Patent Application
20240063397
In at least one aspect, stable positive electrode compositions are provided.
Lithium Ion Battery (LIB) cathodes with high Ni content (Ni>50%) offers high energy density to enable battery electric vehicle (BEV) range and necessary performance features. However, high Ni content cathodes have low thermal stability, and a tendency to release oxygen (02) to the electrolytic solution under a thermal and abuse situation. As the energy density continues to rise in the high nickel cathode technology and competitive market, a solution is necessary to offer higher performance and high stability. The traditional method for non-flammable electrolytes involves strong additives to passivate the electrode active materials and increase the cell's internal resistance, hence leading to poor cell power.
Accordingly, there is a need for alternative methods for making stable positive electrodes used in lithium-ion batteries.
In at least one aspect, a positive electrode material is provided. The positive electrode material includes a plurality of particles composed of a positive electrode active material and a passivating layer disposed over at least a subset of the plurality of particles and/or over the positive electrode material. Advantageously, the passivating layer is thermally insulating and lithium-ion conducting wherein the passivating layer is composed of a carbonate-phosphate composite.
In another aspect, a positive electrode is provided. The positive electrode includes a current collector and a positive electrode active layer disposed over the current collector. The positive electrode active layer includes a plurality of particles composed of a positive electrode active material. A passivating layer is disposed over at least a subset of the plurality of particles and/or over the positive electrode material. Advantageously, the passivating layer is thermally insulating and lithium-ion conducting wherein the passivating layer is composed of a carbonate-phosphate composite.
In another aspect, a rechargeable battery including a plurality of lithium-ion battery cells is provided. Each lithium-ion battery cell includes a positive electrode, a negative electrode including a negative active material, and an electrolyte contacting the positive electrode and the negative electrode. The positive electrode includes a current collector, a positive electrode active layer disposed over the current collector. The positive electrode active layer includes a positive electrode active material. A passivating layer is disposed over at least a subset of the plurality of particles and/or over the positive electrode material. Advantageously, the passivating layer is thermally insulating and lithium-ion conducting wherein the passivating layer is composed of a carbonate-phosphate composite.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
For a further understanding of the nature, objects, and advantages of the present disclosure, reference should be made to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
Reference will now be made in detail to presently preferred compositions, embodiments and methods of the present invention, which constitute the best modes of practicing the invention presently known to the inventors. The Figures are not necessarily to scale. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for any aspect of the invention and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
Except in the examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word “about” in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary: when a given chemical structure includes a substituent on a chemical moiety (e.g., on an aryl, alkyl, etc.) that substituent is imputed to a more general chemical structure encompassing the given structure; percent, “parts of,” and ratio values are by weight; the term “polymer” includes “oligomer,” “copolymer,” “terpolymer,” and the like; molecular weights provided for any polymers refers to weight average molecular weight unless otherwise indicated; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description, and does not necessarily preclude chemical interactions among the constituents of a mixture once mixed; the first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation; and, unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.
It must also be noted that, as used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.
As used herein, the term “about” means that the amount or value in question may be the specific value designated or some other value in its neighborhood. Generally, the term “about” denoting a certain value is intended to denote a range within +/−5% of the value. As one example, the phrase “about 100” denotes a range of 100+/−5, i.e. the range from 95 to 105. Generally, when the term “about” is used, it can be expected that similar results or effects according to the invention can be obtained within a range of +/−5% of the indicated value.
As used herein, the term “and/or” means that either all or only one of the elements of said group may be present. For example, “A and/or B” shall mean “only A, or only B, or both A and B”. In the case of “only A”, the term also covers the possibility that B is absent, i.e. “only A, but not B”.
It is also to be understood that this invention is not limited to the specific embodiments and methods described below, as specific components and/or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing particular embodiments of the present invention and is not intended to be limiting in any way.
The term “comprising” is synonymous with “including,” “having,” “containing,” or “characterized by.” These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps.
The phrase “consisting of” excludes any element, step, or ingredient not specified in the claim. When this phrase appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.
The phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps, plus those that do not materially affect the basic and novel characteristic(s) of the claimed subject matter.
The phrase “composed of” means “including” or “consisting of” Typically, this phrase is used to denote that an object is formed from a material.
With respect to the terms “comprising,” “consisting of,” and “consisting essentially of,” where one of these three terms is used herein, the presently disclosed and claimed subject matter can include the use of either of the other two terms.
The term “one or more” means “at least one” and the term “at least one” means “one or more.” The terms “one or more” and “at least one” include “plurality” and “multiple” as a subset. In a refinement, “one or more” includes “two or more.”
The term “substantially,” “generally,” or “about” may be used herein to describe disclosed or claimed embodiments. The term “substantially” may modify a value or relative characteristic disclosed or claimed in the present disclosure. In such instances, “substantially” may signify that the value or relative characteristic it modifies is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the value or relative characteristic.
It should also be appreciated that integer ranges explicitly include all intervening integers. For example, the integer range 1-10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4 . . . . 97, 98, 99, 100. Similarly, when any range is called for, intervening numbers that are increments of the difference between the upper limit and the lower limit divided by 10 can be taken as alternative upper or lower limits. For example, if the range is 1.1. to 2.1 the following numbers 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 can be selected as lower or upper limits.
When referring to a numeral quantity, in a refinement, the term “less than” includes a lower non-included limit that is 5 percent of the number indicated after “less than.” For example, “less than 20” includes a lower non-included limit of 1 in a refinement. Therefore, this refinement of “less than 20” includes a range between 1 and 20. In another refinement, the term “less than” includes a lower non-included limit that is, in increasing order of preference, 20 percent, 10 percent, 5 percent, or 1 percent of the number indicated after “less than.”
The term “positive electrode” means a battery cell electrode from which current flows out when the lithium-ion battery cell or battery is discharged. Sometimes a “positive electrode” is referred to as a “cathode.”
The term “negative electrode” means a battery cell electrode to which current flows in when the lithium-ion battery cell is discharged. Sometimes a “negative electrode” is referred to as an “anode.”
The term “cell” or “battery cell” means an electrochemical cell made of at least one positive electrode, at least one negative electrode, an electrolyte, and a separator membrane.
The term “battery” or “battery pack” means an electric storage device made of at least one battery cell. In a refinement, “battery” or “battery pack” is an electric storage device made of a plurality of battery cells.
In a variation, a positive electrode material includes a plurality of particles composed of a positive electrode active material where the passivating layer disposed over each particle of at least a subset of the plurality of particles. In other words, only a subset of or all of the particles may be coated with the passivating layer. Characteristically, the passivating layer is thermally insulating and lithium-ion conducting wherein the passivating layer is composed of a carbonate-phosphate composite.
Typically, the carbonate-phosphate composite includes a carbonate-based solvent or residue thereof and a phosphate. In a refinement, the carbonate-phosphate composite includes a carbonate-based solvent selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, ethylmethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, vinyl ethylene carbonate, vinylene carbonate and combinations thereof or a residue thereof. In a further refinement, the carbonate-phosphate composite includes a phosphate selected from the group consisting of trimethyl phosphate (TMP), triphenyl phosphate (TPP), triallyl phosphates, and combinations thereof.
In a variation, the passivating layer includes partial surface patches of high Li+ ion conductive film with a low thermally conductive film, either in layers or in-planar combination. In other words, the passivating layer can have a non-uniform thickness profile such that thinner regions can be more efficient in conducting lithium ions therethrough.
In a variation, the passivating layer includes an element that creates vacancies in a sufficient amount to allow effective lithium-ion transport. In a refinement, the element that creates vacancies is boron.
In some variations, the positive electrode material includes nickel in an amount greater than about 50 weight percent of the total weight of the positive electrode material. In a refinement, the positive electrode material includes nickel in an amount from about 35 weight percent to about 85 weight percent of the total weight of the positive electrode material. In some variations, the positive electrode material includes nickel in an amount of at least in increasing order of preference 35 weight percent, 40 weight percent, 45 weight percent, 50 weight percent, or 55 weight percent of the total weight of the positive electrode material. In a refinement, the positive electrode material includes nickel in an amount of at most in increasing order of preference 90 weight percent, 85 weight percent, 80 weight percent, 75 weight percent, or 70 weight percent of the total weight of the positive electrode material. In other refinement, the positive electrode material includes a component selected from the group consisting of nickel cobalt manganese oxide (NCM), nickel cobalt aluminum oxide (NCA), nickel cobalt manganese aluminum oxide (NCMA), and combinations thereof.
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The passivating layers set forth can be formed by applying one or more charging cycles to a newly formed battery cell. The container holding the battery cells includes an electrolyte (carbonate-based solvent) and a phosphate additive as described above. In a variation, the electrolyte is added and then one or more charging cycles are run. The phosphate is then added and one or more additional charging cycles are run. Characteristically, a sufficient number of charging cycles are run to form the passivating layer. In some refinement, the charging of the cell is performed over 1 to 30 minutes such that a passivating layer having a non-uniform thickness (i.e., patches) is formed.
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The negative electrode binder binds negative active material particles with one another and with a current collector. The binder can be a non-aqueous binder, an aqueous binder, or a combination thereof. Examples of non-aqueous binder may be polyvinylchloride, carboxylated polyvinylchloride, polyvinylfluoride, an ethylene oxide-containing polymer, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or a combination thereof. Aqueous binders can be rubber-based binders or polymer resin binders. Examples of rubber-based binders include but are not limited to styrene-butadiene rubbers, acrylated styrene-butadiene rubbers, acrylonitrile-butadiene rubbers, acrylic rubbers, butyl rubbers, fluorine rubbers, and combinations thereof. Examples of polymer resin binders include but are not limited to polyethylene, polypropylene, ethylenepropylene copolymer, polyethyleneoxide, polyvinylpyrrolidone, epichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, ethylenepropylenediene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, a polyester resin, an acrylic resin, a phenolic resin, an epoxy resin, polyvinyl alcohol and combinations thereof.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
