WO2023011293A1 - Séparateur composite, appareil électrochimique, dispositif électronique et terminal mobile - Google Patents

Séparateur composite, appareil électrochimique, dispositif électronique et terminal mobile Download PDF

Info

Publication number
WO2023011293A1
WO2023011293A1 PCT/CN2022/108337 CN2022108337W WO2023011293A1 WO 2023011293 A1 WO2023011293 A1 WO 2023011293A1 CN 2022108337 W CN2022108337 W CN 2022108337W WO 2023011293 A1 WO2023011293 A1 WO 2023011293A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
aramid
composite
aramid fiber
ceramic particles
Prior art date
Application number
PCT/CN2022/108337
Other languages
English (en)
Chinese (zh)
Inventor
阳东方
田雷雷
李枝贤
谢封超
Original Assignee
华为技术有限公司
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 华为技术有限公司 filed Critical 华为技术有限公司
Publication of WO2023011293A1 publication Critical patent/WO2023011293A1/fr

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
    • 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
    • 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

Definitions

  • the application belongs to the technical field of battery separators, and in particular relates to a composite separator, an electrochemical device, an electronic device and a mobile terminal.
  • the separator is used as a separator to separate the positive and negative electrodes of the battery.
  • the separator plays an important role in battery safety.
  • the most commonly used diaphragm is polyethylene diaphragm, the heat shrinkage rate of the diaphragm is usually MD>10% (150°C/1h), TD>10% (150°C/1h); and the membrane rupture temperature of the diaphragm is usually ⁇ 155 °C. Therefore, when the battery works under high temperature conditions, the separator is heated and melts and shrinks severely. The damage of the diaphragm leads to direct contact between the positive and negative electrodes of the battery, which triggers a severe short circuit inside the battery and thermal runaway of the battery.
  • the surface of the diaphragm is usually coated with a coating, which is usually an inorganic ceramic layer (silicon oxide, aluminum oxide, and magnesium oxide, etc.), an organic polymer viscous coating (PVDF, PMMA, etc.) or Organic high temperature resistant polymer coating (PI and aramid fiber layer, etc.).
  • a coating which is usually an inorganic ceramic layer (silicon oxide, aluminum oxide, and magnesium oxide, etc.), an organic polymer viscous coating (PVDF, PMMA, etc.) or Organic high temperature resistant polymer coating (PI and aramid fiber layer, etc.).
  • the inorganic ceramic layer and organic high-temperature-resistant polymer coating are used to improve the thermal stability of the separator, meet the reliability and safety of related products in high-temperature application scenarios, and prevent the battery from igniting, burning or even exploding.
  • the organic polymer adhesive coating is used to improve the interface adhesion with the electrode sheet, improve the overall hardness and strength of the battery, prevent the deformation of the battery cell, and ensure the reliability and safety of the battery cell.
  • polymer materials such as aramid fibers
  • the heat shrinkage rate of the coating reaches 6% (150°C/1h), which reduces the safety of the battery.
  • the purpose of this application is to provide a composite diaphragm and its preparation method, as well as electrochemical devices, electronic equipment and mobile terminals containing the above-mentioned composite diaphragm, aiming at solving the problem that the aramid layer on the surface of the diaphragm has a high thermal shrinkage rate and increases the short circuit in the battery. Risks, issues affecting battery safety performance.
  • the first aspect of the present application provides a composite diaphragm, comprising a polyolefin layer, a composite layer bonded to one or both sides of the polyolefin layer, the composite layer including a mixture layer, and a composite layer bonded to one side of the mixture layer an aramid fiber layer on the surface, and both the mixture layer and the aramid fiber layer are laminated with the polyolefin layer;
  • the mixture layer includes aramid fibers and first ceramic particles, and a coupling agent is bound on the surface of the first ceramic particles; wherein, the coupling agent contains an inorganic group and an organophilic group, and the coupling agent passes through The inorganic-philic group is connected to the surface of the first ceramic particle, and is connected to the aramid fiber through the organophilic group.
  • the composite diaphragm provided by the application includes a composite layer arranged on one or both sides of the polyolefin layer, and the composite layer includes a mixture layer and an aramid fiber layer.
  • the aramid fiber layer can withstand a high temperature of 200°C, so that the membrane rupture temperature of the composite diaphragm can be increased to make the membrane rupture temperature greater than 200°C.
  • the battery with aramid layer in the diaphragm can withstand the high temperature of 200 °C without melting when it is subjected to thermal abuse and mechanical abuse, so as to effectively isolate the positive and negative electrodes of the battery and avoid direct contact between the positive and negative electrodes to cause severe Internal short circuit improves battery safety.
  • the heat shrinkage rate of the aramid fiber layer is relatively high, which increases the risk of short circuit in the battery.
  • the present application introduces a mixture layer containing aramid fibers and first ceramic particles on the surface of the aramid fiber layer, and the surface of the first ceramic particles is bound with a coupling agent.
  • the coupling agent contains inorganic and organophilic groups, it serves as a "molecular bridge" with one end connected to the surface of the first ceramic particle, and the other end connected to the aramid fiber in the mixture layer, thereby strengthening the connection between the first ceramic particle and the aramid fiber.
  • the binding force between the fibers makes the aramid fiber act as a crosslinking agent to crosslink and fix the ceramic particles and form a continuous and stable film layer.
  • the mixture layer has better structural stability, which is not only conducive to improving the structural stability of the composite diaphragm under high temperature conditions, but also the first ceramic particles play a role in the aramid molecular chain in the aramid layer.
  • the role of rigid support can relieve the molecular bond curling of the polymer bond of aramid fiber at high temperature, thereby improving the heat shrinkage performance of the aramid fiber layer, so that the heat shrinkage rate of the composite diaphragm is ⁇ 4%@150°C/1h (ie: put After the composite separator is heat-treated for 1 hour at a temperature of 150° C., its heat shrinkage rate is less than 4%).
  • the battery containing the mixture layer can alleviate the risk of internal short circuit caused by the heat shrinkage of the separator at the head and tail of the cell when the composite separator is heated, thereby improving the safety of the battery.
  • the composite separator provided by this application has a membrane rupture temperature > 240°C and a thermal shrinkage rate ⁇ 4%@150°C/1h, which can effectively solve the problem of thermal runaway of the battery due to the thermal shrinkage and melting of the separator due to the short circuit of the battery, resulting in safety hazard issues.
  • the coupling agent is a silane coupling agent.
  • the silane coupling agent is bound to the surface of the first ceramic particle through the siloxane group. Because there are a large number of organophilic groups on the surface of the first ceramic particles combined with the coupling agent, the organophilic groups can form hydrogen bonds with the aramid molecules dispersed in the first ceramic particles, and the hydrogen bonds make the aramid fibers and the second ceramic particles A ceramic particle is closely combined to form a structurally stable mixture layer, and then the aramid fiber layer is stabilized by means of the first ceramic particle in the mixture layer.
  • the silane coupling agent is selected from at least one of vinylsilane, aminosilane, epoxysilane, mercaptosilane and methacryloxysilane.
  • the siloxane group in the above-mentioned silane coupling agent is combined on the surface of the first ceramic particle, so that the surface of the modified first ceramic particle forms a large number of terminal tentacles, these terminal tentacles can form hydrogen bonds with the aramid fibers, realize the connection between the aramid fibers and the first ceramic particles, and improve the binding force between the aramid fibers and the first ceramic particles.
  • the weight of the coupling agent is 0.3-2% of the total weight of the first ceramic particles.
  • the content of the coupling agent is within the above range, it can effectively play the role of "molecular bridge" and improve the binding force between the first ceramic particle and the aramid fiber.
  • the content of the coupling agent connected to the surface of the first ceramic particles is appropriate, and the formed mixture layer has better air permeability, so that the composite diaphragm can maintain good air permeability and improve the diaphragm. Affinity with electrolyte increases ionic conductivity. If the content of the coupling agent is too high, the air permeability of the composite membrane will be reduced.
  • the mixture layer includes a first surface in contact with the aramid fiber layer and a second surface away from the first surface, along the second surface to the In the direction of the first surface, the aramid content in the mixture layer gradually increases.
  • the side close to the aramid fiber layer has better structural stability, so that the mixture layer can effectively stabilize the aramid fiber layer through the first ceramic particles therein, reducing the heat shrinkage rate of the aramid fiber.
  • the weight percentage of the aramid fiber is 0.1-20%, and the weight percentage of the first ceramic particles is Mineral content is 80 ⁇ 99.9%.
  • a small amount of aramid fiber acts as a cross-linking agent to fix the granular first ceramic particles and form a continuous film layer; at the same time, because the aramid fiber undertakes the cross-linking effect in the separator particles, the aramid fiber can withstand 200°C The above high temperature keeps the mixture layer intact at a high temperature above 200°C, which increases the membrane rupture temperature of the mixture layer.
  • the first ceramic particles in the mixture layer play a rigid support role in the aramid molecular chain, which relieves the molecular bond curling of the aramid polymer bond in the aramid layer at high temperature, thereby improving the thermal stability of the composite diaphragm.
  • Shrinkage performance so that the heat shrinkage rate of the composite diaphragm is ⁇ 4%@150°C/1h.
  • the thickness of the mixture layer is 0.1-6um.
  • the thickness of the mixture layer can achieve the effect of reducing the thermal shrinkage rate of the composite separator; moreover, since the thickness of the mixture layer is within a controllable range, the influence of the mixture layer on the energy density of the battery can be reduced.
  • the thickness of the mixture layer is in the range of 1-4um.
  • the thickness of the mixture layer is within the above range, the effect of reducing the thermal shrinkage rate of the composite separator and the effect of reducing the mixture layer on the energy density of the battery can be better taken into account.
  • the aramid fiber in the mixture layer is at least one of para-aramid fiber and meta-aramid fiber.
  • the aramid fibers mentioned above can achieve cross-linking of the first ceramic particles and increase the membrane rupture temperature of the mixture layer.
  • the median diameter D50 of the first ceramic particles is 0.01-2.0 ⁇ m.
  • the first ceramic particles have a suitable particle size and can form a dense and complete film layer under the crosslinking action of the aramid fiber.
  • the weight percentage of the aramid fiber is 50-100%.
  • the aramid fiber layer can maintain the characteristics of the aramid fiber material and effectively increase the membrane rupture temperature of the composite diaphragm.
  • the weight percentage of the aramid fiber is 100%.
  • the aramid fiber layer is composed of aramid fiber, which can improve the compound The effect of membrane rupture temperature.
  • the weight percentage of the aramid fiber is between 50% and 100%, but not 100%.
  • the aramid layer contains aramid and other materials. Other materials include porogens to impart porosity to the aramid layer.
  • the aramid fiber layer when the weight percentage of the aramid fiber is not 100%, the aramid fiber layer further includes second ceramic particles with a weight percentage of 0-50% .
  • the porosity of the aramid fiber layer can be increased by adding the second ceramic particles with a weight percentage of 0-50% in the aramid fiber layer, so that the porosity of the aramid fiber layer is above 20%.
  • the second ceramic particles introduced into the aramid layer can improve the thermal stability of the aramid layer, improve the thermal shrinkage performance of the aramid layer, and finally reflect the improvement of the thermal shrinkage performance of the composite diaphragm.
  • the median diameter D50 of the second ceramic particles is 0.1-1 ⁇ m.
  • the second ceramic particles play a pore-forming role to increase the porosity of the aramid fiber layer, and the median particle diameter D50 is in the above range, which can endow the aramid fiber layer with proper porosity and pore size.
  • the thickness of the aramid fiber layer is 0.1-6um.
  • the thickness of the aramid layer can not only achieve the effect of increasing the rupture temperature of the composite separator; moreover, since the thickness of the aramid layer is within a controllable range, the influence of the aramid layer on the energy density of the battery can be reduced.
  • the thickness of the aramid fiber layer is 0.5-3um.
  • the thickness of the aramid fiber layer is within the above range, the effect of increasing the rupture temperature of the composite separator and reducing the influence of the aramid fiber layer on the energy density of the battery can be better taken into account.
  • the aramid fiber in the aramid fiber layer is at least one of para-aramid fiber and meta-aramid fiber.
  • the obtained aramid layer has excellent high temperature resistance, which can endow the composite separator with excellent membrane rupture performance, increase its membrane rupture temperature, and finally improve the safety performance of the battery using the composite separator.
  • the polyolefin layer has a thickness of 0.2-20 ⁇ m. Because the application forms a composite layer containing the above-mentioned aramid layer and the mixture layer on one surface of the polyolefin layer, which improves the film breaking temperature and thermal shrinkage performance of the polyolefin layer, therefore, the thickness of the polyolefin layer provided by the application It can be as low as 0.2 ⁇ m, and the polyolefin layer with a thickness of 0.2-20 ⁇ m can be used as the polyolefin layer of the separator matrix, which can effectively isolate the positive and negative electrodes of the battery.
  • the mixture layer is bonded to one surface of the polyolefin layer, and the aramid layer is bonded to the surface of the mixture layer away from the polyolefin layer .
  • the aramid layer has better heat resistance, and as a surface protective layer, it can block the influence of high temperature on the polyolefin film layer, making the membrane rupture temperature of the composite diaphragm > 240°C; on the other hand
  • the mixture layer is arranged between the aramid layer and the polyolefin layer, and at the same time provides rigid support for the polyolefin layer and the aramid layer, and relieves the thermal shrinkage of the composite diaphragm, thereby reducing the thermal shrinkage rate of the composite diaphragm.
  • the composite diaphragm can be made by first forming first ceramic particles on the surface of polyolefin, and then pouring aramid fibers on the surface of the first ceramic particles.
  • the pores between the particles permeate downwards, and spread out on the surface of the first ceramic particles to realize the preparation of the mixture layer and the aramid fiber layer, and improve the process feasibility.
  • the composite layer includes n laminated layers formed of a mixture layer and an aramid fiber layer, wherein n is an integer of 2-5.
  • the mixture layer and the aramid fiber layer are arranged alternately, thereby improving the performance stability of the composite layer.
  • the second aspect of the present application provides a method for preparing a composite diaphragm, comprising the following steps:
  • the first film is one of the mixture layer and the aramid layer
  • the second film is another layer of the mixture layer and the aramid layer
  • the mixture layer includes aramid and the first ceramic particles
  • a coupling agent is bound on the surface of the first ceramic particle.
  • the preparation method of the composite separator provided by the application can sequentially prepare a mixture layer (or aramid layer) and an aramid layer (or mixture layer) on one or both sides of the polyolefin layer, wherein the first mixture layer A coupling agent is bound on the surface of the ceramic particles.
  • the coupling agent contains inorganic and organophilic groups
  • the coupling agent bound to the surface of the first ceramic particle acts as a "molecular bridge" and
  • the aramid fibers forming the mixture layer are connected, thereby enhancing the bonding force between the first ceramic particles and the aramid fibers, making the aramid fibers act as a crosslinking agent to crosslink and fix the ceramic particles, and form a continuous and stable mixture layer.
  • the mixture layer has better structural stability, which is not only conducive to improving the structural stability of the composite diaphragm under high temperature conditions, but also the first ceramic particles play a role in the aramid molecular chain in the aramid layer.
  • the role of rigid support can alleviate the molecular bond curling of the aramid polymer bond at high temperature, and then improve the thermal shrinkage performance of the adjacent layer, that is, the aramid layer, so that the thermal shrinkage rate of the composite diaphragm is ⁇ 4%@150°C/ 1h.
  • the prepared composite diaphragm can increase the rupture temperature of the diaphragm; at the same time, it can also reduce the thermal shrinkage rate of the diaphragm to achieve the effect of the thermal shrinkage rate ⁇ 4%@150°C/1h.
  • the composite film thus prepared can effectively improve the thermal stability of the separator and ensure the safety of the battery.
  • the first film is a mixture layer
  • the second film is an aramid fiber layer.
  • the first material is a material containing first ceramic particles
  • the prefabricated film is a ceramic layer
  • the second material is aramid fiber slurry.
  • the preparation of the mixture layer and the aramid layer is realized by first forming the first ceramic particles on the surface of the polyolefin, and then pouring the aramid slurry on the surface of the first ceramic particles, which improves the process feasibility.
  • the first ceramic particles are spread on the surface of the polyolefin layer to form a ceramic layer, that is, a prefabricated film.
  • the stability of the ceramic layer formed by laying ceramic particles is poor.
  • the aramid fiber slurry is poured on the surface of the ceramic layer, that is, the surface of the prefabricated film, the aramid fiber in the slurry will permeate downward along the pores between the first ceramic particles, and spread evenly around the surface of the first ceramic particles.
  • the downward penetrating aramid fiber fills the pores between the first ceramic particles, and the aramid fiber acts as a cross-linking agent to fix the granular first ceramic particles; at the same time, the coupling agent combines with the aramid fiber through hydrogen bonds, so that the second A ceramic particle is cross-linked with the aramid fiber through a coupling agent, the first ceramic particle is fixed to form a film, and after crystallization and solidification, a mixture layer with a stable structure is finally formed.
  • the first material is ceramic slurry.
  • a prefabricated film is formed on one or both surfaces of the polyolefin layer.
  • the ceramic slurry is a slurry formed by dispersing the first ceramic particles with the coupling agent bound on the surface in a dispersion liquid.
  • ceramic slurry is coated on one or both sides of the polyolefin layer, and after drying treatment, a prefabricated film formed of first ceramic particles is formed on one or both sides of the polyolefin layer, and the second A coupling agent is combined on the surface of ceramic particles.
  • the ceramic slurry is a slurry containing a coupling agent, first ceramic particles and additives.
  • ceramic slurry is coated on one or both sides of the polyolefin layer, and after drying treatment, a prefabricated film formed of first ceramic particles is formed on one or both sides of the polyolefin layer, and the second A coupling agent is combined on the surface of ceramic particles.
  • the auxiliary agent can be at least one of dispersant, thickener, binder and wetting agent.
  • the dispersant is beneficial to improve the dispersibility of the first ceramic particles in the slurry; adding a wetting agent in the slurry can improve the wetting of the slurry on the polyolefin surface when the ceramic slurry is coated on the polyolefin surface. Wet and spreadability; thickener can increase the viscosity of the slurry; binder can bond the first ceramic particles after coating the ceramic particles on the polyolefin surface, and initially fix them on the polyolefin surface to form a ceramic layer , the prefabricated film.
  • the preparation method of the ceramic slurry is as follows: dispersing the first ceramic particles, the coupling agent and the auxiliary agent in deionized water, and mixing them to obtain the ceramic slurry. Under the action of the auxiliary agent, the first ceramic particles disperse and form a slurry, which is beneficial for coating the surface of the polyolefin layer.
  • the ceramic slurry is coated on the surface of the polyolefin layer, and after drying to remove the solvent, the ceramic layer can be formed, that is, the prefabricated film.
  • the ceramic slurry includes the following components added in the following parts by weight:
  • the first ceramic particles and the coupling agent have better dispersion uniformity, which is conducive to the uniform combination of the coupling agent on the surface of the first ceramic particles, and then is conducive to entering the pores of the first ceramic particles
  • the combination of the aramid fibers and the first ceramic particles; at the same time, the slurry has suitable viscosity and spreadability, which is beneficial to initially fix the first ceramic particles on the surface of the polyolefin layer.
  • the coupling agent is a silane coupling agent.
  • the silane coupling agent is combined on the surface of the first ceramic particles through the siloxane group, and there are a large number of organophilic groups at the other end of the silane coupling agent.
  • the organophilic group at the other end of the coupling agent forms a hydrogen bond with the aramid fiber molecule that enters the gap between the first ceramic particles, and the hydrogen bond makes the aramid fiber and the first ceramic particle
  • the particles are closely combined, which enhances the bonding force between the reinforced ceramic particles and the aramid fiber, and finally forms a structurally stable mixture layer.
  • the coupling agent is at least one of vinylsilane, aminosilane, epoxysilane, mercaptosilane and methacryloxysilane, but is not limited thereto.
  • the above-mentioned silane coupling agent contains functional groups capable of forming hydrogen bonds with the aramid fibers, which is beneficial to realize the connection between the aramid fibers and the first ceramic particles, and improve the binding force between the aramid fibers and the first ceramic particles.
  • the preparation method of the ceramic slurry is:
  • the silane coupling agent and the first ceramic particles After mixing the silane coupling agent and the first ceramic particles, add a dispersant for mixing treatment, so that the silane coupling agent and the first ceramic particles are evenly dispersed and then add other additives, which helps to improve the silane coupling agent and the first ceramic particles.
  • the dispersion uniformity of the ceramic particles thereby improving the distribution uniformity of the silane coupling agent on the surface of the first ceramic particles.
  • the second material containing aramid fiber is added on the surface of the prefabricated film, the aramid fiber enters the pores between the first ceramic particles, and with the help of the silane coupling agent uniformly distributed on the surface of the first ceramic particles, it is combined with the second material.
  • the connection of one ceramic particle realizes the fixation of the first ceramic particle, and finally forms a mixture layer, that is, the first film.
  • the first film is an aramid layer
  • the second film is a mixture layer
  • the first material is an aramid slurry
  • the second film is an aramid fiber layer.
  • the second material is a ceramic material.
  • the aramid slurry is first coated on the surface of the polyolefin layer to form a prefabricated film; then ceramic materials are added to the surface of the prefabricated film and dried, and finally an aramid layer and a mixture layer are formed on the surface of the polyolefin layer. composite layer.
  • the aramid fiber size is the size whose matrix material is aramid fiber.
  • the aramid fiber size is a size made of aramid fiber.
  • the aramid fiber slurry contains aramid fiber and additives. In these two possible implementation manners, after using the first material on one or both surfaces of the polyolefin layer, the aramid slurry is formed on one or both surfaces of the polyolefin layer.
  • the auxiliary agent includes a porogen.
  • the solid content of the aramid pulp is 1.5-10%.
  • the aramid slurry has suitable viscosity and spreading properties, and the aramid fiber layer is formed on the surface of the substrate (ceramic layer or polyolefin layer).
  • the preparation method of the aramid pulp is:
  • the method can directly prepare the aramid fiber slurry from raw materials, and the method is simple and has strong controllability in operation.
  • the coating includes one of dip coating, spray coating, doctor blade, coating wire bar and micro gravure roll coating.
  • the preparation method further includes: before the drying treatment, immersing the sample obtained after coating the second slurry into a plasticizing bath. Before drying, the sample obtained after coating the second slurry is immersed in a plasticizing bath, so that the aramid fiber is in a highly plastic state, so as to facilitate the stretching of the aramid fiber.
  • the third aspect of the present application provides an electrochemical device, including a positive electrode sheet, a negative electrode sheet, an electrolyte, and a diaphragm arranged between the positive electrode sheet and the negative electrode sheet, and the diaphragm is the one described in the first aspect of the present application.
  • Composite diaphragm is the one described in the first aspect of the present application.
  • the electrochemical device provided by the present application has low thermal shrinkage rate and high membrane rupture temperature due to the above-mentioned composite separator, which can solve the problem of shrinkage and melting of the separator, reduce the risk of thermal runaway caused by short circuit of the battery, and further improve the safety performance of the battery.
  • At least one surface of the composite separator is provided with at least one polymer layer.
  • the polymer layer can improve the interfacial adhesion between the composite separator and the electrode sheet, improve the overall hardness and strength of the battery, and prevent the deformation of the battery cell.
  • the polymer layer is a material layer formed by at least one of PVDF, PMMA, dopamine, CMC, SBR, PTFE and PVA; as the electrochemical device of the present application
  • the polymer layer is a polymer laminate formed by at least two of PVDF, PMMA, dopamine, CMC, SBR, PTFE and PVA, and the polymer in the polymer laminate is composed, which can be One or more of the above polymers.
  • the above-mentioned polymer material can improve the bonding strength between the composite film and the electrode sheet provided by the first aspect, and keep the battery structure stable.
  • the electrochemical device is a lithium secondary battery, a potassium secondary battery, a sodium secondary battery, a zinc secondary battery, a magnesium secondary battery or an aluminum secondary battery.
  • the structure of the electrochemical device is one or more of a wound structure and a laminated structure.
  • the electrochemical device further includes an encapsulation case, and one or more electrochemical device units are encapsulated in the encapsulation case.
  • the fourth aspect of the present application provides an electronic device, including a housing, electronic components and electrochemical devices accommodated in the housing, the electrochemical device is the electrochemical device described in the third aspect of the present application, and the The electrochemical device is used for powering the electronic components.
  • the terminal is a computer, a mobile phone, a tablet, or a wearable product.
  • the fifth aspect of the present application provides a mobile device, the mobile device includes the electrochemical device described in the third aspect.
  • Fig. 1 is the first structural schematic diagram of the composite diaphragm provided by the embodiment of the present application.
  • Fig. 2 is a second structural schematic diagram of the composite diaphragm provided by the embodiment of the present application.
  • Fig. 3 is a kind of preparation process flowchart of the composite diaphragm provided in the embodiment of the present application.
  • Fig. 4 is a flow chart of another preparation process of the composite diaphragm provided in the embodiment of the present application.
  • the term "and/or” describes the association relationship of associated objects, indicating that there may be three relationships, for example, A and/or B may mean: A exists alone, A and B exist simultaneously, and B exists alone Condition. Among them, A and B can be singular or plural.
  • the character "/" generally indicates that the contextual objects are an "or" relationship.
  • At least one means one or more, and “multiple” means two or more.
  • At least one of the following” or similar expressions refer to any combination of these items, including any combination of single or plural items.
  • at least one item (unit) of a, b, or c or “at least one item (unit) of a, b, and c” can mean: a, b, c, a-b( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.
  • sequence numbers of the above-mentioned processes do not mean the order of execution, and some or all steps may be executed in parallel or sequentially, and the execution order of each process shall be based on its functions and The internal logic is determined and should not constitute any limitation to the implementation process of the embodiment of the present application.
  • the weight of the relevant components mentioned in the description of the embodiments of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the various components.
  • the scaling up or down of the content of the fraction is within the scope disclosed in the description of the embodiments of the present application.
  • the mass described in the description of the embodiments of the present application may be ⁇ g, mg, g, kg and other well-known mass units in the chemical industry.
  • first and second are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features.
  • first XX can also be called the second XX
  • second XX can also be called the first XX.
  • a feature defined as “first” and “second” may explicitly or implicitly include one or more of these features.
  • MD is the abbreviation of "Machine direction", which means the mechanical direction
  • TD is the abbreviation of "Transverse direction", which means perpendicular to the machine direction;
  • PE is the abbreviation of "Polyethylene”, which means polyethylene
  • DSC is an abbreviation for "Differential scanning calorimetry", which means differential scanning calorimetry
  • SOC is the abbreviation of "State of charge”, which means the state of charge
  • PVDF polyvinylidenefluoride
  • PMMA is an abbreviation for “polymethyl methacrylate”, which means polymethyl methacrylate
  • SBR is an abbreviation for "Styrene-butadiene", which means styrene-butadiene rubber
  • NMP is the abbreviation of "N-Methyl-2-pyrrolidone", which means N-methylpyrrolidone, also known as 1-methyl 2-pyrrolidone;
  • CNTs is an abbreviation for “Carbon nanotubes”, which means carbon nanotubes
  • CMC is an abbreviation for "Carboxymethyl Cellulose", which means carboxymethyl cellulose
  • SP is the abbreviation of "Super P”, which means conductive carbon black
  • PP is an abbreviation for "Polypropylene", which means polypropylene
  • PTFE is an abbreviation for "Polytetrafluoroethylene", which means polytetrafluoroethylene
  • PVA is an abbreviation for "Polyvinyl alcohol”, which means polyvinyl alcohol.
  • battery is expressed as "Battery” in English, which refers to a device that utilizes the potential difference of two electrodes to generate a potential difference, thereby causing electrons to flow and generate current.
  • the device can convert chemical energy into electrical energy.
  • positive electrode is expressed in English as "Cathode”.
  • the positive electrode refers to the electrode where the current flows out or the potential is higher, and the positive electrode receives electrons for reduction; in the electrolytic cell, the positive electrode is the electrode connected to the positive electrode of the power supply, and loses electrons for oxidation.
  • negative electrode is expressed in English as "Anode".
  • the negative electrode refers to the electrode that the current flows into or the electrode with a lower potential.
  • the negative electrode loses electrons for oxidation; in the electrolytic cell, the negative electrode is the electrode connected to the negative electrode of the power supply, and the electrons are obtained for reduction.
  • electrostatic electrostatic charge is expressed as "Electrolyte” in English, which refers to the medium that provides ion exchange between the positive and negative electrodes of the battery.
  • diaphragm is expressed as "Separator” in English, which refers to the medium used to separate the positive and negative electrodes in the battery and prevent the positive and negative electrodes from being directly contacted and short-circuited.
  • the basic characteristics of the separator are porosity (can provide channels for ion transmission) and electronic insulation (prevent leakage).
  • Heat abuse is expressed as "Heat abuse” in English, which refers to: the abuse test of the battery cell in terms of heat (or high temperature), such as the hot box test (high temperature ⁇ 130 degrees to bake the battery cell).
  • mechanical abuse is expressed in English as “Machenical abuse”, which can refer to the mechanical abuse of the battery. Cells can be tested for mechanical abuse using needle penetration tests, impact tests, etc.
  • Elongation which can also be called the elongation at break, which indicates the percentage of the length increment when the diaphragm is broken relative to the initial length.
  • a tensile test can be performed on the diaphragm under specific conditions, and when the diaphragm is just broken, the increase in the length of the diaphragm divided by the initial length of the diaphragm can be used to characterize the elongation. The larger the elongation value, the less likely the diaphragm will be broken and the better the elongation.
  • the elongation can be divided into longitudinal (MD, ie along the long side of the separator) elongation and transverse (TD, perpendicular to MD, ie along the short side of the separator) elongation.
  • Tensile strength is expressed in English as "Tensile strength", which indicates the critical strength value of the plastic deformation of the diaphragm, which can characterize the maximum bearing capacity of the diaphragm under uniform stretching conditions.
  • Tensile strength can refer to the stress obtained by dividing the maximum load force of the diaphragm by the initial cross-sectional area of the diaphragm when the diaphragm is just pulled off. The tensile strength is divided into longitudinal (MD, ie along the long side direction of the separator) tensile strength and transverse direction (TD, perpendicular to MD, ie along the short side direction of the separator) tensile strength.
  • MD longitudinal
  • TD transverse direction
  • Puncture strength is expressed in English as "Puncture strength", which can refer to the use of a spherical steel needle with a diameter of 1.0mm to pierce the diaphragm at a speed of 300 ⁇ 10mm/min, and the force required for the steel needle to penetrate the diaphragm is the diaphragm. puncture strength.
  • Heat shrinkage which means that the diaphragm is in the longitudinal/transverse direction before and after heating (longitudinal MD, that is, along the long side direction of the diaphragm; transverse direction TD, perpendicular to MD, that is, along the short side direction of the diaphragm ) The rate of dimensional change in the direction.
  • the test method of thermal shrinkage rate may include: measuring the size of the diaphragm in the longitudinal/transverse (MD/TD) direction; placing a diaphragm with a certain size in the longitudinal/transverse (MD/TD) direction in an incubator; Oven to a specific temperature; measure the dimension of the separator in the longitudinal/transverse (MD/TD) direction after heating.
  • air permeability is “Gurley”, which means the degree to which the membrane allows gas to pass through.
  • Gurley means the degree to which the membrane allows gas to pass through.
  • the air permeability can be obtained by measuring the time required for a unit volume of gas (100cc) to pass through the membrane at a specific pressure (0.05MPa).
  • Opturator temperature which means the temperature at which the diaphragm begins to melt and block some of the previously formed pores during the heating process.
  • membrane rupture temperature is expressed in English as “Rupture temperature”, which means the temperature at which the diaphragm melts to a certain extent and ruptures to cause a partial or comprehensive short circuit.
  • the separator is mainly used to prevent the short circuit of the positive and negative electrodes, which plays a key role in the safety of the battery.
  • the separator is prone to melting and thermal shrinkage in high-temperature scenes, resulting in a short circuit between the positive and negative electrodes and causing a safety hazard.
  • the present application provides a composite separator that can improve battery safety performance.
  • the embodiment of the present application provides a composite diaphragm, including a polyolefin layer, a composite layer bonded to one side of the polyolefin layer, the composite layer includes a mixture layer, and an aramid layer bonded to one side of the mixture layer, and The mixture layer or the aramid fiber layer and the polyolefin layer are arranged on the surface of the polyolefin layer.
  • the polyolefin layer plays the role of separating the positive electrode and the negative electrode in the battery cell, preventing the positive and negative electrodes from directly contacting and short circuiting.
  • Polyolefin has porous properties, so polyolefin is also called porous polyolefin, which can provide channels for ion transmission; at the same time, polyolefin has electronic insulation, which can prevent leakage.
  • the polyolefin layer in the embodiment of the present application is also called a porous polyolefin layer.
  • the polyolefin material in the polyolefin layer may be at least one of polyethylene (PE) and polypropylene (PP).
  • the polyolefin layer is made of one polyolefin material; in some embodiments, the polyolefin layer is made of a combination of two or more polyolefins. In this embodiment, the two or more polyolefins may be two or more different types of polyolefin materials.
  • the polyolefin materials of the polyolefin layer are polyethylene (PE) and polypropylene (PP) composition; It can also be two or more types of polyolefins that are the same but have different viscosity-average molecular weights.
  • the polyolefin material of the polyolefin layer is a variety of polyethylenes with different viscosity-average molecular weights. combination.
  • the polyolefin layer has a thickness of 0.2-20 ⁇ m. Since the embodiment of the present application forms a composite layer containing an aramid fiber layer and a mixture layer on one surface of the polyolefin layer, the film breaking temperature and thermal shrinkage performance of the polyolefin layer are improved, therefore, the polyolefin layer provided by the application The thickness can be as low as 0.2 ⁇ m, and the polyolefin layer with a thickness of 0.2-20 ⁇ m is used as the polyolefin layer of the separator matrix, which can effectively isolate the positive and negative electrodes of the battery.
  • the thickness of the polyolefin layer may be 0.2 ⁇ m, 0.5 ⁇ m, 0.8 ⁇ m, 1.0 ⁇ m, 2.0 ⁇ m, 3.0 ⁇ m, 4.0 ⁇ m, 5.0 ⁇ m, 6.0 ⁇ m, 7.0 ⁇ m, 8.0 ⁇ m, 9.0 ⁇ m, 10.0 ⁇ m, 11.0 ⁇ m, 12.0 ⁇ m, 13.0 ⁇ m, 14.0 ⁇ m, 15.0 ⁇ m, 16.0 ⁇ m, 17.0 ⁇ m, 18.0 ⁇ m, 19.0 ⁇ m, 20.0 ⁇ m.
  • the thickness of the polyolefin layer is 0.5-17um.
  • a composite layer is provided on one or both sides of the polyolefin layer, the composite layer includes a mixture layer, and an aramid layer bonded to one side of the mixture layer, and both the mixture layer and the aramid layer are laminated with the polyolefin layer Arrangement, that is, the mixture layer and the aramid layer are arranged parallel to the polyolefin layer.
  • a composite layer is formed on one surface of the polyolefin layer, and the other surface is left untreated (ie, a blank design is left).
  • the closed cell temperature of polyolefin is about 140°C, this characteristic enables the battery containing polyolefin separator to cut off the ion transport channel by itself (the micropores of polyolefin are closed) at the closed cell temperature.
  • a composite layer is simultaneously formed on both sides of the polyolefin layer to increase the rupture temperature of the composite membrane and reduce its heat shrinkage rate.
  • the limiting oxygen index of the aramid fiber material in the aramid fiber layer is greater than 28%, which belongs to the flame retardant fiber and has flame retardancy. Due to the flame-retardant properties of the aramid fiber material, the use of the aramid fiber layer as the protective layer of the polyolefin separator can increase the membrane rupture temperature of the separator, so that the membrane rupture temperature of the composite film can be greater than 200 ° C, so that when the battery is subjected to thermal and mechanical abuse , the composite separator can withstand high temperature > 200°C without melting, can effectively isolate the positive and negative electrodes of the battery, avoid direct contact between the positive and negative electrodes and cause severe internal short circuit, and improve battery safety.
  • the aramid fiber content is 50-100% by weight.
  • the weight percentage of the aramid fiber is more than 50%, the characteristics of the aramid fiber material can be maintained, and the formed aramid fiber layer can effectively increase the membrane rupture temperature of the composite diaphragm.
  • This embodiment includes two situations, respectively: the situation that the weight percentage of the aramid fiber is 100%, and the situation that the weight percentage of the aramid fiber is not 100%.
  • the weight percentage of the aramid fiber is between 50% and 100%, but not 100%.
  • the aramid layer contains aramid and other materials.
  • the weight percentage of the aramid fiber can be 50%, 55%, 50%, 55%, 50%, 55%, 50%, 55%, 50% %, 55%, 100% and other specific weight percentages.
  • the other material includes a porogen to impart some porosity to the aramid layer.
  • the pore-forming agent is one or more of inorganic pore-forming agents.
  • the inorganic pore-forming agent is lithium chloride, sodium chloride, magnesium chloride, calcium carbonate, calcium chloride, and one or more.
  • the aramid fiber layer when the weight percentage of the aramid fiber is not 100%, the aramid fiber layer includes the second ceramic particles with a weight percentage of 0-50%, and the second ceramic particles serve as a pore-forming agent.
  • the porosity of the aramid fiber layer can be increased by adding the second ceramic particles with a weight percentage of 0-50% in the aramid fiber layer, so that the porosity of the aramid fiber layer is above 20%.
  • the second ceramic particles introduced into the aramid layer can improve the thermal stability of the aramid layer, improve the thermal shrinkage performance of the aramid layer, and finally reflect the improvement of the thermal shrinkage performance of the composite diaphragm.
  • the weight percentage of the second ceramic particles can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7% , 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% and other specific weight percentages.
  • the median diameter D50 of the second ceramic particles as the pore forming agent may be 0.01 ⁇ 2 ⁇ m. In some embodiments, the median diameter D50 of the second ceramic particles is 0.1-1 ⁇ m. In this case, the second ceramic particles play a pore-forming role to increase the porosity of the aramid fiber layer, and the median particle diameter D50 is in the above range, which can give the aramid fiber layer suitable porosity and pore size, which is beneficial to obtain Aramid layer for better breathability and heat resistance.
  • the average median diameter D50 of the second ceramic particles may be 0.01 ⁇ m, 0.02 ⁇ m, 0.05 ⁇ m, 0.08 ⁇ m, 0.1 ⁇ m, 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.5 ⁇ m, 0.6 ⁇ m, 0.7 ⁇ m, 0.8 ⁇ m, 0.9 ⁇ m, 1.0 ⁇ m, 1.1 ⁇ m, 1.2 ⁇ m, 1.3 ⁇ m, 1.4 ⁇ m, 1.5 ⁇ m, 1.6 ⁇ m, 1.7 ⁇ m, 1.8 ⁇ m, 1.9 ⁇ m, 2.0 ⁇ m.
  • the second ceramic particle is aluminum oxide, silicon dioxide, aluminum oxide, zirconium dioxide, magnesium oxide, zinc oxide, barium oxide, magnesium hydroxide, calcium oxide, boehmite, titanium dioxide, and sulfuric acid at least one of barium.
  • the total weight of the aramid fiber layer is 100%, and the weight percentage of the aramid fiber is 100%. role. It should be understood that when the aramid fiber weight percentage in the aramid fiber layer is 100%, the aramid fiber layer also has a certain porosity, but the pore former is formed in the process of forming the aramid fiber layer or in the process of forming the aramid fiber layer. has since been eliminated.
  • the pore-forming agent and aramid fiber are used as raw materials to form a prefabricated film.
  • the organic pore-forming agent volatilizes to form a pore structure in the aramid fiber layer.
  • the thickness of the aramid layer is 0.1-6um.
  • the thickness of the aramid fiber layer can achieve the effect of increasing the rupture temperature of the composite separator. Since the aramid material as a diaphragm material does not contribute capacity to the battery, when the aramid content is too high, the volume percentage in the battery will also increase, which will lower the energy density of the battery.
  • the thickness of the aramid layer is 0.1-6um, the thickness of the aramid layer is within a controllable range, which can reduce the influence of the aramid layer on the energy density of the battery.
  • the thickness of the aramid fiber layer can be 0.1um, 0.2um, 0.3um, 0.4um, 0.5um, 0.6um, 0.7um, 0.8um, 0.9um, 1.0um, 1.5um, 2.0um, 2.5um, 3.0um, 3.5um, 4.0um, 4.5um, 5.0um, 5.5um, 6.0um and other specific thicknesses.
  • the thickness of the aramid layer is 0.5-3um.
  • the thickness of the aramid fiber layer is within the above range, the effect of increasing the rupture temperature of the composite separator and reducing the influence of the aramid fiber layer on the energy density of the battery can be better taken into account.
  • the aramid in the aramid layer is at least one of para-aramid and meta-aramid.
  • the obtained aramid layer has excellent high temperature resistance, which can endow the composite separator with excellent membrane rupture performance, increase its membrane rupture temperature, and finally improve the safety performance of the battery using the composite separator.
  • the composite layer further includes a mixture layer, and the mixture layer includes aramid fibers and first ceramic particles.
  • a coupling agent is bound on the surface of the first ceramic particle. That is, the ceramic particles in the mixture layer are the first ceramic particles modified by the coupling agent.
  • the coupling agent on the surface of the first ceramic particle contains an inorganic group and an organic group. Therefore, as a "molecular bridge", one end is connected to the surface of the first ceramic particle, and the other end is connected to the aramid fiber in the mixture layer, thereby strengthening
  • the binding force between the first ceramic particles and the aramid fiber makes the aramid fiber act as a cross-linking agent to cross-link and fix the first ceramic particles and form a continuous and stable film layer.
  • the mixture layer has better structural stability, which is not only conducive to improving the structural stability of the composite diaphragm under high temperature conditions, but also the first ceramic particles play a role in the aramid molecular chain in the aramid layer. It can play a rigid support role, alleviate the molecular bond curling of the aramid polymer bond at high temperature, reduce the thermal shrinkage of the aramid material, especially the aramid molecule in the aramid layer, and then improve the thermal shrinkage performance of the aramid layer. Make the thermal shrinkage rate of the composite diaphragm ⁇ 4%@150°C/1h.
  • the aramid fiber in this layer undertakes the crosslinking function in the ceramic particles, and the aramid fiber can withstand high temperatures above 200°C, so that the mixture layer continues to remain intact at high temperatures above 200°C, and the membrane rupture temperature of the layer is increased.
  • the battery containing the mixture layer can alleviate the risk of internal short circuit caused by the heat shrinkage of the separator at the head and tail of the cell when the composite separator is heated, thereby improving the safety of the battery.
  • the coupling agent is a silane coupling agent.
  • the silane coupling agent is bound to the surface of the first ceramic particle through the siloxane group.
  • organophilic groups on the surface of the first ceramic particle modified by the silane coupling agent, and the organophilic group can form a hydrogen bond with the aramid fiber molecular chain dispersed in the ceramic particle, and the hydrogen bond makes the aramid fiber and
  • the first ceramic particles are closely combined to form a structurally stable mixture layer, and then the aramid fiber layer is stabilized by virtue of the rigid support of the ceramic particles in the mixture layer. That is, the silane coupling agent builds a "molecular bridge" between the ceramic particles and the aramid fiber interface to improve the bonding force between the ceramic particles and the aramid fiber.
  • the silane coupling agent is selected from at least one of vinylsilane, aminosilane, epoxysilane, mercaptosilane and methacryloxysilane.
  • epoxy silane is also called epoxy silane crosslinking agent;
  • mercapto silane refers to a silane coupling agent containing mercapto in the molecule, exemplary, such as 3-mercaptopropyltriethoxysilane;
  • methacrylic Acyloxysilane refers to a silane coupling agent containing a methacryloxy group in its molecular structure, for example, methacryloxymethyltrimethoxysilane.
  • the siloxane group in the above-mentioned silane coupling agent is combined on the surface of the first ceramic particles, so that a large number of vinyl groups, amino groups, epoxy groups, mercapto groups, acryloyloxy groups and the like are formed on the surface of the modified first ceramic particles.
  • the terminal tentacles of the group can form hydrogen bonds with the aramid fiber, realize the connection between the aramid fiber and the first ceramic particle, and improve the binding force between the aramid fiber and the first ceramic particle.
  • the weight of the coupling agent is 0.3-2% of the total weight of the first ceramic particles.
  • the content of the coupling agent is within the above range, it can effectively play the role of "molecular bridge" and improve the binding force between the first ceramic particle and the aramid fiber.
  • the content of the coupling agent connected to the surface of the first ceramic particles is appropriate, and the formed mixture layer has better air permeability, so that the composite diaphragm can maintain good air permeability and improve the diaphragm. Affinity with electrolyte increases ionic conductivity. If the content of the coupling agent is too high, the air permeability of the composite membrane will be reduced.
  • the content of the coupling agent in the total weight of the ceramic particles is 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 1.1wt% , 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.0wt% and other specific values.
  • the weight percentage of the aramid fiber is 0.1-20%, and the weight percentage of the first ceramic particles is 80-99.9%.
  • a small amount of aramid fiber acts as a cross-linking agent to fix the granular first ceramic particles and form a continuous film layer; at the same time, because the aramid fiber undertakes the cross-linking effect in the separator particles, the aramid fiber can withstand 200°C The above high temperature keeps the mixture layer intact at a high temperature above 200°C, which increases the membrane rupture temperature of the mixture layer.
  • the first ceramic particles in the mixture layer play a rigid support role in the aramid molecular chain, relieve the molecular bond curling of the aramid polymer bond in the aramid layer at high temperature, and maintain the structure of the aramid layer , thereby improving the thermal shrinkage performance of the composite diaphragm, so that the thermal shrinkage rate of the composite diaphragm is ⁇ 4%@150°C/1h.
  • the composite diaphragm is heated, it can alleviate the risk of internal short circuit at the head and tail of the cell due to the heat shrinkage of the diaphragm, improving battery safety.
  • the weight percentage of aramid fiber can be 0.1%, 0.2%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4% , 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc. weight percent content.
  • the aramid in the mixture layer is at least one of para-aramid and meta-aramid.
  • the aramid fiber mentioned above can achieve cross-linking of the first ceramic particles by means of a coupling agent, fix the first ceramic particles to form a film, and increase the film rupture temperature of the mixture layer.
  • the mixture layer is composed of a mixture group formed by the first ceramic particles and aramid fiber.
  • the mixture layer in addition to the first ceramic particles and the aramid fiber, the mixture layer also contains a small amount of additives.
  • the auxiliary agent can be selected from at least one of a dispersant, a thickener, a binder and a wetting agent.
  • the dispersant is conducive to improving the dispersibility of the first ceramic particles in the material such as slurry;
  • the wetting agent is conducive to improving the first ceramic particles in the polyolefin layer or The wettability and spreadability of the surface of the aramid layer;
  • the thickener can form a ceramic slurry with a suitable viscosity, so that the first ceramic particles are formed on the surface of the polyolefin layer or the aramid layer;
  • the binder can form the ceramic particles After the polyolefin surface, the first ceramic particles are bonded and initially fixed on the polyolefin surface.
  • the dispersant is one or more of nonionic dispersants such as polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyethylene oxide;
  • the thickener is sodium carboxymethyl cellulose , hydroxyethylcellulose, sodium alginate, hydroxypropylmethylcellulose and lithium hydroxymethylcellulose;
  • the binder is polyvinylidene fluoride, polytetrafluoroethylene, poly Amide, sodium carboxymethyl cellulose, styrene-butadiene rubber, acrylate, methacrylic acid-methyl/methyl acrylate-maleic anhydride terpolymer, methacrylic acid-methyl methacrylate-vinyl carbazole tripolymer At least one of meta-copolymers and polyimide derivatives;
  • the wetting agent is polyether siloxane copolymer, Tween-90, fluoroalkyl ethoxy alcohol ether, fatty alcohol poly One or more of oxyethylene
  • the mixture layer has a thickness of 0.1-6 um.
  • the thickness of the mixture layer can achieve the effect of reducing the thermal shrinkage rate of the composite separator. Since the first ceramic particles and aramid fiber in the mixture layer do not contribute capacity to the battery as separator materials, when the content of the first ceramic particles and aramid fiber is too much, the volume percentage in the battery will also increase, which will lower the battery capacity. Energy Density. When the thickness of the mixture layer is 0.1-6um, the thickness of the aramid fiber layer is within a controllable range, which can reduce the influence of the mixture layer on the energy density of the battery.
  • the thickness of the mixture layer can be 0.1um, 0.2um, 0.3um, 0.4um, 0.5um, 0.6um, 0.7um, 0.8um, 0.9um, 1.0um, 1.5um, 2.0um, 2.5um, 3.0um um, 3.5um, 4.0um, 4.5um, 5.0um, 5.5um, 6.0um and other specific thicknesses.
  • the mixture layer has a thickness in the range of 1-4 um.
  • the thickness of the mixture layer is within the above range, the effect of reducing the thermal shrinkage rate of the composite separator and the effect of reducing the mixture layer on the energy density of the battery can be better taken into account.
  • the median diameter D50 of the first ceramic particles is 0.01-2.0 ⁇ m.
  • the first ceramic particles have a suitable particle size and can form a dense and complete film layer under the crosslinking action of the aramid fiber.
  • the average median diameter D50 of ceramic particles can be 0.01 ⁇ m, 0.02 ⁇ m, 0.05 ⁇ m, 0.08 ⁇ m, 0.1 ⁇ m, 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.5 ⁇ m, 0.6 ⁇ m, 0.7 ⁇ m, 0.8 ⁇ m , 0.9 ⁇ m, 1.0 ⁇ m, 1.1 ⁇ m, 1.2 ⁇ m, 1.3 ⁇ m, 1.4 ⁇ m, 1.5 ⁇ m, 1.6 ⁇ m, 1.7 ⁇ m, 1.8 ⁇ m, 1.9 ⁇ m, 2.0 ⁇ m.
  • the arrangement of the aramid fiber layer and the mixture layer in the composite layer of the embodiment of the present application includes two situations.
  • the mixture layer is bonded to at least one surface of the polyolefin layer, and the aramid layer is bonded to the surface of the mixture layer facing away from the polyolefin layer. That is, the mixture layer and the aramid fiber layer are sequentially laminated and bonded on at least one surface of the polyolefin layer.
  • a composite layer is formed on one side of the polyolefin layer, the mixture layer in the composite layer is bonded to one side of the polyolefin layer, and the aramid layer is bonded to the surface of the mixture layer away from the polyolefin layer .
  • the composite separator 10 includes polyolefin 11 , a mixture layer 12 bonded to the surface of the polyolefin 11 , and an aramid layer 13 bonded to the surface of the mixture layer 12 away from the polyolefin 11 .
  • the aramid fiber layer has better heat resistance, and as a surface layer protection layer, it can block the influence of high temperature on the polyolefin film layer, making the membrane rupture temperature of the composite diaphragm > 240 ° C; on the other hand
  • the mixture layer is arranged between the aramid layer and the polyolefin layer, and at the same time provides rigid support for the polyolefin layer and the aramid layer, and relieves the thermal shrinkage of the composite diaphragm, thereby reducing the thermal shrinkage rate of the composite diaphragm.
  • the composite diaphragm can be made by first forming first ceramic particles on the surface of polyolefin, and then pouring aramid fibers on the surface of the first ceramic particles.
  • the pores between the particles permeate downwards, and spread out on the surface of the first ceramic particles to realize the preparation of the mixture layer and the aramid fiber layer, and improve the process feasibility.
  • a composite layer is formed on both surfaces of the polyolefin layer, the mixture layer in the composite layer is bonded to both surfaces of the polyolefin layer, and the aramid layer is bonded to the surface of the mixture layer away from the polyolefin layer .
  • the aramid fiber layer is bonded to at least one surface of the polyolefin layer, and the mixture layer is bonded to the surface of the aramid fiber layer facing away from the polyolefin layer. That is, the aramid fiber layer and the mixture layer are sequentially laminated and bonded on at least one surface of the polyolefin layer.
  • the composite layer formed in this way can also increase the membrane rupture temperature of the composite diaphragm and reduce the thermal shrinkage performance.
  • the first ceramic particles are rigid particles
  • the mixture layer whose main component is the first ceramic particles forms a film on the surface of the aramid fiber layer. layer.
  • a composite layer is formed on one surface of the polyolefin layer, the aramid fiber layer is bonded to one side surface of the polyolefin layer, and the mixture layer is arranged on the side surface of the aramid fiber away from the polyolefin layer.
  • the composite separator 10 includes polyolefin 11 , an aramid layer 13 bonded to the surface of the polyolefin 11 , and a mixture layer 12 bonded to the surface of the aramid layer 13 away from the polyolefin 11 .
  • a composite layer is formed on one side of the polyolefin layer, the aramid fiber layer in the composite layer is bonded to one side surface of the polyolefin layer, and the mixture layer is arranged on a side where the aramid fiber is away from the polyolefin layer. side surface.
  • a composite layer is formed on both sides of the polyolefin layer, the aramid fiber layer in the composite layer is bonded to both sides of the polyolefin layer, and the mixture layer is bonded to the side of the aramid fiber layer away from the polyolefin layer surface.
  • the composite layer includes n laminated layers formed by the mixture layer and the aramid fiber layer, wherein n is an integer of 2-5.
  • the mixture layer and the aramid fiber layer are alternately arranged to improve the performance stability of the composite layer.
  • n is 2, 3, 4 or 5.
  • n is 2 or 3.
  • the composite diaphragm provided in the examples of the present application can be prepared by the following method.
  • the embodiment of the present application provides a method for preparing a composite diaphragm, including the following steps:
  • the first film is one of the mixture layer and the aramid layer
  • the second film is the other layer of the mixture layer and the aramid layer
  • the material of the mixture layer includes aramid and the first ceramic particles
  • a coupling agent is bound on the surface of the first ceramic particles.
  • the embodiment of the present application is divided into two implementation situations according to the types of the first film and the second film.
  • the first film is a mixture layer and the second film is an aramid layer.
  • the first material is a ceramic material containing first ceramic particles
  • the prefabricated film is a ceramic layer formed by the first ceramic particles
  • the second material is aramid fiber slurry.
  • the stability of the ceramic layer formed by laying ceramic particles is poor.
  • the aramid fiber slurry is poured on the surface of the ceramic layer, that is, the surface of the prefabricated film, the aramid fiber in the slurry will permeate downward along the pores between the first ceramic particles, and spread evenly around the surface of the first ceramic particles.
  • the downward penetrating aramid fiber will fill the pores between the first ceramic particles, and the aramid fiber will act as a crosslinking agent to fix the granular first ceramic particles; at the same time, the coupling agent will combine with the aramid fiber through hydrogen bonding, so that the The first ceramic particles are cross-linked with the aramid fiber through a coupling agent, the first ceramic particles are fixed to form a film, and after crystallization and solidification, a mixture layer with a stable structure is finally formed.
  • the preparation method of composite diaphragm as shown in Figure 3, comprises the following steps:
  • a ceramic layer is formed on one or both surfaces of the polyolefin layer by forming a ceramic material on one or both surfaces of the polyolefin layer.
  • the ceramic material is a ceramic slurry formed by dispersing the first ceramic particles with the coupling agent bound on the surface in the dispersion liquid.
  • a ceramic slurry is coated on one or both sides of the polyolefin layer, and after drying to remove the solvent, a ceramic layer formed of first ceramic particles is formed on one or both sides of the polyolefin layer. , and the surface of the first ceramic particle is bound with a coupling agent.
  • the first ceramic particles are granular inorganic materials, in the ceramic layer formed by this method, the first ceramic particles are formed in granular form on the surface of the polyolefin layer, and the resulting ceramic layer has poor structural stability.
  • the ceramic material is a ceramic slurry containing a coupling agent, first ceramic particles and additives.
  • ceramic slurry is coated on one or both sides of the polyolefin layer, and after drying treatment, a ceramic layer formed of first ceramic particles is formed on one or both sides of the polyolefin layer, and the second A coupling agent is combined on the surface of ceramic particles.
  • the auxiliary agent can be at least one of dispersant, thickener, binder and wetting agent.
  • the dispersant is beneficial to improve the dispersibility of the first ceramic particles in the slurry; adding a wetting agent in the slurry can improve the wetting of the slurry on the polyolefin surface when the ceramic slurry is coated on the polyolefin surface. wettability and spreadability; the thickener can increase the viscosity of the slurry; the binder can bond the first ceramic particles after the ceramic particles are coated on the polyolefin surface, and initially fix them on the polyolefin surface to form the first Ceramic particle film, that is, prefabricated film.
  • the thickener is at least one of sodium carboxymethylcellulose, hydroxyethylcellulose, sodium alginate, hydroxypropylmethylcellulose and lithium hydroxymethylcellulose; exemplary, viscose
  • the binder is polyvinylidene fluoride, polytetrafluoroethylene, polyamide, sodium carboxymethyl cellulose, styrene-butadiene rubber, acrylate, methacrylic acid-methyl/methyl acrylate-maleic anhydride terpolymer, methyl At least one of acrylic acid-methyl methacrylate-vinyl carbazole terpolymer and polyimide derivatives;
  • the wetting agent is polyether siloxane copolymer, Tween-90 , fluoroalkyl ethoxy alcohol ether, fatty alcohol polyoxyethylene ether, sodium butylnaphthalene sulfonate, sodium isethionate, sodium dodecylsulfonate; exemplary , the dispersant is one or more
  • the preparation method of the ceramic slurry is as follows: dispersing the first ceramic particles, the coupling agent and the auxiliary agent in deionized water, and mixing them to obtain the ceramic slurry. Under the action of the auxiliary agent, the first ceramic particles disperse and form a slurry, which is beneficial for coating the surface of the polyolefin layer.
  • the ceramic slurry is coated on the surface of the polyolefin layer, and the ceramic layer can be formed after drying to remove the solvent. At this point, the ceramic layer is the prefabricated film.
  • the ceramic slurry includes the following components added in the following parts by weight:
  • the first ceramic particles and the coupling agent have better dispersion uniformity, which is conducive to the uniform combination of the coupling agent on the surface of the first ceramic particles, and then is conducive to entering the pores of the first ceramic particles
  • the combination of the aramid fibers and the first ceramic particles; at the same time, the slurry has suitable viscosity and spreadability, which is beneficial to initially fix the first ceramic particles on the surface of the polyolefin layer.
  • the coupling agent is a silane coupling agent.
  • the silane coupling agent is combined on the surface of the first ceramic particle through the siloxane group.
  • the aramid slurry When the aramid slurry is added to the surface of the ceramic layer, the aramid slurry enters the pores of the ceramic layer, and the organophilic group at the other end of the coupling agent forms a hydrogen bond with the aramid molecule that enters the gap between the first ceramic particles.
  • the effect makes the aramid fibers closely bond with the first ceramic particles, so that the first ceramic particles are fixed on the surface of the polyolefin layer to form a structurally stable mixture layer.
  • the coupling agent is at least one of vinylsilane, aminosilane, epoxysilane, mercaptosilane and methacryloxysilane.
  • the preparation method of ceramic slurry is:
  • Thickening agent, binding agent and wetting agent are added into the ceramic dispersion liquid, stirred and mixed to obtain ceramic slurry.
  • the silane coupling agent and the first ceramic particles are mixed, and then the dispersant is added for mixing treatment, so that the silane coupling agent and the first ceramic particles are uniformly dispersed, and then other additives are added, which helps to improve the silane coupling.
  • the dispersion uniformity of the agent and the first ceramic particles thereby improving the distribution uniformity of the silane coupling agent on the surface of the first ceramic particles.
  • the aramid fiber slurry when added on the surface of the ceramic layer, the aramid fiber enters the pores between the first ceramic particles and is connected to the first ceramic particles by means of the silane coupling agent uniformly distributed on the surface of the first ceramic particles , to achieve the immobilization of the first ceramic particles, and finally to form a structurally stable mixture layer, that is, the first film.
  • the first ceramic particles are at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, calcium oxide, boehmite, titanium dioxide, and barium sulfate.
  • the median diameter D50 of the first ceramic particles is 0.01-2.0 ⁇ m.
  • the method of using ceramic material to form a ceramic layer on one or both sides of the polyolefin layer is as follows: coating the above ceramic slurry on one or both sides of the polyolefin layer, A ceramic layer is formed.
  • the coating method is one of dip coating, spray coating, doctor blade, coating wire bar and micro gravure roll coating.
  • the ceramic slurry is coated on one or both sides of the polyolefin layer, it is dried to remove the solvent in the ceramic slurry to form a ceramic layer.
  • the solvent volatilizes after drying, the first ceramic particles are dispersed on the surface of the polyolefin layer, and the obtained ceramic layer cannot be firmly structured on the surface of the polyolefin.
  • the ceramic slurry contains a binder, the binder can bind the first ceramic particles, preliminarily fix the first ceramic particles on the surface of the polyolefin layer, and form a ceramic layer.
  • the manner of the above drying treatment is not strictly limited, and the ceramic layer is obtained after drying.
  • the aramid fiber slurry is a slurry whose matrix material is aramid fiber.
  • the aramid fiber size is a size made of aramid fiber.
  • the aramid fiber slurry contains aramid fiber and additives.
  • the auxiliary agent includes a porogen.
  • a pore structure can be formed in the aramid fiber layer when the aramid fiber layer is prepared, and the porosity of the aramid fiber layer can be increased.
  • the pore-forming agent is one or more of inorganic pore-forming agents.
  • the inorganic pore-forming agent is lithium chloride, sodium chloride, magnesium chloride, calcium carbonate, calcium chloride, the second One or more of the ceramic particles.
  • the porogen is a second ceramic particle.
  • the porosity of the aramid fiber layer can be increased, so that the porosity of the aramid fiber layer is above 20%.
  • the second ceramic particles introduced into the aramid layer can improve the thermal stability of the aramid layer, improve the thermal shrinkage performance of the aramid layer, and finally reflect the improvement of the thermal shrinkage performance of the composite diaphragm.
  • the second ceramic particles account for 0-50wt% of the total weight of the second ceramic particles and the aramid fibers, so as to impart proper porosity to the aramid fiber layer. At this time, while a small amount of second ceramic particles play a role in forming holes, the influence of the second ceramic particles on the performance of the aramid fiber layer is reduced.
  • the median diameter D50 of the second ceramic particles as the pore forming agent may be 0.01 ⁇ 2 ⁇ m. In some embodiments, the median diameter D50 of the second ceramic particles is 0.1-1 ⁇ m. In this case, the second ceramic particles play a pore-forming role to increase the porosity of the aramid fiber layer, and the median particle diameter D50 is in the above range, which can give the aramid fiber layer suitable porosity and pore size, which is beneficial to obtain Aramid layer for better breathability and heat resistance.
  • the second ceramic particle is aluminum oxide, silicon dioxide, aluminum oxide, zirconium dioxide, magnesium oxide, zinc oxide, barium oxide, magnesium hydroxide, calcium oxide, boehmite, titanium dioxide, and sulfuric acid at least one of barium.
  • the pore-forming agent is an organic pore-forming agent, and the organic pore-forming agent volatilizes during the heating and forming of the aramid fiber layer, thereby forming micropores in the aramid fiber layer.
  • the organic pore-forming agent is selected from any one of methanol, ethanol, propanol, glycerol, polyethylene glycol, acetone, acetic acid, tetrahydrofuran, polyvinylpyrrolidone, ethyl acetate, petroleum ether, white oil, and paraffin one or more species.
  • the preparation method of aramid fiber slurry is:
  • the method can directly prepare the aramid fiber slurry from raw materials, and the method is simple and has strong controllability in operation.
  • the aramid pulp is at least one of para-aramid pulp and meta-aramid pulp.
  • the preparation method of aramid fiber slurry is as follows: configure an organic solution of phenylenediamine, lower the temperature to below 10°C, add phthaloyl chloride, add alkali to adjust the pH to neutral, and then add the second ceramic particles to obtain Aramid sizing.
  • the method can directly prepare the aramid fiber slurry from raw materials, and the method is simple and has strong controllability in operation.
  • phenylenediamine is p-phenylenediamine or m-phenylenediamine
  • the organic solvent in the organic solution is N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylformamide or o- Any one or more of the dimethyl phthalates, the selection of the pore-forming agent is as above, and will not be repeated here.
  • additives that increase the solubility of the aramid fiber may also be added, for example, the additives are lithium chloride and calcium chloride.
  • the lithium ions and chloride ions in lithium chloride replace the hydrogen bonds between the aramid molecules, so that the aramid molecules are separated and the aramid fibers are dissolved faster.
  • a base such as a strong base is added to adjust the pH of the reaction solution.
  • the base may be sodium hydroxide, calcium hydroxide, potassium hydroxide and the like.
  • a pore forming agent is added to finally obtain a light yellow liquid, that is, aramid pulp.
  • the amount of the pore-forming agent added accounts for 0-10% by weight of the total reaction system.
  • the solid content of the aramid pulp is 1.5-10%.
  • the aramid slurry has suitable viscosity and spreading properties, and the aramid fiber layer is formed on the surface of the polyolefin layer.
  • the aramid fiber in the slurry will permeate downward along the pores between the first ceramic particles of the ceramic layer, and spread evenly around the surface of the first ceramic particles.
  • the downward penetrating aramid fiber is distributed in the pores between the first ceramic particles, and the aramid fiber acts as a crosslinking agent to fix the granular first ceramic particle; at the same time, the coupling agent combines with the aramid fiber through hydrogen bonding, so that the first
  • the ceramic particles are cross-linked with the aramid fiber through the coupling agent, the first ceramic particles are fixed, and after crystallization and solidification, a mixture layer with a stable structure is finally formed.
  • the method of adding the aramid slurry on the surface of the ceramic layer is to coat the aramid slurry on the surface of the ceramic layer.
  • the coating includes one of dip coating, spray coating, doctor blade, coating wire bar and micro gravure roll coating.
  • the aramid fiber slurry is added to the surface of the ceramic layer and then dried.
  • the aramid fibers flowing into the ceramic layer are connected with the first ceramic particles under the action of a coupling agent. It is solidified in heating and drying, and the first ceramic particles are fixed on the surface of the polyolefin layer to form a mixture layer containing the first ceramic particles and aramid fibers.
  • the aramid above the ceramic layer that is, the aramid that has not flowed into the ceramic layer, solidifies into a film during the heating and drying process to form the aramid layer.
  • the organic pore-forming agent volatilizes and overflows during the heating and drying process, forming a pore structure in the aramid fiber layer.
  • a mixture layer is formed on the surface of the polyolefin, and an aramid fiber layer is formed on the surface of the mixture layer away from the polyolefin.
  • the preparation method of the composite diaphragm further includes: before the heating and drying treatment, immersing the sample obtained after coating the aramid fiber slurry into a plasticizing bath. Before drying, the sample obtained after coating the aramid slurry is immersed in a plasticizing bath, so that the formed aramid fiber is in a highly plastic state, so as to facilitate the stretching of the aramid fiber.
  • the plasticizing bath is N,N-dimethylacetamide, but not limited thereto. The samples immersed in the plasticizing bath were dried for the second time and then wound up to obtain a composite separator.
  • the first film is an aramid layer and the second film is a mixture layer.
  • the first material is aramid fiber slurry
  • the prefabricated film is aramid fiber prefabricated layer
  • the second material is a ceramic material containing the first ceramic particles.
  • the preparation method of composite diaphragm as shown in Figure 4, comprises the following steps:
  • an aramid fiber prefabricated layer is formed on one or both surfaces of the polyolefin layer by forming the aramid fiber slurry on one or both surfaces of the polyolefin layer.
  • Aramid pulp is a pulp whose base material is aramid fiber.
  • the composition of aramid pulp (comprising the composition of aramid pulp, auxiliary agents such as the type of pore-forming agent), solid content and its preparation method or formation method refers to step S12 of the first implementation situation above, in order to save space , which will not be repeated here.
  • the method of using the aramid slurry on one or both sides of the polyolefin layer is to coat the aramid slurry on one or both sides of the polyolefin layer.
  • the coating includes one of dip coating, spray coating, doctor blade, coating wire bar and micro gravure roll coating.
  • the fluidity of the slurry is reduced by heating or natural drying so that it can be fixed on the surface of the polyolefin layer, Aramid prefabricated layers are obtained. At this point, the aramid prefabricated layer is not fully cured. Among them, the way of heating can make aramid raw materials react to produce aramid.
  • the aramid raw material is reacted by heating to form aramid, and the aramid prefabricated layer is obtained.
  • the aramid fibers in the aramid fiber preform layer are cured by heat treatment.
  • the heating process also causes the organic pore-forming agent in the aramid fiber to volatilize and overflow, forming pores in the aramid fiber.
  • the composition of the ceramic material (including the state of matter of the ceramic material, the composition of the ceramic material, the type and content of the auxiliary agent) ), solid content and its preparation method or formation method refer to step S11 of the first implementation situation above, and in order to save space, details are not repeated here.
  • the first ceramic particles can be directly added on the surface of the incompletely cured prefabricated layer, and the surface of the first ceramic particles is bonded with a coupling agent. In this case, the first ceramic particles sink toward the aramid fiber prefabricated layer, thereby realizing the mixing of the first ceramic particles and the aramid fiber.
  • ceramic material is added on the surface of the aramid fiber prefabricated layer, the first ceramic particles in the ceramic material sink, and the first ceramic particles are trapped in the aramid fiber prefabricated layer.
  • the aramid fiber prefabricated layer close to the polyolefin layer is cured to form an aramid fiber layer; the aramid fiber prefabricated layer far away from the polyolefin layer, the first ceramic particles trapped in it are combined with the aramid fiber by the coupling agent on its surface. connected and cured by heating, so as to fix the first ceramic particles and form a mixture layer of the first ceramic particles and aramid fibers.
  • the ceramic material is a mixed slurry containing ceramics and aramid fibers, which is obtained by mixing raw materials containing ceramic particles and aramid fibers.
  • the mixed slurry also contains auxiliary agents, such as dispersants, thickeners, etc., but is not limited thereto.
  • the method for adding ceramic materials on the surface of the aramid fiber prefabricated layer may be: coating the above ceramic slurry on the surface of the aramid fiber prefabricated layer.
  • the coating method is one of dip coating, spray coating, doctor blade, coating wire bar and micro gravure roll coating.
  • the aramid fiber in the aramid fiber slurry and the aramid fiber in the ceramic material may be the same or different.
  • the heat shrinkage rate of the composite diaphragm is ⁇ 4%@150°C/1h; at the same time, the aramid fiber layer is used as a protective layer , so that the membrane rupture temperature of the composite separator is greater than 200° C., and the composite separator thus obtained can significantly improve the safety performance of the battery.
  • the obtained composite diaphragm was tested for performance, and it was found that: when the puncture strength test was performed on the composite diaphragm, 90% SOC needles all passed; when the thermal shrinkage rate test was performed on the composite diaphragm at 150°C, the passing rate of heating at 150°C for 60 minutes increased.
  • the embodiment of the present application provides an electrochemical device, including a positive electrode sheet, a negative electrode sheet, an electrolyte, and a separator arranged between the positive electrode sheet and the negative electrode sheet, and the separator is the composite separator according to the first aspect of the embodiment of the present application.
  • the electrochemical device provided in the embodiment of the present application contains the above-mentioned composite separator, which has a low thermal shrinkage rate and a high membrane rupture temperature, which can solve the problem of shrinkage and melting of the separator, reduce the risk of thermal runaway caused by short circuit of the battery, and improve the safety performance of the battery.
  • the polymer layer can improve the interfacial adhesion between the composite separator and the electrode sheet, improve the overall hardness and strength of the battery, and prevent the deformation of the battery cell.
  • the polymer layer can be activated after shaping with heat. Exemplarily, after the polymer is formed on the surface of the composite membrane, heat treatment is performed at a pressure of 0.1-2.0 MPa and a temperature of 25° C.-100° C. for 20-300 minutes of activation. In some embodiments, the pressure is 0.5-1.0 Mpa, the temperature is 60° C.-90° C., and the activation time is 60-150 minutes.
  • the polymer layer is a material layer formed by at least one of PVDF, PMMA, dopamine, CMC, SBR, PTFE and PVA; as a possible implementation of the electrochemical device of the present application, the polymer layer is PVDF , PMMA, dopamine, CMC, SBR, PTFE and PVA formed by at least two polymer laminates, and the polymers that make up the polymer laminate can be one or more of the above polymers.
  • the above-mentioned polymer material can improve the bonding strength between the composite film and the electrode sheet provided by the first aspect, and keep the battery structure stable.
  • the electrochemical device is a lithium secondary battery, potassium secondary battery, sodium secondary battery, zinc secondary battery, magnesium secondary battery, or aluminum secondary battery.
  • the structure of the electrochemical device is one or more of a wound structure and a laminated structure.
  • the electrochemical device further includes a packaging case, and one or more electrochemical device units are packaged in the packaging case.
  • the electrochemical device unit may be an electric core including a positive electrode sheet, a negative electrode sheet, an electrolyte and a composite separator.
  • the fourth aspect of the present application provides an electronic device, including a housing, electronic components and electrochemical devices accommodated in the housing, the electrochemical device is the electrochemical device of the third aspect of the embodiment of the present application, and the electrochemical device is used for Provide power to electronic components.
  • the electronic device may be a mobile terminal.
  • the terminal is a computer, a mobile phone, a tablet, or a wearable product.
  • a fourth aspect of the present application provides a mobile device, which includes the electrochemical device of the third aspect.
  • the mobile device is a terminal product that needs to carry a power source, such as a new energy vehicle, but is not limited to a new energy vehicle.
  • polyolefin layer in the following examples is a porous polyolefin layer, and the H-HE7.0um wet-process PE film produced by Chongqing Newmi Technology Co., Ltd. is selected.
  • the indicators are shown in Table 1.
  • a kind of composite diaphragm, its preparation method comprises:
  • the liquid is aramid fiber slurry, wherein the content of aramid fiber is 3.5wt.%.
  • the water-based high-temperature resistant ceramic slurry prepared in step (1) is coated on one side of a PE monolayer film with a thickness of 7 ⁇ m by gravure roll coating, and the ceramic layer is obtained after drying;
  • step (2) Spray the aramid slurry prepared in step (2) on one side of the ceramic layer by spraying. After coating, immerse in the plasticizing bath.
  • the plasticizing bath is N,N-dimethyl ethyl alcohol After being dried, it is rolled up to obtain a composite diaphragm, which includes sequentially laminated aramid fiber layers, a mixed layer formed of ceramic particles and aramid fibers, and a porous polyolefin layer.
  • the thickness of the aramid fiber layer is about 2um, and the thickness of the mixture layer is about 2um.
  • a composite diaphragm the difference between its preparation method and Example 1 lies in the preparation of the aramid slurry in the composite diaphragm, specifically, the preparation method of the aramid slurry is:
  • the thickness of the ceramic layer is 2um
  • the thickness of the aramid fiber layer is 2um
  • a composite diaphragm the difference between its preparation method and Example 1 lies in the preparation of the aramid slurry in the composite diaphragm, specifically, the preparation method of the aramid slurry is:
  • the thickness of the mixture layer is 2um
  • the thickness of the aramid fiber layer is 2um
  • a kind of composite diaphragm, its preparation method differs from embodiment 1 in the preparation of the ceramic slurry in the composite diaphragm, specifically, the preparation method of the ceramic slurry is:
  • the thickness of the mixture layer is 2um
  • the thickness of the aramid fiber layer is 2um
  • a kind of composite diaphragm, its preparation method differs from embodiment 1 in the preparation of the ceramic slurry in the composite diaphragm, specifically, the preparation method of the ceramic slurry is:
  • the thickness of the mixture layer is 2um
  • the thickness of the aramid fiber layer is 2um
  • a kind of composite diaphragm, its preparation method differs from embodiment 1 in that, the preparation method of composite diaphragm is:
  • the plasticizing bath After coating, immerse in a plasticizing bath, the plasticizing bath is N,N-dimethylacetamide, and wind up after drying to obtain a composite diaphragm, which includes a mixture of ceramic particles and aramid fiber laminated in sequence layer, aramid layer, and porous polyolefin layer.
  • the thickness of the aramid fiber layer is about 2um, and the thickness of the mixture layer is about 2um.
  • a kind of composite diaphragm, its preparation method differs from embodiment 1 in that, the preparation method of composite diaphragm is:
  • the water-based high-temperature-resistant ceramic slurry prepared in step (1) is coated on both sides of a PE monolayer film with a thickness of 7 ⁇ m by gravure roll coating;
  • step (2) Spray the aramid slurry prepared in step (2) on the surface of the ceramic layer by spraying, after coating, immerse in the plasticizing bath, the plasticizing bath is N,N-dimethylacetamide After being dried, it is rolled up to obtain a composite diaphragm, which includes an aramid fiber layer laminated in sequence, a mixed layer formed of ceramic particles and aramid fiber, and a porous polyolefin layer.
  • the thickness of the aramid fiber layer is about 2um/side, and the thickness of the mixture layer is about 2um/side.
  • a diaphragm, its preparation method comprises:
  • the liquid is aramid fiber slurry, wherein the content of aramid fiber is 3.5wt.%.
  • the prepared aramid slurry was coated on one side surface of a PE monolayer film with a thickness of 7 ⁇ m by gravure roll coating. After coating, it was immersed in a plasticizing bath.
  • the plasticizing bath was N, N-di Methyl acetamide, after being dried, is rolled to obtain a separator, which includes an aramid fiber layer and a porous polyolefin layer stacked in sequence.
  • the thickness of the aramid fiber layer was 4um.
  • a diaphragm, its preparation method comprises:
  • the prepared ceramic slurry was coated on one side surface of a PE monolayer film with a thickness of 7 ⁇ m by gravure roll coating, and after drying, a separator was obtained, which included sequentially laminated ceramic layers and porous polyolefin layers.
  • the thickness of the ceramic layer was 4um.
  • a diaphragm, its preparation method comprises:
  • the prepared ceramic slurry was coated on one side surface of a PE monolayer film with a thickness of 7 ⁇ m by gravure roll coating, and after drying, a separator was obtained, which included sequentially laminated ceramic layers and porous polyolefin layers.
  • the thickness of the ceramic layer was 4um.
  • a kind of composite diaphragm, its preparation method differs from embodiment 1 in the preparation of the ceramic slurry in the composite diaphragm, specifically, the preparation method of the ceramic slurry is:
  • the thickness of the aramid fiber layer is about 2um, and the thickness of the mixture layer is about 2um.
  • the composite diaphragm provided in Examples 1-7 of the present application can retain a lower closed cell temperature after sequentially laminating ceramic particles/aramid layer and aramid layer on the surface of the porous polyolefin layer,
  • the closed cell temperature is about 140°C.
  • the composite films obtained in Examples 1-7 of the present application have significantly lower heat shrinkage rates in the machine direction and perpendicular to the machine direction, and the heat shrinkage rates are all ⁇ 4%@150°C/1h; and
  • the diaphragm provided in Comparative Example 1 does not contain a mixture layer formed of ceramic particles and aramid fiber, so the resulting diaphragm has a higher heat shrinkage rate.
  • the membrane rupture temperature of the composite films obtained in Examples 1-7 of the present application was significantly increased. This shows that the composite layer including the aramid layer and the mixture layer provided on the surface of the polyolefin layer in the embodiment of the present application can improve the heat shrinkability of the separator and increase the membrane rupture temperature, thereby effectively improving the safety performance of the battery.
  • Example 1-7 The composite separator obtained in Example 1-7 and the separator obtained in Comparative Example 1-3 are made into an electrochemical device, and the preparation method is as follows:
  • Positive electrode sheet Dissolve the binder PVDF in NMP and disperse to obtain 7.0wt.% PVDF glue, then add carbon nanotube conductive liquid to disperse evenly, and finally add the active material lithium cobaltate and stir to form a positive electrode slurry.
  • the cloth equipment evenly coats the positive electrode slurry on both sides of the aluminum foil, and dries in an oven to remove the NMP solvent.
  • the coated pole piece is made into a positive pole piece after cold pressing, slitting, and tab welding processes.
  • the above-mentioned positive and negative pole pieces and the diaphragm are wound together to form a bare cell.
  • the capacity of the cell is 4.5Ah, and the working voltage range is 3.0-4.48V.
  • the cell is then packaged, baked, injected, and formed and other processes to make lithium-ion batteries.
  • Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 90% SOC acupuncture 5/5 pass 3/5 pass 0/5 pass 3/5 pass 150°C, 1h hot box 0/5 passed 0/5 pass 3/5 pass 3/5 pass
  • Comparative Example 1 only contained an aramid layer , Aramid fiber is prone to curling at high temperature, which causes the battery separator to curl easily at high temperature; while Comparative Example 2 only contains ordinary ceramic coating, which has collapsed and melted at 150°C, and cannot effectively isolate the positive and negative electrodes, and the battery will be short-circuited Combustion; Comparative Example 3 only contains high-temperature ceramic coating, and the membrane rupture temperature is 180°C; when baked at 150°C for 1 hour, the strength of the separator is low, and the positive and negative electrodes can no longer be effectively isolated, and the battery will short-circuit and burn.
  • Sampling Take a sample of 1 ⁇ 10 3 mm 2 from the diaphragm (the area of the sample can be ⁇ 1.5 ⁇ 10 3 mm 2 ), and the number of test points depends on the condition of the diaphragm (usually not less than 10 points).
  • Test The test is carried out with a 10,000-degree thickness measuring instrument at a temperature of 23 ⁇ 2°C.
  • Sampling For products with a width of less than 200mm: determine a point every 40mm ⁇ 5mm along the longitudinal (MD) direction, the number of test points is not less than 10, and the number of test points can be determined according to the width of the diaphragm. less than 20mm;
  • Test Test each test point with a thickness measuring instrument at a temperature of 23 ⁇ 2°C. The diameter of the measuring surface is between 2.5mm and 10mm, and the load applied to the sample on the measuring surface should be 0.5N ⁇ between 1.0N.
  • the overall porosity P of the sample can be calculated by the following formula:
  • m can be the mass of the sample
  • skeleton density ⁇ can be the material true density of the sample
  • V can be the volume of the sample.
  • a. Sampling cut a rectangular sample with a 237 ⁇ 170mm plate sampler. When cutting samples, keep as far away from the edge of the diaphragm as possible (for example, more than 50mm from the edge of the diaphragm).
  • the porosity is measured by the density method, including measuring n (n can be greater than or equal to 9) points of the sample, and the n points can be distributed in an equidistant lattice.
  • m i is the mass of each point
  • ⁇ is the skeleton density of the sample (can be calculated according to the material ratio)
  • V i is the total volume of each point (can be calculated according to the length, width and thickness of the sample );
  • the overall porosity P of the sample can be calculated by the following formula:
  • m can be the mass of the sample
  • skeleton density ⁇ can be the material true density of the sample
  • V can be the volume of the sample.
  • Test Test according to the method specified in the standard JIS P8117-2009. Specifically include: setting the pressure of the cylinder-driven pressure reducing valve to 0.25MPa, the test pressure to 0.05MPa, and selecting "JIS" as the test standard.
  • a. Sampling Cut 6 square samples with a 100 ⁇ 100mm plate sampler. When cutting samples, keep as far away from the edge of the diaphragm as possible (for example, more than 50mm from the edge of the diaphragm). Each sample is evenly distributed on the membrane (that is, the full width of the membrane is evenly divided to obtain 6 areas, and one sample is cut in each area of the 6 areas).
  • Test Test according to the method specified in the standard JIS P8117-2009. Specifically include: setting the pressure of the cylinder-driven pressure reducing valve to 0.25MPa, the test pressure to 0.05MPa, and selecting "JIS" as the test standard.
  • test needle fix the sample on the fixture in the center, the test needle is spherical (made of ruby) with a diameter of 1mm, ensure that the sample extends to or exceeds the edge of the clamping disc in all directions, and confirm that the sample is completely fixed on the ring fixture on, no slippage.
  • the diaphragm is punctured, and the speed of the machine is set at 300 ⁇ 10mm/min until the punctured ball completely breaks the sample, and the puncture resistance is the maximum force recorded during the test.
  • a. Sampling Cut 6 rectangular samples with a 237 ⁇ 170mm plate sampler. When cutting the sample, it should be as far away from the edge of the diaphragm as possible (for example, more than 50mm from the edge of the diaphragm). Each sample is evenly distributed on the membrane (that is, the full width of the membrane is evenly divided to obtain 6 areas, and one sample is cut in each area of the 6 areas).
  • test Test according to the method specified in the standard ASTMD4833-07. Specifically, it may include: the test needle is a spherical needle with a diameter of 1mm (the material is sapphire); fix the sample on the fixture in the center, ensure that the sample extends to or exceeds the edge of the clamping disc in all directions, and confirm that the sample is completely fixed in the ring There is no slippage on the fixture; during the test, the speed of the machine is set at 300 ⁇ 10mm/min, and the diaphragm is punctured until the test needle completely breaks the sample; the puncture resistance is the maximum force recorded during the test.
  • the test needle is a spherical needle with a diameter of 1mm (the material is sapphire); fix the sample on the fixture in the center, ensure that the sample extends to or exceeds the edge of the clamping disc in all directions, and confirm that the sample is completely fixed in the ring There is no slippage on the fixture; during the test, the speed of the machine is set at 300 ⁇ 10mm/min
  • a. Sampling On the overall width sample, cut the diaphragm according to the MD and TD directions respectively, and obtain multiple strip-shaped samples with a length ⁇ 50 mm and a width of about 15 ⁇ 0.1 mm (for MD testing, the sample The width of the sample can be along the TD direction of the diaphragm, and the length of the sample can be along the MD direction of the diaphragm; for TD testing, the width of the sample can be along the MD direction of the diaphragm, and the length of the sample can be along the TD direction of the diaphragm).
  • a. Sampling Cut 6 rectangular samples with a 237 ⁇ 170mm plate sampler. When cutting the sample, it should be as far away from the edge of the diaphragm as possible (for example, more than 50mm from the edge of the diaphragm). Each sample is evenly distributed on the diaphragm (that is, along the MD and TD directions of the diaphragm, the entire width of the diaphragm is evenly separated to obtain 6 regions, and one sample is cut in each region of the 6 regions). Afterwards, a strip-shaped sample with a length ⁇ 150 mm and a width 15 ⁇ 0.1 mm is cut by a sampler.
  • Test measure according to the method stipulated in GB/T1040.3-2006. Specifically include: the distance between the clamps can be 100 ⁇ 5mm, and the stretching speed can be 100 ⁇ 1mm/min.
  • Sampling Randomly cut 6 samples from the full width.
  • the specific sampling of each sample can include: cutting 100mm along the MD direction of the diaphragm; when the TD direction of the diaphragm is greater than 100mm, the length of the test sample in the TD direction can be 100mm; when the TD direction of the microporous membrane is less than 100mm , the length of the test sample in the TD direction can be based on actual conditions.
  • T can be the thermal shrinkage rate (%) of the sample
  • L 0 can be the length (mm) of the sample before heating
  • L can be the length (mm) of the sample after heating.
  • the temperature rise internal resistance method is used for testing.
  • the diaphragm is placed in a stainless steel fixture or other similar fixtures and injected with an appropriate amount of electrolyte.
  • the above fixture is placed in an oven, and the temperature is raised at a certain speed. At the same time, the resistance and temperature of the fixture are monitored. When the resistance value changes with the temperature to the initial resistance value The temperature corresponding to 10 times is the closed cell temperature of the diaphragm by default.
  • the membrane rupture temperature was measured by the baking method. Put the diaphragm in a 9*9cm fixture, put the above fixture in an oven, heat up at a certain speed, and monitor whether the diaphragm in the fixture is ruptured at the same time, when the diaphragm ruptures with the temperature change, record it as the rupture temperature of the diaphragm .
  • test After charging to 90% SOC in standard charging mode, test within 12-24 hours. Then put the battery in an explosion-proof box at 25°C, and pierce the steel nail into the center of the battery cell at a speed of 150mm/s until it penetrates, and then withdraw the needle after 10 minutes. If the battery is not thermally out of control, the test is passed, and the pass rate of the test is recorded.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Cell Separators (AREA)

Abstract

La présente demande concerne le domaine technique des séparateurs de batterie, et concerne un séparateur composite, un appareil électrochimique, un dispositif électronique et un terminal mobile. Le séparateur composite comprend une couche de polyoléfine, une couche composite qui est liée à une surface ou aux deux surfaces latérales de la couche de polyoléfine et comprend une couche de mélange, et une couche d'aramide qui est liée à une surface latérale de la couche de mélange, la couche de mélange et la couche d'aramide étant empilées avec la couche de polyoléfine. La couche de mélange comprend un aramide et des premières particules de céramique, et la surface des premières particules de céramique est liée à un agent de couplage, l'agent de couplage contenant un groupe inorganophile et un groupe organophile, et l'agent de couplage est lié à la surface des premières particules de céramique au moyen du groupe inorganophile, et est lié à l'aramide au moyen du groupe organophile. Le séparateur composite selon la présente demande présente une température de rupture de film supérieure à 240 °C et un taux de retrait thermique inférieur à 4 % à 150 °C/1 h, et peut résoudre efficacement le problème des risques potentiels de sécurité d'une batterie provoqué par un emballement thermique qui se produit pendant un court-circuitage de la batterie en raison d'un séparateur sujet au retrait thermique et à la fusion.
PCT/CN2022/108337 2021-07-31 2022-07-27 Séparateur composite, appareil électrochimique, dispositif électronique et terminal mobile WO2023011293A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110877240.XA CN115693024A (zh) 2021-07-31 2021-07-31 复合隔膜、电化学装置、电子设备和移动终端
CN202110877240.X 2021-07-31

Publications (1)

Publication Number Publication Date
WO2023011293A1 true WO2023011293A1 (fr) 2023-02-09

Family

ID=85059913

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/108337 WO2023011293A1 (fr) 2021-07-31 2022-07-27 Séparateur composite, appareil électrochimique, dispositif électronique et terminal mobile

Country Status (2)

Country Link
CN (1) CN115693024A (fr)
WO (1) WO2023011293A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118054158A (zh) * 2024-04-15 2024-05-17 深圳欣界能源科技有限公司 一种复合阻燃隔膜及其制备方法和应用

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104868156A (zh) * 2014-12-22 2015-08-26 上海恩捷新材料科技股份有限公司 锂离子电池
CN108711603A (zh) * 2018-04-27 2018-10-26 青岛蓝科途膜材料有限公司 一种芳纶聚合物涂布有色陶瓷涂覆膜及其制备方法
CN109935760A (zh) * 2019-04-12 2019-06-25 重庆云天化纽米科技股份有限公司 杂化芳纶涂覆的锂电池复合隔膜及其制备方法
CN110048063A (zh) * 2019-03-25 2019-07-23 重庆云天化纽米科技股份有限公司 无机纳米颗粒改性芳纶浆液及芳纶涂覆的锂电池复合隔膜
CN111509168A (zh) * 2019-01-31 2020-08-07 青岛蓝科途膜材料有限公司 一种具有耐高温涂层的锂离子电池隔膜及其制备方法
CN111969160A (zh) * 2020-08-31 2020-11-20 佛山市金辉高科光电材料股份有限公司 复合锂离子电池隔膜及其制备方法和锂离子电池、电子产品

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104868156A (zh) * 2014-12-22 2015-08-26 上海恩捷新材料科技股份有限公司 锂离子电池
CN108711603A (zh) * 2018-04-27 2018-10-26 青岛蓝科途膜材料有限公司 一种芳纶聚合物涂布有色陶瓷涂覆膜及其制备方法
CN111509168A (zh) * 2019-01-31 2020-08-07 青岛蓝科途膜材料有限公司 一种具有耐高温涂层的锂离子电池隔膜及其制备方法
CN110048063A (zh) * 2019-03-25 2019-07-23 重庆云天化纽米科技股份有限公司 无机纳米颗粒改性芳纶浆液及芳纶涂覆的锂电池复合隔膜
CN109935760A (zh) * 2019-04-12 2019-06-25 重庆云天化纽米科技股份有限公司 杂化芳纶涂覆的锂电池复合隔膜及其制备方法
CN111969160A (zh) * 2020-08-31 2020-11-20 佛山市金辉高科光电材料股份有限公司 复合锂离子电池隔膜及其制备方法和锂离子电池、电子产品

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118054158A (zh) * 2024-04-15 2024-05-17 深圳欣界能源科技有限公司 一种复合阻燃隔膜及其制备方法和应用

Also Published As

Publication number Publication date
CN115693024A (zh) 2023-02-03

Similar Documents

Publication Publication Date Title
CN108878751B (zh) 导电陶瓷复合隔膜和固态电池
CN111326697B (zh) 一种涂覆的隔膜及其制备方法
WO2018040903A1 (fr) Séparateur de batterie au lithium-ion et son procédé de préparation , et batterie au lithium-ion
JP6173328B2 (ja) 耐熱性及び安定性に優れたポリオレフィン系複合微多孔膜
JP6872932B2 (ja) 蓄電デバイス用セパレータ
WO2022161088A1 (fr) Matériau de revêtement pour séparateur de batterie au lithium-ion léger, son procédé de préparation et séparateur composite de batterie au lithium-ion léger
WO2014083988A1 (fr) Séparateur pour batteries secondaires non aqueuses, et batterie secondaire non aqueuse
CN103618059A (zh) 一种高分子无机涂层锂离子电池隔膜及其制备方法
JP5439772B2 (ja) 多孔性フィルムおよび蓄電デバイス
CN112521616B (zh) 接枝陶瓷粉体及制备方法、陶瓷隔膜及制备方法、锂离子电池、电池模组和电池包
CN112216928A (zh) 一种改性复合耐热锂离子电池隔膜及其制备方法
JP6378998B2 (ja) 蓄電デバイス用セパレータの製造方法
CN112072047B (zh) 一种溶胶涂层隔膜及其制备方法
CN112701417A (zh) 一种聚乙烯基膜、锂电池隔膜浆料及其制备的锂电池隔膜
WO2023011293A1 (fr) Séparateur composite, appareil électrochimique, dispositif électronique et terminal mobile
CN113161692A (zh) 陶瓷涂层、陶瓷涂覆隔膜及其制备方法与应用
CN110660947B (zh) 电池隔膜及其制备方法和锂离子电池及电动汽车
JP6404512B1 (ja) 非水系電解液電池用セパレータおよび非水電解液電池
WO2023138287A1 (fr) Séparateur composite, appareil électrochimique et borne
CN116454534A (zh) 一种芳纶纳米纤维/导电涂层涂覆聚烯烃复合隔膜及其制备方法和应用
WO2023071543A1 (fr) Séparateur composite, appareil électrochimique et dispositif électronique
CN114883746A (zh) 一种新型聚酰亚胺微球浆料及其涂覆隔膜
TW201351759A (zh) 離子聚合物膜材料及其製備方法和鋰二次電池
CN113540691A (zh) 一种锂离子电池隔膜及其制备方法、锂离子电池
JP7557563B2 (ja) 非水系二次電池用セパレータ及び非水系二次電池

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22852007

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22852007

Country of ref document: EP

Kind code of ref document: A1