Composite cathodes containing polymer electrolytes and nickel-based cathode active materials

Abstract

The present invention relates to a solid composite cathode comprising a polymer electrolyte and a high-potential NMC-type cathode active material. The polymer electrolyte comprises an electrolyte composition, preferably comprising a deep eutectic solvent (DES), and a polymer network with a polyacrylamide backbone. JPEG2025531373000013.jpg33170

Description

[Technical Field]

[0001] The present invention relates to a composite cathode comprising a polymer electrolyte and a cathode active material comprising Li, M, and O, where M comprises Ni and one or both of Mn and Co. The polymer electrolyte comprises an electrolyte composition including a deep eutectic solvent (DES) and a polymer network having a polyacrylamide backbone. [Background technology]

[0002] In recent years, electronic products, electronic devices, and communication devices have rapidly become smaller and lighter. Similarly, electric vehicles, which have emerged as an environmentally friendly means of transportation, have become widely used. These factors have led to a demand for higher performance in secondary batteries used as power sources for these products. Furthermore, lithium secondary batteries have attracted attention as high-performance batteries due to their high energy density and high reference electrode potential.

[0003] Conventional lithium secondary batteries contain liquid electrolytes, such as organic solvents. A significant drawback of liquid electrolytes is that the compositions, particularly the solvents, are flammable, posing a significant safety risk during normal operation, especially in the event of an accident. Another drawback, inherent to the liquid nature of the electrolyte, is the increased risk of leakage and environmental contamination in the event of a spill or leak.

[0004] In recent years, efforts have been made to develop solid-state electrolytes that can provide solid-state lithium-ion batteries. Such solid-state batteries have significantly reduced EHS (environment, health, and safety) hazards. Conventional solid electrolytes can include oxide-based solid electrolytes, polymer-based solid electrolytes, and sulfide-based electrolytes. Polymer-based electrolytes are commonly used due to their low flammability, high flexibility, excellent thermal stability, and safety.

[0005] The difficulty of developing solid electrolytes with high ionic conductivity, wide electrochemical windows, and mechanical / thermal stability has led to the concept of solid-liquid composite materials, such as solid composite electrolytes (SCEs). These electrolytes contain a liquid lithium-ion conducting electrolyte encapsulated within a solid framework or network. Examples include ionic liquids confined within inorganic (e.g., silica) or polymer (e.g., poly(ethylene glycol) diacrylate (PEODA)) solid frameworks.

[0006] A major challenge in the fabrication of solid composite electrolytes is the selection of a polymer backbone that is stable to sol-gel synthesis and can effectively encapsulate the liquid lithium-ion electrolyte. Furthermore, it is difficult to develop a solid composite electrolyte that is compatible with high-potential cathode materials such as NMC622 or NMC811 and exhibits satisfactory anode stability. For example, the most common solid polymer electrolyte, PEO (polyethylene oxide), is poorly resistant to Li + It has anodic stability limited to a potential of about 4.0 V vs. Li.

[0007] Energy Environ. Sci., 2021, 14, 931-939 contemplates the use of alkali metal bis(trifluoromethane)-sulfonimide (TFSI) salts in polymer electrolytes containing an N-isopropylacrylamide (NIPAM) polymer backbone.

[0008] Chem. Mater. 2020, 32, 3783-3793 proposes the use of lithium bis(trifluoromethane)-sulfonimide lithium salt (LiTFSI) and N-methylacetamide (MAc) based deep eutectic solvent in a polymer electrolyte containing an ethylene glycol 4-acryloylmorpholine (AcMo) backbone.

[0009] U.S. Patent Application Publication No. 2020 / 0343586(A1) contemplates the use of various deep eutectic solvents in polymer electrolytes containing various polymer backbones, including a polymer electrolyte containing lithium bis(trifluoromethane)-sulfonimide lithium salt (LiTFSI) and N-methylacetamide (MAc)-based deep eutectic solvent in a polymer network containing an acrylate backbone. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0343586(A1) [Non-patent literature]

[0011] [Non-Patent Document 1] Energy Environ.Sci.,2021,14,931-939 [Non-patent document 2] Chem.Mater.2020,32,3783-3793 Summary of the Invention [Problem to be solved by the invention]

[0012] It is an object of the present invention to provide a composite cathode comprising a polymer electrolyte, which comprises a composite cathode comprising a polymer network that is compatible with a deep eutectic solvent. It is a further object of the present invention to provide a composite cathode containing a polymer electrolyte that is compatible with high voltage cathode active materials, particularly NMC622.

[0013] It is a further object of the present invention to provide a composite cathode containing a polymer electrolyte that has high anodic stability. It is a further object of the present invention to provide a composite cathode containing a polymer electrolyte that has good mechanical flexibility. [Means for solving the problem]

[0014] The present inventors have discovered that polymer electrolytes comprising polymer networks based on specific (meth)acrylamide monomers effectively encapsulate deep eutectic solvents (DESs) and are surprisingly compatible with electrode active materials containing Li, M, and O, where M includes Ni and one or both of Mn and Co. As shown in the accompanying examples, the polymer electrolytes described herein have been found to have excellent cycling stability when combined with high-potential electrode active materials, such as NMC622. Furthermore, the present inventors have discovered that the polymer electrolytes can be synthesized in the presence of cathode active materials, thereby providing composite cathode materials. One or more of the objects of the present invention are achieved by different aspects of the present invention described herein.

[0015] Accordingly, in a first aspect of the present invention there is provided a composite cathode comprising a cathode active material and a polymer electrolyte, wherein the cathode active material comprises Li, M, and O, wherein M comprises Ni and one or both of Mn and Co, and the polymer electrolyte comprises an electrolyte composition and a polymer network, the electrolyte composition preferably comprising a deep eutectic solvent (DES), and the polymer electrolyte is obtained by polymerizing a precursor composition comprising the electrolyte composition and a first monomer according to formula (I): [ka] [In the formula, R 1 represents a first substituent having 1 to 8 carbon atoms and optionally containing at least one functional group selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof, and preferably R 1 is C1-C6 alkyl, C1-C6 hydroxyalkyl, -(CH2-CH2-O) n -H, R 2represents H or a second substituent having 1 to 8 carbon atoms and optionally containing at least one functional group selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof, and preferably R 2 is H, C1-C6 alkyl, C1-C6 hydroxyalkyl, -(CH2-CH2-O) n -H, R 3 is selected from H, methyl, or ethyl; and n is an integer from 1 to 5], a composite cathode is provided.

[0016] The precursor composition typically further comprises a first crosslinker, preferably allyl (-CH3-CH=CH2), oxiranyl (-C2H3O), glycidyl (-CH2-C2H3O), vinyl ether (-O-CH=CH2), vinyl ester (-C(O)-O-CH=CH2), vinylamide (-C(O)-NH-CH=CH2), vinylamine (-NH-CH=CH2), norbornene, maleate, fumarate, itaconate, alkynyl [ka] The first crosslinker is selected from a crosslinker containing two or more functional groups selected from the group consisting of styrene (-Ph-CH=CH2), acrylamide (-NH-C(O)-CH=CH2), methacrylamide (-NH-C(O)-C(CH3)=CH2), acrylate (-OC(O)-CH=CH2), methacrylate (-OC(O)-C(CH3)=CH2), and combinations thereof, preferably the first crosslinker is selected from a crosslinker containing two or more functional groups selected from acrylamide (-NH-C(O)-CH=CH2), methacrylamide (-NH-C(O)-C(CH3)=CH2), acrylate (-OC(O)-CH=CH2), methacrylate (-OC(O)-C(CH3)=CH2), and combinations thereof.

[0017] In another aspect of the present invention, there is provided a method for making a composite cathode, comprising the steps of: (a1) providing a cathode active material in particulate form comprising Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; (b1) providing a polymer electrolyte as described herein in particulate form; (c1) blending the cathode active material of step (a) with the polymer electrolyte of step (b) to form a homogeneous blend; Including, (d1) optionally compressing the blend obtained in step (c); A method of manufacturing is provided, which may include:

[0018] In another aspect of the present invention, there is provided a method for making a composite cathode, comprising the steps of: (a2) providing a cathode active material comprising Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; (b2) providing a precursor composition as described herein; (c2) contacting the precursor composition with a cathode active material; (d2) polymerizing the precursor composition in the presence of a cathode active material; A method of manufacturing is provided, comprising:

[0019] In another aspect of the present invention, there is provided the use of the composite cathode of the present invention as an electrochemical cell component.

[0020] In another aspect of the present invention, an electrochemical cell is provided that includes an anode and the composite cathode of the present invention.

[0021] In another aspect of the present invention, there is provided a battery, more particularly a lithium ion battery or a lithium metal battery, comprising at least one electrochemical cell as described herein, e.g., two or more electrochemical cells according to the present invention.

[0022] In another aspect of the present invention, there is provided a method of manufacturing or operating stationary facilities such as cars, computers, personal digital assistants, cell phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communication devices, remote car locks, and energy storage devices for power plants by using at least one battery or at least one electrochemical cell as described herein.

[0023] In another aspect of the present invention, there is provided the use of an electrochemical cell comprising the composite cathode of the present invention in a motorized vehicle, a bicycle powered by an electric motor, a robot, an aircraft (e.g., an unmanned aerial vehicle including a drone), a ship, a satellite, or a stationary energy storage device. [Brief explanation of the drawings]

[0024] [Figure 1] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Example 1. [Figure 2] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Example 2. [Figure 3] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Example 3. [Figure 4] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Example 4. [Figure 5] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Example 5. [Figure 6] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Comparative Example 6. [Figure 7] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Comparative Example 7. [Figure 8] 1 shows anodic linear sweep voltammetry performed on the polymer electrolyte of Example 8. [Figure 9]1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing NMC622 electrodes and the polymer electrolyte of Example 1. [Figure 10] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing NMC622 electrodes and the polymer electrolyte of Example 2. [Figure 11] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing NMC622 electrodes and the polymer electrolyte of Example 3. [Figure 12] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing NMC622 electrodes and the polymer electrolyte of Example 4. [Figure 13] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing an NMC622 electrode and the polymer electrolyte of Comparative Example 5. [Figure 14] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing an NMC622 electrode and the polymer electrolyte of Comparative Example 6. [Figure 15] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing NMC622 electrodes and the polymer electrolyte of Example 7. [Figure 16] 1 shows EIS characterization (impedance after 6 hour rest) of a symmetric cell containing NMC622 electrodes and the polymer electrolyte of Example 8. [Figure 17] Figure 1 shows the cycling capacity of cells containing NMC622 and Li electrodes with the electrolytes of Examples 1 and 2. The discharge capacity is the average of three cells for each C-rate. The capacity is normalized to the mass of the positive electrode active material. [Figure 18] Figure 1 shows the cycling capacity of cells containing NMC622 and Li electrodes with the electrolytes of Examples 3 and 4. The discharge capacity is the average of three cells for each C-rate. The capacity is normalized to the mass of the positive electrode active material. [Figure 19]Figure 1 shows the cycling capacity of cells containing NMC622 and Li electrodes with the electrolytes of Comparative Examples 5 and 6. The discharge capacity is the average of three cells for each C-rate. The capacity is normalized to the mass of the positive electrode active material. [Figure 20] Figure 1 shows the cycling capacity of cells containing NMC622 and Li electrodes with the electrolytes of Examples 7 and 8. The discharge capacity is the average of three cells for each C-rate. The capacity is normalized to the mass of the positive electrode active material. [Figure 21] 1 shows EIS characterization (impedance every 6 hours) of an NMC622 electrode impregnated with the polymer electrolyte of Example 9 and a control cell containing the polymer electrolyte of Example 9. [Figure 22] 1 shows EIS characterization (impedance every 6 hours) of a symmetric cell containing an NMC622 electrode and the polymer electrolyte of Comparative Example 10. DETAILED DESCRIPTION OF THE INVENTION

[0025] In the following detailed description, preferred embodiments are described in detail to enable the practice of the present invention. While the present invention is described with reference to these particular preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. To the contrary, however, the present invention encompasses numerous alternatives, modifications, and equivalents, as will become apparent from a consideration of the following detailed description.

[0026] As used herein, the expression "comprise" and its variations, such as "comprises" and "comprising," should be interpreted in an open and inclusive sense, meaning that the described embodiments include the recited features, but do not exclude the presence of other features unless doing so would render the embodiment inoperable.

[0027] As used herein, the phrases "one embodiment," "a particular embodiment," "an embodiment," and the like should be interpreted to mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of such phrases in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. For example, particular features of the present disclosure that are described in this specification in the context of separate embodiments are also expressly contemplated as being combined in a single embodiment.

[0028] As used herein, the singular forms "a," "an," and "the" should be construed to include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally used in its broadest sense, i.e., meaning "and / or," unless the content clearly dictates otherwise.

[0029] As used herein, the expression "cathode active material" is also interchangeably referred to as "positive electrode active material." As will be understood by those skilled in the art, cathode polarity can be positive or negative depending on the operating mode of the electrochemical cell containing the cathode active material. As used herein and in the claims, the term "cathode active material" or "positive electrode active material" is defined as a material that is electrochemically active in a positive electrode or cathode. An active material is understood to be a material that can capture and release Li-ions when exposed to a voltage change over a period of time.

[0030] As used herein, the expression "(meth)acrylamide" should be interpreted as "methacrylamide, acrylamide, or a combination thereof." For example, N-dialkyl(meth)acrylamide should be interpreted as "N-dialkylmethacrylamide, N-dialkylacrylamide, or a combination thereof."

[0031] In the context of the present disclosure, when it is noted that a substituent (optionally) contains a certain number of functional groups (e.g., one or two), this should be interpreted as meaning that the substituent has exactly the recited number of functional groups. For example, the expression "selected from C1-C6 hydroxyalkyl, wherein the C1-C6 hydroxyalkyl contains one hydroxyl functional group" should be interpreted as meaning that exactly one hydroxyl functional group is present.

[0032] The parameters x, y, z, and a referred to herein in the context of the composition of the cathode active material are measured by inductively coupled plasma optical emission spectroscopy (ICP-OES).

[0033] Ionic conductivity referred to herein refers to the ionic conductivity determined by electrochemical impedance spectroscopy (EIS) (using a Biologic SP-300) of the polymer electrolyte in a symmetrical stainless steel|electrolyte|stainless steel Swagelok-type cell at a specific temperature by perturbing the open circuit potential with an AC sinusoidal potential of 10 mV amplitude in the frequency range of 10 kHz to 100 mHz.

[0034] The "anodic stability limit" referred to herein is determined by linear sweep voltammetry (preferably using a Bio-Logic SP-300) of a polymer electrolyte sandwiched between a stainless steel working electrode and lithium metal reference and counter electrodes in a coin cell setup, with the working electrode voltage exceeding 10 mV s. -1 At a scan rate of , the anodic scan is performed from the open circuit potential to Li + The potential was swept up to 6 V vs. / Li. The stability limit was determined as the onset of electrolyte oxidation, which can be observed by a sudden increase in the measured current.

[0035] Composite cathode of the present invention In a first aspect of the present invention, there is provided a composite cathode comprising a cathode active material and a polymer electrolyte, wherein the cathode active material comprises Li, M, and O, wherein M comprises Ni and one or both of Mn and Co, and the polymer electrolyte comprises an electrolyte composition and a polymer network, the electrolyte composition preferably comprising a deep eutectic solvent (DES), and the polymer electrolyte is prepared by dissolving a precursor composition comprising the electrolyte composition and a first monomer according to formula (I): [ka] [In the formula, R 1 represents a first substituent having 1 to 8 carbon atoms and optionally containing at least one functional group selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof, and preferably R 1 is C1-C6 alkyl, C1-C6 hydroxyalkyl, -(CH2-CH2-O) n -H, R 2 represents H or a second substituent having 1 to 8 carbon atoms and optionally containing at least one functional group selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof, and preferably R 2 is H, C1-C6 alkyl, C1-C6 hydroxyalkyl, -(CH2-CH2-O) n -H, R 3 is selected from H, methyl, or ethyl; n is an integer from 1 to 5. A composite cathode is provided, which is obtained by polymerizing

[0036] In some embodiments of the present invention, a composite cathode as described herein is provided with the proviso that the monomer according to formula (I) is not N,N-dimethylacrylamide.

[0037] The polymer network referred to in this disclosure is a three-dimensional network obtained by polymerization of one or more monomers according to formula (I) in the presence of a crosslinker. Such three-dimensional polymer networks are also called gels, and the polymer electrolytes described in the context of the present invention are also called "gel polymer electrolytes." For the purposes of this disclosure, a gel polymer refers to a polymer network (i.e., a three-dimensional crosslinked system) that does not exhibit flow when in a steady state but allows the diffusion of a liquid phase through the polymer network. Preferably, the gel is self-supporting. Such gels typically exhibit a combination of flexibility, mechanical robustness, low vapor pressure, and preferably non-flammability.

[0038] As one skilled in the art will understand based on this disclosure, the electrolyte composition is contained within a polymer network. The electrolyte composition is typically confined within the polymer network, meaning that substantially no electrolyte composition spontaneously flows from the polymer electrolyte of the present invention when placed on a surface (e.g., a ceramic lab bench) without the application of external pressure. In all aspects of the present invention, it is highly preferred that the electrolyte composition, absent the polymer network, is a liquid at 20°C.

[0039] In a preferred embodiment of the present invention, there is provided a cathode composite of the present invention, wherein the first monomer is selected from compounds according to formula (I): R 1 represents a first substituent having 1 to 6 carbon atoms and optionally containing one or two functional groups selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof; R 2 represents H or a second substituent having 1 to 6 carbon atoms and optionally containing one or two functional groups selected from alcohols, amines, ethers, ketones, amides, acetals, ketals, aminoacetals, hemiaminal ethers, or combinations thereof, and preferably R 2is H, C1-C6 alkyl, C1-C6 hydroxyalkyl, -(CH2-CH2-O) n -H, R 3 is selected from H, methyl, or ethyl; There is provided a cathode composite of the present invention, wherein n is an integer from 1 to 5.

[0040] In a more preferred embodiment of the present invention, there is provided a cathode composite of the present invention, wherein the first monomer is selected from compounds according to formula (I): R 1 represents a first substituent having 1 to 6 carbon atoms and optionally containing one or two functional groups selected from an alcohol; R 2 represents H or a second substituent having 1 to 6 carbon atoms and optionally containing one or two functional groups selected from alcohols, preferably R 2 is selected from H, C1-C6 alkyl, C1-C6 hydroxyalkyl, wherein C1-C6 hydroxyalkyl contains one hydroxyl function; R 3 is selected from H, methyl, or ethyl; There is provided a cathode composite of the present invention, wherein n is an integer from 1 to 5.

[0041] In a highly preferred embodiment of the present invention, the first monomer is selected from the following options A, B, or C: AR 1 is selected from C1-C6 alkyl, preferably R 1 is a C3 alkyl, and R 2 is selected from H or methyl, preferably R 2 is H and R 3 is selected from H or methyl, preferably R 3 is H; or BR 1 is selected from C1-C6 alkyl, preferably R 1 is a C2 alkyl, and R 2is selected from C1-C6 alkyl, preferably R 2 is a C2 alkyl, and R 3 is selected from H or methyl, preferably R 3 is H; or CR 1 is selected from C1-C6 hydroxyalkyl, wherein the C1-C6 hydroxyalkyl contains one hydroxyl function, preferably R 1 is 2-hydroxyethyl, and R 2 is selected from H or methyl, preferably R 2 is H and R 3 is selected from H or methyl, preferably R 3 is H; A cathode composite is provided according to the present invention.

[0042] In some embodiments of the present invention, a cathode composite is provided wherein the first monomer is according to option B, with the proviso that the first monomer is not N,N-dimethylacrylamide.

[0043] In a preferred embodiment of the present invention, a cathode composite is provided wherein the first monomer according to Formula (I) is selected from the group consisting of N-isopropylamide (NIPAM), N,N-diethylacrylamide (DEAA), N-(2-hydroxyethyl)acrylamide (HEAA), and combinations thereof.

[0044] In preferred embodiments of the invention, the first monomer constitutes at least 80 mol %, preferably at least 90 mol %, and more preferably at least 95 mol % of all monomers in the precursor composition of the polymer network of the electrochemical cell. In highly preferred embodiments of the invention, the first monomer constitutes at least 98 mol %, 99 mol %, or about 100 mol % of all monomers in the composition. For purposes of determining the total amount of monomers in the precursor composition, any compound polymerizable with the first monomer and having a functionality of 1 is considered a monomer, with the functionality being determined based on the acrylamide functionality and the free-radically polymerizable functionality of the first monomer.

[0045] The composite cathode of the present invention can be provided in various forms. In some embodiments of the present invention, the composite cathode comprises a homogeneous mixture of cathode active material particles and polymer electrolyte particles. The homogeneous mixture may comprise additional components. In preferred embodiments of the present invention, the cathode active material is porous, and the polymer electrolyte is coated on and / or at least partially embedded in the cathode active material. Such coated or embedded materials can be obtained by contacting a precursor composition with the cathode active material and polymerizing the precursor composition in the presence of the cathode active material. This is described in more detail elsewhere herein.

[0046] Crosslinking agent According to a preferred embodiment of the present invention, the precursor composition further comprises a first crosslinking agent. Because the first monomer ((meth)acrylamide according to formula (I)) is monofunctional, including a crosslinking agent in the precursor composition allows for the formation of a three-dimensional polymer network. The crosslinking agent can be selected from any compound that is polymerizable with the first monomer and has a functionality of 2 or greater, where the functionality is determined based on the acrylamide functionality and the free-radically polymerizable functional group of the first monomer.

[0047] The first crosslinker may be any of allyl (-CH3-CH=CH2), oxiranyl (-C2H3O), glycidyl (-CH2-C2H3O), vinyl ether (-O-CH=CH2), vinyl ester (-C(O)-O-CH=CH2), vinylamide (-C(O)-NH-CH=CH2), vinylamine (-NH-CH=CH2), norbornene, maleate, fumarate, itaconate, alkynyl [ka] Preferably, the first crosslinker is selected from a crosslinker containing two or more functional groups selected from the group consisting of styrene (-Ph-CH=CH2), acrylamide (-NH-C(O)-CH=CH2), methacrylamide (-NH-C(O)-C(CH3)=CH2), acrylate (-OC(O)-CH=CH2), methacrylate (-OC(O)-C(CH3)=CH2), and combinations thereof, and preferably, the first crosslinker is selected from a crosslinker containing two or more functional groups selected from acrylamide (-NH-C(O)-CH=CH2), methacrylamide (-NH-C(O)-C(CH3)=CH2), acrylate (-OC(O)-CH=CH2), methacrylate (-OC(O)-C(CH3)=CH2), and combinations thereof. In some embodiments of the present invention, the first crosslinker comprises two, three, or four functional groups selected from the aforementioned functional groups, although it is preferred that the first crosslinker comprises two of the same or different functional groups selected from the aforementioned functional groups.

[0048] Examples of suitable and therefore preferred embodiments of the first crosslinker include those in which the first crosslinker is selected from the group consisting of allyl methacrylate, allyl acrylate, glycidyl methacrylate, ethylene glycol dicyclopentyl ether methacrylate, ethylene glycol dicyclopentyl ether acrylate, triethylene glycol divinyl ether, poly(ethylene glycol) diacrylamide, poly(ethylene glycol) dimethacrylate, poly(ethylene glycol) diacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate. Triethylene glycol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, propanediol dimethacrylate, propanediol diacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol dimethacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,10-bis(acryloyloxy)decane, 1,12-dodecanediol dimethacrylate, 1,12-Dodecanediol Diacrylate, Poly(Silicone-alt-PEG) Dimethacrylate, Poly(Silicone-alt-PEG) Diacrylate, Poly(propylene glycol) Dimethacrylate, Poly(propylene glycol) Diacrylate, Bisphenol A Propoxylate Dimethacrylate, Bisphenol A Propoxylate Diacrylate, Neopentyl Glycol Propoxylate Dimethacrylate, Neopentyl Glycol Propoxylate Diacrylate, Glycerol Ethoxylate-co-Propoxylate Dimethacrylate, Glycerol Ethoxylate -co-propoxylate diacrylate, propylene glycol dimethacrylate, propylene glycol diacrylate, polycaprolactone dimethacrylate, polycaprolactone diacrylate, pentaerythritol propoxylate dimethacrylate, pentaerythritol propoxylate diacrylate, tri(propylene glycol) dimethacrylate, tri(propylene glycol) diacrylate, diurethane dimethacrylate (DUDMA), 1,3,5-triallyl-2,4,6(1H,3H,5H)-trione, 2,4,6,-triallyloxy-1,3,5,Triazine, trimethylolpropane propoxylate trimethacrylate, trimethylolpropane propoxylate triacrylate, glycerol propoxylate trimethacrylate, glycerol propoxylate triacrylate, polycaprolactone trimethacrylate (PCLTMA), polycaprolactone triacrylate, tris-(4-hydroxyphenyl)ethane trimethacrylate, tris-(4-hydroxyphenyl)ethane triacrylate, trimethylolpropane ethoxylate trimethacrylate, trimethylolpropane ethoxylate triacrylate, glycerol ethoxylate trimethacrylate, glycerol ethoxylate triacrylate, pentaerythritol ethoxylate trimethacrylate, pentaerythritol ethoxylate triacrylate, ethylenediaminetetrakis(ethoxylate-block-propoxylate)tetramethacrylate acrylate, ethylenediaminetetrakis(ethoxylate-block-propoxylate) tetraacrylate, and pentaerythritol propoxylate tetramethacrylate, pentaerythritol propoxylate tetraacrylate, N,N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide, N,N'-ethylenebisacrylamide, N,N'-ethylenebismethacrylamide, N,N'-propylenebisacrylamide, N,N'-propylenebismethacrylamide, N,N'-butylenebisacrylamide, N,N'-butylenebismethacrylamide, N,N'-pentylenebisacrylamide, N,N'-pentylenebismethacrylamide, N,N'-hexylenebisacrylamide, N,N'-hexylenebismethacrylamide, N,N'-heptylenebisacrylamide, N,N'-heptylenebismethacrylamide, N,N'-octylenebisacrylamide, N,In a preferred embodiment of the present invention, the first crosslinker is selected from poly(ethylene glycol) dimethacrylate, poly(ethylene glycol) diacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, propanediol dimethacrylate, propanediol diacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol dimethacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,10-bis(acryloyloxy)-2,2-dimethyl-2,3-dimethyl-2,4 ... ) Decane, 1,12-dodecanediol dimethacrylate, 1,12-dodecanediol diacrylate, N,N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide, N,N'-ethylenebisacrylamide, N,N'-ethylenebismethacrylamide, N,N'-propylenebisacrylamide, N,N'-propylenebismethacrylamide, N,N'-butylenebisacrylamide, N,N'-butylene In a highly preferred embodiment of the present invention, the first crosslinker is selected from ethylene glycol dimethacrylate, ethylene glycol diacrylate, N,N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide, and combinations thereof.

[0049] In some embodiments of the present invention, the first cross-linking agent is selected from a compound according to Formula (IIa), a compound according to Formula (IIb), or a combination thereof. [ka] [ka] [In the formula, R 4 , R 5 , R 6 , and R 7 are each independently selected from H, methyl, or ethyl; R 8 and R 9 are each independently selected from H or methyl; X is an alkanediyl or polyoxyalkylene, preferably X is (—CH—) m or -CH2-CH2(-O-CH2-CH2) o - and Y is an alkanediyl or polyoxyalkylene, preferably Y is (—CH—) n or -CH2-CH2(-O-CH2-CH2) p - and m is an integer ranging from 1 to 10; n is an integer ranging from 1 to 10, o is an integer in the range of 1 to 200; and p is an integer ranging from 1 to 200. As shown in the accompanying examples, these crosslinkers have been found to have excellent compatibility with the first monomer, resulting in polymer electrolytes with desirable electrochemical and mechanical properties.

[0050] In a preferred embodiment of the present invention, X is (—CH—) m wherein m is in the range of 1 to 6, preferably in the range of 1 to 4, and more preferably m is equal to 2.

[0051] In a preferred embodiment of the present invention, Y is (—CH—) nwherein n is in the range of 1 to 6, preferably in the range of 1 to 4, and more preferably n is equal to 1.

[0052] As will be appreciated by those skilled in the art, X may be -CH2-CH2(-O-CH2-CH2) o - or Y is -CH2-CH2(-O-CH2-CH2) p -, the compounds of formula (IIa) or (IIb) are in fact provided in the form of a mixture of compounds with different degrees of ethoxylation and therefore different numbers of o and p. The precursor composition comprises one or more crosslinkers according to formula (IIa), where X is -CH2-CH2(-O-CH2-CH2). o -, it is preferred that the number average o determined over all compounds of formula (IIa) in the precursor composition is in the range of 1 to 200, preferably in the range of 2 to 20. Similarly, it is preferred that the precursor composition comprises one or more crosslinkers according to formula (IIb), where Y is -CH2-CH2(-O-CH2-CH2) p -, it is preferred that the number average p determined over all compounds of formula (IIb) in the precursor composition is in the range of 1 to 200, preferably in the range of 2 to 20.

[0053] The precursor composition may generally contain additional crosslinkers other than the first crosslinker. However, in some preferred embodiments of the present invention, the first crosslinker is the only crosslinker present. Generally, the average functionality determined across all crosslinkers in the precursor composition is within the range of 2 to 3, preferably within the range of 2 to 2.5, and most preferably within the range of 2 to 2.2. For purposes of determining this average functionality, any compound polymerizable with the first monomer and having a functionality of 2 or greater is considered a crosslinker, with functionality determined based on the acrylamide functionality and free-radically polymerizable functionality of the first monomer.

[0054] As will be appreciated by those skilled in the art, the amount of crosslinker used in the precursor composition affects the mechanical and electrochemical properties of the resulting polymer electrolyte. In a preferred embodiment of the present invention, the first crosslinker is included in the precursor composition in an amount such that the molar ratio of the total amount of first monomers included in the precursor composition to the total amount of first crosslinker included in the precursor composition is within the range of 99.5:0.5 to 80:20, preferably 98:2 to 80:20, and more preferably 95:5 to 85:15. When the precursor composition includes additional crosslinkers other than the first crosslinker, the total amount of crosslinkers in the precursor composition is preferably within the range of 99.5:0.5 to 80:20, preferably 98:2 to 80:20, and more preferably 95:5 to 85:15. For purposes of determining the total amount of crosslinker, any compound polymerizable with the first monomer and having a functionality of 2 or greater is considered a crosslinker, with the functionality being determined based on the acrylamide functionality and free-radically polymerizable functional groups of the first monomer.

[0055] According to a preferred embodiment of the present invention, the precursor composition further comprises one or more radical initiators, preferably one or more radical initiators selected from thermal initiators, photoinitiators, and combinations thereof.

[0056] Suitable thermal radical initiators include benzoyl peroxide, dibenzoyl peroxide, succinic acid peroxide, dilauroyl peroxide, didecanoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, di-t-amyl peroxide, α,α'-di(t-butylperoxy)diisopropyl-benzene, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di-( t-Butylperoxy)hexyne-3, t-butylcumyl peroxide, α-cumylperoxyneodecanoate, α-cumylperoxyneopheptanoate, t-amylperoxyneodecanoate, t-butylperoxyneodecanoate, di-(2-ethylhexyl)peroxydicarbonate, t-amylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2 ,5-bis(2-ethyl-hexanoylperoxy)hexane, dibenzoyl peroxide, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, 1,1-di-(t-amylperoxy)cyclohexane, 1,1-di-(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-di-(t-butylperoxy)cyclohexane, OO-t-amyl-O(2-ethylhexanoylperoxy)hexane sil) monoperoxycarbonate, OO-t-butyl O-isopropyl monoperoxycarbonate, OO-t-butyl O-(2-ethylhexyl) monoperoxycarbonate, t-amyl peroxybenzoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, ethyl 3,3-di-(t-amylperoxy)butyrate, ethyl 3,3-di-(t-butylperoxy)butyrate, dicumyl peroxide;and azo compounds such as 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(cyclohexanecarbonitrile), azobisisobutyronitrile (AIBN), and 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis[2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane disulfate dihydrate, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate Examples of suitable azobis include, but are not limited to, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(1-imino-1-pyrrolidino-2-ethylpropane)dihydrochloride, 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], cumene hydroperoxide, and ammonium persulfate;

[0057] Suitable radical photoinitiators include benzophenone (e.g., "IRGACURE 500"), 3-methylbenzophenone, 2-methylbenzophenone, 3,4-dimethylbenzophenone, 3-hydroxybenzophenone, 4-hydroxybenzophenone, 4,4'-dihydroxybenzophenone, 4-benzoylbenzoic acid, 2-benzoylbenzoic acid, methyl 2-benzoylbenzoate, 4,4'-carbonyldiphthalic anhydride, methyl benzoyl formate (e.g., "DAROCUR MBF"), 1-hydroxy-cyclohexyl-phenyl-ketone (e.g., "IRGACURE 184"), 2-hydroxy-2-methyl-1-phenyl-1-propanone (e.g., "DAROCUR 1173"), 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (e.g., "IRGACURE 1173"). 2959"), oxy-phenyl-acetic acid 2-[2oxo-2phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester (e.g., "IRGACURE 754"), α,α-dimethoxy-α-phenylacetophenone (also known as 2,2-dimethoxy-2-phenyl-acetophenone (DMPA), e.g., "IRGACURE 651"), 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone (e.g., "IRGACURE 369"), 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (e.g., "IRGACURE 907"), diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide (e.g., "DAROCURE 754"). TPO), phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl) (e.g., IRGACURE 819), bis(η5-2,4-cyclopentadien-1-yl)bis[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl]titanium (e.g., "IRGACURE 784"), 1-hydroxy-cyclohexyl-phenyl-ketone (e.g., ("IRGACURE 184"), 2-hydroxy-2-methyl-1-phenyl-1-propanone (e.g., "DAROCUR 1173"), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (e.g., "IRGACURE 127"), 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (e.g., "IRGACURE 127"). 2959"), phenyl glyoxylate, oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester, oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester, phenyl glyoxylic acid methyl ester (e.g., "DAROCUR MBF"), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (e.g., "LUCIRIN TPO"), 2,4,6-trimethylbenzoyl-diphenylphosphinate (e.g., "LUCIRIN TPO-L"), liquid blends of acylphosphine oxides (e.g., "IRGACURE 2100"), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (e.g., "IRGACURE 819"), titanocene, bis(η5-2,4-cyclopentadien-1-yl)bis[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl] (e.g., "IRGACURE 784"), [1-(4-phenylsulfanylbenzoyl)heptylideneamino]benzoate (e.g., "IRGACURE OXE 01"), [1-[9-ethyl-6-(2-methylbenzoyl)carbazol-3-yl]ethylideneamino]acetate (e.g., "IRGACURE OXE 02"), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (e.g., "IRGACURE 907"), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (e.g., "IRGACURE 907"). 369"), 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (e.g., "IRGACURE 379"), benzil dimethyl ketal, 2,2-dimethoxy-1,2-diphenylethan-1-one (e.g., "IRGACURE 651"), camphorquinone, acetophenone, 4'-hydroxyacetophenone, 3'-hydroxyacetophenone, 4-(dimethylamino)-benzophenone, 4,4'-bis(dimethylamino)-benzophenone, 4,4'-bis(diethylamino)-benzophenone, 4,4'-dichlorobenzophenone, 4-phenylbenzophenone, 1,4-dibenzoylbenzene, 4-(p-tolylthio)-benzophenone, dibenzosuberenone, benzyl, p-anisyl, methylbenzoylformate, 9,10-phenanthrenequinone, 2-benzoyl- 2-Propanol, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 1-benzoylcyclohexanol, benzoin, anisoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-diethoxyacetophenone, benzil dimethyl ketal, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-isonitrosopropiophenone, 9,Examples of suitable thiol compounds include, but are not limited to, 10-phenanthrenequinone, 2-ethylanthraquinone, sodium anthraquinone-2-sulfonate, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-isopropylthioxanthone, 2,4-diethylthioxanthen-9-one, 2,7-dimethyloxythioxanthone, 2,2'-bis(2-chlorophenyl)4,4',5,5'-tetraphenyl-1,2'-biimidazole, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, lithium phenyl-(2,4,6-trimethylbenzoyl)phosphinate, and ferrocene.

[0058] In some embodiments of the present invention, the precursor composition further comprises one or more radical initiators selected from 2,2-dimethoxy-2-phenyl-acetophenone (DMPA), azobisisobutyronitrile (AIBN), and combinations thereof.

[0059] The one or more radical initiators are preferably used in an amount such that the molar ratio of the total amount of the first monomer contained in the precursor composition to the total amount of the one or more radical initiators contained in the precursor composition is within a range of 99.8:0.2 to 80:20, preferably within a range of 99:1 to 85:15, and more preferably within a range of 98:2 to 90:10.

[0060] electrolyte composition As will be appreciated by those skilled in the art, to obtain a gel-type polymer electrolyte, the polymer is preferably synthesized in the presence of the electrolyte composition, thereby effectively encapsulating the electrolyte composition within the polymer network. However, without being bound by any theory, other methods for obtaining the polymer electrolytes described herein may be possible, such as exchanging another liquid composition (e.g., a solvent) encapsulated in the polymer for the electrolyte composition, absorbing the electrolyte composition into a preformed polymer network, or injecting the electrolyte composition into a preformed polymer network. Thus, according to the present invention, the polymer electrolyte included in the composite cathode can be obtained by polymerizing a precursor composition containing the electrolyte composition and other components discussed throughout this disclosure (e.g., monomers, crosslinkers, initiators, etc.). In all aspects of the present invention, it is highly preferred that the electrolyte composition, absent the polymer network, be liquid at 20°C.

[0061] As shown in the accompanying examples, the inventors have discovered that deep eutectic solvent (DES)-filled polymer electrolytes exhibit exceptional performance, particularly in combination with high potential cathode active materials such as NMC622. Thus, in accordance with highly preferred embodiments of the present invention, the electrolyte composition comprises or consists of a deep eutectic solvent (DES). The deep eutectic solvent is preferably liquid at 20°C.

[0062] Various relative amounts of DES to polymer have been found to result in functional electrolyte materials. The precursor composition preferably comprises about 45-95% by volume (based on the total volume of the precursor composition), preferably about 55-90% by volume, and more preferably about 70-90% by volume of deep eutectic solvent (DES). Precursor compositions having about 85% by volume of DES have been found to provide excellent ionic conductivity and mechanical properties (increased flexibility). Thus, in highly preferred embodiments of the present invention, the precursor composition comprises about 75-90% by volume (based on the total volume of the precursor composition), preferably about 80-90% by volume, and most preferably about 83-87% by volume of deep eutectic solvent (DES). The remainder of the precursor composition consists of a first monomer, optionally additional monomers, a first crosslinker, optionally additional crosslinkers, one or more radical initiators, and optional additional components. In some embodiments, the remainder of the precursor composition consists essentially of a first monomer, optionally additional monomers, a first crosslinker, optionally additional crosslinkers, and one or more radical initiators.

[0063] Deep eutectic solvents (DES) preferably have a eutectic point of 25° C. or less, preferably a eutectic point of 15° C. or less, more preferably 0° C. or less. In a highly preferred embodiment of the present invention, the deep eutectic solvent (DES) has a eutectic point of −15° C. or less, most preferably −25° C. or less, allowing the DES to remain in a liquid state over the typical operating temperature window of electrochemical cells for typical applications such as automobiles. The eutectic points referred to herein are determined at a pressure of about 101 kPa.

[0064] The deep eutectic solvent (DES) preferably comprises at least one hydrogen bond acceptor and at least one hydrogen bond donor. The molar ratio of hydrogen bond acceptor to hydrogen bond donor is preferably at least 1:1, more preferably at least 1:2, and more preferably at least 1:3. In a preferred embodiment of the present invention, the electrolyte composition comprises or consists of (preferably consists of) a deep eutectic solvent (DES) comprising at least one hydrogen bond acceptor and at least one hydrogen bond donor, and the molar ratio of hydrogen bond acceptor to hydrogen bond donor is in the range of 1:1 to 1:8, preferably in the range of 1:2 to 1:6, and more preferably in the range of 1:3 to 1:5. A highly preferred molar ratio of hydrogen bond acceptor to hydrogen bond donor (particularly when the hydrogen bond acceptor is lithium bis(trifluoromethanesulfonyl)imide, as described elsewhere herein, and / or when the hydrogen bond donor is N-methylacetamide, as described elsewhere herein) is in the range of 1:3.5 to 1:4.5, e.g., about 1:4.

[0065] In a preferred embodiment of the present invention, the hydrogen bond acceptor comprises a lithium salt, a zinc salt, or a combination thereof, preferably a lithium salt. In a more preferred embodiment, the hydrogen bond acceptor is selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiOTf), lithium chloride (LiCl), lithium hexafluorophosphate (LiPF), lithium polysulfide, lithium perchlorate (LiClO), lithium bromide (LiBr), lithium iodide (LiI), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF), lithium hexafluoroarsenate (LiAsF), lithium bis(oxalato)borate (LiBOB), lithium fluoroalkylphosphate (LFAP[LiPF(CFCF)]), and combinations thereof, preferably lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and / or the hydrogen bond donor is selected from the group consisting of urea, N-methylurea, N,N-dimethylurea, N,N'-diisopropyl urea, N,N'-dimethyl ... Methylurea, N,N,N'-trimethylurea, thiourea, N-methylthiourea, N,N-dimethylthiourea, N,N'-dimethylthiourea, N,N,N'-trimethylthiourea, ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,4-diol, 1,2,3-propanetriol, acetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanoic acid The alkyl acrylate or alkyl acrylate copolymer is selected from the group consisting of benzoic acid, glycolic acid, citric acid, 2-hydroxypropionic acid, 2-hydroxyisobutyric acid, o-phenylenediamine, choline chloride, acetamide, N-methylacetamide, trifluoroacetamide, N-methyltrifluoroacetamide, benzamide, benzenesulfonic acid, p-toluenesulfonic acid, o-toluenesulfonic acid, m-toluenesulfonic acid, and combinations thereof, preferably N-methylacetamide.

[0066] Thus, in some embodiments of the present invention, the electrolyte composition comprises a deep eutectic solvent (DES) comprising, preferably consisting of, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and N-methylacetamide, wherein the molar ratio of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to N-methylacetamide is in the range of 1:1 to 1:8, preferably in the range of 1:2 to 1:6, more preferably in the range of 1:3 to 1:5, e.g., about 1:4.

[0067] The electrolyte composition preferably comprises at least 90 wt. % (based on the total weight of the electrolyte composition), preferably at least 95 wt. %, and more preferably at least 99 wt. % DES. In some embodiments, the electrolyte composition comprises water, e.g., 0.1 to 30 wt. % (based on the total weight of the electrolyte composition) water, or 0.1 to 10 wt. % (based on the total weight of the electrolyte composition) water. In other preferred embodiments, the electrolyte composition comprises less than 5 wt. % water, preferably less than 0.1 wt. % water, and more preferably less than 0.01 wt. % water. In some embodiments, the electrolyte composition is substantially free of water. The latter is particularly preferred for use in combination with moisture-sensitive electrodes such as Li or graphite. In all embodiments described herein, the electrolyte composition preferably comprises a deep eutectic solvent (DES).

[0068] As will be understood by those skilled in the art, in the context of the present disclosure, a precursor composition consists essentially of the electrolyte composition described herein in combination with a first monomer, a first crosslinker, and one or more initiators described herein. Thus, according to preferred embodiments of the present invention, the precursor composition comprises at least 90 wt % (based on the total weight of the precursor composition), preferably at least 95 wt % (based on the total weight of the precursor composition), and more preferably at least 99 wt % (based on the total weight of the precursor composition) of the electrolyte composition, the first monomer, optionally additional monomers, the first crosslinker, optionally additional crosslinkers, and one or more radical initiators. In some embodiments, the precursor composition comprises at least 90 wt % (based on the total weight of the precursor composition), preferably at least 95 wt % (based on the total weight of the precursor composition), and more preferably at least 99 wt % (based on the total weight of the precursor composition) of the electrolyte composition, the first monomer, the first crosslinker, and one or more radical initiators. As previously described herein, any compound polymerizable with a first monomer and having a functionality of 1 is considered a monomer, and any compound polymerizable with a first monomer and having a functionality of 2 or greater is considered a crosslinker, with the functionality being determined based on the acrylamide functionality and the free-radically polymerizable functionality of the first monomer. Thus, according to preferred embodiments of the present invention, the polymer electrolyte comprises at least 90 wt. % (based on the total weight of the polymer electrolyte), more preferably at least 98 wt. % (based on the total weight of the polymer electrolyte), and most preferably at least 99 wt. % (based on the total weight of the polymer electrolyte) of the combined weight of the polymer network and the electrolyte composition. In some embodiments, the polymer electrolyte consists essentially of the polymer network and the electrolyte composition.

[0069] In a preferred embodiment of the present invention, the polymer electrolyte contains at least Li + 4.6V vs. Li, preferably at least Li + A composite cathode of the present invention is provided that has an anode stability limit of 4.7 V vs. / Li.

[0070] Cathode Active Material As shown in the accompanying examples, the inventors have found that the polymer electrolytes used in the composite cathodes of the present invention exhibit surprisingly good electrochemical performance when used in combination with a high potential cathode active material. Thus, the cathode active material is preferably Li + At least 4.3V vs. Li / , preferably Li + / Li, more preferably at least 4.4V + It has an upper cutoff voltage of at least 4.5 V vs. / Li.

[0071] The cathode active material preferably comprises Li, M, and O, where M is Ni with a content x, where 50.0 mol%≦x≦95.0 mol%, preferably 55.0 mol%≦x≦95.0 mol%, Mn with a content y, where 0.0 mol%≦y≦40.0 mol%; Co with a content z, where 0.0 mol%≦z≦40.0 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x+y+z+a is 100.0 mol%, Preferably, M is Ni with a content x, where 50.0 mol%≦x≦85.0 mol%; Mn with a content y, where 7.5 mol%≦y≦25.0 mol%; Co with a content z, where 7.5 mol%≦z≦25.0 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x+y+z+a is 100.0 mol%, More preferably, M is Ni with a content x, where 50.0 mol%≦x≦80.0 mol%; Mn with a content y, where 10.0 mol%≦y≦25.0 mol%; Co with a content z, where 10.0 mol%≦z≦25.0 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x+y+z+a is 100.0 mol%, More preferably, M is Ni with a content x, where 55.0 mol%≦x≦75.0 mol%, Mn with a content y, where 12.5 mol%≦y≦22.5 mol%; Co with a content z, where 12.5 mol%≦z≦22.5 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x+y+z+a is 100.0 mol%, Most preferably, M is Ni with a content x, where 55.0 mol%≦x≦70.0 mol%; Mn with a content y, where 15.0 mol%≦y≦22.5 mol%; Co with a content z of 15.0 mol%≦z≦22.5 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; and x+y+z+a is 100.0 mol%.

[0072] As known to those skilled in the art, NMC cathode active materials can contain impurities or be doped or coated to result in an overall cathode active material that includes one or more elements other than Li, Ni, Mn, Co, and O, which is reflected in the parameter "D" used herein. In preferred embodiments of the present invention, D is an element selected from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, Zr, and Zn; preferably, Al, B, Cr, Nb, S, Si, Ti, Y, Zr, and W; more preferably, B, Nb, Ti, Zr, and W.

[0073] Examples of suitable cathode active materials are NMC532, NMC622, NMC811, preferably NMC622 or NMC811, more preferably NMC622.

[0074] Further composite cathode components The present invention is not particularly limited with respect to the additional materials used in the composite cathode, and any additive known to those skilled in the art to be suitable may be included.

[0075] An optional but preferred additional component of the composite cathode of the present invention is a conductive additive, particularly a carbon-based conductive additive. The carbon-based conductive additive may be any carbon-rich material, for example, any material containing at least 95% by weight of carbon, preferably at least 99% by weight of carbon. Examples of suitable materials include graphite, carbon black, carbon fiber, carbon nanotubes, graphene, and combinations thereof. Carbon black is known to those skilled in the art and includes variants such as acetylene black or Super C65.

[0076] In a preferred embodiment, the carbon-based conductive aid described herein is present in the solid composite cathode of the present invention in an amount of at least 0.5 wt% (based on the combined weight of the polymer electrolyte and the cathode active material), preferably at least 1 wt% (based on the combined weight of the polymer electrolyte and the cathode active material), and more preferably at least 3 wt% (based on the combined weight of the polymer electrolyte and the cathode active material). Typically, the carbon-based conductive aid is present in an amount of less than 12 wt% (based on the combined weight of the polymer electrolyte and the cathode active material), preferably less than 9 wt% (based on the combined weight of the polymer electrolyte and the cathode active material), and more preferably less than 7 wt% (based on the combined weight of the polymer electrolyte and the cathode active material).

[0077] Another optional but preferred additional component of the composite cathode of the present invention is a binder. In some embodiments of the present invention, the solid composite cathode of the present invention further comprises a binder, for example, a polymer binder. The binder is not particularly limited and can be any suitable polymer binder, for example, polyimide (PI), polyvinylidene chloride (PVdC), polyethylene oxide (PEO), polyvinylidene fluoride (PVdF), etc.

[0078] Method for preparing the composite cathode of the present invention As previously described herein, in some embodiments of the present invention, the composite cathode comprises a homogeneous mixture of cathode active material particles and polymer electrolyte particles. Accordingly, another aspect of the present invention provides a method for making a composite cathode, the method comprising: (a1) providing a cathode active material in particulate form comprising Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; (b1) providing a polymer electrolyte as described herein in particulate form; (c1) blending the cathode active material of step (a) with the polymer electrolyte of step (b) to form a homogeneous blend; Including, (d1) optionally compressing the blend obtained in step (c); A method of manufacturing is provided, which may include:

[0079] As previously described herein, in some embodiments of the present invention, the cathode active material is porous and the polymer electrolyte is coated on and / or at least partially embedded in the cathode active material. Accordingly, another aspect of the present invention provides a method for making a composite cathode, comprising: (a2) providing a cathode active material comprising Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; (b2) providing a precursor composition as described herein; (c2) contacting the precursor composition with a cathode active material; (d2) polymerizing the precursor composition in the presence of a cathode active material.

[0080] Embodiments described in this disclosure relating to the composite cathode of the present invention apply mutatis mutandis to the method of preparing the composite cathode. For example, various embodiments relating to the identity and amounts of monomers, crosslinkers, initiators, and electrolyte compositions described herein in the context of the composite cathode are equally applicable to the method of preparing the composite cathode.

[0081] In a preferred embodiment of the method for preparing a composite cathode in which the polymer electrolyte is coated on and / or at least partially embedded in the cathode active material, the precursor composition includes one or more radical initiators, as described hereinabove, and step (d2) includes activating the radical initiator. Activation is preferably carried out by UV irradiation of the precursor composition or by heating the precursor composition to a temperature of at least 50°C, preferably at least 60°C. Step (d2) is preferably carried out under an inert gas atmosphere, preferably an inert atmosphere such as nitrogen or argon. The contacting in step (c2) may include mixing and / or depositing the precursor composition on the surface of the cathode active material. The contacting in step (c2) is preferably carried out for at least 1 minute before polymerization to ensure complete mixing or impregnation. In this manner, a composite cathode comprising the polymer electrolyte of the present invention and the cathode active material can be obtained.

[0082] Electrochemical cells containing the composite cathodes of the present invention In another aspect of the present invention, there is provided an electrochemical cell comprising the composite cathode herein.

[0083] Embodiments described in this disclosure relating to composite cathodes apply mutatis mutandis to electrochemical cells that include composite cathodes. For example, various embodiments relating to the identities and amounts of monomers, crosslinkers, initiators, and electrolyte compositions described herein in the context of composite cathodes are equally applicable to electrochemical cells that include composite cathodes.

[0084] The electrochemical cell preferably includes an anode, a composite cathode of the present invention, and an electrolyte. In some embodiments, the electrolyte includes or consists of the same polymer electrolyte as the polymer electrolyte included in the composite cathode. A polymer electrolyte described herein having a gel-like consistency is considered a solid electrolyte for purposes of the present disclosure. As will be understood by those skilled in the art, it may also function as a separator in an electrochemical cell. For example, an electrochemical cell may include an anode, a cathode composite of the present invention, and a separator that is the same polymer electrolyte as the cathode composite of the present invention. As will be understood by those skilled in the art, to function as a separator, the portion of the solid polymer electrolyte separating the anode and the composite cathode must be substantially free of cathode active material.

[0085] The anode comprises an active anode material. Suitable electrochemically active anode materials are known in the art. For example, the anode may comprise graphitic carbon, metallic lithium, or a metal alloy containing lithium as the active anode material. The anode comprises an active electrode material that is different from the active cathode material contained in the composite cathode of the present invention.

[0086] In particularly preferred embodiments, the cathode active materials described herein are the only cathode active materials contained in the cathode of the electrochemical cell.

[0087] The electrochemical cells described herein preferably have charge transport in a Li +The electrochemical cell is a lithium-ion-containing cell operated by ions. The electrochemical cell can have a disk-like or prismatic shape. The electrochemical cell can include a housing that can be made from steel or aluminum. Multiple electrochemical cells can be combined into an all-solid-state battery with both solid electrodes and a solid electrolyte.

[0088] Method for preparing the electrochemical cell of the present invention In another aspect, the present invention provides a method for manufacturing an electrochemical cell, comprising: (a) providing a composite cathode as described herein; (b) providing an anode; (c) providing an electrolyte; (d) forming an electrochemical cell by assembling the cathode, the anode, and the polymer electrolyte into an electrochemical cell.

[0089] Embodiments described in this disclosure relating to electrochemical cells or composite cathodes apply mutatis mutandis to methods of preparing electrochemical cells. For example, various embodiments relating to the identity and amounts of monomers, crosslinkers, initiators, and electrolyte compositions described herein in the context of composite cathodes are equally applicable to methods of preparing electrochemical cells.

[0090] Use of the composite cathode of the present invention In another aspect of the present invention, there is provided the use of the composite cathode described herein as a cathode for an electrochemical cell.

[0091] Embodiments described in this disclosure relating to composite cathodes apply mutatis mutandis to the use of composite cathodes. For example, various embodiments relating to the identity and amounts of monomers, crosslinkers, initiators, and electrolyte compositions described herein in the context of composite cathodes are equally applicable to the use of composite cathodes.

[0092] The electrochemical cell is preferably an electrochemical cell as described herein in the context of another aspect of the present invention.

[0093] Batteries containing electrochemical cells of the present invention and uses thereof Another aspect of the present invention relates to batteries, more particularly lithium ion or lithium metal batteries, that include at least one electrochemical cell comprising the composite cathode herein, e.g., two or more electrochemical cells described herein.

[0094] The electrochemical cells described herein can be combined with one another, for example, in series or parallel connections. Series connections are preferred. The electrochemical cells or batteries described herein can be used to manufacture or operate stationary equipment such as cars, computers, personal digital assistants, cell phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communications equipment, satellites, or remote car locks, and energy storage devices for power plants.

[0095] A further aspect of the present invention is a method of manufacturing or operating stationary facilities such as cars, computers, personal digital assistants, cell phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communications equipment, satellites, remote car locks, and energy storage devices for power plants by using at least one battery or at least one electrochemical cell described herein comprising the composite cathode of the present invention.

[0096] A further aspect of the invention is the use of an electrochemical cell or battery described herein comprising a composite cathode of the invention in a motorized vehicle, a bicycle powered by an electric motor, a robot, an aircraft (e.g., an unmanned aerial vehicle including a drone), a ship, a satellite, or a stationary energy storage device.

[0097] A further aspect of the present invention is a method of providing electrical power to a device, wherein the power is supplied by an electrochemical cell or battery described herein comprising a composite cathode of the present invention, and wherein the electrochemical cell or battery described herein, preferably the electrochemical cell, operates at a voltage greater than 4.4 V, preferably greater than 4.5 V, more preferably greater than 4.6 V, for example greater than 4.7 V. The device may be any battery-powered device, but is preferably selected from motorized vehicles, computers, personal digital assistants, mobile phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communications equipment, satellites, remote car locks, stationary applications such as energy storage devices for power plants, bicycles operated by electric motors, robots, aircraft (e.g., unmanned aerial vehicles including drones), watercraft, satellites, etc.

[0098] The present invention further provides a device comprising at least one battery or electrochemical cell described herein, comprising the composite cathode of the present invention. Preferred are mobile devices, such as vehicles, e.g., automobiles, bicycles, aircraft, satellites, or water vehicles, e.g., boats or ships. Other examples of mobile devices are portable, such as computers, particularly laptops, telephones, or power tools, e.g., from the construction sector, particularly drills, battery-powered screwdrivers, or battery-powered tackers. [Example]

[0099] 1. Material Preparation An electrolyte composition consisting of a deep eutectic solvent (DES) was prepared by mixing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and N-methylacetamide in a 1:4 molar ratio and vigorously stirring until a homogeneous, clear liquid was obtained. The precursor composition was prepared by mixing the monomers listed in Table 1, the crosslinker listed in Table 1, and the free radical initiator listed in Table 1 into a premix with a molar ratio of (monomer:crosslinker:initiator) of 90:10:5, and then combining the DES with the premix in a volume ratio of 85:15 DES:premix. The resulting mixture was stirred to obtain a homogeneous blend and polymerized by UV irradiation (365 nm) for 1 hour.

[0100] A cathode containing NMC622 as the cathode active material (LiNi 0.6 Mn 0.2 Co 0.2 O2) is 80% by weight of LiNi 0.6 Mn 0.2 Co 0.2 O2, 10 wt% carbon black, and 10 wt% poly(vinylidene fluoride) (PVDF) were compounded by mixing in N-methyl-2-pyrrolidone (NMP). The thoroughly mixed slurry was tape-cast onto aluminum foil and dried in air at 110 °C to a thickness of approximately 18.7 μm and a density of 0.622 mg cm. -2 An electrode with an active material loading of 0.109 mAh cm was obtained. -2 , the theoretical capacity of NMC622 is 175mAh g -1 (Assuming that).

[0101] For use in coin cells, the polymer electrolyte and cathode were cut to the appropriate size with a hollow punch. Li|polymer electrolyte|NMC622 cells were assembled by placing a positive electrode in front of a Li foil negative electrode separated by polymer electrolyte in between. [Table 1]

[0102] 2. Electrochemical Performance Determination Ionic conductivity was determined by electrochemical impedance spectroscopy (EIS) (using a Biologic SP-300) of the polymer electrolyte in a symmetrical stainless steel|electrolyte|stainless steel Swagelok-type cell at a specific temperature by perturbing the open-circuit potential with an AC sinusoidal potential of 10 mV amplitude in the frequency range of 10 kHz to 100 mHz.

[0103] The electrochemical compatibility of the polymer electrolyte with high-voltage cathode materials was studied by electrochemical impedance spectroscopy (EIS) in NMC622|polymer electrolyte|NMC622 symmetric cells.

[0104] The anodic stability limit was determined by linear sweep voltammetry (using a Bio-Logic, SP-300) of the polymer electrolyte sandwiched between a stainless steel working electrode and lithium metal reference and counter electrodes in a coin cell setup, with the working electrode voltage maintained at 10 mV s -1 At a scan rate of , the anodic scan is performed from the open circuit potential to Li + The voltage was swept up to 6 V vs. / Li. The stability limit was determined as the onset of electrolyte oxidation, which can be observed by a sudden increase in the measured current. Without being bound by any theory, the inventors believe that electrolyte oxidation is due to the TFSI - It is believed that this may be due to oxidation of the anion.

[0105] Cycling performance was determined for Li|polymer electrolyte|NMC622 cells prepared as described above using a TOYO battery cycler. + The electrode underwent a 16-hour open circuit potential (OCP) period before galvanostatic cycling from 3.0 to 4.3 V vs. Li. + The cells were activated by two galvanostatic charge / discharge cycles at C / 20 between 3.0 V and 4.3 V vs. Li. The cycling protocol consisted of five cycles each at C / 20, C / 10, C / 5, C / 2, and 1C rates, followed by 100 cycles at C / 10. The capacity values ​​were normalized to the weight of the cathode active material (NMC), and the results were reproducible.

[0106] 3.Results The results of electrochemical characterization of the polymer electrolyte used in the composite cathode of the present invention are shown in Figures 1-20 and Table 2. Table 2 shows the excellent ionic conductivity of the polymer electrolyte used in the composite cathode of the present invention at three different temperatures. Table 2 also highlights the compatibility of the polymer electrolyte used in the composite cathode of the present invention with the NMC622 cathode active material, especially as can be derived from Figures 17-20 (showing cycling performance).

[0107] Table 2 also shows the high anode stability values ​​measured especially for Examples 1, 2, 7, and 8, indicating that they can operate at high voltages.

[0108] Figures 9-16 show EIS results for the NMC622|polymer electrolyte|NMC622 symmetric cell. For the polymer electrolyte used in the composite cathode of the present invention, there is no significant increase in the charge transfer resistance Rct, indicating that the NMC622|polymer electrolyte interface is chemically stable. Conversely, for the comparative example, it can be seen that the polymer electrolyte is not compatible with NMC622.

[0109] 17-20 show the cycling capacity of Li|polymer electrolyte|NMC622 cells, demonstrating the excellent compatibility of the polymer electrolytes of the present invention with high potential cathode materials such as NMC622. [Table 2]

[0110] It was found that the polymer electrolytes of Examples 1 to 8 were all self-supporting and exhibited good mechanical flexibility.

[0111] 4. Composite Cathode Synthesis and Characterization An electrolyte composition consisting of a deep eutectic solvent (DES) was prepared by mixing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and N-methylacetamide in a 1:4 molar ratio and vigorously stirring until a homogeneous, clear liquid was obtained. A precursor composition was prepared by mixing the monomers shown in Table 3, the crosslinker shown in Table 3, and the free radical initiator shown in Table 3 into a premix with a molar ratio of (monomer:crosslinker):initiator of 90:10:5, and combining the DES with the premix at a volumetric ratio of DES:premix of 85:15.

[0112] A cathode containing NMC622 as the cathode active material (LiNi 0.6 Mn 0.2 Co 0.2 O2) is 80% by weight of LiNi0.6 Mn 0.2 Co 0.2 O2, 10 wt% carbon black, and 10 wt% poly(vinylidene fluoride) (PVDF) were compounded by mixing in N-methyl-2-pyrrolidone (NMP). The thoroughly mixed slurry was tape-cast onto aluminum foil and dried in air at 110 °C to obtain an electrode.

[0113] An impregnated composite cathode (Example 9) was prepared by drop-casting the precursor composition onto an NMC622 electrode and allowing it to infiltrate the electrode's pores. A 1-hour UV cure (365 nm) was then applied to form the impregnated electrode. An NMC622-impregnated electrode | polymer electrolyte | NMC622-impregnated electrode cell was assembled using a layer of polymer electrolyte as a separator between symmetrically impregnated electrodes. The polymer electrolyte was prepared by polymerizing the same precursor composition in the absence of cathode material.

[0114] A comparison cell was prepared using unimpregnated electrodes (Example 10).

[0115] Ionic conductivity was determined by electrochemical impedance spectroscopy (EIS) (using a Biologic SP-300) of symmetric cells at specific temperatures by perturbing the open-circuit potential with an AC sinusoidal potential of 10 mV amplitude in the frequency range of 10 kHz to 100 mHz. [Table 3]

[0116] Figure 21 shows EIS characterization of an NMC622-impregnated electrode|polymer electrolyte|NMC622-impregnated electrode cell. Figure 22 shows EIS characterization of a comparative example of an NMC622|polymer electrolyte|NMC622 cell. It can be seen that impregnation of the NMC622 electrode pores with polymer electrolyte does not result in a significant increase in charge transfer resistance, indicating that the composite cathode of the present invention provides good performance.

Claims

1. A composite cathode comprising a cathode active material and a polymer electrolyte, the cathode active material comprises Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; the polymer electrolyte comprises an electrolyte composition and a polymer network; the electrolyte composition comprises a deep eutectic solvent (DES), The polymer electrolyte comprises a precursor composition comprising the electrolyte composition and a first monomer according to formula (I): 【Chemical 1】 [In the formula, R １ represents a first substituent having 1 to 8 carbon atoms and optionally containing at least one functional group selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof, and preferably R １ is C １ ~C ６ Alkyl, C １ ~C ６ Hydroxyalkyl, -(CH ２ -CH ２ -O) ｎ -H, R ２ represents H or a second substituent having 1 to 8 carbon atoms and containing at least one functional group selected from an alcohol, an amine, an ether, a ketone, an amide, an acetal, a ketal, an aminoacetal, a hemiaminal ether, or a combination thereof, and preferably R ２ is H, C １ ~C ６ Alkyl, C １ ~C ６ Hydroxyalkyl, -(CH ２ -CH ２ -O) ｎ -H, R ３ is selected from H, methyl, or ethyl; n is an integer from 1 to 5. and a composite cathode obtained by polymerizing

2. 10. The composite cathode of claim 1 comprising a homogeneous mixture of cathode active material particles and polymer electrolyte particles.

3. 10. The composite cathode of claim 1, wherein the cathode active material is porous and the polymer electrolyte is coated on and / or at least partially embedded in the cathode active material.

4. 4. The composite cathode of claim 3, obtainable by contacting the precursor composition with the cathode active material and polymerizing the precursor composition in the presence of the cathode active material.

5. The first monomer is selected from the following options A, B, or C: A.R. １ But C １ ~C ６ alkyl, preferably R １ But C ３ alkyl, and R ２ is selected from H or methyl, preferably R ２ is H and R ３ is selected from H or methyl, preferably R ３ is H; or B.R. １ But C １ ~C ６ alkyl, preferably R １ But C ２ alkyl, and R ２ But C １ ~C ６ alkyl, preferably R ２ But C ２ alkyl, and R ３ is selected from H or methyl, preferably R ３ is H; or C.R. １ But C １ ~C ６ hydroxyalkyl, preferably R １ is 2-hydroxyalkyl, and R ２ is selected from H or methyl, preferably R ２ is H and R ３ is selected from H or methyl, preferably R ３ is H; The composite cathode according to any one of claims 1 to 4,

6. The composite cathode of any one of claims 1 to 5, wherein the precursor composition further comprises a first crosslinking agent.

7. The first cross-linking agent is allyl (—CH ３ -CH=CH ２ ), oxiranyl (-C ２ H ３ O), glycidyl (-CH ２ -C ２ H ３ O), vinyl ether (—O—CH═CH ２ ), vinyl esters (—C(O)—O—CH═CH ２ ), vinylamide (—C(O)—NH—CH═CH ２ ), vinylamine (—NH—CH═CH ２ ), norbornene, maleate, fumarate, itaconate, alkynyl 【Chemistry 2】 Styrene (-Ph-CH=CH ２ ), acrylamide (—NH—C(O)—CH═CH ２ ), methacrylamide (—NH—C(O)—C(CH ３ ) = CH ２ ), acrylate (—O—C(O)—CH═CH ２ ), methacrylate (—O—C(O)—C(CH ３ ) = CH ２ ), and combinations thereof, and preferably, the first crosslinker is selected from a crosslinker containing two or more functional groups selected from the group consisting of acrylamide (—NH—C(O)—CH═CH ２ ), methacrylamide (—NH—C(O)—C(CH ３ ) = CH ２ ), acrylate (—O—C(O)—CH═CH ２ ), methacrylate (—O—C(O)—C(CH ３ ) = CH ２ 7. The composite cathode of claim 6, wherein the crosslinker is selected from the group consisting of:

8. 8. The composite cathode according to claim 1, wherein the deep eutectic solvent (DES) has a eutectic point of 25° C. or less.

9. 9. The composite cathode of claim 1, wherein the deep eutectic solvent (DES) comprises at least one hydrogen bond acceptor and at least one hydrogen bond donor, and the at least one hydrogen bond acceptor comprises a lithium salt, a zinc salt, or a combination thereof, preferably a lithium salt.

10. The at least one hydrogen bond acceptor may be selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiOTf), lithium chloride (LiCl), lithium hexafluorophosphate (LiPF ６ ), lithium polysulfide, lithium perchlorate (LiClO ４ ), lithium bromide (LiBr), lithium iodide (LiI), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF ４ ), lithium hexafluoroarsenate (LiAsF ６ ), lithium bis(oxalato)borate (LiBOB), lithium fluoroalkylphosphate (LFAP [LiPF ３ (CF ２ CF ３ ) ３ ]), and combinations thereof, preferably lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), Preferably, the at least one hydrogen bond donor is selected from the group consisting of urea, N-methylurea, N,N-dimethylurea, N,N'-dimethylurea, N,N,N'-trimethylurea, thiourea, N-methylthiourea, N,N-dimethylthiourea, N,N'-dimethylthiourea, N,N,N'-trimethylthiourea, ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,4-diol, 1,2,3-propanetriol, acetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and the like.

10. The composite cathode of claim 9, wherein the carboxylic acid is selected from the group consisting of carboxylic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, benzoic acid, glycolic acid, citric acid, 2-hydroxypropionic acid, 2-hydroxyisobutyric acid, o-phenylenediamine, choline chloride, acetamide, N-methylacetamide, trifluoroacetamide, N-methyltrifluoroacetamide, benzamide, benzenesulfonic acid, p-toluenesulfonic acid, o-toluenesulfonic acid, m-toluenesulfonic acid, and combinations thereof, preferably N-methylacetamide.

11. the cathode active material comprises Li, M, and O, wherein M is Ni with a content x of 50.0 mol%≦x≦95.0 mol%, preferably 55.0 mol%≦x≦95.0 mol%; Mn with a content y of 0.0 mol%≦y≦40.0 mol%; Co with a content z of 0.0 mol%≦z≦40.0 mol%; D having a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x + y + z + a is 100.0 mol%, Preferably, M is Ni with a content x, where 50.0 mol%≦x≦85.0 mol%; Mn with a content y of 7.5 mol%≦y≦25.0 mol%; Co with a content z of 7.5 mol%≦z≦25.0 mol%; D having a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x + y + z + a is 100.0 mol%, More preferably, M is Ni with a content x, where 50.0 mol%≦x≦80.0 mol%; Mn with a content y of 10.0 mol%≦y≦25.0 mol%; Co with a content z of 10.0 mol%≦z≦25.0 mol%; D having a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x + y + z + a is 100.0 mol%, More preferably, M is Ni with a content x, where 55.0 mol%≦x≦75.0 mol%; Mn with a content y such that 12.5 mol%≦y≦22.5 mol%; Co with a content z of 12.5 mol%≦z≦22.5 mol%; D having a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; x + y + z + a is 100.0 mol%, Most preferably, M is Ni with a content x, where 55.0 mol%≦x≦70.0 mol%; Mn with a content y in which 15.0 mol%≦y≦22.5 mol%; Co with a content z of 15.0 mol%≦z≦22.5 mol%; D having a content a of 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O; and x+y+z+a is 100.0 mol %.

12. A method for producing the composite cathode according to any one of claims 1 to 11, comprising the steps of: (a1) providing an M cathode active material in particulate form comprising Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; (b1) providing a polymer electrolyte according to any one of claims 1 to 11 in particulate form; (c1) blending the cathode active material of step (a) with the polymer electrolyte of step (b) to form a homogeneous blend; Including, (d1) optionally compressing the blend obtained in step (c); The method of manufacturing may include:

13. A method for producing the composite cathode according to any one of claims 1 to 11, comprising the steps of: (a2) providing a cathode active material comprising Li, M, and O, wherein M comprises Ni and one or both of Mn and Co; (b2) providing a precursor composition according to any one of claims 1 to 11; (c2) contacting the precursor composition with the cathode active material; (d2) polymerizing the precursor composition in the presence of the cathode active material.

14. Use of the composite cathode according to any one of claims 1 to 11 as an electrochemical cell component.

15. An electrochemical cell comprising an anode and a composite cathode according to any one of claims 1 to 11.

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