Cathode active material for cathode electrode having coating comprising transition metal oxide

Abstract

The invention relates to a cathode active material for a cathode electrode having a coating comprising a transition metal oxide. A cathode active material layer for a cathode electrode of a battery cell comprising particles of a cathode active material comprising one or more materials selected from the group consisting of lithium manganese rich (LMR) materials, lithium nickel manganese aluminum oxides (NMC), lithium nickel manganese cobalt aluminum oxides (NMCA), and lithium iron phosphate (LFP). A coating is formed on an outer surface of particles of the cathode active material and includes one or more transition metal oxides.

Description

Technical Field

[0001] The present disclosure relates to battery cells, and more particularly to coated cathode active materials for cathode electrodes of battery cells. Background Art

[0002] The information provided in this section is intended to generally introduce the background of the present disclosure. To the extent that work currently named as inventors is described in this section, and aspects of the specification that may not have been otherwise identified as prior art at the time of filing, are not admitted, either explicitly or implicitly, as prior art to the present disclosure.

[0003] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid vehicles, and / or fuel cell vehicles, include one or more motors and a battery system, which includes one or more battery cells, modules, and / or packs. A battery control module is used to control the charging and / or discharging of the battery system during charging and / or driving. EV manufacturers are committed to improving power density to increase the range of EVs. Summary of the invention

[0004] A cathode active material layer for a cathode electrode of a battery cell, comprising particles of a cathode active material, wherein the cathode active material comprises one or more materials selected from lithium manganese-rich (LMR) materials, lithium nickel manganese aluminum oxide (NMC), lithium nickel manganese cobalt aluminum oxide (NMCA) and lithium iron phosphate (LFP). A coating is formed on the outer surface of the particles of the cathode active material and comprises one or more transition metal oxides.

[0005] In other features, the one or more transition metal oxides are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4) and combinations thereof.

[0006] In other features, the coating has a thickness of 0.5 nm to 20 nm. The one or more transition metal oxides comprise 0.01 wt % to 2 wt % of the coated particles. The cathode active material comprises an LMR material, and the coating comprises Li2MoO4.

[0007] A cathode electrode comprises a cathode current collector. The cathode active material layer is disposed on at least one side of the cathode current collector.

[0008] A battery cell includes one or more cathode current collectors, one or more anode electrodes, and one or more separators.

[0009] A method for making a cathode active material for a battery cell includes providing particles of a cathode active material selected from a lithium manganese rich (LMR) material, a lithium nickel manganese aluminum oxide (NMC), a lithium nickel manganese cobalt aluminum oxide (NMCA), and a lithium iron phosphate (LFP); and coating the outer surface of the particles of the cathode active material with a coating comprising one or more transition metal oxides. The one or more transition metal oxides are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4), and combinations thereof.

[0010] In other features, the one or more transition metal oxides comprise 0.01 wt % to 2 wt % of the coated particles. The cathode active material comprises an LMR material. The cathode active material comprises an LMR material, and the coating comprises Li2MoO4.

[0011] In other features, coating the outer surface of the particle includes adding the particle to an aqueous solution comprising the one or more transition metal oxides; and stirring the aqueous solution at a first predetermined temperature for a first predetermined time.

[0012] In other features, the first predetermined time is 60 to 600 minutes. The first predetermined temperature is 10° C. to 30° C. Coating the outer surface of the particle includes heating the aqueous solution at a second predetermined temperature for a second predetermined time after the first predetermined time.

[0013] In other features, the second predetermined time is 20 to 120 minutes. The second predetermined temperature is 60° C. to 100° C. Coating the outer surface of the particle further comprises calcining at a third predetermined temperature for a third predetermined time.

[0014] In other features, the third predetermined temperature is 200° C. to 600° C. The third predetermined time is 20 to 300 minutes.

[0015] The present invention discloses the following scheme:

[0016] Solution 1. A cathode active material layer for a cathode electrode of a battery cell, comprising:

[0017] Particles of a cathode active material, the cathode active material comprising one or more materials selected from the group consisting of a lithium manganese rich (LMR) material, a lithium nickel manganese aluminum oxide (NMC), a lithium nickel manganese cobalt aluminum oxide (NMCA), and a lithium iron phosphate (LFP); and

[0018] A coating comprising one or more transition metal oxides is formed on the outer surfaces of particles of the cathode active material.

[0019] Option 2. A cathode active material layer according to Option 1, wherein the one or more transition metal oxides are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4) and combinations thereof.

[0020] Option 3. The cathode active material layer according to Option 1, wherein the coating layer has a thickness of 0.5 nm to 20 nm.

[0021] Option 4. A cathode active material according to Option 1, wherein the one or more transition metal oxides account for 0.01 wt% to 2 wt% of the coated particles.

[0022] Option 5. A cathode active material according to Option 1, wherein the cathode active material comprises an LMR material and the coating comprises Li2MoO4.

[0023] Solution 6. A cathode electrode comprising:

[0024] a cathode current collector; and

[0025] The cathode active material layer according to claim 1 is disposed on at least one side of the cathode current collector.

[0026] Solution 7. A battery cell comprising:

[0027] One or more cathode current collectors as described in claim 5;

[0028] one or more anode electrodes; and

[0029] One or more spacers.

[0030] Embodiment 8. A method for manufacturing a cathode active material for a battery cell, comprising:

[0031] providing particles of a cathode active material selected from the group consisting of a lithium manganese rich (LMR) material, a lithium nickel manganese aluminum oxide (NMC), a lithium nickel manganese cobalt aluminum oxide (NMCA), and a lithium iron phosphate (LFP); and

[0032] coating the outer surfaces of the particles of the cathode active material with a coating comprising one or more transition metal oxides,

[0033] The one or more transition metal oxides are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4) and combinations thereof.

[0034] Option 9. A method according to Option 8, wherein the one or more transition metal oxides account for 0.01 wt.% to 2 wt.% of the coated particles.

[0035] Option 10. A method according to Option 8, wherein the cathode active material comprises an LMR material.

[0036] Option 11. A method according to Option 8, wherein the cathode active material comprises an LMR material and the coating comprises Li2MoO4.

[0037] Embodiment 12. The method according to embodiment 8, wherein coating the outer surface of the particle comprises:

[0038] adding the particles to an aqueous solution comprising the one or more transition metal oxides; and

[0039] The aqueous solution is stirred at a first predetermined temperature for a first predetermined time.

[0040] Option 13. The method according to Option 12, wherein the first predetermined time is 60 to 600 minutes.

[0041] Option 14. The method according to Option 12, wherein the first predetermined temperature is 10°C to 30°C.

[0042] Option 15. A method according to Option 12, wherein coating the outer surface of the particle includes heating the aqueous solution at a second predetermined temperature for a second predetermined time after the first predetermined time.

[0043] Option 16. The method according to Option 15, wherein the second predetermined time is 20 to 120 minutes.

[0044] Embodiment 17. The method according to Embodiment 15, wherein the second predetermined temperature is 60°C to 100°C.

[0045] Option 18. The method according to Option 15, wherein coating the outer surface of the particle further comprises calcining at a third predetermined temperature for a third predetermined time.

[0046] Embodiment 19. The method according to Embodiment 18, wherein the third predetermined temperature is 200°C to 600°C.

[0047] Option 20. The method according to Option 18, wherein the third predetermined time is 20 to 300 minutes.

[0048] Embodiment 21. A cathode active material layer for a cathode electrode of a battery cell, comprising:

[0049] Particles of a cathode active material, the cathode active material comprising one or more materials selected from the group consisting of a lithium manganese rich (LMR) material, a lithium nickel manganese aluminum oxide (NMC), a lithium nickel manganese cobalt aluminum oxide (NMCA), and a lithium iron phosphate (LFP), wherein the cathode active material comprises particles having a diameter of 5 μm to 80 μm; and

[0050] a coating layer formed on the outer surface of particles of the cathode active material and comprising a transition metal oxide,

[0051] The coating has a thickness of 0.5 nm to 20 nm, and the transition metal oxide accounts for 0.01 wt % to 2 wt % of the coated particles.

[0052] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present disclosure will be more fully understood through the detailed description and accompanying drawings, in which:

[0054] Figure 1 is a side cross-sectional view of an example of a battery cell including a cathode electrode including a cathode active material coated with a transition metal oxide according to the present disclosure;

[0055] Figure 2 is a side cross-sectional view of an example of a cathode active material prior to coating according to the present disclosure;

[0056] Figure 3 is a side cross-sectional view of an example of a cathode active material after coating with a transition metal oxide according to the present disclosure;

[0057] Figure 4 is a side cross-sectional view of a cathode electrode including a cathode active material coated with a transition metal oxide layer according to the present disclosure;

[0058] Figure 5 is an example of a method for coating a cathode active material with a transition metal oxide layer according to the present disclosure;

[0059] Figure 6 is a graph illustrating capacity retention of a cathode active material coated with a lithium molybdate layer and an uncoated cathode active material as a function of cycle number; and

[0060] Figure 7 is a graph illustrating capacity retention of a cathode active material coated with lithium molybdate and an uncoated cathode active material as a function of cycle number.

[0061] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0062] Although the battery cells including the cathode electrode having the coated cathode active material are described in the context of electric vehicles, the battery cells may be used in stationary applications and / or other types of applications.

[0063] The battery module includes one or more battery cells, and the battery cell includes an anode electrode, a cathode electrode and a separator arranged in a predetermined order. The anode electrode includes an anode current collector and an anode active material layer arranged on one side or both sides of the anode current collector. The cathode electrode includes a cathode current collector and a cathode active material layer arranged on one side or both sides of the cathode current collector. The separator is arranged between the anode electrode and the cathode electrode.

[0064] For LMR batteries, the cathode active material includes LMR cathode active materials. The specific capacity of LMR materials is higher than that of conventional cathode materials, such as lithium iron phosphate (LFP). However, the limited cycle life of LMR cathode electrodes remains a challenge due to deleterious reactions at the cathode-electrolyte interface.

[0065] LMR batteries have high average operating voltage and high reversible capacity. However, LMR batteries experience capacity fade and voltage fade due to electrolyte consumption and / or structural transformation from layered phase to spinel phase.

[0066] The present disclosure relates to a method for making a coating on particles of cathode active materials such as LMR or other cathode materials. The coating forms a barrier to mitigate deleterious reactions at the cathode-electrolyte interface and improve the cycle life of the LMR cathode material.

[0067] The coating is a self-limiting layer formed on the surface of particles of the cathode active material. For example, when the coated LMR cathode active material is coated with lithium molybdate, the discharge capacity retention of the battery cell is significantly improved compared to the uncoated LMR cathode active material. The coating also improves the cycle life of the LMR cathode electrode by reducing interactions at the cathode-electrolyte interface. The self-limiting coating also enables good ionic conductivity. The present disclosure also relates to a low-cost water-based method for coating particles of the LMR cathode active material.

[0068] Reference now Figure 1 , the battery cell 10 includes cathode electrodes 20-1, 20-2, ..., and 20-C, where C is an integer greater than 1. The cathode electrode 20 includes a cathode active material layer 24 disposed on one or both sides of a cathode current collector 26. Particles of the cathode active material are coated with a coating layer including one or more transition metal oxides.

[0069] The battery cell 10 includes anode electrodes 40-1, 40-2, ..., and 40-A, where A is an integer greater than 1. The anode electrode 40 includes an anode active material layer 46 disposed on one or both sides of an anode current collector 42. The cathode electrode 20, the anode electrode 40, and the separator 32 are disposed in a predetermined order in the housing 50. For example, the separator 32 is disposed between the cathode electrode 20 and the anode electrode 40.

[0070] In some embodiments, particles of a cathode active material (e.g., LMR or other cathode active material) are coated with a coating (e.g., lithium molybdate (Li2MoO4) or other transition metal oxides). In some embodiments, the one or more transition metal oxide precursors are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4), and combinations thereof.

[0071] In some embodiments, the cathode active material may include an LMR material or a non-LMR cathode active material, such as nickel manganese cobalt (NMC), nickel manganese cobalt aluminum (NCMA), lithium iron phosphate (LFP), and / or combinations thereof.

[0072] Reference now Figures 2 to 4 , forming a coating on the particles of the cathode active material. Figure 2 In FIG. 1 , particles 114 of cathode active material are shown. In some embodiments, the diameter of particles 114 is between 5 μm and 80 μm. Figure 3 , a particle 114 is shown coated with a coating 118 (e.g., lithium molybdate and / or one or more other transition metal oxide precursors described herein). In some embodiments, the coating 118 has a thickness of 0.5 nm to 20 nm. In other embodiments, the coating 118 has a thickness of 1 nm to 10 nm.

[0073] exist Figure 4 In some embodiments, the coated cathode active material 150 is mixed with a binder 152, (one or more) conductive additives 154, and / or a solvent to produce a slurry. The slurry is applied to one or both sides of the cathode current collector 26 to form the cathode active material layer 24 of the cathode electrode 20. The cathode electrode 20 is disposed in a battery cell (e.g., Figure 1 The battery cell 10 shown in FIG.

[0074] Reference now Figure 5 , showing a method 200 for making a cathode active material. At 210, cathode active material powder or particles are added to an aqueous solution including one or more transition metal oxide precursors (eg, lithium molybdate (Li2MoO4) and / or other transition metal oxide precursors).

[0075] At 214, the mixture is stirred in the container at a first predetermined temperature for a first predetermined time. In other embodiments, sonication is performed. In some embodiments, the first predetermined temperature is 10°C to 30°C (e.g., room temperature (20°C to 22°C)). In some embodiments, the first predetermined time is 60 to 600 minutes (e.g., 120 minutes).

[0076] At 218, the mixture is heated at a second predetermined temperature for a second predetermined time. In some embodiments, the second predetermined temperature is 60°C to 100°C (eg, 75°C). In some embodiments, the second predetermined time is 20 to 120 minutes (eg, 60 minutes).

[0077] At 222, the coated particles are collected, filtered, and washed with a solvent (e.g., water or another solvent) to remove unreacted transition metal oxide. At 226, the coated particles are calcined or heated at a third predetermined temperature for a third predetermined time. In some embodiments, the third predetermined temperature is 200° C. to 600° C. (e.g., 450° C.). In some embodiments, the third predetermined time is 20 to 300 minutes (e.g., 120 minutes).

[0078] Reference now Figure 6 and 7 , showing the performance of a battery cell including a cathode electrode having coated particles 310 (e.g., lithium molybdate (Li2MoO4)) and uncoated particles 320. A half-cell was constructed with particles comprising LMR, carbon black (CB), and polyvinylidene fluoride (PVDF) in a ratio of 94 / 3 / 3 wt%. The first cycle efficiency of the coated particles 310 was 85.8%, and the first cycle efficiency of the uncoated particles 320 was 82.5%. Figure 6 The capacity retention rate of the coated particles 310 after 50 cycles is 93%, while the capacity retention rate of the uncoated particles after 50 cycles is 85%.

[0079] exist Figure 7 , the discharge capacity of the coated particles 310 is higher than that of the uncoated particles 320. The first C / 3 cycle discharge capacity of the coated particles 310 is 233 mAh / g, and the first C / 3 cycle discharge capacity of the uncoated particles 320 is 226 mAh / g. The formation cycle protocol is constant current charge (CCC) at C / 20 to 4.6 V and constant voltage charge (CVC) at 4.6 V until C / 20. The discharge is constant current discharge (CC) at C / 20 to 2.0 V. The life cycle protocol is CCC at C / 3 to 4.6 V and CVC at 4.6 V until C / 20. The discharge is constant current discharge (CC) at C / 3 to 2.0 V.

[0080] The foregoing description is essentially only exemplary and is absolutely not intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be limited thereto, because after studying the drawings, the specification and the following claims, other modifications will become apparent. It should be understood that one or more steps in the method may be implemented in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more features described with respect to any embodiment of the present disclosure may be implemented in any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments are not mutually exclusive, and the mutual replacement of one or more embodiments is still within the scope of the present disclosure.

[0081] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "on," "under," and "disposed." Unless explicitly described as "directly," when describing the relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship in which no other intervening elements exist between the first element and the second element, or an indirect relationship in which one or more intervening 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 interpreted to mean a logical (A or B or C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one A, at least one B, and at least one C."

[0082] In the drawings, the direction of the arrows, as shown by arrows, generally demonstrates the flow of information (such as data or instructions) related to the diagram. 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 diagram, the arrow may 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 may send a request for the information to component A or a receipt of the information.

Claims

1. A cathode active material layer for a cathode electrode of a battery cell, comprising: Particles of a cathode active material, the cathode active material comprising one or more materials selected from the group consisting of lithium manganese rich (LMR) material, lithium nickel manganese aluminum oxide (NMC), lithium nickel manganese cobalt aluminum oxide (NMCA), and lithium iron phosphate (LFP); and A coating comprising one or more transition metal oxides is formed on the outer surfaces of particles of the cathode active material.

2. The cathode active material layer according to claim 1, wherein the one or more transition metal oxides are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4) and combinations thereof.

3. The cathode active material of claim 1, wherein the one or more transition metal oxides comprise 0.01 wt% to 2 wt% of the coated particles.

4. The cathode active material of claim 1, wherein the cathode active material comprises a LMR material and the coating comprises Li2MoO4.

5. A cathode electrode, comprising: a cathode current collector; and The cathode active material layer of claim 1 is disposed on at least one side of a cathode current collector.

6. A battery cell comprising: One or more cathode current collectors as claimed in claim 5; one or more anode electrodes; and One or more spacers.

7. A method of making a cathode active material for a battery cell, comprising: providing particles of a cathode active material selected from the group consisting of a lithium manganese rich (LMR) material, a lithium nickel manganese aluminum oxide (NMC), a lithium nickel manganese cobalt aluminum oxide (NMCA), and a lithium iron phosphate (LFP); and coating the outer surfaces of the particles of the cathode active material with a coating comprising one or more transition metal oxides, The one or more transition metal oxides are selected from ammonium tungstate ((NH4)2WO4), lithium tungstate (Li2WO4), potassium tungstate (K2WO4), sodium tungstate (Na2WO4), ammonium molybdate ((NH4)2MoO4), potassium molybdate (K2MoO4), lithium molybdate (Li2MoO4), sodium molybdate (Na2MoO4), ammonium vanadate (NH4VO3), lithium vanadate (LiVO3), potassium vanadate (KVO3), sodium vanadate (NaVO3), ammonium chromate ((NH4)2CrO4), lithium chromate (Li2CrO4), potassium chromate (K2CrO4), sodium chromate (Na2CrO4) and combinations thereof.

8. The method of claim 7, wherein the one or more transition metal oxides comprise 0.01 wt% to 2 wt% of the coated particles.

9. The method of claim 7, wherein the cathode active material comprises a LMR material.

10. The method of claim 7, wherein the cathode active material comprises a LMR material and the coating comprises Li2MoO4.

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