Positive electrode

Abstract

A positive electrode for a lithium ion secondary battery comprising an active positive electrode material and at least one polymer electrolyte which is a polyether polymer, the active positive electrode material comprising at least one element selected from Li, M', and oxygen, the metal M' being represented by the formula: Ni 1-x-y-z Mn x Co y A z wherein 0.00≦x≦0.70, 0.00≦y≦0.40, and 0.00≦z≦0.10, and A, if present, is different from Ni, Mn, Co, and Li, and preferably is at least one of B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr.

Description

Technical Field

[0001] The present invention relates to a positive electrode for a lithium - ion secondary battery, including a positive electrode active material and at least one polymer electrolyte.

Background Art

[0002] Polymer electrolytes are an interesting alternative to liquid electrolytes in batteries. In this regard, polyethylene oxide (PEO) - based electrolytes have been widely studied in the literature.

[0003] For example, Ruoyuan Tao et al. in J.Appl.Electrochem.35, 163 - 168(2005) disclose a positive electrode containing poly(ethylene oxide) and lithium bis(trifluoromethanesulfonyl)imide (Li(N(SO2CF3)2)), also known as LiTFSI. PEO and LiTFSI were dissolved in acetonitrile to prepare an electrolyte solution. A positive electrode active material was added to this electrolyte solution.

[0004] U.S. Patent No. 7,585,934(B2) discloses the use of EO / PO / AGE as a solid polymer electrolyte membrane and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, Li(N(SO2CF3)2)). This document discloses a copolymerization procedure for EO, PO, and AGE in an example. In particular, LiTFSI was added as a Li salt to a polyether polymer composition containing the EO / PO / AGE copolymer in an amount such that the ratio of (the number of moles of lithium atoms in the electrolyte salt) / (the number of moles of oxygen atoms in the polyether polymer) was 0.05.

[0005] Despite recent progress in this field, capacity leakage is still a problem for positive electrodes containing PEO - based solid electrolytes. Capacity leakage is a phenomenon in which the electrolyte acquires electronic conductivity and leaks an electronic current from the anode to the cathode.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Non-Patent Document

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Therefore, an improved positive electrode, particularly a positive electrode that reduces capacity leakage when used in a battery, is needed.

Means for Solving the Problems

[0009] The present inventors have surprisingly found that it is possible to provide a positive electrode that satisfies the above-mentioned needs.

[0010] Therefore, the main object of the present invention is a positive electrode for a lithium-ion secondary battery including a positive electrode active material and at least one polymer electrolyte, wherein the positive electrode active material contains at least Li, M', and an oxygen element, M' consists of Ni, Mn, Co, and A, and the positive electrode material has a Ni:(Mn + Co + A) molar (or atomic) ratio of (1 - x - y - z):(x + y + z) (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li, and preferably is at least one of Al, or B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr), and the polymer electrolyte is: i. at least one polyether polymer [hereinafter, polymer (P)], and the polymer (P) is: a) At least 70.0 mol% of oxyethylene units (EO), b) 0.0 to 10.0 mol% of oxypropylene units (PO), and c) 1.00 to 4.0 mol% of at least one monomer of general formula (I) or general formula (II):

[0011] [Chemical formula]

[0012] (wherein, each of R1 and R2 is the same as or different from each other, and in each occurrence, is a C1-6 alkanediyl, and the C1-6 alkanediyl is optionally substituted with one or more substituents selected from halide, C1-4 alkyl, C3-6 cycloalkyl, CF3, and OR8, each of R8 is the same as or different from each other, and in each occurrence, is independently selected from the group consisting of hydrogen and C1-4 alkyl, n is an integer of 0 or 1 or 2, each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, and methanesulfonate) of the repeating unit comprising a polymer (P), and ii. Formula (III):

[0013] [Chemical formula]

[0014] (wherein, Each of R3, R4, R5, R6 and R7 is the same as or different from one another and, in each occurrence, is independently selected from the group consisting of C1-6 alkyl, C3-6 cycloalkyl, aryl, C1-6 alkoxy, and heterocyclyl, and the C1-6 alkyl, C3-6 cycloalkyl, aryl, C1-6 alkoxy, and heterocyclyl are optionally substituted with one or more substituents selected from halide, C1-4 alkyl, C3-6 cycloalkyl, CF3, and OR9, and each of R9 is the same as or different from one another and, in each occurrence, is independently selected from the group consisting of hydrogen, C1-4 alkyl, and a hydroxyl protecting group. It is obtained by a reaction between at least one polysiloxane compound having (where m is an integer of at least 3). The at least one polysiloxane compound having formula (III) is grafted onto the at least one polymer (P) via a reaction between at least a part of the -CH=CH2 moiety of monomer (M) and the H-Si moiety of the polysiloxane compound having formula (III), and it is a positive electrode.

[0015] A second object of the present invention is a positive electrode for a lithium-ion secondary battery, comprising a positive electrode active material and at least one polymer electrolyte, wherein the positive electrode active material contains at least an element selected from Li, M', and oxygen, and the metal M' has the formula: Ni 1-x-y-z Mn x Co y A z (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li and is preferably at least one of B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr), and the polymer electrolyte is: i. at least one polyether polymer [hereinafter, polymer (P)], and the polymer (P) is: a) at least 70.0 mol% of oxyethylene units (EO), b) 0.0 to 10.0 mol% of oxypropylene units (PO), and c) 1.00 to 4.0 mol% of general formula (I) or general formula (II):

[0016]

Chemical formula

[0017] (wherein, each of R1 and R2 is the same as or different from each other, and in each occurrence, C 1~6 alkanediyl, and the C 1~6 alkanediyl is optionally substituted with one or more substituents selected from the group consisting of halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR8, and each of R8 is the same as or different from each other, and in each occurrence, independently, is selected from the group consisting of hydrogen and C 1~4 alkyl, n is an integer 0 or 1 or 2, each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, and methanesulfonate) of at least one monomer [hereinafter, monomer (M)]-derived repeating unit comprising a polymer (P), ii. formula (III):

[0018]

Chemical formula

[0019] (wherein, each of R3, R4, R5, R6, and R7 is the same as or different from each other, and in each occurrence, independently, is selected from the group consisting of C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, and the C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl is optionally substituted with halide, C 1~4 alkyl, C 3~6Optionally substituted with one or more substituents selected from cycloalkyl, CF3, OR9, each of R9 being the same as or different from one another and, in each occurrence, independently, hydrogen, C 1~4 alkyl, and a hydroxyl protecting group, and m is an integer of at least 3) obtained by the reaction between at least one polysiloxane compound having With respect to the positive electrode, at least one polysiloxane compound having formula (III) is grafted to at least one polymer (P) via the reaction between at least a part of the -CH=CH2 moiety of monomer (M) and the H-Si moiety of the polysiloxane compound having formula (III).

[0020] A further object of the present invention is to provide a polymer battery comprising the positive electrode.

[0021] A further object of the present invention is to provide an electrochemical cell comprising the positive electrode.

[0022] A further object of the present invention is to provide the use of the positive electrode in a battery.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0024] Positive electrode As used in this specification and the claims, the term "comprising" should not be construed as being limited to the means recited thereafter, and does not exclude other elements or steps. It should be construed as specifying the presence of the recited features, integers, steps, or components as such, but not excluding the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" should not be limited to compositions consisting only of components A and B. It means, with respect to the present invention, that the only relevant components of the composition are A and B. Thus, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of".

[0025] As used herein, "optional" or "optionally" means that the event or circumstance recited thereafter may or may not occur, and the recitation includes both instances where the event or circumstance occurs and instances where it does not occur.

[0026] The term "positive electrode active material" is intended to refer to a substance that is electrochemically active in the positive electrode. The active material can capture and release Li ions when exposed to a voltage change over a given period of time.

[0027] The inventors have surprisingly found that when the positive electrode according to the present invention is used in a battery, particularly in a solid lithium ion battery, capacity leakage is reduced, and as a result, a battery with improved performance as demonstrated in the examples can be obtained.

[0028] In the context of the present invention, the term "positive electrode active material" is defined as a substance that is electrochemically active in the positive electrode. The active material can capture and release Li ions when exposed to a voltage change over a given period of time.

[0029] In the context of the present invention, the expression "at least one polyether polymer [hereinafter polymer (P)]" is intended to mean one or more polymers (P). Similarly, the expressions "at least one polysiloxane compound having formula (III)" and "at least one polymer electrolyte" are intended to indicate one or more polysiloxane compounds having formula (III) and one or more polymer electrolytes, respectively.

[0030] Throughout the remainder of this specification, the expressions "polymer (P)", "polymer electrolyte" and "polysiloxane compound having formula (III)" are understood for the purposes of the present invention to include both the plural and singular forms.

[0031] As used herein, the term "alkyl" has the broadest meaning generally understood in the art and may include moieties that are straight-chain or branched-chain, or combinations thereof.

[0032] The term "alkyl" means, alone or in combination, straight-chain or branched-chain alkane-derived groups, for example, C F-G Alkyl defines a straight-chain or branched-chain alkyl group having from F to G carbon atoms, for example, C 1~4 Alkyl defines a straight-chain or branched-chain alkyl group having from 1 to 4 carbon atoms, such as, for example, methyl, ethyl, 1-propyl, 2-propyl (isopropyl), 1-butyl, 2-butyl, 2-methyl-2-propyl (tert-butyl), 2-methyl-1-propyl (isobutyl).

[0033] The term "cycloalkyl" means, alone or in combination, cyclic alkane-derived groups, for example, C L-M Cycloalkyl defines a cyclic alkyl group having from L to M carbon atoms, for example, C 3~6 Cycloalkyl defines a cyclic alkyl group having from 3 to 6 carbon atoms, such as, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl.

[0034] The term "aryl", alone or in combination, preferably means a phenyl, naphthyl, or anthracenyl that is optionally carbocyclically fused with a 5- to 7-membered ring, more preferably a 5- to 6-membered ring cycloalkyl or heterocyclyl, and / or is substituted with 1 to 5 groups or substituents. Aryl may be optionally substituted, whereby the substituent is bonded to the aryl at one point, or the substituent is bonded to the aryl at two points to form a bicyclic system, for example, benzodioxole, benzodioxane, benzimidazole.

[0035] The term "heterocyclyl", alone or in combination, means a cyclic alkane-derived group in which at least one carbon atom is replaced by a heteroatom independently selected from the group consisting of oxygen, nitrogen, and sulfur (for example, pyrrolidine, piperidine, or morpholine, etc.).

[0036] The term "alkoxy", alone or in combination, means a group derived from a straight-chain or branched-chain alkane, in which the carbon atom having the group is replaced by an oxygen atom. The alkoxy moiety has the structure -O-R x wherein R x is alkyl.

[0037] The term "alkanediyl", alone or in combination, means a divalent group derived from a straight-chain or branched-chain alkyl.

[0038] A first aspect of the present invention is a positive electrode for a lithium-ion secondary battery including a positive electrode active material and at least one polymer electrolyte, the positive electrode active material including Ni, Mn, Co, and A, the positive electrode material having a Ni:(Mn + Co + A) molar ratio of (1 - x - y - z):(x + y + z) (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li, and preferably is at least one of Al, or B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr), and the polymer electrolyte is: i. at least one polyether polymer [hereinafter, polymer (P)], wherein the polymer (P) is: at least 70.0 mol% ethylene oxide units (EO), 0.0 to 10.0 mol% propylene oxide units (PO), and 1.00 to 4.0 mol% of a repeating unit derived from at least one monomer [hereinafter, monomer (M)] of general formula (I) or general formula (II):

[0039]

Chemical formula

[0040] (wherein, each of R1 and R2 is the same as or different from each other, and in each occurrence, is C 1~6 alkanediyl, and the C 1~6 alkanediyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR8, each of R8 is the same as or different from each other, and in each occurrence, is independently selected from the group consisting of hydrogen and C 1~4 alkyl, n is an integer 0 or 1 or 2, each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p - toluenesulfonate, and methanesulfonate) A polymer (P), and ii. Formula (III):

[0041]

Chemical formula

[0042] (wherein each of R3, R4, R5, R6, and R7 is the same as or different from each other, and in each occurrence, independently, C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, selected from the group consisting of, and the C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR9, and each of R9 is the same as or different from each other, and in each occurrence, independently, hydrogen, C 1~4 alkyl, and a hydroxyl protecting group, selected from the group consisting of, m is an integer of at least 3), obtained by the reaction between at least one polysiloxane compound having The at least one polysiloxane compound having formula (III) is grafted to the at least one polymer (P) via the reaction between at least a part of the -CH=CH2 moiety of the monomer (M) and the H-Si moiety of the polysiloxane compound having formula (III), to provide a positive electrode.

[0043] Alternatively, an embodiment of the present invention is a positive electrode for a lithium-ion secondary battery including a positive electrode active material and at least one polymer electrolyte, the positive electrode active material including at least Li, M', and an oxygen element, M' consisting of Ni, Mn, Co, and A, the positive electrode material having a Ni:(Mn + Co + A) molar ratio of (1 - x - y - z):(x + y + z) (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li, and preferably is at least one of Al, or B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr), and the polymer electrolyte being: i. at least one polyether polymer [hereinafter, polymer (P)], the polymer (P) being: at least 70.0 mol% ethylene oxide units (EO), 0.0 to 10.0 mol% propylene oxide units (PO), and 1.00 to 4.0 mol% of general formula (I) or general formula (II):

[0044]

Chemical formula

[0045] (wherein, each of R1 and R2 is the same as or different from each other, and in each occurrence, is C 1~6 alkanediyl, the C 1~6 alkanediyl being optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR8, each of R8 being the same as or different from each other, and in each occurrence, independently selected from the group consisting of hydrogen and C 1~4 alkyl, and n being an integer 0 or 1 or 2), Each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, and methanesulfonate), and is derived from at least one monomer [hereinafter, monomer (M)] and has a repeating unit A polymer (P) containing ii. Formula (III):

[0046]

Chemical formula

[0047] (In the formula, Each of R3, R4, R5, R6, and R7 is the same as or different from each other, and in each occurrence, independently, is C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, and the C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR9, and each of R9 is the same as or different from each other, and in each occurrence, independently, is selected from the group consisting of hydrogen, C 1~4 alkyl, and a hydroxyl protecting group, m is an integer of at least 3), and is obtained by the reaction between at least one polysiloxane compound having The at least one polysiloxane compound having formula (III) is grafted onto the at least one polymer (P) through the reaction between at least a part of the -CH=CH2 moiety of the monomer (M) and the H-Si moiety of the polysiloxane compound having formula (III), providing a positive electrode.

[0048] As described above, the polymer (P) a) At least 70.0 mol% of repeating units of oxyethylene units (EO), b) 0.0 to 10.0 mol% of oxypropylene units (PO), and c) 1.00 to 4.0 mol% of general formula (I) or general formula (II):

[0049] [Chemical formula]

[0050] (wherein, Each of R1 and R2 is the same as or different from each other, and in each occurrence, C 1~6 alkanediyl, and the C 1~6 alkanediyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR8, and each of R8 is the same as or different from each other, and in each occurrence, is independently selected from the group of hydrogen and C 1~4 alkyl, n is an integer 0 or 1 or 2, Each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, and methanesulfonate) of at least one monomer [hereinafter, monomer (M)].

[0051] Therefore, at least 70.0 mol%, preferably at least 80.0 mol%, preferably at least 85.0 mol%, preferably at least 90.0 mol%, more preferably at least 92.0 mol%, more preferably at least 94.0 mol% of the repeating units of the polymer (P) are oxyethylene repeating units (EO).

[0052] It is further understood that at most 99.0 mol%, more preferably at most 98.5 mol%, more preferably at most 98.0 mol% of the repeating units of the polymer (P) are EO units.

[0053] In a preferred embodiment, the polymer (P) comprises at least 80.0 mol% and at most 99.0 mol%, preferably at least 90.0 mol% and at most 98.5 mol%, preferably at least 92.0 mol% and at most 98.5 mol% of EO units, preferably at least 94.0 mol% and at most 98.5 mol% of EO units.

[0054] When oxypropylene repeating units (PO) are present in the polymer (P), at most 10.0 mol%, more preferably at most 6.0 mol%, even more preferably at most 5.0 mol%, even more preferably at most 4.0 mol%, even more preferably at most 3.0 mol% of the repeating units of the polymer (P) are PO units.

[0055] Advantageously, the polymer (P) comprises at least 0.1 mol%, or at least 0.5 mol%, or at least 1.0 mol% of PO units.

[0056] In a preferred embodiment, the polymer (P) comprises at least 0.5 mol% and at most 6.0 mol%, or at least 0.5 mol% and at most 5.0 mol%, or at least 0.5 mol% and at most 4.0 mol%, or at least 1.0 mol% and at most 4.0 mol%, or at least 1.0 mol% and at most 3.0 mol% of PO units.

[0057] The presence of PO units makes it possible to reduce the crystallinity of the polymer (P), which improves its ionic conductivity.

[0058] For the purposes of the present invention, the term "oxypropylene (PO)" is intended to refer to the formula -O-CH2-CH2-CH2- or -O-CH2-CH(CH3)-, preferably -O-CH2-CH(CH3)-.

[0059] Preferably, at least 1.2 mol%, or at least 1.5 mol%, or at least 1.8 mol%, or at least 2.2 mol% of the repeating units of the polymer (P) are repeating units derived from the monomer (M) of the general formula (I) or general formula (II) detailed above.

[0060] It is further understood that at most 4.0 mol%, more preferably at most 3.5 mol%, even more preferably at most 3.0 mol% of the repeating units of the polymer (P) are repeating units derived from the monomer (M) of the general formula (I) or general formula (II) detailed above.

[0061] In a preferred embodiment, the polymer (P) comprises repeating units derived from at least one monomer (M) of the general formula (I) or general formula (II) detailed above, at least 1.2 mol% and at most 4.0 mol%, preferably at least 1.5 mol% and at most 3.5 mol%, preferably at least 1.5 mol% and at most 3.0 mol%.

[0062] When the repeating unit in the polymer (P) is derived from the monomer (M) of the general formula (II), it is understood that the repeating unit is the result of ring-opening polymerization of the epoxide moiety.

[0063] When the repeating unit in the polymer (P) is derived from the monomer (M) of the general formula (I) where X is an acyl chloride or acyl bromide, it is understood that the repeating unit can form an ester moiety by the result of a reaction between the monomer (M) and, for example, the terminal OH groups of the EO units or PO units of dihydroxy-terminated polyethylene oxide (or PEO-co-PPO copolymer).

[0064] When the repeating unit in the polymer (P) is derived from the monomer (M) of general formula (I) where X is trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, or methanesulfonate, the repeating unit can form an ether moiety through alcoholate formation and subsequent substitution of the X moiety of the monomer (M) as a result of a Williamson-type reaction in the presence of a strong base such as NaH between the monomer (M) and the terminal OH groups of the EO units or PO units of, for example, dihydroxy-terminated polyethylene oxide (or PEO-co-PPO copolymer).

[0065] These polymerization reactions are known in the art and are particularly described by H.-Q. Xie, J.-S. Guo, G.-Q. Yu, and J. Zu, in Journal of Applied Polymer Science 2001, 80, 2446.

[0066] Preferably, each of X in the monomer (M) of general formula (I) is a halide selected from the group consisting of halides, more preferably chloride, bromide, and iodide.

[0067] According to a preferred embodiment, the monomer (M) has the formula (II):

[0068]

Chemical formula

[0069] (wherein each of R1 and R2 is the same as or different from each other and, in each occurrence, is C 1~2 alkanediyl, and n is an integer 0 or 1, and preferably, n is 1).

[0070] In another preferred embodiment of the positive electrode for a lithium-ion secondary battery, the monomer (M) according to the present invention has the formulas (IA) to (IF) and (IIA) to (IIE):

[0071] [Chemical formula]

[0072] (wherein X is selected from the group consisting of halides, trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, and methanesulfonate, acyl chloride, and acyl bromide). Preferably, X is a halide, more preferably a halide selected from the group consisting of chloride, bromide, and iodide. Even more preferably, X is bromide.

[0073] More preferably, the monomer (M) according to the present invention is a compound selected from those of formulas (IA) to (IF).

[0074] Most preferably, the monomer (M) is a compound of formula (IA).

[0075] According to a preferred embodiment of the positive electrode for use in a lithium ion secondary battery, the polymer (P) is a) 94.0 to 98.5 mol of EO repeating units, b) 0.5 to 3.0 mol% of PO repeating units, and c) 1.0 to 3.0 mol% of the general formula (II):

[0076] [Chemical formula]

[0077] (wherein each of R1 and R2 is the same as or different from each other, and in each occurrence, C 1~2 alkanediyl, and n is an integer 0 or 1, preferably n is 1) and consists essentially of repeating units derived from the monomer (M). It is understood that chain defects or very small amounts of other units may be present, and it is understood that these latter do not substantially modify the properties of the polymer (P).

[0078] Preferably, the polymer (P) detailed above has an Mw (weight average molecular weight) of at least 10000 g / mol, more preferably at least 20000 g / mol, even more preferably at least 40000 g / mol, and even more preferably at least 50000 g / mol.

[0079] It is understood that the polymer (P) preferably has an Mw of at most 150000 g / mol, more preferably at most 100000 g / mol, as detailed above.

[0080] In a preferred embodiment, the polymer (P) has an Mw of at least 10000 g / mol and at most 150000 g / mol, preferably at least 20000 g / mol and at most 150000 g / mol, more preferably at least 40000 g / mol and at most 100000 g / mol, and even more preferably at least 50000 g / mol and at most 100000 g / mol, as detailed above.

[0081] According to the present invention, Mw is measured by GPC using calibration with PEO standards. Therefore, the Mw mentioned is in terms of PEO equivalents.

[0082] Alternatively and more preferably, the polymer (P) detailed above has an Mn (number average molecular weight) of at least 10000 g / mol, more preferably at least 20000 g / mol, even more preferably at least 40000 g / mol, and even more preferably at least 50000 g / mol.

[0083] It is understood that the polymer (P) preferably has an Mn of at most 150000 g / mol, more preferably at most 100000 g / mol, as detailed above.

[0084] In a preferred embodiment, the polymer (P) has an Mn of at least 10,000 g / mol and at most 150,000 g / mol, preferably at least 20,000 g / mol and at most 150,000 g / mol, more preferably at least 40,000 g / mol and at most 100,000 g / mol, and even more preferably at least 50,000 g / mol and at most 100,000 g / mol, as detailed above.

[0085] According to the present invention, Mn is measured by GPC using calibration with PEO standards. Thus, the Mn mentioned is in PEO equivalents.

[0086] Preferably, the polymer (P) according to the present invention is a random or block copolymer, more preferably a random copolymer.

[0087] Preferably, the polymer (P) according to the present invention is linear or branched, more preferably linear.

[0088] Particularly preferred polymers (P) have a main chain especially of formula (IV):

[0089]

Chemical formula

[0090] (wherein the ratio (o / q) of o to q in formula (IV) of polymer (P) is 25 to 100, or 35 to 75, or 40 to 60) and is a linear random copolymer that can be represented by. The ratio (p / q) of p to q in formula (IV) of polymer (P) is advantageously 0.05 to 1.50, preferably 0.10 to 1.00, preferably 0.20 to 0.60.

[0091] Such polymers (P) are commercially available, in particular, from Meisei Chemical works ltd under the trade name of the Alkox® CP-A series.

[0092] As described above, formula (III):

[0093] [Chemical Formula]

[0094] (wherein each of R3, R4, R5, R6, and R7 is the same as or different from each other, and in each occurrence, independently, C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, and is selected from the group consisting of, and the C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR9, and each of R9 is the same as or different from each other, and in each occurrence, independently, hydrogen, C 1~4 alkyl, and a hydroxyl protecting group, and m is an integer of at least 3) at least one polysiloxane compound having is Grafted to the polymer (P) as described in detail above via the reaction of at least a part of the -CH=CH2 moiety of the monomer (M) with the H-Si moiety of the polysiloxane compound having formula (III).

[0095] Preferably, each of R3 and R4 is the same as or different from each other, and in each occurrence, independently, C 1~6 alkyl, more preferably, each of R3 and R4 is the same as or different from each other, and in each occurrence, methyl, ethyl, propyl, or isopropyl, and even more preferably, each of R3 and R4 is the same as or different from each other, and in each occurrence, methyl.

[0096] Preferably, each of R5 and R6 is the same as or different from each other, and in each occurrence, independently, C 1~4Selected from alkyl or phenyl, the C 1~4 The alkyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, or CF3, and more preferably, each of R5 and R6 is the same as or different from each other, and in each occurrence, is methyl, ethyl, propyl, or isopropyl, and even more preferably, each of R5 and R6 is the same as or different from each other, and in each occurrence, is methyl.

[0097] Preferably, each of R7 is C 1~6 alkyl, and more preferably, each of R7 is C 1~4 alkyl, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, or tert-butyl.

[0098] Preferably, m is an integer of at least 5, more preferably at least 7, and even more preferably at least 8.

[0099] It is further understood that m is preferably an integer of at most 1000, more preferably at most 500, even more preferably at most 100, even more preferably at most 20, and even more preferably at most 15.

[0100] In a preferred embodiment of the present invention, m is an integer of at least 5 and at most 1000, preferably at least 5 and at most 500, more preferably at least 5 and at most 100, even more preferably at least 5 and at most 20, even more preferably at least 7 and at most 20, and even more preferably at least 8 and at most 15.

[0101] Within the context of the present invention, the -CH=CH2 moiety of the monomer (M), as detailed above, is understood to be able to react with the H-Si moiety of the polysiloxane compound having formula (III) to obtain a covalent bond between both moieties. Such a reaction is generally referred to as a hydrosilylation reaction. It is further understood that the reaction may involve the formation of one or more intermediates including metal complexes and sigma complexes.

[0102] As detailed above, several techniques known in the art can be successfully used to react at least a part of the -CH=CH2 moiety of the monomer (M) with the H-Si moiety of the polysiloxane compound having formula (III) detailed above.

[0103] The polymer (P) detailed above and the polysiloxane having formula (III) detailed above can in particular be reacted in the molten state, and for this purpose, a melt compounding machine such as an extruder, a melt kneader, or other devices can advantageously be used.

[0104] The polymer (P) detailed above and the polysiloxane having formula (III) detailed above can in particular be reacted in solution, and according to this embodiment, the polymer (P) and the polysiloxane having formula (III) detailed above are at least partially dissolved in a solvent. Dissolution can be obtained by heating at room temperature, or preferably at least 70 °C, more preferably at least 80 °C, still more preferably at the reflux temperature of the solvent. The choice of this solvent is not important as long as the solvent efficiently solvates both the polymer (P) and the polysiloxane having formula (III) and does not interfere with the hydrosilylation reaction. Generally, an organic solvent is preferably selected. Among these organic solvents, in particular, benzene, toluene, xylene, cymene, etc. can be mentioned.

[0105] Furthermore, the polymer (P) detailed above and the polysiloxane having formula (III) detailed above can in particular be reacted in the presence of a catalyst, in particular a hydrosilylation catalyst.

[0106] Such hydrosilylation catalysts are known in the art. In particular, ruthenium, platinum, or rhodium-based catalysts can be mentioned, for example, in particular, Karstedt's catalyst, Wilkinson's catalyst, Speier's catalyst, and mixtures thereof.

[0107] In the context of the present invention, the expression "via the reaction of at least a part of the -CH=CH2 of the monomer (M) with the H-Si moiety of the polysiloxane compound having the formula (III)" means that only a part or all of the -CH=CH2 of the monomer (M) can react with the H-Si moiety of the polysiloxane compound having the formula (III).

[0108] Preferably, the polysiloxane compound having the formula (III) detailed above is grafted onto the polymer (P) detailed above via the reaction of at least 10 mol%, more preferably at least 15 mol%, even more preferably at least 20 mol%, even more preferably at least 25 mol%, even more preferably at least 30 mol%, even more preferably at least 35 mol%, even more preferably at least 40 mol%, even more preferably at least 45 mol% of the -CH=CH2 moiety of the monomer (M) with the H-Si moiety of the polysiloxane compound having the formula (III).

[0109] It is further understood that the polysiloxane compound having the formula (III) detailed above can be grafted onto the polymer (P) detailed above via the reaction of 100 mol%, preferably at most 95 mol%, more preferably at most 90 mol%, even more preferably at most 85 mol%, even more preferably at most 80 mol%, even more preferably at most 75 mol%, even more preferably at most 70 mol%, even more preferably at most 65 mol%, even more preferably at most 60 mol% of the -CH=CH2 moiety of the monomer (M) with the H-Si moiety of the polysiloxane compound having the formula (III).

[0110] In a preferred embodiment, at least 10 mol% and at most 90 mol%, more preferably at least 30 mol% and at most 70 mol%, even more preferably at least 40 mol% and at most 60 mol% of the -CH=CH2 moiety of the monomer (M) of the polysiloxane compound having the formula (III) detailed above is grafted onto the polymer (P) detailed above through reaction with the H-Si moiety of the polysiloxane compound having the formula (III).

[0111] The reaction can be monitored by using known analytical methods such as, in particular, GPC or 1 1H-NMR method, as exemplified in the experimental section.

[0112] Preferably, the polymer electrolyte is obtained by reaction between the at least one polymer (P) and at least 6 wt% or at least 7 wt% or at least 8 wt% of the at least one polysiloxane compound based on the total amount of the at least one polymer (P) and the at least one polysiloxane compound.

[0113] Preferably, the polymer electrolyte is obtained by reaction between the at least one polymer (P) and at most 27 wt% or at most 25 wt% or at most 22 wt% of the at least one polysiloxane compound based on the total amount of the at least one polymer (P) and the at least one polysiloxane compound.

[0114] In a preferred embodiment, the polymer electrolyte is obtained by reaction between the at least one polymer (P) and at least 6 wt% and at most 27 wt% or at least 7 wt% and at most 25 wt% or at least 8 wt% and at most 22 wt% of the at least one polysiloxane compound based on the total amount of the at least one polymer (P) and the at least one polysiloxane compound.

[0115] As described above, the positive electrode for a lithium-ion secondary battery includes a positive electrode active material and at least one polymer electrolyte. The positive electrode active material contains at least an element selected from Li, M', and oxygen. The metal M' has the formula: Ni 1-x-y-z Mn x Co y A z (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li, and is preferably at least one of B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr). Preferably, A is Al, and the atomic ratio of A to the total amount of Ni, Mn, and / or Co is greater than 0, preferably greater than 0.001, more preferably greater than 0.003, and most preferably greater than 0.006. Preferably, A is Al, and the atomic ratio of A to the total amount of Ni, Mn, and / or Co is less than 0.1, preferably less than 0.05, more preferably less than 0.01, and most preferably less than 0.008. Preferably, A is Al, and the atomic ratio of A to the total amount of Ni, Mn, and / or Co is in the range of 0.001 to 0.1, preferably in the range of 0.002 to 0.05, more preferably in the range of 0.003 to 0.01, and most preferably in the range of 0.006 to 0.008).

[0116] According to a specific embodiment of the positive electrode of the present invention, in the positive electrode according to the present invention, the weight ratio of the polymer electrolyte to the positive electrode active material is at least 5%, more preferably at least 10%, and still more preferably at least 15%.

[0117] In the positive electrode according to the present invention, the weight ratio of the polymer electrolyte to the positive electrode active material is at most 50%, more preferably at most 30%, and even more preferably at most 25%.

[0118] In a preferred embodiment, in the positive electrode according to the present invention, the weight ratio of the polymer electrolyte to the positive electrode active material is 5% to 50%, preferably 10% to 30%, more preferably 15% to 25%. Alternatively, in the positive electrode according to the present invention, the weight ratio of the polymer electrolyte to the positive electrode active material is 5% to 50%, preferably 20% to 45%, more preferably 30% to 40%.

[0119] In a preferred embodiment of the positive electrode of the present invention, the positive electrode includes the above-described polymer electrolyte and the positive electrode active material detailed above, and further includes at least one lithium salt (Li salt) selected from LiTFSI, LiFSI, LiPF6, LiBF4, and LiClO4. Such a positive electrode is defined as a cathode solution. Optionally, the Li salt is present in the positive electrode at a weight ratio of polymer electrolyte:Li salt of 60:40 to 80:20, more preferably 70:30 to 75:25.

[0120] In a preferred embodiment of the positive electrode of the present invention, the [weight ratio x100] of the Li salt to the polymer electrolyte in the positive electrode according to the present invention is 5% to 50%, preferably 20% to 45%, more preferably 30% to 40%.

[0121] In another preferred embodiment, the Li salt is LiTFSI.

[0122] Preferably, the positive electrode active material is a particulate material, particularly a powder, as detailed above.

[0123] Batteries and Electrochemical Cells In another aspect, the present invention provides a polymer battery including the positive electrode according to the first aspect of the present invention.

[0124] In another aspect, the present invention provides an electrochemical cell including the positive electrode according to the first aspect of the present invention.

[0125] In another aspect, the present invention provides the use of the positive electrode according to the present invention in a battery. x + y + z

[0126] In a last aspect, the invention is a battery or an electrochemical cell comprising a positive electrode active material and a polymer electrolyte, the positive electrode active material comprising at least Li, M', and an oxygen element, M' consisting of Ni, Mn, Co, and A, the positive electrode material having a Ni:(Mn + Co + A) molar ratio of (1 - x - y - z):(x + y + z) (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li and is preferably at least one of Al, or B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr), the polymer electrolyte being: i. at least one polyether polymer [hereinafter, polymer (P)], wherein polymer (P) is: a) at least 70.0 mol% ethylene oxide units (EO), b) 0.0 to 10.0 mol% propylene oxide units (PO), and c) 1.00 to 4.0 mol% of general formula (I) or general formula (II):

[0127]

Chemical formula

[0128] (wherein, each of R1 and R2 is the same as or different from each other and, in each occurrence, is C 1~6 alkanediyl, the C 1~6 alkanediyl being optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR8, each of R8 being the same as or different from each other and, in each occurrence, independently selected from the group consisting of hydrogen and C 1~4 alkyl, and n is an integer 0 or 1 or 2), Each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p - toluenesulfonate, and methanesulfonate), and a repeating unit derived from at least one monomer [hereinafter, monomer (M)] A polymer (P) containing ii. Formula (III):

[0129]

Chemical formula

[0130] (In the formula, Each of R3, R4, R5, R6, and R7 is the same as or different from each other, and in each occurrence, independently, C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, and the C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, OR9, and each of R9 is the same as or different from each other, and in each occurrence, independently, hydrogen, C 1~4 alkyl, and a hydroxyl protecting group, m is an integer of at least 3), and is obtained by the reaction between at least one polysiloxane compound having The at least one polysiloxane compound having formula (III) is grafted onto the at least one polymer (P) via the reaction between at least a part of the -CH=CH2 moiety of the monomer (M) and the H - Si moiety of the polysiloxane compound having formula (III), providing a battery or an electrochemical cell.

[0131] One embodiment is a battery or an electrochemical cell comprising a positive electrode active material and a polymer electrolyte, wherein the positive electrode active material contains Ni, Mn, Co, and A, and the positive electrode material has an Ni:(Mn + Co + A) molar ratio of (1 - x - y - z):(x + y + z) (wherein, when measured by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and A, when present, is different from Ni, Mn, Co, and Li, and is preferably at least one of Al, or B, Mg, Al, Nb, Ti, Y, W, S, Ba, Sr, and Zr), and the polymer electrolyte is: i. At least one polyether polymer [hereinafter, polymer (P)], wherein the polymer (P) is: a) At least 70.0 mol% of oxyethylene units (EO), b) 0.0 to 10.0 mol% of oxypropylene units (PO), and c) 1.00 to 4.0 mol% of a monomer of general formula (I) or general formula (II):

[0132]

Chemical formula

[0133] (wherein, Each of R1 and R2 is the same as or different from each other, and in each occurrence, is C 1~6 alkanediyl, and the C 1~6 alkanediyl is optionally substituted with one or more substituents selected from halide, C 1~4 alkyl, C 3~6 cycloalkyl, CF3, and OR8, and each of R8 is the same as or different from each other, and in each occurrence, is independently selected from the group consisting of hydrogen and C 1~4 alkyl, and n is an integer 0 or 1 or 2, Each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p - toluenesulfonate, and methanesulfonate) of at least one monomer [hereinafter, monomer (M)] - derived repeating unit A polymer (P), and ii. Formula (III):

[0134]

Chemical formula

[0135] (In the formula, each of R3, R4, R5, R6, and R7 is the same as or different from each other, and in each occurrence, independently, C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, and is optionally substituted with one or more substituents selected from the group consisting of halide, C 1~6 alkyl, C 3~6 cycloalkyl, aryl, C 1~6 alkoxy, heterocyclyl, and each R9 is the same as or different from each other, and in each occurrence, independently, hydrogen, C 1~4 alkyl, and a hydroxyl protecting group, and 3~6 m is an integer of at least 3), and is obtained by a reaction between at least one polysiloxane compound having 1~4 alkyl, and a hydroxyl protecting group, and m is an integer of at least 3), and is obtained by a reaction between at least one polysiloxane compound having the at least one polysiloxane compound having Formula (III) is grafted to the at least one polymer (P) via a reaction between at least a part of the -CH=CH2 moiety of the monomer (M) and the H-Si moiety of the polysiloxane compound having Formula (III), and is a battery or an electrochemical cell.

[0136] In a preferred embodiment, the battery is a lithium-ion battery.

[0137] In a preferred embodiment, the battery or electrochemical cell of the present invention contains a polymer electrolyte as described in the positive electrode section provided above.

[0138] Examples and Comparative Examples The following examples are intended to clarify the present invention further and are not intended to limit the scope of the present invention.

[0139] 1.1. Materials and Methods Unless otherwise specified, the following materials were used as described below.

[0140] The random polymer (P) was purchased from Mingcheng Chemical Industry under the trade name of CP series CP-A. Alternatively, the polymer (P) can be prepared by the following procedure disclosed in H.-Q. Xie, J.-S. Guo, G.-Q. Yu, and J. Zu, Journal of Applied Polymer Science 2001, 80, 2446.

[0141] The monohydride-terminated polydimethylsiloxane (SiH-terminated PDMS, M w = 850 g / mol) was purchased from Gelest, Inc.

[0142] The silica-supported Karstedt-type catalyst was prepared according to Q.J. Miao, Z.-P. Fang, and G.P. Cai, Catalysis Communications 2003, 4, 637 - 639.

[0143] LiTFSI (lithium bis(trifluoromethanesulfonyl)imide salt, 99.95% trace metal basis) was purchased from Sigma-Aldrich.

[0144] 99.8 wt% anhydrous acetonitrile was purchased from Sigma-Aldrich.

[0145] Timcal Super P is a conductive carbon black powder (CAS number 1333 - 86 - 4) manufactured by Imerys Graphite & Carbon.

[0146] Polyethylene oxide (M of 1,000,000 wThe PEO having [specific property] was purchased from Alfa Aesar.

[0147] 1 The H spectrum was recorded at room temperature using a JEOL JNM ECZ 500 MHz NMR spectrometer. The polymer sample was dissolved in CDCl3, and the internal standard was optimized using tetramethylsilane (TMS).

[0148] Inductively coupled plasma (ICP) measurements were performed using an Agilent 720 ICP-OES (Agilent Technologies, https: / / www.agilent.com / cs / library / brochures / 5990-6497EN%20720-725_ICP-OES_LR.pdf). One gram of the powder sample was dissolved in 50 mL of high-purity hydrochloric acid (at least 37 wt% HCl with respect to the total weight of the solution) in an Erlenmeyer flask. The flask was covered with a watch glass and heated on a hot plate at 380 °C until the powder was completely dissolved. After cooling to room temperature, the solution from the Erlenmeyer flask was poured into the first 250 mL volumetric flask. Then, the 250 mL of the first volumetric flask was filled to the calibration line with deionized water, and subsequently, a complete homogenization method (first dilution) was performed. An appropriate amount of the solution was pipetted out from the first volumetric flask and transferred to the second 250 mL volumetric flask for the second dilution. After filling the second volumetric flask to the 250 mL calibration line with the internal standard element and 10% hydrochloric acid, it was homogenized. Finally, this solution was used for ICP measurements.

[0149] 1.2. Preparation of Polymer Electrolyte The polymer (P), which is a random linear copolymer whose characteristics are shown in Table 2, is reacted with monohydride-terminated polydimethylsiloxane (SiH-terminated PDMS) by hydrosilylation according to the following procedure.

[0150]

Table 1

[0151] A mixture containing 2.0 g of polymer (P) and 0.36 g of SiH-terminated PDMS is added to 50 mL of benzene containing 20 mg of a silica-supported Karstedt's catalyst and heated at 90 °C for 48 h under a nitrogen atmosphere. The heated mixture is filtered through celite to remove the solid catalyst and then placed under reduced pressure to remove the solvent. PDMS is grafted onto polymer (P) via the reaction of the -CH=CH2 of the 50 mol% AGE units with the H-Si moiety of PDMS.

[0152] The success of the grafting was 1 confirmed by 1H-NMR and GPC.

[0153] Polymer (P): 1 1H-NMR (TMS, CDCl3, 500 MHz): δ (ppm) 1.2 (d, CH3 of PO unit), 4 (m, -OCH2-CH=CH2 of AGE unit), 5.2 (m, CH2=CH- of AGE unit), 5.8 (m, -CH=CH2 of AGE unit).

[0154] Monohydride PDMS: 1 1H-NMR (TMS, CDCl3, 500 MHz): δ (ppm) 0.5 (m, -Si-CH2-CH2-), 0.9 (t, CH3-CH2-), 1.3 (br, -Si-CH2-CH2-CH2-CH3), 4.8 (m, H-Si-).

[0155] Polymer electrolyte: 1 1H-NMR (TMS, CDCl3, 500 MHz): δ (ppm): 0.5 (br, -Si-CH2-CH2- of PDMS), 0.9 (br, CH3-CH2- of PDMS), 1.1 (d, CH3 of PO unit), 1.2 (br, -Si-CH2-CH2-CH2-CH3 of PDMS), 1.4 (br, -OCH2-CH2-CH2-Si-).

[0156] Polyelectrolyte 1 The presence of a broad peak at 1.4 ppm and the absence of a peak attributed to H-Si in the 1H-NMR spectrum indicate the success of hydrosilylation.

[0157] Figure 1 shows the GPC elution curves of the polymer electrolyte, polymer (P), and polysiloxane prepared above.

[0158] The shorter elution time of the polymer electrolyte compared to the polymer (P) indicates that the polymer electrolyte has a higher molecular weight than the polymer (P), and thereby PDMS was successfully grafted onto the polymer (P).

[0159] The obtained polymer electrolyte was designated as PE1.

[0160] 1.3. Preparation of Cathode Active Material 1 (AM1) When measured by ICP, a lithium transition metal composite oxide having the general formula Li 1.010 (Ni 0.621 Mn 0.224 Co 0.155 ) 0.990 O 2.00 is prepared as a cathode active material according to the following process. Step 1) Preparation of transition metal hydroxide precursor: When measured by ICP, a nickel-based transition metal hydroxide powder (TMH2) having a metal composition of Ni 0.621 Mn 0.224 Co 0.155 is prepared by coprecipitation in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) First mixing: The TMH1 prepared in Step 1) is mixed with Li2CO3 in an industrial blender to obtain a first mixture with a lithium-to-metal ratio of 0.85. Step 3) First firing: The first mixture from Step 2) is fired at 900 °C for 10 hours in a dry air atmosphere to obtain a first fired cake. The first fired cake is pulverized to obtain a first fired powder. Step 4) Second mixing: The first fired powder from Step 3) is mixed with LiOH in an industrial blender to obtain a second mixture with a lithium-to-metal ratio of 1.01. Step 5) Second firing: The second mixture from Step 4) is fired in dry air at 930 °C for 10 hours, followed by obtaining the second fired powder through a grinding (bead milling) and sieving process. Step 6) Third mixing: The second fired powder from Step 5) is mixed in an industrial blender with 1.5 mol% LiOH with respect to the total molar content of Ni, Mn, and Co to obtain a third mixture. Step 7) Third firing: The third mixture from Step 6) is fired in dry air at 750 °C for 10 hours to obtain AM1.

[0161] 1.4. Preparation of Cathode EX1 A cathode containing PE1 and AM1 is prepared according to the following procedure. Step 1) A step of preparing a polymer electrolyte solution containing the polymer electrolyte PE1 and LiTFSI in 99.8 wt% anhydrous acetonitrile. The polymer electrolyte solution has a polymer electrolyte:LiTFSI weight ratio of 74:26. This weight ratio corresponds to LiTFSI:polymer electrolyte [weight ratio × 100] being 35%. Step 2) A step of mixing the polymer electrolyte solution prepared in Step 1), the cathode active material AM1 prepared according to Section 1.2, and carbon black powder (Timcal Super P carbon black) in an acetonitrile solution at a weight ratio of 21:75:4 to prepare a slurry mixture. The mixing is performed at 5000 rpm for 45 minutes by a homogenizer. Step 3) A step of casting the slurry mixture from Step 2) on one side of an aluminum foil with a thickness of 20 μm with a coater gap of 100 μm. Step 4) A step of drying the foil on which the slurry is cast at 30 °C for 12 hours and then punching it out to obtain a cathode with a diameter of 14 mm.

[0162] The cathode was designated as EX1.

[0163] 1.5. Preparation of Cathode Active Material 2 (AM2) The positive electrode active material AM2 is prepared according to the following process. Step 1) Preparation of a transition metal oxyhydroxide precursor: The nickel-based transition metal oxyhydroxide powder (TMH1) having, as measured by ICP, the metal composition Ni 0.63 Mn 0.22 Co 0.15 is prepared by a coprecipitation method in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) First mixing: The TMH1 prepared in Step 1) is mixed with Li2CO3 in an industrial blender to obtain a first mixture having a lithium-to-metal ratio of 0.85. Step 3) First firing: The first mixture from Step 2) is fired at 900 °C for 10 hours in a dry air atmosphere to obtain a first fired cake. The first fired cake is pulverized to obtain a first fired powder. Step 4) Second mixing: The first fired powder from Step 3) is mixed with LiOH in an industrial blender to obtain a second mixture having a lithium-to-metal ratio of 1.05. Step 5) Second firing: The second mixture from Step 4) is fired at 930 °C for 10 hours in dry air, and then a second fired powder is obtained by a pulverization (bead milling) and sieving process. Step 6) Third mixing: The second fired powder from Step 5) is mixed with, for example, Co from 2 mol% of CO3O4 powder and 5 mol% of LiOH based on the total molar content of Ni, Mn, and Co in an industrial blender to obtain a third mixture. Step 7) Third firing: The third mixture from Step 6) is fired at 775 °C for 12 hours in dry air to produce a third fired powder. Step 8) Fourth mixing: The third fired powder from Step 7) is mixed with 0.2 wt% of nano Al2O3 powder. Step 9) Fourth firing: The fourth mixture from Step 8) is fired at 750 °C for 10 hours in dry air to produce a fourth fired powder. Step 10) Fifth mixing: Mix the fourth calcined powder from Step 9) with 0.3 wt% polyvinylidene fluoride (PVDF). Step 11) Fifth firing: Fire the fifth mixture from Step 10) in dry air at 375 °C for 5 hours to produce AM2.

[0164] 1.6. Preparation of cathode EX2 Prepare a cathode containing AM2 and PE1 according to the following procedure. Step 1) Prepare a polymer electrolyte solution containing polymer electrolyte PE1 and LiTFSI in 99.8 wt% anhydrous acetonitrile. The polymer electrolyte solution has a polymer electrolyte:LiTFSI weight ratio of 74:26. Step 2) Mix the polymer electrolyte solution prepared in Step 1), the cathode active material AM2, and carbon black powder (Timcal Super P carbon black) in an acetonitrile solution at a weight ratio of 21:75:4 in an acetonitrile solution to prepare a slurry mixture. The mixing is carried out at 5000 rpm for 45 minutes using a homogenizer. Step 3) Cast the slurry mixture from Step 2) onto one side of an aluminum foil with a thickness of 20 μm with a coater gap of 100 μm. Step 4) Dry the foil on which the slurry is cast at 30 °C for 12 hours, and then punch it out to obtain a cathode with a diameter of 14 mm.

[0165] The cathode was designated as EX2.

[0166] 1.7. Preparation of cathode CEX1 Prepare a cathode containing PE2 (poly(ethylene oxide) (PEO) powder (Mw = 1,000,000 g / mol)) purchased from Alfa Aesar and AM1 according to the following process. Step 1) Prepare a polymer electrolyte solution containing polymer electrolyte (PE2) and LiTFSI in 99.8 wt% anhydrous acetonitrile. The polymer electrolyte solution has a polymer electrolyte:LiTFSI weight ratio of 74:26. Step 2) The polymer electrolyte solution prepared in Step 1), the positive electrode active material AM1, and the conductive powder (Super P, Timcal (Imerys Graphite & Carbon)) are mixed in an acetonitrile solution at a weight ratio of 21:75:4 to prepare a slurry mixture. The mixing is performed at 5000 rpm for 45 minutes using a homogenizer. Step 3) Casting the slurry mixture from Step 2) onto one side of an aluminum foil with a thickness of 20 μm with a coater gap of 100 μm. Step 4) Drying the foil on which the slurry is cast at 30 °C for 12 hours, and then punching it out to obtain a positive electrode with a diameter of 14 mm.

[0167] The positive electrode was designated as CEX1.

[0168] 1.8. Preparation of Solid Polymer Electrolyte (SPE) A PEO-based solid polymer electrolyte (SPE) is prepared according to the following process. Step 1) Mixing polyethylene oxide (PEO with a molecular weight of 1,000,000) and LiTFSI (purchased from Soulbrain Co., Ltd. instead of Sigma Aldrich) in 99.8 wt% anhydrous acetonitrile using a mixer at 2,000 revolutions per minute (rpm) for 30 minutes. The molar ratio of ethylene oxide to lithium is 20. Step 2) Pouring the mixture from Step 1) into a Teflon (registered trademark) dish and drying it at 25 °C for 12 hours. Step 3) Removing the dried SPE from the dish and punching out the dried SPE to obtain an SPE disk with a thickness of 300 μm and a diameter of 19 mm.

[0169] 1.9. Assembly of Polymer Cell Assemble the coin-type polymer cell from the bottom up in a glove box filled with argon in the order of a 2032 coin cell can, a positive electrode (EX1, EX2, or CEX1), the SPE prepared in Section 1.8, a gasket, a Li anode, a spacer, a wave spring, and a cell cap. Then, completely seal the coin cell to prevent electrolyte leakage.

[0170] 2. Comparison and Test Method (Qtotal) The leakage capacity (Qtotal) was measured for EX1, EX2, and CEX1.

[0171] Each coin-type polymer cell was cycled at 80 °C using a Toscat-3100 computer-controlled constant current cycling station (manufactured by Toyo System, http: / / www.toyosystem.com / image / menu3 / toscat / TOSCAT-3100.pdf). In the test procedure for the coin cell, a current definition of 1C at 160 mA / g was used in the window range of 4.4 to 3.0 V / Li metal according to the following schedule. Step 1) Charge in constant current mode at a C rate of 0.05 with an end condition of 4.4 V, and then pause for 10 minutes. Step 2) Discharge in constant current mode at a C rate of 0.05 with an end condition of 3.0 V, and then pause for 10 minutes. Step 3) Charge in constant current mode at a C rate of 0.05 with an end condition of 4.4 V. Step 4) Switch to constant voltage mode and maintain 4.4 V for 60 hours. Step 5) Discharge in constant current mode at a C rate of 0.05 with an end condition of 3.0 V.

[0172] Q total is defined as the total leakage capacity at high voltage and high temperature in Step 4) according to the described test method. Q total A small value of indicates high stability of the positive electrode active material powder during high-temperature operation.

[0173]

Table 2

[0174]

Table 3

[0175] a Determined by ICP measurement, where Me is the total atomic fraction of Ni + Mn + Co + Al.

[0176]

Table 4

[0177] Figure 2 shows the effect of the polymer electrolyte according to the present invention on the Q total value. The X-axis indicates the polymer electrolyte used in the positive electrode. The legend indicates the positive electrode active material used.

[0178] According to Table 5 and Figure 2, it is observed that EX1 has a lower Q total than CEX1. This observation indicates that the positive electrode containing the combination of the positive electrode active material and the polymer electrolyte according to the present invention provides better electrochemical performance than the combination with the conventional electrolyte PEO. Furthermore, the surface-modified positive electrode active material powder (EX2) according to the present invention has better electrochemical performance than EX1 when using PE1 as the polymer electrolyte. A smaller Q total value indicates higher stability of the lithium-ion secondary battery under high-voltage application at high temperatures.

[0179] 3. Characterization of the Polymer Electrolyte and the Cathode Material Contained in the Cathode Separation of the solid polymer electrolyte and the positive electrode material can be carried out by selectively dissolving the solid polymer electrolyte in a solvent such as DMSO, DMF or acetonitrile, and subsequently separating the liquid phase containing the solid polymer electrolyte and the solid component containing the positive electrode material by filtration or centrifugation. The solid polymer electrolyte is obtained by drying the liquid phase, which can be identified by NMR spectroscopy as described in Example 1.2. Optionally, the solid polymer electrolyte needs to be purified by precipitation in a non-solvent such as hexane or cyclohexane, followed by filtration and drying. ICP analysis of the solid component reveals that the solid component contains the metal composition determined in Table 4 for AM1 or AM2, respectively.

Claims

1. A positive electrode for a lithium-ion secondary battery, comprising a positive electrode active material and at least one polymer electrolyte, wherein the positive electrode active material contains Ni, Mn, Co, and A in a molar ratio of (1−x−y−z):x:y:z, and the positive electrode active material has a Ni:(Mn + Co + A) molar ratio of (1−x−y−z):(x + y + z) (wherein x, y, and z are measured values by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and when A is present, A is Al), and the polymer electrolyte is: i. At least one polyether polymer [hereinafter, polymer (P)], wherein the polymer (P) is: At least 86.0 mol% ethylene oxide units (EO), 0.0 mol% to 10.0 mol% propylene oxide units (PO), and 1.00 mol% to 4.0 mol% of at least one monomer of general formula (I) or general formula (II): 【Chemical 1】 (wherein, R １ and R ２ each of which is the same as or different from each other and, in each occurrence, is C １～６ alkanediyl, said C １～６ alkanediyl is optionally substituted with one or more substituents selected from halide, C １～４ alkyl, C ３～６ cycloalkyl, CF ３ , OR ８ and each of R ８ is the same as or different from each other and, in each occurrence, is independently selected from the group consisting of hydrogen and C １～４ alkyl, and n is an integer of 0 or 1 or 2 Each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p-toluenesulfonate, and methanesulfonate) of at least one monomer [hereinafter, monomer (M)]-derived repeating unit Comprising, a polymer (P), and ii. Formula (III): 【Chemical formula 2】 (wherein, R ３ 、R ４ 、R ５ 、R ６ 、and R ７ each of which is the same as or different from each other and, in each occurrence, independently, is selected from the group consisting of C １～６ alkyl, C ３～６ cycloalkyl, aryl, C １～６ alkoxy, heterocyclyl, and said C １～６ alkyl, C ３～６ cycloalkyl, aryl, C １～６ alkoxy, heterocyclyl is optionally substituted with one or more substituents selected from the group consisting of halide, C １～４ alkyl, C ３～６ cycloalkyl, CF ３ 、OR ９ each of R ９ is the same as or different from each other and, in each occurrence, independently, is selected from the group consisting of hydrogen, C １～４ alkyl, and a hydroxyl protecting group m is an integer of at least 3) of at least one polysiloxane compound, and is a reaction product between The polymer electrolyte has a structure in which the at least one polysiloxane compound having the formula (III) is grafted onto the at least one polymer (P) via a hydrosilylation reaction between at least a part of the —CH═CH part of the monomer (M) and the H—Si part of the polysiloxane compound having the formula (III). ２ A positive electrode having a structure in which the at least one polysiloxane compound having the formula (III) is grafted onto the at least one polymer (P) via a hydrosilylation reaction between at least a part of the —CH═CH part of the monomer (M) and the H—Si part of the polysiloxane compound having the formula (III).

2. The positive electrode according to claim 1, wherein 80.0 mol% to 99.0 mol% of the repeating units of the polymer (P) are EO units.

3. The positive electrode according to claim 1 or claim 2, wherein 0.5 mol% to 6.0 mol% of the repeating units of the polymer (P) are PO units.

4. 1.2 mol% to 4.0 mol% of the repeating units of the polymer (P) are repeating units derived from the monomer (M) of general formula (I) or general formula (II) (wherein R １ , R ２、 n, and X are as defined in claim 1), the positive electrode according to any one of claims 1 to 3.

5. The monomer (M) is of formula (II) 【Chemical Formula 3】 (wherein, R １ and R ２ each of which is the same as or different from one another and, in each occurrence, is C １～２ alkanediyl, and n is an integer of 0 or 1), the positive electrode according to any one of claims 1 to 4.

6. R ３ 、 R ４ and R ７ each is the same as or different from one another and, in each occurrence, independently, C １～６ alkyl, R ５ and R ６ each is the same as or different from one another and, in each occurrence, independently, C １～４ alkyl or phenyl, and the C １～４ alkyl is optionally substituted with one or more substituents selected from halide, C １～４ alkyl or CF ３ and m is an integer of at least 5 and at most 1000. The positive electrode according to any one of claims 1 to 5.

7. The polysiloxane compound having the formula (III) is grafted onto the polymer (P) through the reaction of at least 10 mol% and at most 90 mol% of the -CH=CH part of the monomer (M) with the H-Si part of the polysiloxane compound having the formula (III). ２ The positive electrode according to any one of claims 1 to 6.

8. The positive electrode according to any one of claims 1 to 7, wherein the weight ratio of the polymer electrolyte to the positive electrode active material is 5% to 50%.

9. The positive electrode further includes at least one lithium salt selected from LiTFSI, LiFSI, LiPF ６ , LiBF ４ , and LiClO ４ . The positive electrode according to any one of claims 1 to 8.

10. The atomic ratio of A to the total amount of Ni, Mn, and / or Co is greater than 0, the positive electrode according to any one of claims 1 to 9.

11. A polymer battery comprising the positive electrode according to any one of claims 1 to 10.

12. An electrochemical cell comprising the positive electrode according to any one of claims 1 to 10.

13. Use of the positive electrode according to any one of claims 1 to 10 in a battery.

14. A battery or an electrochemical cell comprising a positive electrode active material and a polymer electrolyte, wherein the positive electrode active material contains Ni, Mn, Co, and A in a molar ratio of (1−x−y−z):x:y:z, and the positive electrode active material has a Ni:(Mn + Co + A) molar ratio of (1−x−y−z):(x + y + z) (wherein x, y, and z are measured values by ICP, 0.00 ≦ x ≦ 0.70, 0.00 ≦ y ≦ 0.40, and 0.00 ≦ z ≦ 0.10, and when A is present, A is Al), and the polymer electrolyte is: i. at least one polyether polymer [hereinafter, polymer (P)], wherein the polymer (P) is: at least 86.0 mol% ethylene oxide units (EO), 0.0 mol% to 10.0 mol% propylene oxide units (PO), and 1.00 mol% to 4.0 mol% of at least one monomer of general formula (I) or general formula (II): 【Chemical Formula 4】 (wherein R １ and R ２ each is the same as or different from each other, and in each occurrence, C １～６ alkanediyl, and said C １～６ alkanediyl is optionally substituted with one or more substituents selected from halide, C １～４ alkyl, C ３～６ cycloalkyl, CF ３ , OR ８ and each of R ８ is the same as or different from each other, and in each occurrence, independently selected from the group consisting of hydrogen and C １～４ alkyl, and n is an integer 0 or 1 or 2. each of X is a leaving group selected from the group consisting of halide, trifluoromethanesulfonate, nonafluorobutanesulfonate, p - toluenesulfonate, and methanesulfonate) [hereinafter, monomer (M)]-derived repeating units comprising polymer (P), and ii. a reaction product between at least one polysiloxane compound having formula (III): 【Chemical Formula 5】 (wherein R ３ 、R ４ 、R ５ 、R ６ 、and R ７ each is the same as or different from each other, and in each occurrence, independently, is selected from the group consisting of C １～６ alkyl, C ３～６ cycloalkyl, aryl, C １～６ alkoxy, heterocyclyl, and the C １～６ alkyl, C ３～６ cycloalkyl, aryl, C １～６ alkoxy, heterocyclyl are optionally substituted with one or more substituents selected from halide, C １～４ alkyl, C ３～６ cycloalkyl, CF ３ 、OR ９ ; each of R ９ is the same as or different from each other, and in each occurrence, independently, is selected from the group consisting of hydrogen, C １～４ alkyl, and a hydroxyl protecting group m is an integer of at least 3). The polymer electrolyte has a structure in which the at least one polysiloxane compound having the formula (III) is grafted to the at least one polymer (P) through a hydrosilylation reaction between at least a part of the —CH═CH part of the monomer (M) and the H—Si part of the polysiloxane compound having the formula (III). ２ A battery or an electrochemical cell having such a structure.

15. LiTFSI, LiFSI, LiPF ６ , LiBF ４ , and LiClO ４ The battery or electrochemical cell according to claim 14, comprising at least one lithium salt selected from

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