CN116826308B - Composite diaphragm, preparation method thereof and secondary battery - Google Patents

Composite diaphragm, preparation method thereof and secondary battery Download PDF

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CN116826308B
CN116826308B CN202311110671.9A CN202311110671A CN116826308B CN 116826308 B CN116826308 B CN 116826308B CN 202311110671 A CN202311110671 A CN 202311110671A CN 116826308 B CN116826308 B CN 116826308B
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compound
groups
inorganic particles
modification
base film
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CN116826308A (en
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田晓丽
高秀玲
马华
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Tianjin EV Energies Co Ltd
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Tianjin EV Energies Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/457—Separators, membranes or diaphragms characterised by the material having a layered structure comprising three or more layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention provides a composite diaphragm, a preparation method thereof and a secondary battery. The composite membrane comprises a base membrane and a functional coating arranged on at least one side of the base membrane; the functional coating comprises modified inorganic particles, wherein the modified inorganic particles are obtained by two times of modification; or the composite membrane comprises a modified base membrane, wherein the modified base membrane is obtained by two times of modification. According to the invention, the specific active groups are grafted on the surfaces of inorganic particles or the surfaces of the diaphragms containing phenolic hydroxyl groups and/or quinone groups, so that the effects of capturing manganese ions and removing hydrofluoric acid are improved, the density/type of the active groups is further improved, the service life and high-temperature performance of the lithium ion battery are greatly improved, and the inorganic particles are more uniformly dispersed.

Description

Composite diaphragm, preparation method thereof and secondary battery
Technical Field
The invention belongs to the technical field of diaphragm materials, and particularly relates to a composite diaphragm, a preparation method thereof and a secondary battery.
Background
With the continuous improvement of the demands for energy storage devices, the market has raised higher demands on the cycle life, energy density and safety performance of lithium ion batteries. Spinel lithium manganate (LiMn) 2 O 4 ) The lithium ion battery has the advantages of rich raw material reserves, high energy density, low cost, no pollution, good safety and the like, and is considered as an ideal positive electrode material of a lithium ion power battery. The decay of the cycling performance of lithium ion batteries during use and storage, particularly at high temperatures, has limited their widespread use in the power domain. Therefore, extending the cycle life of lithium ion batteries is one of the key points of current research.
It is widely considered that manganese element is dissolved out from the positive electrode and migrates to the negative electrode to generate reduction reaction due to the action of trace hydrofluoric acid in the electrolyte, so that the solid electrolyte film on the surface of the negative electrode material is destroyed, the internal resistance of the battery is improved, active lithium is consumed, and serious capacity attenuation of the battery is caused.
In the prior art, the cycle performance of the lithium ion battery is improved by optimizing the performance of the diaphragm, on one hand, crown ether group-containing active groups are introduced into the diaphragm material and are complexed with manganese ions, but the method can only realize capture of manganese ions, and the problem of dissolution of manganese elements is not fundamentally solved, so that the method has limited space for improving the cycle performance, and the method has the advantages of complex process, high cost, no mature equipment matching and difficulty in realizing industrialization.
On the other hand, the prior art also discloses that the inorganic particles coated on the surface of the diaphragm are subjected to radical modification, so that the capability of complexing manganese ions of the diaphragm material is improved, but a part of active groups are consumed in the forming process of the coating, and meanwhile, in order to avoid dissolution of the material into electrolyte caused by long-term circulation, a strong oxidant is used for improving the polymerization degree, so that a large number of active groups are oxidized, the number of active groups contained in the coating structure is less, and the capability of complexing manganese ions is poor.
Therefore, development of a membrane modification method having advantages of low cost, simple process, excellent performance and the like is needed.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a composite diaphragm, a preparation method thereof and a secondary battery. According to the invention, the specific active groups are grafted on the surfaces of inorganic particles or the surfaces of the diaphragms containing phenolic hydroxyl groups and/or quinone groups, so that the effects of capturing manganese ions and removing hydrofluoric acid are improved, the density/type of the active groups is further improved, the service life and high-temperature performance of the lithium ion battery are greatly improved, and the inorganic particles are more uniformly dispersed.
In order to achieve the aim of the invention, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a composite membrane comprising a base membrane and a functional coating disposed on at least one side of the base membrane;
the functional coating comprises modified inorganic particles, wherein the modified inorganic particles are obtained by two modifications: carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups; performing secondary modification on the inorganic particles containing phenolic hydroxyl groups and/or quinone groups by using a first compound and/or a second compound to obtain modified inorganic particles; wherein the reactive group in the first compound comprises a carboxyl group and an amino group; the reactive group in the second compound comprises at least two amino groups; or alternatively
The composite membrane comprises a modified base membrane, wherein the modified base membrane is obtained by two modifications: the base film is subjected to primary modification to obtain a base film containing phenolic hydroxyl groups and/or quinone groups; performing secondary modification on the base film containing phenolic hydroxyl groups and/or quinone groups by using a first compound and/or a second compound to obtain a modified base film; wherein the reactive group in the first compound comprises a carboxyl group and an amino group; the reactive group in the second compound comprises at least two amino groups.
Preferably, the structural formula of the first compound is shown as formula I:
i
Wherein each R 1 Identical or different, independently of one another, from H, halogen, CN, NO 2 NO, OH, SH, COOH, unsubstituted or substituted by one, two or more R a1 Substituted with the following groups: c (C) 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1- 4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
A 1 Selected from unsubstituted or substituted by one, two or more R b1 Substituted C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl; or A 1 Selected from unsubstituted or optionally substituted by one, two or more R c1 Substituted O, C (O), C (O) O, S, S (O) 2 、N、C 1-6 Alkylene, ch= N, N = N, CH =n-n=ch, ch=ch-CO-CH 2 -CO-CH=CH。
m is an integer of 0 to 12.
Each R a1 、R b1 、R c1 Identical or different, independently of one another, from H, halogen, CN, OH, SH, =o, =nh, NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
Each R is 1-2 、R 1-3 、R 1-4 、R 1-5 、R 1-6 、R 1-7 、R 1-8 、R 1-9 、R 1-10 、R 1-11 The same or different, independently of one another, from H, halogen, NH 2 、CN、OH、SH、=O、NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl.
Preferably, the first compound comprises any one or a combination of at least two of amino acids, L-glutamine or aminobenzoic acid.
Preferably, the structural formula of the second compound is shown as formula II:
II type
Wherein each R 2 Identical or different, independently of one another, from H, halogen, CN, NO 2 NO, OH, SH, COOH, unsubstituted or substituted by one, two or more R a1 Substituted with the following groups: c (C) 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1- 4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
A 2 Selected from unsubstituted or substituted by one, two or more R b1 Substituted C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl; or A 2 Selected from unsubstituted or optionally substituted by one, two or more R c1 Substituted O, C (O), C (O) O, S, S (O) 2 、N、C 1-6 Alkylene, ch= N, N = N, CH =n-n=ch, ch=ch-CO-CH 2 -CO-CH=CH。
p is an integer of 0 to 12.
Each R a1 、R b1 、R c1 Identical or different, independently of one another, from H, halogen, CN, OH, SH, =o, =nh, NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
Each R is 1-2 、R 1-3 、R 1-4 、R 1-5 、R 1-6 、R 1-7 、R 1-8 、R 1-9 、R 1-10 、R 1-11 The same or different, independently of one another, from H, halogen, NH 2 、CN、OH、SH、=O、NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl.
Preferably, the second compound comprises any one or a combination of at least two of phenylenediamine, para-toluenediamine, diaminophenol, diamine, polyethyleneimine, polyethylenepolyamine, benzidine, guanidine, or melamine.
Preferably, the thickness of the base film or the modified base film is 5-200 μm.
Preferably, the thickness of the functional coating is 2 nm-10 mu m.
In a second aspect, the present invention provides a method of preparing a composite separator according to the first aspect, the method comprising the steps of:
(A1) Carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups;
(A2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(A3) Placing the inorganic particles containing phenolic hydroxyl groups and/or quinone groups into the second modification solution, reacting, and separating to obtain modified inorganic particles;
(A4) Coating the modified inorganic particles on at least one side of a base film to obtain the composite membrane; or,
(B1) Carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups;
(B2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(B3) Coating the inorganic particles containing phenolic hydroxyl groups and/or quinone groups on at least one side of a base film to obtain a coated membrane;
(B4) Placing the coated diaphragm in the second modification solution, and separating to obtain the composite diaphragm through reaction; or,
(C1) Carrying out primary modification on the base film to obtain a base film containing phenolic hydroxyl groups and/or quinone groups;
(C2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(C3) And placing the base film containing the phenolic hydroxyl group and/or the quinone group in the second modification solution, and separating to obtain the composite membrane through reaction.
Preferably, the mass concentration of the first compound in the second modification solution is 0.002-100 g/L, and/or the mass concentration of the second compound in the second modification solution is 0.002-380 g/L.
Preferably, the temperature of the reaction is 4-90 ℃, preferably 10-60 ℃.
Preferably, the reaction time is 0.01-72 h, preferably 0.5-48 h.
Preferably, the separation comprises washing with ethanol and/or distilled water at least three times.
In a third aspect, the present invention provides a secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and a separator, the separator being the composite separator according to the first aspect.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a composite membrane, which comprises a base membrane and a functional coating with modified inorganic particles, or comprises a modified base membrane, wherein the modified inorganic particles or the modified base membrane are obtained by two modifications: after primary modification, inorganic particles or base films containing phenolic hydroxyl groups and/or quinone groups are obtained, and after secondary modification by using the first compound and/or the second compound, the modified inorganic particles or the modified base films contain amino groups, imino groups, carboxyl lithium and other active groups, so that the active groups not only enhance the capability of complexing manganese ions (such as amino groups, imino groups and carboxyl groups), but also enhance the effect of removing hydrofluoric acid (such as amino groups, imino groups and carboxyl lithium), thereby improving the service life and high-temperature performance of the lithium ion battery.
Detailed Description
The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.
On one hand, in order to solve the technical problems of damage to SEI film caused by manganese deposited on a negative electrode and higher hydrofluoric acid content in a battery system, and on the other hand, in order to solve the technical problems of lower active group density caused by adding a strong oxidant in the preparation process of a modified coating disclosed in the prior art, the invention provides a composite diaphragm which has higher active group density and the prepared secondary battery has good electrochemical performance.
In a first aspect, the present invention provides a composite membrane, in some embodiments, comprising a base membrane and a functional coating disposed on at least one side of the base membrane; the functional coating comprises modified inorganic particles, wherein the modified inorganic particles are obtained by two modifications: carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups; carrying out secondary modification on inorganic particles containing phenolic hydroxyl groups and/or quinone groups by using a first compound and/or a second compound to obtain modified inorganic particles; wherein the reactive groups in the first compound include carboxyl and amino groups; the reactive group in the second compound comprises at least two amino groups.
In other embodiments, the composite separator comprises a modified base film that is modified twice to obtain: the base film is subjected to primary modification to obtain a base film containing phenolic hydroxyl groups and/or quinone groups; performing secondary modification on the base film containing phenolic hydroxyl and/or quinone groups by using a first compound and/or a second compound to obtain a modified base film; wherein the reactive groups in the first compound include carboxyl and amino groups; the reactive group in the second compound comprises at least two amino groups.
In the present invention, the inorganic particles or the base film may be secondarily modified with the first compound alone or with the second compound alone, or the inorganic particles or the base film may be secondarily modified with the first compound and the second compound at the same time.
In the present invention, the composite separator includes a base film and a functional coating layer having modified inorganic particles, or the composite separator includes a modified base film, wherein the modified inorganic particles or the modified base film are each obtained by two modifications: after primary modification, inorganic particles or base films containing phenolic hydroxyl groups and/or quinone groups are obtained, and after secondary modification by using the first compound and/or the second compound, the modified inorganic particles or the modified base films contain amino groups, imino groups, carboxyl lithium and other active groups, so that the active groups not only enhance the capability of complexing manganese ions (such as amino groups, imino groups and carboxyl groups), but also enhance the effect of removing hydrofluoric acid (such as amino groups, imino groups and carboxyl lithium), thereby improving the service life and high-temperature performance of the lithium ion battery.
In the present invention, the above inorganic particles include, but are not limited to, al 2 O 3 、SiO 2 、ZrO 2 、TiO 2 、BaSO 4 、BaTiO 3 、Li 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 、Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 、LiHAl(PO 4 )O 0.96 F 0.08 、Li 3x La 2/3-x TiO 3 、Li 10 GeP 2 S 12 、Li 7 P 3 S 11 、Li 7 La 3 Zr 2 O 12 Or Li (lithium) 6.5 La 3 Zr 1.5 Ta 0.5 O 12 At least one of, for example, including but not limited to Al 2 O 3 And SiO 2 In combination with ZrO 2 、TiO 2 And BaSO 4 BaTiO, combinations of (a) and BaTiO 3 And Li (lithium) 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 Combinations of (a) and the like. Wherein Li is 3x La 2/3-x TiO 3 Where 0 < x < 0.16, x may be, for example, 0.01, 0.05, 0.1, 0.12, 0.14, or 0.15, etc.
In some embodiments, the first compound has the structural formula of formula i:
i
Wherein each R 1 Identical or different, independently of one another, from H, halogen, CN, NO 2 NO, OH, SH, COOH, unsubstituted or substituted by one, two or more R a1 Substituted with the following groups: c (C) 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1- 4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
A 1 Selected from unsubstituted or substituted by one, two or more R b1 Substituted C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl; or A 1 Selected from unsubstituted or optionally substituted by one, two or more R c1 Substituted O, C (O), C (O) O, S, S (O) 2 、N、C 1-6 Alkylene, ch= N, N = N, CH =n-n=ch, ch=ch-CO-CH 2 -CO-CH=CH。
m is an integer of 0 to 12, and may be, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or the like.
Each R a1 、R b1 、R c1 Identical or different, independently of one another, from H, halogen, CN, OH, SH, =o, =nh, NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
Each R is 1-2 、R 1-3 、R 1-4 、R 1-5 、R 1-6 、R 1-7 、R 1-8 、R 1-9 、R 1-10 、R 1-11 The same or different, independently of one another, from H, halogen, NH 2 CN, OH, SH, oxo (=o), NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl.
In some embodiments, the first compound includes, but is not limited to, any one or a combination of at least two of glycylglutamine, alanylglutamine, 2, 6-diaminopimelic acid, L-2, 4-diaminobutyric acid, amino acids, L-glutamine, or aminobenzoic acid.
Further, the first compound includes any one or a combination of at least two of amino acids, L-glutamine or aminobenzoic acid, including, for example, but not limited to, a combination of amino acids and L-glutamine, a combination of L-glutamine and aminobenzoic acid, a combination of amino acids, L-glutamine and aminobenzoic acid, and the like.
In some embodiments, the second compound has the structural formula of formula ii:
II type
Wherein each R 2 Identical or different, independently of one another, from H, halogen, CN, NO 2 、NO、OH、SH、COOH、Unsubstituted or substituted by one, two or more R a1 Substituted with the following groups: c (C) 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1- 4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
A 2 Selected from unsubstituted or substituted by one, two or more R b1 Substituted C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl; or A 2 Selected from unsubstituted or optionally substituted by one, two or more R c1 Substituted O, C (O), C (O) O, S, S (O) 2 、N、C 1-6 Alkylene, ch= N, N = N, CH =n-n=ch, ch=ch-CO-CH 2 -CO-CH=CH。
p is an integer of 0 to 12, and may be, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or the like.
Each R a1 、R b1 、R c1 Identical or different, independently of one another, from H, halogen, CN, OH, SH, =o, =nh, NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 。
Each R is 1-2 、R 1-3 、R 1-4 、R 1-5 、R 1-6 、R 1-7 、R 1-8 、R 1-9 、R 1-10 、R 1-11 The same or different, independently of one another, from H, halogen, NH 2 CN, OH, SH, oxo (=o), NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl.
In some embodiments of the present invention, in some embodiments, the second compound includes, but is not limited to, phenylenediamine and salts thereof, p-toluenediamine, 2, 3-dimethyl-p-phenylenediamine, 2, 6-dimethyl-p-phenylenediamine, 2, 3-diethyl-p-phenylenediamine, 2, 5-dimethyl-p-phenylenediamine, 2-hydroxyethyl-p-phenylenediamine sulfate, 2-fluoro-p-phenylenediamine, 2-isopropyl-p-phenylenediamine, 2-hydroxymethyl-p-phenylenediamine, 2-hydroxyethoxy-p-phenylenediamine, 2-acetamidoethoxy-p-phenylenediamine, N- (4-aminobenzyl) biguanide, 2-nitro-1, 4-phenylenediamine, 2-chloro-1, 4-phenylenediamine, 2, 5-dichloro-1, 4-phenylenediamine, 2, 5-toluenediamine sulfate 4-chloro-1, 2-phenylenediamine, amiloride hydrochloride, 4, 5-dichloro-1, 2-phenylenediamine, 3, 4-diaminotoluene, 3-nitro-1, 2-phenylenediamine, 4-nitro-1, 2-phenylenediamine, 3, 4-diaminobenzoic acid, 4-chloro-1, 3-phenylenediamine, 2, 6-diaminotoluene, 2, 4-diaminoanisole and salts thereof, 3, 5-diaminobenzoic acid and salts thereof, diaminophenol, 2, 4-diaminobenzenesulfonic acid, 2, 3-diaminopyridine, 2,4, 6-triaminopyrimidine, 2, 4-diamino-6-methyl-1, 3, 5-triazine, melamine, 6-phenyl-1, 3, 5-triazine-2, 4-diamine, veratrine, 2,4, 5-triamino-6-hydroxypyrimidine sulfate, trimethoprim, phenazopyridine hydrochloride, pyrimethamine, isofradine maleate, trimethoprim, 4-amino-6-chlorobenzene-1, 3-disulfonamide, m-aminophenylsemicarbazide, 3, 4-diaminobenzophenone, basic orange 2, o-tolidine and salts thereof, 4' -diaminobiphenyl and salts thereof, benzidine, bis (4-amino-3-chlorophenyl) methane, 4' -diaminodiphenylmethane, 4' -diaminodiphenyl ether, 4' -diaminodiphenyl sulfide, and salts thereof 4,4' -diaminobenzophenone, 4' -diaminodibenzyl, 4' -diaminodiphenyl sulfone, 4' -diaminodiphenylamine and salts thereof, 3' -dimethyl-4, 4' -diaminodiphenyl methane, 4,5' -diaminodiphenyl sulfide, 1, 4-diaminobutane diamines, polyethylene polyamines, spermidines, homospermidines, aminopropylamines, norspermines, spermines, thermophilic pentylamines, thermophilic homopentylamines, thermophilic hexylamines, thermophilic homohexylamines, 3' -iminodipropylamine, N, N ' -bis (3-aminopropyl) -1, 3-propanediamine, urea, thiosemicarbazide, biuret, thiosemicarbazide, acrylamide methylene urea, guanidine, biguanidine nitrate, glycylglutamine, alanylglutamine, glutamine, N- (2-guanethyl) guanidine, 2, 6-diaminopimelic acid, 2, 4-diaminobutyric acid dihydrochloride, tranin, 2, 3-diaminopropionic acid, aminoguanidine sulfonate, oxalylaminoguanidine, any one or a combination of at least two of triamino guanidine hydrochloride, aminoguanidine, agmatine, polyvinylamine, polyethyleneimine, 1, 2-diaminoanthraquinone, 1, 5-diaminoanthraquinone, 1, 4-diaminoanthraquinone, 4' -diaminodicyclohexylmethane, 1, 2-diaminocyclohexane, streptavidin, 2, 3-diaminonaphthalene, 1, 8-diaminonaphthalene, 1, 5-diaminonaphthalene, triamterene, methotrexate or dihydrazine sulfate.
Further, the second compound includes any one or a combination of at least two of phenylenediamine, paratoluenediamine, diaminophenol, diamine, polyethyleneimine, polyethylenepolyamine, benzidine, guanidine, or melamine, including, for example, but not limited to, a combination of diamine and polyethylenepolyamine, a combination of polyethyleneamine and polyethyleneimine, or a combination of diamine, polyethylenepolyamine, polyethyleneamine, and polyethyleneimine, etc.
In the present invention, the diamine includes any one or a combination of at least two of ethylenediamine, butanediamine, hexamethylenediamine, phenylenediamine and lysine, for example, including but not limited to a combination of ethylenediamine and butanediamine, a combination of hexamethylenediamine, phenylenediamine and lysine, or a combination of ethylenediamine, butanediamine, hexamethylenediamine, phenylenediamine and lysine, etc.
In the present invention, the polyethylene polyamine is any one or a combination of at least two of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine, and for example, includes, but is not limited to, a combination of diethylenetriamine and triethylenetetramine, a combination of tetraethylenepentamine and pentaethylenehexamine, or a combination of triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine, etc.
In some embodiments, the thickness of the base film or modified base film is 5 to 200 μm, for example, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, etc. may be used.
In the present invention, the base film may include one of a single-layer polyolefin microporous film, a multi-layer polyolefin microporous film, a single-component nonwoven film, or a multi-component nonwoven film, including, for example, but not limited to, a combination of a single-component nonwoven film and a single-component nonwoven film, a combination of a single-component nonwoven film and a multi-component nonwoven film, or the like.
In the invention, the polyolefin microporous membrane material comprises polyethylene or polypropylene; the non-woven fabric membrane material component comprises one or more of cellulose, polyacrylonitrile, polyvinylidene fluoride, polyamide, phenolic resin, polyethylene oxide or polyvinyl alcohol, and comprises, for example, but not limited to, a combination of cellulose and polyacrylonitrile, a combination of polyethylene oxide and polyvinyl alcohol, a combination of polyamide, phenolic resin and polyethylene oxide, or a combination of cellulose, polyamide, phenolic resin and polyethylene oxide.
In some embodiments, the functional coating has a thickness of 2nm to 10 μm, for example, 2nm, 5nm, 8nm, 10nm, 50nm, 80nm, 100nm, 300nm, 500nm, 800nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc.
The thickness of the functional coating refers to the total thickness of the inorganic particle coating in the membrane, and if the functional coating is arranged on one side of the base membrane, the total thickness of one side of the functional coating is the total thickness of one side of the functional coating; if the functional coating is arranged on two sides of the base film, the total thickness of the two sides of the functional coating is the total thickness of the two sides of the functional coating.
In a second aspect, the present invention provides a method of preparing a composite separator according to the first aspect, the method comprising the steps of:
(A1) Carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups;
(A2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(A3) Placing inorganic particles containing phenolic hydroxyl groups and/or quinone groups into a second modification solution, reacting, and separating to obtain modified inorganic particles;
(A4) And coating the modified inorganic particles on at least one side of the base film to obtain the composite diaphragm.
In other embodiments, the present invention provides a method of making a composite separator according to the first aspect, the method comprising the steps of:
(B1) Carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups;
(B2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(B3) Coating inorganic particles containing phenolic hydroxyl groups and/or quinone groups on at least one side of a base film to obtain a coated separator;
(B4) And (3) placing the coated diaphragm in a second modification solution, reacting, and separating to obtain the composite diaphragm.
In other embodiments, the present invention provides a method of making a composite separator according to the first aspect, the method comprising the steps of:
(C1) Carrying out primary modification on the base film to obtain a base film containing phenolic hydroxyl groups and/or quinone groups;
(C2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(C3) And (3) placing the base film containing the phenolic hydroxyl and/or the quinone group in a second modification solution, reacting, and separating to obtain the composite membrane.
In the present invention, the primary modified solution includes a benzenediol compound and a polyamine compound, the benzenediol compound including, but not limited to, at least one of catechol, hydroquinone, resorcinol, and derivatives thereof; the polyamine-based compound includes, but is not limited to, at least one of diamine, polyethylene polyamine, polyethylene amine, or polyethylene imine.
According to the invention, the benzenediol compound and the polyamine compound are mixed for polymerization reaction, and inorganic particles or base films are modified/coated through the reaction between phenolic hydroxyl groups and amino groups, so that modified inorganic particles or modified base films with phenolic hydroxyl groups, quinolyl groups, amino groups, imino groups and the like are obtained. The content of phenolic hydroxyl groups and quinone groups can be increased by adjusting the types and the addition ratio of the benzenediol compound and the polyamine compound. The above preparation method is known to those skilled in the art from the prior art, and is exemplified as paragraphs [0019] - [0021] of the inventor's prior application CN 202211722850.3. However, the modified inorganic particles or the modified base film after the primary modification not only have phenolic hydroxyl groups/quinoyl groups but also can have amino groups, but because of the use of a strong oxidant, the density of active groups is lower and the capability of complexing manganese ions is poor
In some embodiments, the mass concentration of the first compound in the second modification solution is 0.002-100 g/L, for example, 0.002g/L, 0.005g/L, 0.008g/L, 0.01g/L, 0.02g/L, 0.05g/L, 0.08g/L, 0.1g/L, 0.2g/L, 0.5g/L, 0.8g/L, 1g/L, 2g/L, 5g/L, 8g/L, 10g/L, 20g/L, 30g/L, 40g/L, 50g/L, 60g/L, 70g/L, 80g/L, 90g/L, 100g/L, etc. Further, the mass concentration of the first compound in the second modification solution is preferably 0.1-20 g/L.
In the invention, the mass concentration of the first compound is adjusted to realize high-efficiency grafting of the first compound, and when the concentration is too low, the grafting density of active groups is reduced, otherwise, the grafting efficiency of the first compound is reduced.
In some embodiments, the mass concentration of the second compound in the second modification solution is 0.002-380 g/L, for example, 0.002g/L, 0.005g/L, 0.008g/L, 0.01g/L, 0.02g/L, 0.05g/L, 0.08g/L, 0.1g/L, 0.2g/L, 0.5g/L, 0.8g/L, 1g/L, 2g/L, 5g/L, 8g/L, 10g/L, 20g/L, 30g/L, 40g/L, 50g/L, 60g/L, 70g/L, 80g/L, 90g/L, 100g/L, 120g/L, 150g/L, 180g/L, 200g/L, 220g/L, 250g/L, 280g/L, 300g/L, 320g/L, 350g/L, 380g/L, etc. Further, the mass concentration of the second compound in the second modification solution is preferably 0.1 to 20g/L.
In the invention, the mass concentration of the second compound is adjusted to realize high-efficiency grafting of the second compound, and when the concentration is too low, the grafting density of active groups is reduced, otherwise, the grafting efficiency of the second compound is reduced.
In some embodiments, the second modification solution includes an oxidizing agent, which may be, for example, cuSO 4 、H 2 O 2 Or at least one of persulfates.
In the present invention, the addition of the oxidizing agent can further improve the grafting efficiency of the first compound and/or the second compound.
In some embodiments, the molar concentration of the oxidizing agent in the second modification solution is 0.0005mol/L to 40mol/L, and may be, for example, 0.0005mol/L, 0.0008mol/L, 0.001mol/L, 0.005mol/L, 0.01mol/L, 0.05mol/L, 0.1mol/L, 0.5mol/L, 1mol/L, 5mol/L, 10mol/L, 15mol/L, 20mol/L, 25mol/L, 30mol/L, 35mol/L, 40mol/L, or the like. Further, the molar concentration of the oxidant in the second modification solution is 0.005mol/L to 20mol/L.
In some embodiments, the second modification solution includes an alkaline substance therein, which may be, for example, at least one of LiOH, naOH, or KOH.
In the present invention, the addition of an alkaline substance facilitates the reaction.
In some embodiments, the pH ranges from 7.5 to 13, for example, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, etc. Too low a pH can result in failure to graft or poor grafting efficiency; too high a pH, dissolution of the functional coating may occur.
In some embodiments, the reaction temperature is 4 to 90 ℃, for example, 4 ℃, 8 ℃, 10 ℃, 12 ℃, 15 ℃, 20 ℃, 40 ℃, 60 ℃, 80 ℃, 90 ℃, and the like can be used. Further, the reaction temperature is 10-60 ℃.
In some embodiments, the reaction time is 0.01-72 h, for example, 0.01h, 0.05h, 0.1h, 0.5h, 1h, 5h, 10h, 20h, 30h, 40h, 48h, 50h, 60h, 70h, 72h, etc. Further, the reaction time is 0.5-48 h.
In some embodiments, the separating comprises washing at least three times with ethanol and/or distilled water.
In a third aspect, the present invention provides a secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and a separator, the separator being a composite separator according to the first aspect.
The battery prepared by the diaphragm has smaller capacity attenuation, higher cycle performance and longer service life.
Example 1
The embodiment provides a composite membrane, which comprises a polyethylene-based membrane and functional coatings arranged on two sides of the polyethylene-based membrane.
The embodiment also provides a preparation method of the composite diaphragm, which comprises the following steps:
2g of pyrogallol and 2g of 1, 6-hexamethylenediamine are dissolved in 1L of Tris-hydrochloric acid buffer solution (pH 8.5, 50 mmol/L), and CuSO is added 4 (5 mmol/L) and H 2 O 2 (20 mol/L), mixing, adding 10g Al 2 O 3 Stirring at 30deg.C and 1500rpm for 0.5 hr, centrifuging at 6000 Xg for 10min, and cleaning with ethanol and distilled water respectively for three times to obtain primary modified Al 2 O 3 Particles;
2g of lysine and 2g of polyethyleneimine are dissolved in 1L of distilled water, the pH is 11.5, and 10g of Al after one-time modification is added 2 O 3 The particles are stirred at a high speed of 1500rpm for 0.5h at 40 ℃, centrifuged for 10min at 6000 Xg, and washed with distilled water for three times to obtain the secondarily modified Al 2 O 3 And (3) particles. Secondarily modified Al 2 O 3 The particles were coated on the surface of a polyethylene-based film, and dried (thickness: 13 μm, base film thickness: 9 μm, double-sided coating) to obtain a composite separator.
Example 2
The embodiment provides a composite membrane, which comprises a polyethylene-based membrane and functional coatings arranged on two sides of the polyethylene-based membrane.
The embodiment also provides a preparation method of the composite diaphragm, which comprises the following steps:
2g of pyrogallol and 2g of 1, 6-hexamethylenediamine are dissolved in 1L of Tris-hydrochloric acid buffer solution (pH 8.5, 50 mmol/L), and CuSO is added 4 (5 mmol/L) and H 2 O 2 (20 mol/L), mixing, adding 10g Al 2 O 3 Stirring at 30deg.C and 1500rpm for 0.5 hr, centrifuging at 6000 Xg for 10min, and cleaning with ethanol and distilled water respectively for three times to obtain primary modified Al 2 O 3 Particles;
dissolving 20g of arginine and 0.1g of p-phenylenediamine in 1L of distilled water, regulating the pH to 12 by using 0.5mol/L KOH, adding ammonium persulfate (50 mmol/L), uniformly mixing, and adding 10g of Al after primary modification 2 O 3 The particles are stirred at a high speed of 1500rpm for 1h at 30 ℃, centrifuged for 10min at 6000 Xg, and washed with distilled water for three times to obtain the secondarily modified Al 2 O 3 And (3) particles. Secondarily modified Al 2 O 3 The particles were coated on the surface of a polyethylene-based film, and dried (thickness: 11 μm, base film thickness: 9 μm, double-sided coating) to obtain a composite separator.
Example 3
The embodiment provides a composite membrane, which comprises a polyethylene-based membrane and functional coatings arranged on two sides of the polyethylene-based membrane.
The embodiment also provides a preparation method of the composite diaphragm, which comprises the following steps:
2g of pyrogallol and 2g of 1, 6-hexamethylenediamine are dissolved in 1L of Tris-hydrochloric acid buffer solution (pH 8.5, 50 mmol/L), and CuSO is added 4 (5 mmol/L) and H 2 O 2 (20 mol/L), uniformly mixing, immersing a polyethylene diaphragm (thickness: 9 mu m) in the solution, stirring at 30 ℃ and 50rpm for 0.5h, taking out the diaphragm, respectively flushing with ethanol and distilled water for three times, and airing to obtain a polyethylene diaphragm after primary modification;
0.1g of 3, 4-diaminobenzoic acid was dissolved in 1L of distilled water, the pH was adjusted to 13 with 0.5mol/L LiOH, the once-modified polyethylene-based film (thickness: 9 μm) was immersed in the above solution, magnetically stirred at 60 ℃ and 50rpm for 2 hours, the film was taken out, washed three times with ethanol and distilled water, respectively, and dried to obtain a composite film (thickness: 9 μm).
Example 4
The embodiment provides a composite membrane, which comprises a polyethylene-based membrane and functional coatings arranged on two sides of the polyethylene-based membrane.
The embodiment also provides a preparation method of the composite diaphragm, which comprises the following steps:
2g of pyrogallol and 2g of 1, 6-hexamethylenediamine are dissolved in 1L of Tris-hydrochloric acid buffer solution (pH 8.5, 50 mmol/L), and CuSO is added 4 (5 mmol/L) and H 2 O 2 (20 mol/L), mixing, adding 10g Al 2 O 3 Stirring at 30deg.C and 1500rpm for 0.5 hr, centrifuging at 6000 Xg for 10min, and cleaning with ethanol and distilled water respectively for three times to obtain primary modified Al 2 O 3 And (3) particles. Al after primary modification 2 O 3 Coating the particles on the surface of a polyethylene film, and drying (thickness: 13 μm, base film thickness: 9 μm, double-sided coating) to obtain primary modified Al 2 O 3 A separator (coated separator);
20g of diethylenetriamine was dissolved in 1L of distilled water, and CuSO was added 4 (5 mmol/L) and H 2 O 2 (20 mol/L), mixing, and adding modified Al 2 O 3 The membrane (thickness: 13 μm, base film thickness: 9 μm, double-sided coating) was immersed in the above solution, magnetically stirred at 10℃and 50rpm for 48 hours, the membrane was taken out, washed three times with ethanol and distilled water, and dried to obtain a composite membrane (thickness: 13 μm; double-sided coating).
Example 5
This example differs from example 1 in that lysine was replaced with L-glutamine, and the other is the same as in example 1.
Example 6
This example differs from example 1 in that the polyethyleneimine is replaced by p-phenylenediamine, all of which are identical to example 1.
Example 7
This example differs from example 1 in that the concentration of lysine in the functional coating solution was 110g/L by mass, and the other was the same as in example 1.
Example 8
This example differs from example 1 in that the mass concentration of polyethylenimine in the functional coating solution is 400g/L, all other things being equal to example 1.
Example 9
This example differs from example 2 in that ammonium persulfate is not added, and the other is the same as example 2.
Comparative example 1
This comparative example provides a polyethylene separator (thickness: 9 μm).
Comparative example 2
This comparative example provides an Al 2 O 3 Separator (thickness: 13 μm, polyethylene-based film thickness: 9 μm, double-sided coating), al 2 O 3 Is not modified.
Comparative example 3
This comparative example provides an Al 2 O 3 Diaphragm (thickness: 13 μm, base film thickness: 9 μm, double-sided coating), al 2 O 3 Only one modification was performed, and the one modification method was the same as in example 1.
Comparative example 4
This comparative example differs from example 1 in that Al after one modification is 2 O 3 The particles are replaced by equal mass of Al which is not subjected to primary modification 2 O 3 The pellets were the same as in example 1.
Examples 1 to 9 and comparative examples 1 to 4
The composite separators provided in examples 1 to 9 and comparative examples 1 to 4 were prepared to obtain lithium ion batteries, and the preparation method was as follows:
preparation of a positive plate: the positive electrode active material LiMn with the mass ratio of 85:10:5 is prepared 2 O 4 Mixing conductive carbon black and PVDF to prepare positive electrode slurry, coating the positive electrode slurry on the surface of an aluminum current collector, and drying to obtain a positive electrodeA pole piece;
preparing a negative plate: mixing graphite, conductive carbon black and polyvinylidene fluoride in a mass ratio of 90:3:7 to prepare negative electrode slurry, coating the negative electrode slurry on the surface of a copper current collector, and drying to obtain a negative electrode plate;
Preparation of electrolyte: dissolving the dried lithium hexafluorophosphate in a mixed solvent (ethylene carbonate/dimethyl carbonate) with the volume ratio of 1:1, wherein the concentration of the lithium hexafluorophosphate is 1mol/L;
preparation of a lithium ion battery: and assembling the positive plate, the negative plate and the composite diaphragm to obtain the lithium ion battery.
Test conditions and results
(1) The ceramic particles prepared in example 1 and comparative example 3 were immersed in Mn dissolved in each of them 2+ And Mn of 3+ In the above electrolyte, after 24 hours of reaction, mn in the electrolyte was measured 2+ And Mn of 3+ Concentration.
The test results are shown in table 1:
TABLE 1
As can be seen from Table 1, the ceramic particles were subjected to secondary modification (example 1), and Mn in the electrolyte was higher than that in the case of the primary modification alone (comparative example 3) 2+ And Mn of 3+ The concentration is obviously reduced, and the capability of capturing manganese ions is obviously improved.
(2) The lithium ion batteries provided in examples 1 to 9 and comparative examples 1 to 4 were tested as follows:
battery state of life (SOH) test: the test was performed after 100 cycles at 25℃with a magnification of 0.2C.
The test results are shown in table 2:
TABLE 2
As can be seen from Table 2, the composite separator of the present invention has a functional coating comprising a compound having a specific active group such as amino group, imino group, carboxyl group, etc. The diaphragm has the advantages of improving the effects of capturing manganese ions and removing hydrofluoric acid, further improving the types and density of active groups and prolonging the service life of the lithium ion battery.
As is clear from application example 1 (or application example 2) and comparative application example 3, application example 1 (or application example 2) has a higher SOH value because the species and density of the active groups can be further improved and the cycle performance of the battery can be improved by grafting a compound having a specific active group such as an amino group, a carboxyl group, or the like.
As is clear from the comparison between application example 1 and application examples 3 and 4, the SOH value of application example 1 is significantly higher than application example 3 because the surface of the ceramic particle is secondarily modified due to the large specific surface area and the density of the graft active groups, compared with the surface modification directly on the base film or the ceramic separator.
As can be seen from comparative application example 3 and comparative application example 1, the secondary modification of the base film makes the surface of the base film have active groups, which can significantly improve the cycle performance of the separator.
As can be seen from the comparison of the application example 1 and the comparison of the application example 2, the SOH value of the application example 1 is significantly higher than that of the comparison of the application example 2, and the application example 1 has better cycle performance because the surface of the diaphragm is provided with active groups such as amino, imino, carboxyl and the like by carrying out secondary modification on the inorganic particles, so that manganese ions can be captured and hydrofluoric acid can be eliminated.
As can be seen from comparison of application example 1 and comparative application example 4, the SOH value of application example 1 is significantly higher than that of comparative application example 4, since if Al 2 O 3 The surface of the modified material does not contain active groups such as phenolic hydroxyl groups and/or quinone groups, and therefore the first compound and/or the second compound cannot be grafted, and therefore capture of manganese ions cannot be achieved, so that the SOH value of comparative application example 4 is significantly lower than that of application example 1, and is equivalent to that of comparative application example 2.
As can be seen from the comparison between application examples 2 and 9, the addition of the oxidizing agent in the present invention can further enhance the modificationPost polyethylene separator or modified Al 2 O 3 The content of quinone groups on the surface of the particles further improves the grafting efficiency of the first compound and/or the second compound. In application example 9, the oxidizing agent was not added, but the pH was adjusted to 12 to promote the reaction, but the effect was limited, so that the SOH value of application example 2 was higher and the life was longer than in application example 9.
The applicant states that the process of the invention is illustrated by the above examples, but the invention is not limited to, i.e. does not mean that the invention must be carried out in dependence on the above process steps. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of selected raw materials, addition of auxiliary components, selection of specific modes, etc. fall within the scope of the present invention and the scope of disclosure.

Claims (9)

1. A method of making a composite separator, the composite separator comprising a base film, the method comprising the steps of:
(A1) Carrying out primary modification on the inorganic particles, wherein the primary modification solution comprises a benzenediol compound and a polyamine compound to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups;
(A2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(A3) Placing the inorganic particles containing phenolic hydroxyl groups and/or quinone groups into the second modification solution, reacting, and separating to obtain modified inorganic particles;
(A4) Coating the modified inorganic particles on at least one side of a base film to obtain the composite membrane; or,
(B1) Carrying out primary modification on the inorganic particles, wherein the primary modification solution comprises a benzenediol compound and a polyamine compound to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups;
(B2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(B3) Coating the inorganic particles containing phenolic hydroxyl groups and/or quinone groups on at least one side of a base film to obtain a coated membrane;
(B4) Placing the coated diaphragm in the second modification solution, and separating to obtain the composite diaphragm through reaction; or,
(C1) Performing primary modification on the base film, wherein the primary modified solution comprises a benzenediol compound and a polyamine compound to obtain a base film containing phenolic hydroxyl and/or quinolyl;
(C2) Mixing the first compound and/or the second compound with a solvent, and adjusting the pH to be alkaline to obtain a second modification solution;
(C3) Placing the base film containing phenolic hydroxyl and/or quinone in the second modification solution, and separating to obtain the composite membrane through reaction;
wherein the reactive group in the first compound comprises a carboxyl group and an amino group; the reactive group in the second compound comprises at least two amino groups;
the mass concentration of the first compound in the second modification solution is 0.002-100 g/L, and/or the mass concentration of the second compound in the second modification solution is 0.002-380 g/L.
2. The method according to claim 1, wherein the reaction temperature is 4-90 ℃ and the reaction time is 0.01-72 h.
3. A composite separator prepared by the method for preparing a composite separator according to claim 1, wherein,
The composite membrane comprises a base membrane and a functional coating arranged on at least one side of the base membrane;
the functional coating comprises modified inorganic particles, wherein the modified inorganic particles are obtained by two modifications: carrying out primary modification on the inorganic particles to obtain inorganic particles containing phenolic hydroxyl groups and/or quinone groups; performing secondary modification on the inorganic particles containing phenolic hydroxyl groups and/or quinone groups by using a first compound and/or a second compound to obtain modified inorganic particles; wherein the reactive group in the first compound comprises a carboxyl group and an amino group; the reactive group in the second compound comprises at least two amino groups; or alternatively
The composite membrane comprises a modified base membrane, wherein the modified base membrane is obtained by two modifications: the base film is subjected to primary modification to obtain a base film containing phenolic hydroxyl groups and/or quinone groups; performing secondary modification on the base film containing phenolic hydroxyl groups and/or quinone groups by using a first compound and/or a second compound to obtain a modified base film; wherein the reactive group in the first compound comprises a carboxyl group and an amino group; the reactive group in the second compound comprises at least two amino groups.
4. The composite separator of claim 3 wherein the first compound has the structural formula of formula i:
I
Wherein each R 1 Identical or different, independently of one another, from H, halogen, CN, NO 2 NO, OH, SH, COOH, unsubstituted or substituted by one, two or more R a1 Substituted with the following groups: c (C) 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 ；
A 1 Selected from unsubstituted or substituted by one, two or more R b1 Substituted C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 CycloalkynesRadical, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl; m is an integer of 0 to 12;
each R a1 、R b1 The same or different, independently of each other, are selected from halogen, CN, OH, SH, =o, =nh, NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1- 10 R 1-11 ；
Each R is 1-2 、R 1-3 、R 1-4 、R 1-5 、R 1-6 、R 1-7 、R 1-8 、R 1-9 、R 1-10 、R 1-11 The same or different, independently of one another, from halogen, NH 2 、CN、OH、SH、=O、NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl.
5. The composite separator of claim 3 wherein the first compound comprises any one or a combination of at least two of L-glutamine or aminobenzoic acid.
6. The composite separator of claim 3 wherein the second compound has the structural formula of formula ii:
II type
Wherein each R 2 Identical or different, independently of one another, from H, halogen, CN, NO 2 NO, OH, SH, COOH, unsubstituted or substituted by one, two or more R a1 Substituted with the following groups: c (C) 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1-10 R 1-11 ；
A 2 Selected from unsubstituted or substituted by one, two or more R b1 Substituted C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl;
p is an integer of 0 to 12;
each R a1 、R b1 The same or different, independently of each other, are selected from halogen, CN, OH, SH, =o, =nh, NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl, C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl, -OR 1-2 、-SR 1-3 、-NR 1-4 R 1-5 、-C(O)R 1-6 、-OC(O)R 1-7 、-S(O) 2 R 1-8 、-OS(O) 2 R 1-9 、-P(O)R 1- 10 R 1-11 ；
Each R is 1-2 、R 1-3 、R 1-4 、R 1-5 、R 1-6 、R 1-7 、R 1-8 、R 1-9 、R 1-10 、R 1-11 The same or different, independently of one another, from halogen, NH 2 、CN、OH、SH、=O、NO 2 、COOH、C 1-40 Alkyl, C 2-40 Alkenyl, C 2-40 Alkynyl, C 3-40 Cycloalkyl, C 3-40 Cycloalkenyl group,C 3-40 Cycloalkynyl radicals, C 6-20 Aryl, 5-20 membered heteroaryl, 3-20 membered heterocyclyl.
7. The composite separator of claim 3 wherein the second compound comprises any one or a combination of at least two of phenylenediamine, para-toluenediamine, diaminophenol, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, benzidine, guanidine, or melamine.
8. The composite membrane of claim 3, wherein the base film or modified base film has a thickness of 5 μιη to 200 μιη;
the thickness of the functional coating is 2 nm-10 mu m.
9. A secondary battery, characterized in that the secondary battery comprises a positive electrode, a negative electrode, an electrolyte, and a separator, which is the composite separator according to any one of claims 3 to 8.
CN202311110671.9A 2023-08-31 2023-08-31 Composite diaphragm, preparation method thereof and secondary battery Active CN116826308B (en)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103943805A (en) * 2014-04-22 2014-07-23 宁德新能源科技有限公司 Lithium ion secondary battery and diaphragm thereof
CN106887556A (en) * 2017-03-10 2017-06-23 厦门益舟新能源科技有限公司 A kind of organo-mineral complexing modified diaphragm and its preparation method and application
CN110993859A (en) * 2019-12-25 2020-04-10 武汉中兴创新材料技术有限公司 Polymer coating diaphragm with improved structure and preparation method thereof
CN111969160A (en) * 2020-08-31 2020-11-20 佛山市金辉高科光电材料股份有限公司 Composite lithium ion battery diaphragm and preparation method thereof, lithium ion battery and electronic product
CN115528380A (en) * 2021-06-25 2022-12-27 恒大新能源技术(深圳)有限公司 Battery diaphragm, preparation method thereof and lithium battery
CN115579583A (en) * 2022-09-09 2023-01-06 广汽埃安新能源汽车有限公司 Diaphragm slurry, battery diaphragm, preparation method of battery diaphragm and lithium battery
CN115612403A (en) * 2021-07-14 2023-01-17 中国科学院天津工业生物技术研究所 Self-assembly strong-adhesion copolymer film, film coating method and application
CN116190915A (en) * 2022-12-30 2023-05-30 天津市捷威动力工业有限公司 Diaphragm and preparation method and application thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3110537A1 (en) * 2014-02-24 2017-01-04 Vito NV Method for increasing the fouling resistance of inorganic membranes by grafting with organic moieties

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103943805A (en) * 2014-04-22 2014-07-23 宁德新能源科技有限公司 Lithium ion secondary battery and diaphragm thereof
CN106887556A (en) * 2017-03-10 2017-06-23 厦门益舟新能源科技有限公司 A kind of organo-mineral complexing modified diaphragm and its preparation method and application
CN110993859A (en) * 2019-12-25 2020-04-10 武汉中兴创新材料技术有限公司 Polymer coating diaphragm with improved structure and preparation method thereof
CN111969160A (en) * 2020-08-31 2020-11-20 佛山市金辉高科光电材料股份有限公司 Composite lithium ion battery diaphragm and preparation method thereof, lithium ion battery and electronic product
CN115528380A (en) * 2021-06-25 2022-12-27 恒大新能源技术(深圳)有限公司 Battery diaphragm, preparation method thereof and lithium battery
CN115612403A (en) * 2021-07-14 2023-01-17 中国科学院天津工业生物技术研究所 Self-assembly strong-adhesion copolymer film, film coating method and application
CN115579583A (en) * 2022-09-09 2023-01-06 广汽埃安新能源汽车有限公司 Diaphragm slurry, battery diaphragm, preparation method of battery diaphragm and lithium battery
CN116190915A (en) * 2022-12-30 2023-05-30 天津市捷威动力工业有限公司 Diaphragm and preparation method and application thereof

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