CN114512764A - Nano alumina diaphragm paint and preparation method thereof - Google Patents

Nano alumina diaphragm paint and preparation method thereof Download PDF

Info

Publication number
CN114512764A
CN114512764A CN202210156615.8A CN202210156615A CN114512764A CN 114512764 A CN114512764 A CN 114512764A CN 202210156615 A CN202210156615 A CN 202210156615A CN 114512764 A CN114512764 A CN 114512764A
Authority
CN
China
Prior art keywords
alumina
nano alumina
nano
particles
coating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210156615.8A
Other languages
Chinese (zh)
Inventor
赵丽萍
何金波
彭诚
徐宽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Kaijin New Material Technology Co ltd
Original Assignee
Shanghai Kaijin New Material Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Kaijin New Material Technology Co ltd filed Critical Shanghai Kaijin New Material Technology Co ltd
Priority to CN202210156615.8A priority Critical patent/CN114512764A/en
Publication of CN114512764A publication Critical patent/CN114512764A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • 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
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/417—Polyolefins
    • 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
    • H01M50/434—Ceramics
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Abstract

A nanometer alumina diaphragm coating and its preparation method, wherein, the nanometer alumina diaphragm coating includes nanometer alumina particle, acrylic acid series polymer particle, carboxymethyl cellulose, polyoxyethylene dodecyl ether and pure water, the solid content is 38-42% (mass percent), the viscosity is 100-300 mPa.s, pH value is 8-9, the particle size distribution of the nanometer alumina particle is D50 between 0.4-0.8 μm and D90 is not greater than 2.5 μm; the preparation method comprises the steps of preparing nano alumina slurry and carboxymethyl cellulose slurry, preparing alumina cellulose mixed liquor, alumina cellulose polymer mixed liquor and alumina cellulose polymer alkyl ether mixed liquor, adjusting the pH value and the like. The invention has novel formula, reasonable proportion, better coating construction performance and product stability, unique preparation method, and can ensure the quality of the lithium ion battery diaphragm and improve the comprehensive performance of the lithium ion battery.

Description

Nano alumina diaphragm paint and preparation method thereof
Technical Field
The invention relates to a diaphragm coating coated on the surface of a lithium ion battery diaphragm and a preparation method thereof, in particular to a nano alumina diaphragm coating and a preparation method thereof, belonging to the technical field of production and preparation of lithium ion battery diaphragm coating materials.
Background
A lithium ion battery is a secondary battery, which is a so-called rechargeable battery, and is charged and discharged by movement of lithium ions between a positive electrode and a negative electrode. During the charge and discharge of Li+Between two electrodes, in which Li is charged+The lithium ion battery is released from the positive electrode, is inserted into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state.
In the structure of the lithium ion battery, a diaphragm is one of the key inner layer components, mainly has the functions of separating the positive electrode and the negative electrode of the battery, preventing the two electrodes from contacting and short-circuiting, and enabling electrolyte ions to pass through; the performance of the diaphragm determines the interface structure, internal resistance and the like of the battery, directly influences the capacity, circulation, safety performance and other characteristics of the battery, and has an important effect on improving the comprehensive performance of the battery.
At present, polyolefin microporous membranes such as Polyethylene (PE) and polypropylene (PP) membranes are mainly used for commercial lithium ion battery membranes. Although the diaphragm has good electrochemical stability and mechanical strength, due to the inherent non-polar surface and low melting temperature of the material, the polyolefin diaphragm has the defects of poor wettability and thermal stability to electrolyte, and the like, thereby affecting the electrochemical performance and safety performance of the lithium ion battery.
In order to overcome the defects of only using a polyolefin microporous membrane as a lithium ion battery diaphragm, the prior art adopts a coating technology, namely a layer of coating is coated on the polyolefin microporous membrane to form a composite material so as to meet the requirements of a lithium ion battery, such as a PP + ceramic coating membrane, a PE + ceramic coating membrane and other polyolefin microporous membranes in composite forms which are formed by coating nanometer ceramic particles on the diaphragm, and the polyolefin microporous membrane in the composite forms can effectively improve the affinity and the thermal stability to electrolyte, so the polyolefin microporous membrane is increasingly applied to the lithium ion battery diaphragm.
The core of the excellent characteristics of composite materials such as PP + ceramic coating films, PE + ceramic coating films, etc. is their ceramic layer.
The main raw material of the ceramic is kaolin, and the main component of the ceramic is SiO2And Al2O3. Because the high-purity nano alumina has the characteristics of insulation, heat insulation, flame retardance, high temperature resistance, self-turn-off and the like, the polyolefin microporous membrane can be effectively prevented from being melted and disconnected due to overhigh temperature when coated on the surface of the polyolefin microporous membrane, so the high-purity nano alumina is an ideal coating material of a lithium ion battery diaphragm, and at present, the ceramic material which is most applied as the coating layer of the lithium ion battery diaphragm is mainly alumina.
However, the existing alumina diaphragm coating for coating the lithium ion battery diaphragm has the defects of easy precipitation of alumina slurry, poor wettability and cohesiveness with a PE film or a PP film and the like, so that the quality of the lithium ion battery diaphragm is influenced, and finally the characteristics of the lithium ion battery such as capacity, cycle performance, safety performance and the like are influenced.
Disclosure of Invention
In order to overcome the defects of the prior art, the embodiment of the invention provides a nano aluminum oxide diaphragm coating and a preparation method thereof, aiming at:
the nano alumina diaphragm coating which has good stability, is not easy to delaminate, has good adhesion and wettability with the lithium ion battery diaphragm, strong cohesiveness, is easy to coat and is not easy to fall off powder is provided for the lithium ion battery diaphragm, and the preparation method thereof simplifies the production flow, improves the product quality, and improves the capacity, the cycle performance, the safety performance and other characteristics of the lithium ion battery while improving the quality of the lithium ion battery diaphragm.
In order to achieve the above purpose, an embodiment of the present invention first provides a nano alumina separator coating for coating a surface of a lithium ion battery separator, and the technical scheme includes:
a nanometer alumina diaphragm coating comprises nanometer alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene dodecyl ether and pure water, wherein:
the solid content of the nano alumina diaphragm coating is between 38 and 42 percent (mass percentage), the viscosity of the nano alumina diaphragm coating is between 100 and 300mPa.s, and the pH value of the nano alumina diaphragm coating is between 8 and 9; and is
The nano alumina diaphragm coating comprises the following nano alumina particles in particle size distribution: d50 is between 0.4-0.8 μm, and D90 is not more than 2.5 μm.
Further:
the nano alumina particles have the purity of more than or equal to 99 percent (mass percentage) and the specific surface area of 6.5-10. m2(ii)/g; and is
The nano alumina particles also meet the particle size distribution conditions that D10 is not less than 0.2 μm and D99 is not more than 4.0 μm;
the metal impurity element limit (tested by an ICP method) of the nano alumina particle meets all of the following impurity limit conditions a) to f), wherein the impurity limit conditions are as follows:
a) ca does not exceed 750ppm, b) Fe does not exceed 50ppm, c) Mg does not exceed 150ppm, d) Co does not exceed 10ppm, e) Ni does not exceed 10ppm, f) Zn does not exceed 10 ppm.
Further, the nano aluminum oxide diaphragm coating also comprises a dispersing agent.
Further:
the nano alumina particles, the acrylic polymer particles, the carboxymethyl cellulose, the polyoxyethylene dodecyl ether, the dispersing agent and the pure water satisfy the following mass proportion relation:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene lauryl ether, a dispersant and pure water, wherein the ratio of the nano alumina particles to the acrylic polymer particles to the carboxymethyl cellulose to the polyoxyethylene lauryl ether is 100: 10 to 20: 1.0 to 2.0: 0.10 to 0.15: 0.5 to 1.0: 141 to 167.
Further:
the acrylic polymer fine particles are a mixture of polystyrene, 2-ethylhexyl acrylate and butyl acrylate, and the average particle size of the acrylic polymer fine particles is 380 nm.
Optionally:
the acrylic polymer fine particles are Japanese Ramarion acrylic polymer (ZEON BM-900B), and the dispersant is a Pasteur dispersant (Dispex AA 4040).
The embodiment of the invention also provides a preparation method of the nano aluminum oxide diaphragm coating, which comprises the following steps:
mixing the nano alumina particles with pure water and grinding the mixture into nano alumina slurry;
stirring and mixing carboxymethyl cellulose and pure water to prepare carboxymethyl cellulose pulp;
mixing the nano alumina slurry and the carboxymethyl cellulose slurry and stirring to prepare an alumina cellulose mixed solution; or
Mixing the nano alumina slurry and the carboxymethyl cellulose slurry, adding a dispersing agent, and stirring to prepare an alumina cellulose mixed solution;
adding acrylic polymer particles into the alumina cellulose mixed solution, and stirring and mixing to prepare alumina cellulose polymer mixed solution;
adding polyoxyethylene dodecyl ether into the alumina cellulose polymer mixed solution, and stirring and mixing to prepare alumina cellulose polymer alkyl ether mixed solution;
and adding an inorganic alkaline solution into the mixed solution of the alumina cellulose polymer and the alkyl ether, and stirring to adjust the pH value of the mixed solution to be alkalescent, thereby obtaining the nano alumina diaphragm coating.
Further, in the preparation method of the nano aluminum oxide diaphragm coating:
the nano alumina diaphragm coating has a solid content of 38-42% (mass percentage), a viscosity of 100-300 mPa.s and a pH value of 7-9, wherein the particle size distribution of nano alumina particles is that D50 is between 0.4-0.8 μm and D90 is not more than 2.5 μm, or the particle size distribution of nano alumina particles is that D10 is not less than 0.2 μm, D50 is between 0.4-0.8 μm, D90 is not more than 2.5 μm and D99 is not more than 4.0 μm; or
The nano aluminum oxide diaphragm coatingThe solid content of the nano-alumina particles is 38-42% (mass percent), the viscosity of the nano-alumina particles is 100-300 mPa.s, the pH value of the nano-alumina particles is 8-9, the particle size distribution of the nano-alumina particles is that D50 is between 0.4-0.8 mu m and D90 is not more than 2.5 mu m or the particle size distribution of the nano-alumina particles is that D10 is not less than 0.2 mu m, D50 is between 0.4-0.8 mu m, D90 is not more than 2.5 mu m and D99 is not more than 4.0 mu m, the purity of the nano-alumina particles is not less than 99% (mass percent), and the specific surface area of the nano-alumina particles is 6.5-10. m2The limiting amount of metal impurity elements (measured by an ICP method) of the aluminum alloy meets all of the following impurity limiting conditions a) to f), wherein the impurity limiting conditions are as follows:
a) ca does not exceed 750ppm, b) Fe does not exceed 50ppm, c) Mg does not exceed 150ppm, d) Co does not exceed 10ppm, e) Ni does not exceed 10ppm, f) Zn does not exceed 10 ppm.
Further, in the preparation method of the nano aluminum oxide diaphragm coating:
the nano alumina diaphragm coating satisfies the following mass proportion relations among the nano alumina particles, the acrylic polymer particles, the carboxymethyl cellulose, the polyoxyethylene dodecyl ether, the dispersing agent and the pure water:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene dodecyl ether, a dispersing agent and pure water, wherein the ratio of the nano alumina particles to the acrylic polymer particles to the carboxymethyl cellulose to the polyoxyethylene dodecyl ether is 100: 10-20: 1.0-2.0: 0.10-0.15: 0.5-1.0: 141-167; and is
The acrylic polymer particles are a mixture of polystyrene, 2-ethylhexyl acrylate and butyl acrylate, the average particle size of the acrylic polymer particles is 380nm, and the specification model of the acrylic polymer particles is Japanese Ruizian acrylic polymer ZEON BM-900B;
the dispersant was a basf dispersant (Dispex AA 4040).
Further, the preparation method of the nano alumina diaphragm coating also comprises the following steps:
and (3) detecting the purity of the alumina, the specific surface area of the alumina, the particle size distribution of the alumina and the limited amount of metal impurity elements on the nano alumina particles and/or the nano alumina slurry.
Optionally:
the detection of the purity of the alumina comprises the steps of firstly measuring the content of Al element in the nano alumina particles or the nano alumina slurry by adopting an inductively coupled plasma emission spectrometer (ICP-AES), and converting the content into Al element2O3The mass percentage of (A);
the detection of the specific surface area of the alumina particles comprises the steps of measuring by a nitrogen adsorption method by using a specific surface analyzer, wherein the degassing time is 2 hours, and the degassing temperature is 200 ℃;
the detection of the particle size distribution of the alumina particles is carried out by adopting a laser particle sizer, wherein the parameters of the laser particle sizer are set as follows: the refractive index is 1.76, the light shading degree is 5-20%, the light absorption rate is 0.1, the pump speed is 3000r/min, and the dispersion medium is pure water;
the limit of the metal impurity elements is measured by an inductively coupled plasma emission spectrometer.
Further, the preparation method of the nano alumina diaphragm coating also comprises the following steps:
and detecting the solid content, the viscosity and the pH value of the nano alumina slurry.
Optionally:
the detection of the solid content is carried out by adopting a rapid halogen moisture tester, wherein the detection temperature is set to be 150 ℃, and the sampling quantity of the nano alumina diaphragm coating to be detected is 2.000-3.000 g;
the viscosity is measured using a rotational viscometer, wherein the rotor of the rotational viscometer is 62#The rotating speed is set to be 30rpm, and the testing temperature is set to be 25 +/-0.5 ℃;
the pH value is measured by a pH meter.
Further:
in the step of mixing and grinding the nano-alumina particles and the pure water into the nano-alumina slurry, the grinding operation is carried out by adopting a ball mill, wherein the ball mill is used for grinding ZrO material2The diameter of the ball milling beads is 0.65-1.5 mm, and the ball milling beads are filledThe rate is 85% of the volume of the ball mill;
in the step of mixing carboxymethyl cellulose and pure water and then stirring the mixture to prepare carboxymethyl cellulose pulp, or mixing and stirring the nano alumina pulp and the carboxymethyl cellulose pulp to prepare alumina cellulose mixed liquor, or mixing the nano alumina pulp and the carboxymethyl cellulose pulp and adding a dispersing agent and then stirring the mixture to prepare alumina cellulose mixed liquor, or adding acrylic polymer particles into the alumina cellulose mixed liquor and stirring and mixing the mixture to prepare alumina cellulose polymer mixed liquor, the stirring speed is 2000-2500 r/min respectively;
and adding polyoxyethylene dodecyl ether into the alumina cellulose polymer mixed solution, stirring and mixing to obtain an alumina cellulose polymer alkyl ether mixed solution, and adjusting the pH value of the alumina cellulose polymer alkyl ether mixed solution to be alkalescent by adding an inorganic alkaline solution and stirring, wherein the stirring speed is 300-500 r/min respectively.
Further, in the preparation method of the nano alumina diaphragm coating, the inorganic alkaline solution is a NaOH solution with the concentration of 3 mol/L.
Compared with the prior art, the invention has the beneficial effects and remarkable progress that:
1) the nano alumina diaphragm coating provided by the invention takes nano alumina particles as aggregate coated on the surface of a lithium ion battery diaphragm, has the characteristics of insulation, heat insulation, flame retardance, high temperature resistance, self-turn-off and the like, and the aggregate can not be layered for a long time through the suspension dispersion of carboxymethyl cellulose, so that the good stability of the aggregate is ensured;
2) the nano-alumina diaphragm coating provided by the invention takes the acrylic polymer as a film-forming coating agent, so that not only can nano-alumina particles be well dispersed, but also the nano-alumina particles can be well wrapped and combined with the lithium ion battery diaphragm to form a composite layer which is difficult to fall off powder, so that the quality of the lithium ion battery diaphragm is improved, and the characteristics of the lithium ion battery such as capacity, cycle performance, safety performance and the like are improved;
3) the nano alumina diaphragm coating provided by the invention is added with the nonionic surfactant polyoxyethylene dodecyl ether, so that the dispersibility and suspension stability of nano alumina particles in the nano alumina diaphragm coating are further improved, and meanwhile, the wettability and permeability of the nano alumina diaphragm coating provided by the invention are also improved, so that the bonding performance of the nano alumina diaphragm coating with a lithium ion battery diaphragm is further improved, and the nano alumina diaphragm coating is easier to coat;
4) the aggregate particles of the nano alumina diaphragm coating provided by the invention are finer and more uniform, and the given acid and alkali can ensure the stability of the ingredients, so that the coating uniformity can be ensured, and the nano alumina diaphragm coating has good coating workability, thereby ensuring the quality of a lithium ion battery diaphragm and improving the comprehensive performance of the lithium ion battery.
5) The preparation method of the nano aluminum oxide diaphragm coating provided by the invention is novel, unique and complete, the whole preparation method is designed according to the characteristics of all materials, the process is stable, simple and reliable, a satisfactory unique effect can be achieved, no pollution is caused to the environment in the production process, and the product performance is excellent, so that the preparation method has great popularization and application values.
Drawings
To more clearly illustrate the technical solution of the present invention, the drawings required for the embodiment of the present invention will be briefly described below.
Obviously:
the drawings in the following description are only part of the embodiments of the present invention, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts, but the other drawings also belong to the drawings required to be used by the embodiments of the present invention.
FIG. 1 is a photograph showing the coating effect of a conventional commercially available lithium ion battery separator surface coating product on a PP lithium ion battery separator;
fig. 2 is a photograph showing the coating effect of the nano alumina membrane coating on the PP lithium ion battery membrane provided in example 2 of the present invention and case 1 thereof;
FIG. 3 is a photograph showing the rubbing result of a PP lithium ion battery separator coated with a conventional commercially available lithium ion battery separator surface coating material;
fig. 4 is a photograph of rubbing results of the PP lithium ion battery separator coated with the nano alumina separator coating provided in example 2 and case 1 of the present invention.
Detailed Description
In order to make the objects, technical solutions, advantages and significant progress of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings provided in the embodiments of the present invention, and it is obvious that all of the described embodiments are only some embodiments of the present invention, but not all embodiments;
all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that:
the terms "first," "second," and the like in the description and claims of the present invention and in the drawings of embodiments of the present invention, are used for distinguishing between different objects and not for describing a particular order;
furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to the listed steps or elements, but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It is to be understood that:
in the description of the embodiments of the present invention, some basic operation terms commonly used in the art, for example, "heating", "stirring", "mixing", "dissolving", "washing", "filtering", and "drying", etc., are used, and it should be understood that these terms are used in a broad sense, and may be performed by various conventional apparatuses and instruments in the art, or may be performed by the latest apparatuses, such as program control operation, unmanned automatic operation, etc., unless otherwise specifically limited, and those skilled in the art can understand the specific meaning of the above terms in the present invention according to specific situations and use specific operation methods to achieve the operation purpose.
It should also be noted that:
the following embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments;
further, raw materials, equipment, facilities, reagents and the like referred to in the following specific examples are commercially available.
The technical means of the present invention will be described in detail below with specific examples.
Example 1
The embodiment provides a nano-alumina diaphragm coating for coating the surface of a lithium ion battery diaphragm.
The nano aluminum oxide diaphragm coating provided by the embodiment comprises:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene dodecyl ether and pure water, wherein:
the solid content of the nano alumina diaphragm coating is between 38 and 42 percent (mass percentage), the viscosity of the nano alumina diaphragm coating is between 100 and 300mPa.s, and the pH value of the nano alumina diaphragm coating is between 8 and 9; and is
The nano alumina diaphragm coating has the following particle size distribution: d50 is between 0.4-0.8 μm and D90 is not more than 2.5 μm.
From the above description, it can be seen that:
firstly, in the embodiment, nano alumina particles with the characteristics of insulation, heat insulation, flame retardance, high temperature resistance, self-turn-off and the like are selected as aggregates of a coating material nano alumina diaphragm coating on the surface of a lithium ion battery diaphragm, and on the basis, carboxymethyl cellulose which is rich in source and low in price but has good thickening, film forming, adhesion, colloid protection, emulsification, suspension and other effects is used as an adhesive and a suspending agent, so that the suspended nano alumina particles can be effectively dispersed and can not be layered in the nano alumina diaphragm coating for a long time, and the nano alumina diaphragm coating has good stability;
secondly, the acrylic polymer with good water resistance, good chemical resistance, fast drying, convenient construction and easy coating is used as a film-forming coating agent, so that the nano alumina particles can be well dispersed, the nano alumina particles can be well wrapped and combined with the lithium ion battery diaphragm to form a film, and the nano alumina particles are firmly coated on the lithium ion battery diaphragm material to form a composite layer which is not easy to fall off powder, so that the quality of the lithium ion battery diaphragm is improved, and the characteristics of the lithium ion battery, such as capacity, cycle performance, safety performance and the like, are improved;
thirdly, because the nonionic surfactant polyoxyethylene dodecyl ether which is easily soluble in water, stable to acid and alkali and has good wetting, penetrating, emulsifying, dispersing and solubilizing effects is added into the nano alumina diaphragm coating provided by the embodiment, the dispersibility and suspension stability of the nano alumina particles in the nano alumina diaphragm coating are further improved, and meanwhile, the wettability and permeability of the nano alumina diaphragm coating provided by the embodiment are also improved, so that the nano alumina diaphragm coating is improved in combination with a lithium ion battery diaphragm and is easier to coat;
in addition, on the basis of the unique composition formula, the nano alumina membrane coating provided by the embodiment further specifies that the solid content is between 38% and 42% (mass percent), the viscosity is between 100 mpa.s and 300mpa.s, the pH value is between 8 and 9, and the particle size distribution of the nano alumina particles is as follows: d50 is between 0.4 ~ 0.8 mu m and D90 is not more than 2.5 mu m, thereby guarantee that its aggregate granule is more exquisite, even, give the optimum alkalescence environment of carboxymethyl cellulose as adhesive and suspending agent, thereby guarantee that the coating is more stable, and make the coating whole not only can guarantee to coat evenly, and can guarantee that it has good coating workability, the levelling nature is good, be difficult for appearing sagging, wrinkling, the phenomenon such as shrink limit, thereby guarantee the quality of lithium ion battery diaphragm, improve lithium ion battery's comprehensive properties.
Further:
the nano alumina membrane coating provided by the embodiment has the purity of more than or equal to 99% (mass percent) and the specific surface area of 6.5-10. m2(ii)/g; and the particle size distribution of the nano alumina particles also meets the particle size distribution conditions that D10 is not less than 0.2 mu m and D99 is not more than 4.0 mu m, and the limit amount of metal impurity elements (tested by an ICP method) meets all of the following impurity limit conditions a) to f), wherein the impurity limit conditions are as follows:
a) ca does not exceed 750ppm, b) Fe does not exceed 50ppm, c) Mg does not exceed 150ppm, d) Co does not exceed 10ppm, e) Ni does not exceed 10ppm, f) Zn does not exceed 10 ppm.
From the above description, it can be seen that:
in the nano alumina diaphragm coating provided by the embodiment, the aggregate nano alumina particles have high purity and better particle size distribution, so that the nano alumina diaphragm coating can ensure the characteristics of better insulation, heat insulation, flame retardance, high temperature resistance, self-turn-off and the like, can have better adhesive wettability and cohesiveness with a lithium ion battery diaphragm, and is more stable and easy to coat.
Further, the nano alumina diaphragm coating provided by the embodiment also comprises a dispersant.
Further, in the nano alumina membrane coating provided by the embodiment:
the nano alumina particles, the acrylic polymer particles, the carboxymethyl cellulose, the polyoxyethylene dodecyl ether, the dispersing agent and the pure water satisfy the following mass proportion relation:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene lauryl ether, a dispersant and pure water, wherein the ratio of the nano alumina particles to the acrylic polymer particles to the carboxymethyl cellulose to the polyoxyethylene lauryl ether is 100: 10 to 20: 1.0 to 2.0: 0.10 to 0.15: 0.5 to 1.0: 141 to 167.
Further, in this embodiment:
the acrylic polymer fine particles are a mixture of polystyrene, 2-ethylhexyl acrylate and butyl acrylate, and the acrylic polymer fine particles have an average particle diameter of 380 nm.
Optionally, in this embodiment:
the acrylic polymer fine particles used were Japanese Raynaud acrylic polymer (ZEON BM-900B) and the dispersant used was a Pasteur dispersant (Dispex AA 4040).
From the above description, it can be seen that:
the nano aluminum oxide diaphragm coating provided by the embodiment has the advantages of simple and easily obtained composition materials, reasonable proportion and higher cost performance, and can achieve the purpose of providing a diaphragm coating which is good in stability, not easy to layer, good in adhesion and wettability with a lithium ion battery diaphragm, strong in cohesiveness, easy to coat and not easy to fall off powder for a lithium ion battery diaphragm.
Example 2
The embodiment provides a preparation method of the nano aluminum oxide diaphragm coating in the embodiment 1.
A preparation method of a nano alumina diaphragm coating comprises the following steps:
mixing the nano alumina particles with pure water and grinding the mixture into nano alumina slurry;
stirring and mixing carboxymethyl cellulose and pure water to prepare carboxymethyl cellulose pulp;
mixing and stirring the nano alumina slurry and the carboxymethyl cellulose slurry to prepare an alumina cellulose mixed solution; or
Mixing the nano alumina slurry and the carboxymethyl cellulose slurry, adding a dispersing agent, and stirring to prepare an alumina cellulose mixed solution;
adding acrylic polymer particles into the alumina cellulose mixed solution, and stirring and mixing to prepare the alumina cellulose polymer mixed solution;
adding polyoxyethylene dodecyl ether into the alumina cellulose polymer mixed solution, and stirring and mixing to prepare alumina cellulose polymer alkyl ether mixed solution;
adding an inorganic alkaline solution into the mixed solution of the alumina cellulose polymer and the alkyl ether, and stirring to adjust the pH value of the mixed solution to be alkalescent so as to obtain the nano alumina diaphragm coating;
in the nano alumina diaphragm coating described in this embodiment, the following components:
the solid content is 38-42% (mass percentage), the viscosity is 100-300 mPa.s, the pH value is 8-9, the particle size distribution of the nano alumina particles is that D50 is between 0.4-0.8 μm and D90 is not more than 2.5 μm, or the particle size distribution of the nano alumina particles is that D10 is not less than 0.2 μm, D50 is between 0.4-0.8 μm, D90 is not more than 2.5 μm and D99 is not more than 4.0 μm; or
In the nano alumina diaphragm coating described in this embodiment:
the solid content of the nano-alumina particles is 38-42% (mass percent), the viscosity of the nano-alumina particles is 100-300 mPa.s, the pH value of the nano-alumina particles is 8-9, the particle size distribution of the nano-alumina particles is that D50 is between 0.4-0.8 mu m and D90 is not more than 2.5 mu m or the particle size distribution of the nano-alumina particles is that D10 is not less than 0.2 mu m, D50 is between 0.4-0.8 mu m, D90 is not more than 2.5 mu m and D99 is not more than 4.0 mu m, the purity of the nano-alumina particles is not less than 99% (mass percent), and the specific surface area of the nano-alumina particles is 6.5-10. m2The limiting amount of metal impurity elements (tested by an ICP method) of the nano alumina particles meets all the following impurity limiting conditions a) to f), wherein the impurity limiting conditions are as follows:
a) ca does not exceed 750ppm, b) Fe does not exceed 50ppm, c) Mg does not exceed 150ppm, d) Co does not exceed 10ppm, e) Ni does not exceed 10ppm, f) Zn does not exceed 10 ppm.
Further, in the preparation method of the nano alumina diaphragm coating provided by the embodiment:
the nano alumina particles, the acrylic polymer particles, the carboxymethyl cellulose, the polyoxyethylene dodecyl ether, the dispersing agent and the pure water satisfy the following mass proportion relation:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene dodecyl ether, a dispersing agent and pure water, wherein the ratio of the nano alumina particles to the acrylic polymer particles to the carboxymethyl cellulose to the polyoxyethylene dodecyl ether is 100: 10-20: 1.0-2.0: 0.10-0.15: 0.5-1.0: 141-167; and is
The acrylic polymer particles are a mixture of polystyrene, 2-ethylhexyl acrylate and butyl acrylate, the average particle diameter of the acrylic polymer particles is 380nm, and the specification model is Japanese Rui Wen acrylic polymer ZEON BM-900B;
the dispersant was a basf dispersant (Dispex AA 4040).
From the above description, it can be seen that:
the preparation method of the nano aluminum oxide diaphragm coating provided by the embodiment is novel, unique and complete, the whole preparation method is designed according to the characteristics of all materials, the formula is simple and reasonable, the process is stable, simple and reliable, a satisfactory unique effect can be achieved, no pollution is caused to the environment in the production process, the product performance is excellent, the quality of the lithium ion battery diaphragm can be ensured, and the comprehensive performance of the lithium ion battery can be improved.
Further, the preparation method of the nano alumina diaphragm coating provided by the embodiment further includes:
respectively carrying out detection steps of alumina purity, alumina particle specific surface area, alumina particle size distribution and metal impurity element limit on the nano alumina particles and/or the nano alumina slurry, wherein:
the purity of the alumina can be detected by firstly measuring the content of Al element in the nano alumina particles or nano alumina slurry by using an inductively coupled plasma emission spectrometer (ICP-AES), and converting into Al element2O3The mass percentage of (A);
the detection of the specific surface area of the alumina particles may include measuring by a nitrogen adsorption method using a specific surface analyzer, wherein a degassing time is 2 hours and a degassing temperature is 200 ℃;
the detection of the particle size distribution of the alumina particles can be carried out by using a laser particle sizer, wherein the parameters of the laser particle sizer are set as follows: the refractive index is 1.76, the light shading degree is 5-20%, the light absorption rate is 0.1, the pump speed is 3000r/min, and the dispersion medium is pure water;
the limit of metal impurity elements can be measured by an inductively coupled plasma emission spectrometer.
Further, the preparation method of the nano alumina diaphragm coating provided by the embodiment further includes:
detecting the solid content, the viscosity and the pH value of the nano alumina slurry, wherein:
the detection of the solid content can be carried out by adopting a rapid halogen moisture tester, wherein the detection temperature is set to be 150 ℃, and the sampling quantity of the nano alumina diaphragm coating to be detected is 2.000-3.000 g;
the viscosity can be measured by a rotational viscometer, the rotor of which is 62#The rotating speed is set to be 30rpm, and the testing temperature is set to be 25 +/-0.5 ℃;
the pH value can be measured by using a pH meter.
Further, in the preparation method of the nano alumina diaphragm coating:
the step of mixing and grinding the nano alumina particles and the pure water into the nano alumina slurry can be carried out by adopting a ball mill, wherein the ball milling beads of the ball mill are made of ZrO2The diameter of the ball milling beads is 0.65-1.5 mm, and the filling rate of the ball milling beads is 85% of the volume of the ball milling machine;
mixing carboxymethyl cellulose and pure water, stirring to prepare carboxymethyl cellulose pulp, mixing and stirring nano alumina pulp and carboxymethyl cellulose pulp to prepare alumina cellulose mixed liquor, or mixing nano alumina pulp and carboxymethyl cellulose pulp, adding a dispersing agent, stirring to prepare alumina cellulose mixed liquor, adding acrylic polymer particles into the alumina cellulose mixed liquor, stirring and mixing to prepare alumina cellulose polymer mixed liquor, wherein the stirring speed is set to 2000-2500 r/min respectively;
adding polyoxyethylene dodecyl ether into the alumina cellulose polymer mixed solution, stirring and mixing to obtain alumina cellulose polymer alkyl ether mixed solution, and adjusting the pH value of the alumina cellulose polymer alkyl ether mixed solution to be neutral or alkalescent by adding inorganic alkaline solution and stirring, wherein the stirring speed is set to be 300-500 r/min respectively.
Furthermore, in the preparation method of the nano alumina diaphragm coating, the inorganic alkaline solution can adopt NaOH solution with the concentration of 3 mol/L.
To better help understanding of the technical solutions provided by the embodiments of the present invention and the specific operation processes of the embodiments of the present invention, the following further describes the technical solutions by specific examples.
It should be noted that:
in the following examples, nano alumina was prepared by Anhui Shitong materials science and technology Co., Ltd, carboxymethyl cellulose (CMC for short) was produced by Daicel chemical industries, Japan (Daicel Finechem Ltd.), acrylic polymer fine particles were acrylic polymer (ZEON BM-900B) produced by ZEON Corporation, polyoxyethylene lauryl ether was EMULGEN 107 produced by Kao Corporation, Japan, and dispersant was Pasteur dispersant (Dispex AA4040, A40 for short) produced by BASF SE.
Of course, the above materials may also be products produced by other manufacturers as long as the related quality indexes are consistent or equivalent to those of the above materials.
In addition, in the following embodiments:
the ball mill is a nanorod pin type sand mill CNB-30L produced by Dongguan Conbo mechanical Co., Ltd, wherein ball milling beads of the ball mill are made of ZrO2The diameter of the ball milling beads is 0.65-1.5 mm, and the filling rate of the ball milling beads is 85% of the volume of the ball milling machine;
the viscosity measurement was carried out using a rotational viscometer manufactured by Brookfield corporation of Bolifei USA, wherein the spindle of the rotational viscometer is 62#The rotating speed is set to be 30rpm, and the testing temperature is set to be 25 +/-0.5 ℃;
the pH value was measured by using a pH meter FE28 manufactured by Mettler Tolyduo group (METTLER TOLEDO).
Of course, the above-mentioned instruments and equipment may also be products produced by other manufacturers, as long as the relevant technical indexes are consistent with or equal to those of the above-mentioned instruments and equipment.
Case 1
1) Preparing NaOH solution with the concentration of 3mol/L for later use;
2) adding 2117.4g of pure water into 1838.0g of nano alumina particles, mixing, and grinding for 1 hour by using a ball mill to prepare nano alumina slurry;
3) taking 29.96g of carboxymethyl cellulose (CMC), adding 719.0g of pure water, stirring for 1 hour by a stirrer at the rotating speed of 2000r/min, and measuring the viscosity by a rotary viscometer to prepare carboxymethyl cellulose pulp with the mass percentage concentration of 4.0 +/-0.2%;
4) mixing the nano alumina slurry prepared in the step 2) with the carboxymethyl cellulose slurry prepared in the step 3) and 14.70g of a Pasteur dispersing agent (Dispex AA4040, namely A40), and stirring for 1 hour at the rotating speed of 2000r/min by using a stirrer to prepare an alumina cellulose mixed solution;
5) 288.6g of acrylic polymer particles are mixed with the alumina cellulose mixed solution prepared in the step 4), and then the mixture is stirred for 1 hour by a stirrer at the rotating speed of 2000r/min to prepare the alumina cellulose polymer mixed solution;
6) adding 2.30g of polyoxyethylene dodecyl ether into the mixture of the alumina cellulose polymer mixed solution, and stirring the mixture for 30 minutes by a stirrer at the rotating speed of 300r/min to prepare the alumina cellulose polymer alkyl ether mixed solution;
7) adding the prepared NaOH solution into the mixed solution of the alumina cellulose polymer and the alkyl ether, uniformly stirring the mixed solution by using a stirrer at the rotating speed of 300r/min, and detecting the pH value of the mixed solution to be 8-9 to obtain the nano alumina diaphragm coating.
Case 2
In this case, the operation steps are the same as those in case 2, and the difference is that the mixture ratio and the stirring speed of each material are different, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 183.8g of acrylic polymer particles, 2836.4g of pure water, 2.30g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in the steps 3) to 5) is 2250r/min, and the stirring speed in the steps 6) to 7) is 450 r/min.
Case 3
In this case, the operation steps are the same as those in case 2, and the difference is that the mixture ratio and the stirring speed of each material are different, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 367.6g of acrylic polymer particles, 2836.4g of pure water, 2.30g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in steps 3) to 5) is 2150r/min, and the stirring speed in steps 6) to 7) is 350 r/min.
Case 4
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 18.38g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2836.4g of pure water, 2.30g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in steps 3) to 5) was 2500r/min, and the stirring speed in steps 6) to 7) was 320 r/min.
Case 5
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 36.76g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2836.4g of pure water, 2.30g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in the steps 3) to 5) is 2100r/min, and the stirring speed in the steps 6) to 7) is 350 r/min.
Case 6
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2836.4g of pure water, 2.30g of polyoxyethylene dodecyl ether and 9.19g of a Pasteur dispersant (Dispex AA4040, A40);
the stirring speed in the steps 3) to 5) is 2300r/min, and the stirring speed in the steps 6) to 7) is 330 r/min.
Case 7
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2836.4g of pure water, 2.30g of polyoxyethylene dodecyl ether and 18.38g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in steps 3) to 5) is 2200r/min, and the stirring speed in steps 6) to 7) is 300 r/min.
Case 8
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2836.4g of pure water, 1.84g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in steps 3) to 5) is 2500r/min, and the stirring speed in steps 6) to 7) is 350 r/min.
Case 9
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2836.4g of pure water, 2.76g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in steps 3) to 5) was 2500r/min, and the stirring speed in steps 6) to 7) was 300 r/min.
Case 10
In this case: the operation steps are basically the same as those of case 1, and the difference is only that the mixture ratio and the stirring speed of each material are different, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 2591.6g of pure water, 2.30g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in the steps 3) to 5) is 2200 r/min;
the stirring speed in steps 6) to 7) was 320 r/min.
Case 11
In this case, the operation steps are substantially the same as those in case 1, and the difference is only the difference between the mixture ratio of the materials and the stirring speed thereof, wherein:
1838.0g of nano alumina particles, 29.96g of carboxymethyl cellulose (CMC), 288.6g of acrylic polymer particles, 3069.5g of pure water, 2.30g of polyoxyethylene dodecyl ether and 14.70g of a Pasteur dispersant (Dispex AA4040, namely A40);
the stirring speed in the steps 3) to 5) is 2100r/min, and the stirring speed in the steps 6) to 7) is 350 r/min.
Case 12
In this case, the operations 1) to 6) were substantially the same as in case 1, except that step 7) was not performed since the obtained alumina cellulose polymer alkyl ether mixed solution was not added with a sodium hydroxide solution.
Effect embodiment:
to better help understanding of the technical solutions provided by the embodiments of the present invention and the technical effects obtained by the specific operation processes of the embodiments of the present invention, the following further describes the technical effects through related detection data.
The detection data included in the embodiment of the present invention are detection results obtained by using the nano alumina membrane coating prepared in each case of the above embodiment 2 as a sample, and include the following technical indexes:
solid content, viscosity, pH value, particle size distribution (D50 and D90), wettability and cohesiveness when combined with PP lithium ion battery separator, stability of coating and purity of nano alumina particles, metal impurity element limitation, particle size distribution (D10, D50, D90, D99), specific surface area, wherein:
the solid content is measured by adopting a rapid halogen moisture tester QL-720A produced by Xiamen Mide electronic technology limited, and the measuring temperature is set to be 150 ℃, and the sampling quantity of the measured nano alumina diaphragm coating is 2.000-3.000 g;
the viscosity was measured using a rotational viscometer manufactured by Brookfield corporation of America with a spindle of 62#The rotating speed is set to be 30rpm, and the testing temperature is set to be 25 +/-0.5 ℃;
detecting pH value with pH meter FE28 produced by Mettler-Toriledo group (METTLER TOLEDO);
the purity of the nano alumina particles is measured by an inductively coupled plasma emission spectrometer (ICP-AES) to obtain the content of Al element in the nano alumina particles or the nano alumina slurry, and then the content is converted into Al element2O3The mass percentage of (A);
the particle size distribution of the nano alumina particles is detected by a laser particle size analyzer Malvern-MS 3000E + EV produced by Malvern instruments ltd (Malvern), UK, wherein the detection parameters of the laser particle size analyzer are set as follows: the refractive index is 1.76, the light shading degree is 5-20%, the light absorption rate is 0.1, the pump speed is 3000r/min, and the dispersion medium is pure water;
measuring the specific surface area of the nano alumina particles by a nitrogen adsorption method by using a specific surface analyzer, wherein the degassing time is 2 hours, and the degassing temperature is 200 ℃;
the metal impurity element limit of the nano alumina particles is measured by adopting an inductively coupled plasma emission spectrometer;
the wettability of the nano aluminum oxide diaphragm coating when being combined with a PP lithium ion battery diaphragm is judged by adopting an actual coating test according to the results of visual observation and somatosensory observation;
the adhesion of the nano alumina diaphragm coating when being combined with the PP lithium ion battery diaphragm is tested by rubbing observation;
the stability of the nano alumina diaphragm coating is tested by adopting a standing observation method.
The test results are shown in the following table, in which:
table 1 shows the measured data of the solid content, viscosity and pH of the nano alumina membrane coating prepared in each case of example 2;
table 2 shows the measured data of the purity, the particle size distribution and the specific surface area of the nano alumina particles of the nano alumina membrane coating prepared in each case of example 2;
table 3 shows the detection data of the metallic impurity elements of the nano alumina membrane coatings prepared in each case of example 2;
table 4 shows:
the nano alumina membrane coating prepared in each case in example 2 has test results of wettability and cohesiveness and detection results of respective stability when the coating is applied to a PE lithium ion battery membrane, a PP lithium ion battery membrane, and a commercially available existing nano alumina membrane coating for coating the surface of a lithium ion battery membrane, wherein:
comparative sample 1#Is a nano alumina diaphragm coating (ACZ17050501) of Suzhou Jieli new energy materials GmbH;
comparative sample 2#Is a nano alumina diaphragm coating (ACZ17050901) of Suzhou Jieli new energy materials Co.
TABLE 1
Figure BDA0003512469160000161
From table 1, it can be seen that:
the nano alumina membrane coating prepared by each case in the embodiment 2 of the invention has the solid content of 38-42% (mass percentage), the viscosity of 100-300 mPa.s, the particle size distribution of D50 of 0.4-0.8 μm and D90 of 2.5 μm, the pH value of each nano alumina membrane coating prepared by cases 1-11 is 8-9, the pH value of the nano alumina membrane coating prepared by case 12 is not adjusted, the pH value is lower, but still is alkalescent, meets the specified requirements, thereby showing that each nano alumina membrane coating has the most suitable alkalescent environment, not only ensuring the stability of the nano alumina membrane coating, but also having better viscosity, so that the whole nano alumina membrane coating can be coated uniformly and has good coating construction performance, the leveling property is good, and the phenomena of sagging, wrinkling, edge shrinkage and the like are not easy to occur, so that the quality of the lithium ion battery diaphragm can be ensured, and the comprehensive performance of the lithium ion battery is improved.
TABLE 2
Figure BDA0003512469160000171
TABLE 3
Figure BDA0003512469160000181
From tables 2 and 3, it can be seen that:
the nano alumina diaphragm coating prepared in each case in embodiment 2 of the invention has high purity, good particle size distribution and extremely high specific surface area of aggregate nano alumina particles, and respective metal impurity elements can be controlled in an extremely low limited range, so that the nano alumina diaphragm coating can ensure that the aggregate nano alumina particles have better characteristics of insulation, heat insulation, flame retardance, high temperature resistance, self-turn-off and the like, can have better adhesive wettability and cohesiveness with a lithium ion battery diaphragm, is more stable in product, is easy to coat, can ensure the quality of the lithium ion battery diaphragm, and can improve the comprehensive performance of the lithium ion battery.
TABLE 4
Figure BDA0003512469160000191
From table 4, it can be seen that:
the nano alumina diaphragm coating provided by each case in embodiment 2 of the invention has good wettability and cohesiveness with the existing PE lithium ion battery diaphragm and PP lithium ion battery diaphragm, respectively shows good stability, is easy to coat and not easy to fall off, is more stable in product, can ensure the quality of the lithium ion battery diaphragm, and can improve the comprehensive performance of the lithium ion battery.
Further:
FIG. 1 shows the coating effect of a lithium ion battery separator surface coating (ACZ17050501) produced by Suzhou Jieli New energy materials Co.Ltd on a PP lithium ion battery separator;
fig. 2 shows the coating effect of the nano alumina diaphragm coating provided by the example 1 on the PP lithium ion battery diaphragm in the embodiment 2 of the present invention;
FIG. 3 shows the rubbing results of PP lithium ion battery separator coated with a lithium ion battery separator surface coating (ACZ17050501) produced by Suzhou Jieli New energy materials, Inc., on the market;
fig. 4 shows the rubbing result of the PP lithium ion battery separator coated with the nano alumina separator coating provided in example 2 of the present invention and case 1 thereof.
From the above figures, it can be seen that:
the nano-alumina membrane coating provided by the embodiment 1 in the embodiment 2 of the invention is obviously superior to the existing commercial lithium ion battery membrane surface coating in both coating effect and kneading result.
In summary, it can be seen that:
firstly, the nano aluminum oxide diaphragm coating provided by the embodiment of the invention has the advantages of novel and unique formula, simple and reasonable proportioning, higher cost performance, high solid content, proper viscosity and acidity and alkalinity, better coating construction performance and better product stability;
secondly, the nano alumina diaphragm coating provided by the embodiment of the invention has high purity, better particle size distribution and extremely large specific surface area, and can ensure the characteristics of good insulation, heat insulation, flame retardance, high temperature resistance, self-turn-off and the like;
the preparation method of the nano aluminum oxide diaphragm coating provided by the embodiment is novel, unique and complete, the whole preparation method is designed according to the characteristics of all materials, the formula is simple and reasonable, the process is stable, simple and reliable, a satisfactory unique effect can be achieved, no pollution is caused to the environment in the production process, the product performance is excellent, the quality of the lithium ion battery diaphragm can be ensured, and the comprehensive performance of the lithium ion battery can be improved.
During the description of the above description:
the description of the terms "present embodiment," "as shown at … …," "further," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention, and the exemplary expressions of the terms in this specification are not necessarily referring to the same embodiment or example, and that the particular feature, structure, material, or characteristic described may be combined or coupled in any suitable manner in any one or more embodiments or examples, and further that features of different embodiments or examples and features of different embodiments or examples described in this specification may be combined or coupled by one of ordinary skill in the art without generating a contradiction.
Finally, it should be noted that:
although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made on the technical solutions described in the foregoing embodiments, or some or all of the technical features of the embodiments can be equivalently replaced, and the corresponding technical solutions do not depart from the technical solutions of the embodiments of the present invention.

Claims (15)

1. A nanometer alumina diaphragm coating is used for coating the surface of a lithium ion battery diaphragm and is characterized by comprising the following components:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene dodecyl ether and pure water, wherein:
the solid content of the nano alumina diaphragm coating is 38-42% (mass percentage), the viscosity of the nano alumina diaphragm coating is 100-300 mPa.s, and the pH value of the nano alumina diaphragm coating is 8-9; and is
The nano alumina diaphragm coating comprises the following nano alumina particles in particle size distribution: d50 is between 0.4-0.8 μm, and D90 is not more than 2.5 μm.
2. The nano alumina membrane coating of claim 1, wherein:
the nano alumina particles have the purity of more than or equal to 99 percent (mass percentage) and the specific surface area of 6.5-10. m2(ii)/g; and is provided with
The nano alumina particles also meet the particle size distribution conditions that D10 is not less than 0.2 μm and D99 is not more than 4.0 μm;
the nano alumina particles have metal impurity element limiting values (tested by an ICP method) which meet all of the following impurity limiting conditions a) to f), wherein:
the limited impurity conditions are as follows:
a) ca does not exceed 750ppm, b) Fe does not exceed 50ppm, c) Mg does not exceed 150ppm, d) Co does not exceed 10ppm, e) Ni does not exceed 10ppm, f) Zn does not exceed 10 ppm.
3. The nano alumina membrane coating of claim 1 or 2, wherein: also includes a dispersant.
4. The nano alumina membrane coating of claim 3, wherein:
the nano alumina particles, the acrylic polymer particles, the carboxymethyl cellulose, the polyoxyethylene dodecyl ether, the dispersing agent and the pure water satisfy the following mass proportion relation:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene lauryl ether, a dispersant and pure water, wherein the ratio of the nano alumina particles to the acrylic polymer particles to the carboxymethyl cellulose to the polyoxyethylene lauryl ether is 100: 10 to 20: 1.0 to 2.0: 0.10 to 0.15: 0.5 to 1.0: 141 to 167.
5. The nano alumina membrane coating of claim 4, wherein:
the acrylic polymer fine particles are a mixture of polystyrene, 2-ethylhexyl acrylate and butyl acrylate, and the average particle size of the acrylic polymer fine particles is 380 nm.
6. The nano alumina membrane coating of claim 5, wherein:
the acrylic polymer fine particles are Japanese Raynaud acrylic polymer (ZEON BM-900B), and the dispersant is a Pasteur dispersant (DispexAA 4040).
7. A preparation method of a nano alumina diaphragm coating is characterized by comprising the following steps:
mixing the nano alumina particles with pure water and grinding the mixture into nano alumina slurry;
stirring and mixing carboxymethyl cellulose and pure water to prepare carboxymethyl cellulose pulp;
mixing the nano alumina slurry and the carboxymethyl cellulose slurry and stirring to prepare an alumina cellulose mixed solution; or
Mixing the nano alumina slurry and the carboxymethyl cellulose slurry, adding a dispersing agent, and stirring to prepare an alumina cellulose mixed solution;
adding acrylic polymer particles into the alumina cellulose mixed solution, and stirring and mixing to prepare alumina cellulose polymer mixed solution;
adding polyoxyethylene dodecyl ether into the alumina cellulose polymer mixed solution, and stirring and mixing to prepare alumina cellulose polymer alkyl ether mixed solution;
and adding an inorganic alkaline solution into the mixed solution of the alumina cellulose polymer and the alkyl ether, and stirring to adjust the pH value of the mixed solution to be alkalescent, thereby obtaining the nano alumina diaphragm coating.
8. The method for preparing the nano alumina diaphragm coating according to claim 7, wherein the method comprises the following steps:
the nano alumina diaphragm coating has a solid content of 38-42% (mass percentage), a viscosity of 100-300 mPa.s and a pH value of 8-9, wherein the particle size distribution of nano alumina particles is that D50 is between 0.4-0.8 μm and D90 is not more than 2.5 μm, or the particle size distribution of nano alumina particles is that D10 is not less than 0.2 μm, D50 is between 0.4-0.8 μm, D90 is not more than 2.5 μm and D99 is not more than 4.0 μm; or
The nano alumina diaphragm coating has the solid content of 38-42% (mass percent), the viscosity of 100-300 mPa.s and the pH value of 8-9, the particle size distribution of nano alumina particles is that D50 is between 0.4-0.8 mu m and D90 is not more than 2.5 mu m or the particle size distribution of nano alumina particles is that D10 is not less than 0.2 mu m, D50 is between 0.4-0.8 mu m, D90 is not more than 2.5 mu m and D99 is not more than 4.0 mu m, the purity of the nano alumina particles is not less than 99% (mass percent), and the specific surface area of the nano alumina particles is 6.5-10. m2The limiting amount of metal impurity elements (measured by an ICP method) of the aluminum alloy meets all of the following impurity limiting conditions a) to f), wherein the impurity limiting conditions are as follows:
a) ca does not exceed 750ppm, b) Fe does not exceed 50ppm, c) Mg does not exceed 150ppm, d) Co does not exceed 10ppm, e) Ni does not exceed 10ppm, f) Zn does not exceed 10 ppm.
9. The method for preparing the nano alumina diaphragm coating according to claim 7, wherein the method comprises the following steps:
the nano alumina diaphragm coating satisfies the following mass proportion relations among the nano alumina particles, the acrylic polymer particles, the carboxymethyl cellulose, the polyoxyethylene dodecyl ether, the dispersing agent and the pure water:
nano alumina particles, acrylic polymer particles, carboxymethyl cellulose, polyoxyethylene dodecyl ether, a dispersing agent and pure water, wherein the ratio of the nano alumina particles to the acrylic polymer particles to the carboxymethyl cellulose to the polyoxyethylene dodecyl ether is 100: 10-20: 1.0-2.0: 0.10-0.15: 0.5-1.0: 141-167; and is
The acrylic polymer particles are a mixture of polystyrene, 2-ethylhexyl acrylate and butyl acrylate, the average particle size of the acrylic polymer particles is 380nm, and the specification model of the acrylic polymer particles is Japanese Ruizian acrylic polymer ZEON BM-900B;
the dispersant is a basf dispersant (dispex aa 4040).
10. The method for preparing the nano alumina membrane coating of claim 7, further comprising:
and (3) detecting the purity of the alumina, the specific surface area of the alumina, the particle size distribution of the alumina and the limited amount of metal impurity elements on the nano alumina particles and/or the nano alumina slurry.
11. The method for preparing the nano alumina diaphragm coating according to claim 10, wherein the method comprises the following steps:
the detection of the purity of the alumina comprises the steps of firstly measuring the content of Al element in the nano alumina particles or the nano alumina slurry by adopting an inductively coupled plasma emission spectrometer (ICP-AES), and converting the content into Al element2O3The mass percentage of (A);
the detection of the specific surface area of the alumina particles comprises the steps of measuring by a nitrogen adsorption method by using a specific surface analyzer, wherein the degassing time is 2 hours, and the degassing temperature is 200 ℃;
the detection of the particle size distribution of the alumina particles is carried out by adopting a laser particle sizer, wherein the parameters of the laser particle sizer are set as follows: the refractive index is 1.76, the light shading degree is 5-20%, the light absorption rate is 0.1, the pump speed is 3000r/min, and the dispersion medium is pure water;
the limit of the metal impurity elements is measured by an inductively coupled plasma emission spectrometer.
12. The method for preparing the nano alumina membrane coating of claim 7, further comprising:
and detecting the solid content, the viscosity and the pH value of the nano alumina slurry.
13. The method for preparing the nano alumina diaphragm coating of claim 12, wherein:
the detection of the solid content is carried out by adopting a rapid halogen moisture tester, wherein the detection temperature is set to be 150 ℃, and the sample volume of the detected nano-alumina diaphragm coating is 2.000-3.000 g;
the viscosity is measured using a rotational viscometer, wherein the rotor of the rotational viscometer is 62#The rotating speed is set to be 30rpm, and the testing temperature is set to be 25 +/-0.5 ℃;
the pH value is measured by a pH meter.
14. The method for preparing the nano alumina diaphragm coating according to claim 7, wherein the method comprises the following steps:
in the step of mixing and grinding the nano-alumina particles and the pure water into the nano-alumina slurry, the grinding operation is carried out by adopting a ball mill, wherein the ball mill is used for grinding ZrO material2The diameter of the ball milling beads is 0.65-1.5 mm, and the filling rate of the ball milling beads is 85% of the volume of the ball milling machine;
in the step of mixing carboxymethyl cellulose and pure water and then stirring the mixture to prepare carboxymethyl cellulose pulp, or mixing and stirring the nano alumina pulp and the carboxymethyl cellulose pulp to prepare alumina cellulose mixed liquor, or mixing the nano alumina pulp and the carboxymethyl cellulose pulp and adding a dispersing agent and then stirring the mixture to prepare alumina cellulose mixed liquor, or adding acrylic polymer particles into the alumina cellulose mixed liquor and stirring and mixing the mixture to prepare alumina cellulose polymer mixed liquor, the stirring speed is 2000-2500 r/min respectively;
and adding polyoxyethylene dodecyl ether into the alumina cellulose polymer mixed solution, stirring and mixing to obtain an alumina cellulose polymer alkyl ether mixed solution, and adjusting the pH value of the alumina cellulose polymer alkyl ether mixed solution to be alkalescent by adding an inorganic alkaline solution and stirring, wherein the stirring speed is 300-500 r/min respectively.
15. The method for preparing the nano alumina diaphragm coating according to claim 7, wherein the method comprises the following steps: the inorganic alkaline solution is NaOH solution with the concentration of 3 mol/L.
CN202210156615.8A 2022-02-21 2022-02-21 Nano alumina diaphragm paint and preparation method thereof Pending CN114512764A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210156615.8A CN114512764A (en) 2022-02-21 2022-02-21 Nano alumina diaphragm paint and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210156615.8A CN114512764A (en) 2022-02-21 2022-02-21 Nano alumina diaphragm paint and preparation method thereof

Publications (1)

Publication Number Publication Date
CN114512764A true CN114512764A (en) 2022-05-17

Family

ID=81552112

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210156615.8A Pending CN114512764A (en) 2022-02-21 2022-02-21 Nano alumina diaphragm paint and preparation method thereof

Country Status (1)

Country Link
CN (1) CN114512764A (en)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104269509A (en) * 2014-10-14 2015-01-07 上海电气集团股份有限公司 Ceramic coating diaphragm for lithium battery and preparation method of ceramic coating diaphragm
CN104269505A (en) * 2014-10-27 2015-01-07 沧州明珠隔膜科技有限公司 Composite lithium ion battery diaphragm and preparation method thereof
CN104379257A (en) * 2012-06-18 2015-02-25 埃克森美孚化学专利公司 Synthesis of crystalline molecular sieves having the EUO framework type
CN106654171A (en) * 2015-10-29 2017-05-10 深圳市比克动力电池有限公司 A composite dispersant, lithium ion battery anode slurry, an anode and a lithium ion battery
CN107611320A (en) * 2017-09-08 2018-01-19 上海凯矜新材料科技有限公司 Lithium battery applies cloth diaphragm water paste, lithium battery applies cloth diaphragm and their preparation method
CN109239179A (en) * 2018-08-27 2019-01-18 新疆众和股份有限公司 The measuring method of trace impurity in a kind of high purity aluminium oxide polycrystal material
CN109336148A (en) * 2018-11-21 2019-02-15 方复(上海)新材料科技有限公司 Lithium battery ceramic diaphragm coating aluminium oxide and preparation method thereof
CN109686900A (en) * 2017-10-19 2019-04-26 上海恩捷新材料科技股份有限公司 A kind of lithium ion battery separator and preparation method thereof
CN109728233A (en) * 2018-12-19 2019-05-07 乐凯胶片股份有限公司 Ceramic slurry, ceramic diaphragm and lithium ion battery
CN111039313A (en) * 2019-12-17 2020-04-21 中国铝业股份有限公司 Easily dispersible submicron alumina and preparation method thereof
CN113611981A (en) * 2021-06-28 2021-11-05 湖南烁普新材料有限公司 Low-moisture lithium ion battery diaphragm slurry, preparation method thereof and battery diaphragm

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104379257A (en) * 2012-06-18 2015-02-25 埃克森美孚化学专利公司 Synthesis of crystalline molecular sieves having the EUO framework type
CN104269509A (en) * 2014-10-14 2015-01-07 上海电气集团股份有限公司 Ceramic coating diaphragm for lithium battery and preparation method of ceramic coating diaphragm
CN104269505A (en) * 2014-10-27 2015-01-07 沧州明珠隔膜科技有限公司 Composite lithium ion battery diaphragm and preparation method thereof
CN106654171A (en) * 2015-10-29 2017-05-10 深圳市比克动力电池有限公司 A composite dispersant, lithium ion battery anode slurry, an anode and a lithium ion battery
CN107611320A (en) * 2017-09-08 2018-01-19 上海凯矜新材料科技有限公司 Lithium battery applies cloth diaphragm water paste, lithium battery applies cloth diaphragm and their preparation method
CN109686900A (en) * 2017-10-19 2019-04-26 上海恩捷新材料科技股份有限公司 A kind of lithium ion battery separator and preparation method thereof
CN109239179A (en) * 2018-08-27 2019-01-18 新疆众和股份有限公司 The measuring method of trace impurity in a kind of high purity aluminium oxide polycrystal material
CN109336148A (en) * 2018-11-21 2019-02-15 方复(上海)新材料科技有限公司 Lithium battery ceramic diaphragm coating aluminium oxide and preparation method thereof
CN109728233A (en) * 2018-12-19 2019-05-07 乐凯胶片股份有限公司 Ceramic slurry, ceramic diaphragm and lithium ion battery
CN111039313A (en) * 2019-12-17 2020-04-21 中国铝业股份有限公司 Easily dispersible submicron alumina and preparation method thereof
CN113611981A (en) * 2021-06-28 2021-11-05 湖南烁普新材料有限公司 Low-moisture lithium ion battery diaphragm slurry, preparation method thereof and battery diaphragm

Similar Documents

Publication Publication Date Title
CN109449354A (en) Ceramic slurry, Ceramic Composite diaphragm and lithium ion battery
WO2017185519A1 (en) Aqueous ceramic-coated separator for lithium ion battery and preparation method therefor
JP6659012B2 (en) Negative electrode slurry for secondary battery for improving dispersibility and decreasing resistance, negative electrode containing the same, lithium secondary battery, battery module and battery pack
CN110416472B (en) Mesoporous silica microsphere lithium ion battery diaphragm and lithium ion battery
CN103907222A (en) Micro-porous polyolefin composite film having excellent heat resistance and stability and method for producing same
CN106711380A (en) Composite ceramic membrane for lithium ion battery
CN112820863B (en) Modified pre-lithiated silica material, preparation method and application thereof, and lithium ion battery
CN106784795B (en) Single-crystal spherical lithium manganate material, preparation method thereof and positive electrode material
WO2015183568A1 (en) Improved lithium metal oxide cathode materials and method to make them
US20220131153A1 (en) Ionic conductor slurry, preparation method therefor and application thereof
CN109037676A (en) Lithium ion battery cathode slurry and preparation method thereof
CN109616605B (en) Lithium ion battery diaphragm and preparation method thereof
CN112646303B (en) Al with high adhesion and high wetting efficiency2O3-PMMA composite material, preparation method thereof and polyolefin composite diaphragm
Grießl et al. Effect of the slurry mixing process on the structural properties of the anode and the resulting fast-charging performance of the lithium-ion battery cell
CN113113731A (en) Diaphragm, preparation method thereof and lithium ion battery
CN110504402B (en) Modified alumina, alumina slurry and preparation method thereof, and ceramic coating lithium battery diaphragm and preparation method thereof
CN108172764A (en) A kind of height ratio capacity silicon-based anode and its manufacturing method
CN113707933B (en) Preparation method of solid electrolyte nano dispersion liquid of lithium ion battery and solid electrolyte nano dispersion liquid
CN108963338B (en) Preparation method of electrolyte containing graphene
CN114512764A (en) Nano alumina diaphragm paint and preparation method thereof
CN111653715B (en) Modified ceramic diaphragm, preparation method thereof and lithium ion battery
CN106803576B (en) Nano ceramic powder composition for lithium ion battery and preparation method and application thereof
JP2020035682A (en) Non-aqueous electrolyte secondary battery and manufacturing method of non-aqueous electrolyte secondary battery
CN103879996A (en) Pretreatment method of artificial graphite material and obtained product and application
CN112751140B (en) Diaphragm functional coating material for improving liquid retention capacity and safety performance of lithium ion battery electrolyte

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination