70. In Figure 3B , the cathode active material 62 is coated with a first metal oxide coating 70 including one or more metal oxides and a second metal oxide coating 72 including one or more metal oxides.

[0082] Now referring to Figure 4 , a method of manufacturing a cathode material is shown. At 110, one or more organometallic isopropoxide precursors are dissolved in a solvent such as toluene and stirred at a first predetermined temperature (e.g., room temperature). At 114, the cathode active material powder is added to the solution and stirred for a first predetermined period of time. In some examples, the first predetermined period of time is from 30 minutes to 24 hours (e.g., 12 hours).

[0083] At 118, the mixture is heated to a second predetermined temperature and held for a second predetermined period of time, then cooled (e.g., to room temperature). In some examples, the first predetermined temperature is from 80 °C to 250 °C (e.g., 150 °C). In some examples, the first predetermined period of time is from 10 minutes to 3 hours (e.g., 1 hour).

[0084] At 126, the mixture is filtered to recover the solid. The solid is washed with a solvent and then dried. At 130, the solid is calcined at the second predetermined temperature for a second predetermined period of time. In some examples, the second predetermined temperature is from 300 °C to 550 °C (e.g., 450 °C). In some examples, the second predetermined period of time is from 10 minutes to 5 hours (e.g., 2 hours).

[0085] For example, aluminum isopropoxide and titanium isopropoxide are dissolved in toluene and stirred at room temperature. Once the metal precursors are dissolved, the cathode active material powder is added to the solution and stirred at room temperature for 12 hours. The mixture is heated at 150 °C for 1 hour and then cooled to room temperature. The solid is recovered by filtering the solution. The solid is washed with acetone and dried (e.g., air-dried). The dried solid is calcined at 450 °C for 2 hours and then used for the cathode active material layer.

[0086] Now referring to Figure 5 , the discharge capacity and the percentage of discharge capacity retention of the coated and uncoated cathode active materials including LMR are shown. The working voltage window at C / 3 is 2 V to 4.6 V. The battery cell of the battery pack includes a cathode electrode that includes LMR / carbon black / PVDF in a 94 / 3 / 3 ratio. The anode electrode contains 5.5% SiO x -graphite. The electrode loading is ~5 mAh / cm 2 positive capacity and 5.5 mAh / cm 2 negative capacity. The active material loading on the cathode electrode is 24 to 25 mg / cm 2 . The diameter of the cathode is 12.7 mm. It can be seen that the coated LMR exhibits improved discharge capacity and percentage of discharge capacity retention.

[0087] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Thus, while the disclosure includes specific examples, the true scope of the disclosure should not be so limited since other modifications will become apparent after study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be implemented in a different order (or concurrently) without altering the principles of the disclosure. Further, although the embodiments are described above as having certain features, any one or more of the features described with respect to any one embodiment of the disclosure may be implemented in any other embodiment and / or combined with the features of any other embodiment, even if not explicitly described in combination. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments are within the scope of the disclosure.

[0088] Various terms are used to describe the spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected", "joined", "coupled", "adjacent", "next to", "on top of", "on", "under", and "disposed". Unless explicitly described as "direct", when the relationship between a first element and a second element is described in the foregoing disclosure, the relationship can be a direct relationship in which no other intermediate element exists between the first element and the second element, or an indirect relationship in which one or more intermediate elements exist between the first element and the second element (spatially or functionally). The phrase "at least one of A, B, and C" as used herein should be construed to mean a logical (A or B or C) using non-exclusive logical OR and should not be construed to mean "at least one A, at least one B, and at least one C".

[0089] In the drawings, the direction of the arrowhead as indicated by the arrow generally demonstrates the flow of information (such as data or instructions) related to the illustration. For example, when component A and component B exchange various information but the information transmitted from component A to component B is related to the illustration, the arrow can point from component A to component B. Such a unidirectional arrow does not mean that no other information is transmitted from component B to component A. In addition, for the information transmitted from component A to component B, component B can send a request for the information or receive an acknowledgment to component A.

Claims

1. A method for manufacturing a cathode electrode, comprising: a) dissolving one or more first organic isopropoxide precursors in a first solvent to form a mixture; b) adding cathode active material particles to the mixture; c) heating and stirring the mixture to a first predetermined temperature and for a first predetermined period of time to form a first metal oxide coating on the cathode active material particles; d) filtering the cathode active material particles from the mixture; and e) calcining the cathode active material particles at a second predetermined temperature for a second predetermined period of time. 2 . The method according to claim 1 , wherein the first predetermined temperature is 80° C. to 250° C. The method according to claim 1 , wherein the second predetermined temperature is 300° C. to 550° C.

4. The method according to claim 1, wherein: The one or more first organic isopropoxide precursors are selected from isopropoxides of aluminum (Al), titanium (Ti), niobium (Nb), zirconium (Zr), strontium (Sr), tin (Sn), barium (Ba), lithium (Li), antimony (Sb), lanthanum (La), samarium (Sm), germanium (Ge), gadolinium (Gd), yttrium (Y), scandium (Sc), boron (B), and cerium (Ce); and The cathode active material is selected from lithium manganese-rich layered oxide (LMR), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium nickel cobalt manganese aluminum oxide (NCMA), lithium nickel manganese cobalt oxide (NMC), lithium nickel oxide (LNO), lithium manganese oxide (LMO) and combinations thereof.

5. The method of claim 1, wherein the one or more first organic isopropoxide precursors comprise a single organic isopropoxide precursor and the first metal oxide coating on the cathode active material particles comprises a single metal oxide coating.

6. The method of claim 1, wherein the one or more first organic isopropoxide precursors comprise N organic isopropoxide precursors, and the first metal oxide coating on the cathode active material particles comprises an N-metal oxide coating, wherein N is an integer greater than 1. 7 . The method of claim 1 , wherein the first metal oxide coating on the cathode active material particles has a thickness of 2 nm to 50 nm. 8 . The method of claim 1 , wherein the first metal oxide coating on the cathode active material particles has a thickness of 5 nm to 20 nm.

9. The method according to claim 1, further comprising after d) and before e): f) rinsing the cathode active material particles including the first metal oxide coating; g) producing a mixture by adding one or more second organic isopropoxide precursors to a second solvent; h) stirring the mixture until the one or more second organic isopropoxide precursors are dissolved; i) adding cathode active material particles including the first metal oxide coating to the mixture; j) heating the mixture to a first predetermined temperature and for a first predetermined period of time to form a second metal oxide coating on the cathode active material particles; and k) filtering the cathode active material particles from the mixture. 10 . The method of claim 1 , further comprising washing the cathode active material particles and drying the cathode active material particles after d) and before e).

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