CN219321558U

CN219321558U - Battery separator with thermally inert protective structure and apparatus for making same

Info

Publication number: CN219321558U
Application number: CN202221724894.5U
Authority: CN
Inventors: C·格伦·温斯利; 卡洛斯·R·纳格力特; 吉尔·V·沃森
Original assignee: Celgard LLC
Current assignee: Celgard LLC
Priority date: 2022-07-06
Filing date: 2022-07-06
Publication date: 2023-07-07
Anticipated expiration: 2032-07-06

Abstract

A battery separator having a thermally inert protective structure and apparatus for its manufacture, said microporous battery separator comprising: a separator first layer which is a microporous membrane; and a separator second layer which is a three-dimensional porous structure surface layer deposited on at least one side of the microporous film, wherein the separator second layer is a gel coating, a precipitation coating or an electrostatic filament deposition layer containing a high glass transition temperature polymer, is saturated with air bubbles, forms a thermal inert protection structure, and forms a thermal inert protection structure for the separator first layer, thereby the separator first layer still does not melt above the melting temperature thereof, still maintains the size and the structural integrity, and still ensures that the separator first layer and the separator second layer are independently molded with each other, so that the battery continues to operate for at least 5 minutes; regarding the diameter of the heat-spreading hole of the battery separator, the maximum value of the present utility model is also smaller than the minimum value of the prior art.

Description

Battery separator with thermally inert protective structure and apparatus for making same

Technical Field

The present utility model relates to a battery separator having a thermally inert protective structure such that the back mesh layer of the battery separator does not excessively heat up even in a state where the ambient temperature is higher than the melting point of the back mesh layer of the battery separator, thereby remaining at a temperature below the melting point thereof, and thus the battery separator can still normally operate under such extreme conditions, and the battery can still exert a normal power supply function for a certain period of time. The utility model also relates to a manufacturing device of the battery separator with the thermal inertia protection structure.

Background

In the prior art, battery separators have a surface coating. The surface coating itself can withstand high temperatures but is not thermally insulating. That is, the surface coating itself may transfer heat, be thermally conductive. Therefore, even though the surface coating itself can withstand a high temperature of 260 ℃ or higher, the substrate of the battery separator also rises to 260 ℃ at a high temperature of 260 ℃. However, the melting point of the polyolefin material as the battery separator substrate is only 120 ℃ to 140 ℃, and at an ambient temperature of 260 ℃, the polyolefin material as the battery separator substrate has already melted, loses its microporosity or porosity, ions can no longer pass therethrough, the separator can no longer function normally, and the battery can not perform a normal power supply function.

Therefore, in the prior art, the coating of the battery separator can realize high temperature resistance and oxidation resistance, but the working temperature of the battery separator is still 120-140 ℃, and the working temperature limit of the battery cannot be improved.

In fact, the prior art adopts the battery separator with the high-temperature-resistant surface coating, and only solves the problem of oxidization resistance of the battery separator.

The art is constantly striving to produce lithium ion rechargeable batteries that close at extremely high temperatures. Celgard, LLC, charlotte, north Carolina, manufactures polyolefin lithium ion rechargeable battery separators, but the market expects high temperature retrofit or new battery separators, high melt temperature microporous lithium ion rechargeable battery separators, membranes, composites, components, etc., that will remain at elevated temperatures for a period of time while still preventing shorting between anode and cathode.

There is also a need in the marketplace for improved or new battery separators for certain high temperature applications, high melt temperature coated microporous lithium ion rechargeable battery separators, high melt temperature microporous lithium ion rechargeable electrostatic wire coated battery separators, electrostatic wire separators, and the like, and/or lithium ion rechargeable batteries including one or more such coated separators, electrostatic wire separators, and the like.

There is a strong market demand for a battery separator that will not melt even at ambient temperatures above the melting temperature of its substrate, will remain dimensionally and structurally intact, will still ensure that the substrate and the skin are formed independently of each other, and will ensure that the battery will continue to operate at least in part for at least 5 minutes, at least 15 minutes, and even 60 minutes.

Disclosure of Invention

It is an object of the present utility model to provide a microporous battery separator with a thermally inert protective structure such that the separator first layer remains unmelted above its melting temperature, remains dimensionally and structurally intact, and yet is formed independently of the separator first layer and the separator second layer such that the battery continues to operate for at least a portion of at least 5 minutes, at least 15 minutes, or at least 60 minutes.

It is another object of the present utility model to provide an apparatus for manufacturing a microporous battery separator which can form a thermally inert protective structure to the separator first layer such that the separator first layer remains unmelted above its melting temperature, remains dimensionally and structurally intact, and yet ensures that the separator first layer and the separator second layer are formed independently of each other such that the battery continues to operate for at least a portion of at least 5 minutes, at least 15 minutes, or at least 60 minutes.

To this end, according to a first aspect of the present utility model, there is provided a microporous battery separator having a thermally inert protective structure comprising: a separator first layer which is a microporous membrane; and a baffle plate (a)Two layers which are three-dimensional porous surface layer structures deposited on at least one side of the microporous film, wherein the second layer of the separator is a gel coating, a precipitation coating or an electrostatic silk deposition layer containing high glass transition temperature polymer, is saturated with air bubbles and forms a thermal inert protection structure, and forms a thermal inert protection structure for the first layer of the separator, so that the first layer of the separator still does not melt above the melting temperature of the first layer of the separator, still keeps the size and the structure intact, still ensures that the first layer of the separator and the second layer of the separator are independently molded with each other, and the battery continues to operate at least partially for at least 5 minutes, at least 15 minutes or at least 60 minutes; diameter of heat propagation hole of the battery separator

The method meets the following conditions: the maximum value is also smaller than the minimum value in the prior art.

Preferably, the method comprises the steps of,

or->

In the prior art

The microporous membrane is a pretreatment membrane;

the coating is a coating;

the microporous film itself is a single layer film, a double layer film, a three layer film, or a multilayer film;

the microporous battery separator is a high melting temperature microporous battery separator; and/or the number of the groups of groups,

the microporous film is a self-sustaining high glass transition temperature polymer film.

Preferably, the microporous battery separator is used in a lithium ion rechargeable battery, cell, stack, cell, accumulator, or capacitor.

Preferably, a microporous inner wall coating is provided within a plurality of micropores in the microporous film;

the material of the microporous inner wall coating is different from or the same as the material of the second layer of the separator;

the two surfaces of the first layer of the separator are respectively provided with a positive electrode rib and a negative electrode rib, and the negative electrode rib is provided with at least one bubble rising channel arranged along the up-down direction along the left-right direction;

the rising channel is positioned between the two areas; the ascending channel is a straight channel or a curve channel;

at least one area is internally provided with ribs which are at least partially not parallel to the left-right direction and the up-down direction;

At least one region is provided with at least partially intermittent ribs; at least one region having a continuous rib at least partially notched therein;

at least one area is internally provided with parallel ribs with at least part of different heights; at least one area is provided with ribs with at least part of cross sections being narrow at the upper part and wide at the lower part;

at least one area is provided with ribs with at least part of cross-section side surfaces being curved or straight;

at least one region is provided with at least partially curved or wavy ribs;

at least one area is internally provided with ribs which are at least partially arranged in a matrix; at least one area is internally provided with a rib array which is at least partially arranged in bilateral symmetry; and/or

At least one area is provided with a rib array with at least part of row spacing changing.

According to a second aspect of the present utility model there is provided a lithium ion rechargeable battery comprising a microporous battery separator according to the present utility model.

According to a third aspect of the present utility model, there is provided an apparatus for manufacturing a microporous battery separator, comprising:

a coating liquid applying device for applying a solution containing a high glass transition temperature polymer on the advancing microporous film;

at least one sequentially arranged gel dipping tanks arranged downstream of the coating liquid applying device; and

The microporous film moving out of the gelation dipping tank continuously moves forward and enters the drying box to be dried;

the distance between the coating liquid applying device and the nearest gelling and impregnating tank is as small as possible; the coating liquid applying device performs operation in a vacuum environment; and/or, the inlet and the outlet between the microporous membrane and the gelation impregnation tank are provided with sealing members,

thus, the microporous film from the upstream extrusion, rolling or unwinding device is deposited onto the microporous film during its advancement and the solvent of the coating solution is removed to create a three-dimensional porous structure in the high glass transition temperature polymer coating, forming an adiabatically deposited layer of the microporous film, forming a thermally inert protective structure for the separator first layer, thereby allowing the separator first layer to remain unmelted above its melting temperature, yet remain dimensionally and structurally intact, yet still ensuring that the separator first layer and the separator second layer are formed independently of each other, such that the battery continues to operate at least partially for at least 5 minutes, at least 15 minutes, or at least 60 minutes.

Preferably, the manufacturing apparatus further includes a tenter that further dries the microporous film moving out of the drying box and prevents the microporous film from shrinking or curling.

Preferably, the manufacturing apparatus further comprises an advancing direction guide of the microporous film.

Preferably, the manufacturing apparatus further comprises a vacuum sealing means of the gel impregnation tank.

According to a fourth aspect of the present utility model, there is provided an apparatus for manufacturing a microporous battery separator comprising:

a syringe for containing the noodle-type deposition surface layer solution, the nozzle of the syringe having a freely swingable capillary tip from which the noodle-type deposition surface layer solution is ejected in random directions and thrown toward a direction in which the object is an electric field ground plate;

an electric field retainer disposed between said injector and said electric field ground plate such that during pulling of the noodle deposition skin solution from said capillary tips thereof to the electric field ground plate, the noodle deposition skin solution is deposited as long as possible on the microporous film surface as the first layer of the separator plate to form the second layer of the separator plate, which forms a thermally inert protective structure to the first layer of the separator plate, thereby allowing the first layer of the separator plate to remain unmelted above its melting temperature, remain dimensionally and structurally intact, and remain formed independently of each other between said first layer of the separator plate and said second layer of the separator plate, such that the battery continues to operate at least partially for at least 5 minutes, at least 15 minutes, or at least 60 minutes.

Preferably, the extrusion device extrudes a flat film without ribs or the microporous film with longitudinal ribs and/or with transverse ribs, the longitudinal ribs being formed by longitudinal grooves of the extrusion device and the transverse ribs being formed by roll surface grooves of an extrusion roll of the extrusion device; or alternatively

The roll press device forms a flat film without ribs or the microporous film with longitudinal ribs formed by the circumferential grooves of the extrusion rolls of the extrusion device and/or with transverse ribs formed by the roll surface grooves of the extrusion rolls of the extrusion device.

According to a fifth aspect of the present utility model there is provided a microporous battery separator directly obtainable by a manufacturing apparatus according to the present utility model, the separator second layer of which forms a thermally inert protective structure for the separator first layer, whereby the separator first layer remains unmelted above its melting temperature, remains dimensionally and structurally intact, and is still ensured to be formed independently of each other between the separator first layer and the separator second layer, such that the battery continues to operate at least partially for at least 5 minutes, at least 15 minutes or at least 60 minutes.

The present utility model relates to high melting temperature microporous lithium ion rechargeable battery separators, membranes, films, composites, components, etc., that can still prevent shorting between anode and cathode when the battery is at extremely high temperatures for a period of time; systems for manufacturing, testing and/or using such separators, membranes, composites, components, and the like; and/or lithium ion rechargeable batteries including one or more such separators, membranes, composites, and the like.

The present utility model is an improved or novel battery separator for use in at least some high temperature environments; a high melting temperature coated microporous lithium ion rechargeable battery separator; a high melting temperature microporous lithium ion charged electrostatic filament coated battery separator; an electrostatic wire separator; systems for making and/or using such coated separators, electrostatic filament films; and/or lithium ion rechargeable batteries including one or more such coated separators, electrostatically deposited wire separators, and the like.

The field of lithium ion batteries is directed to obtaining lithium ion rechargeable batteries capable of operating normally at high temperatures (e.g., at about 160 ℃, about 180 ℃, about 200 ℃, about 220 ℃ or higher) at least partially for at least a short period of time. Such partially normal operation includes at least maintaining the anode and cathode of the cell physically separated at high temperature for at least a short period of time, and may also include closing or turning off, fully closing, partially closing, allowing or providing at least partial ion flow, or even complete ion flow, between the electrodes. For example, one layer of the battery separator may be closed at about 130 ℃, but the other layer of the battery separator remains physically separated from the battery anode and cathode at about 160 ℃, about 180 ℃, about 200 ℃, about 220 ℃ or more for at least 5 minutes, 15 minutes, or even 60 minutes, i.e.: and partially operates normally at high temperatures.

In one embodiment, the battery separator may hold the battery anode and cathode physically apart for at least 5 minutes, at least 15 minutes, or at least 60 minutes, and begin to close at 130 ℃, providing full closure (no ion flow) between the electrodes at about 160 ℃. In another embodiment, the battery separator maintains the battery anode and cathode physically separated for at least 5 minutes, at least 15 minutes, or at least 60 minutes at about 180 ℃. In another embodiment, the battery separator maintains the battery anode and cathode physically separated for at least 5 minutes, at least 15 minutes, or at least 60 minutes at about 200 ℃. In another embodiment, the battery separator maintains the battery anode and cathode physically separated for at least 5 minutes, at least 15 minutes, or at least 60 minutes at about 250 ℃ or above.

The high temperature separator has at least one layer or component having a high melting temperature of >160 ℃, >180 ℃, >200 ℃, or >220 ℃ and has a high degree of dimensional or structural integrity required to still prevent shorting between anode and cathode when the battery is at extremely high temperatures for a period of time of at least 5 minutes, at least 15 minutes, or at least 60 minutes, and preferably is closed at 130 ℃.

Preferably, the high temperature separator has a high melting temperature of >180 ℃ or >200 ℃ and has the high degree of dimensional or structural integrity required to still prevent shorting between anode and cathode when the cell is at extremely high temperatures for a period of time.

Preferably, the high temperature separator has at least one temperature (T) _g ) Is about 250 ℃ or higher (high T) _g Polymer) and T in electrolyte _g Inhibit at about 50 ℃ or less (effective T in electrolyte _g About 200 ℃ or greater) and has at least one layer having a high degree of dimensional or structural integrity sufficient to prevent shorting between the anode and cathode when the cell is at an extremely high temperature for a period of time. High T _g The polymer is soluble in at least one solvent or solvent mixture and has a high T _g The polymer is soluble in at least one moderately volatile solvent, such as DMAc.

The high melting temperature separator has at least one layer having a high level of dimensional and/or structural integrity sufficient to prevent shorting between anode and cathode when the battery is at an extremely high temperature, preferably >160 ℃, >180 ℃, >200 ℃, or >220 ℃, for a period of time, preferably at least 5 minutes, at least 15 minutes, or at least 60 minutes, and preferably providing closure at about 120 ℃, 125 ℃, or 130 ℃. Such separators are so-called "high temperature melt integrity separators with closure".

According to the utility model, either a high melting temperature battery separator comprising a porous membrane coated on at least one side with a high glass transition temperature (T _g ) The polymer or blend (referred to as a "binder" when used with fillers or particles) is either a freestanding porous film (single or multi-layer sheet) having at least one high T _g Layers made of polymers or blends, preferably non-thermosetting, high T _g Polymers or co-polymersAnd (3) mixing. High T _g The polymer is soluble in at least one solvent or solvent mixture, and preferably in at least one moderately volatile solvent, such as DMAc.

Preferably, the high temperature separator has at least one temperature (T) _g ) T at about 250 ℃ or above and in the electrolyte _g Inhibit at about 50 ℃ or less (effective T in electrolyte _g About 200 ℃ or above) high T _g A layer of polymer, and having the high degree of dimensional or structural integrity required to still prevent shorting between anode and cathode when the cell is at extremely high temperatures for a period of time. Preferably, the height T _g The polymer is soluble in at least one solvent or solvent mixture, preferably in at least one moderately volatile solvent.

It is at least one object of the present utility model to provide a high melting temperature microporous lithium ion rechargeable battery separator, membrane, film or composite having at least one layer, component or coating capable of maintaining its physical structure in a lithium ion rechargeable battery (battery, cell, stack, accumulator, capacitor, etc.) up to 200 ℃ or 250 ℃ for at least a short period of time. Preferably, the separator, membrane or composite comprises at least one layer consisting of or comprising one or more polymers having an effective glass transition temperature (T) in the electrolyte of greater than 160 ℃, greater than 180 ℃ or at least 200 ° _g ). Preferably, the separator, membrane or composite comprises a polymer having a glass transition temperature (T) _g ) Such as polyimidazoles, polybenzimidazoles (PBI), polyimides, polyamideimides, polyaramides, polysulfones, aromatic polyesters, polyketones, and/or blends, mixtures, and combinations thereof.

Preferably, the separator, membrane or composite comprises a single or double sided high T applied to a microporous base membrane or membrane _g A polymeric microporous coating (with or without high temperature fillers or particles) or consisting of said microporous coating; is self-sustaining high T _g Polymeric microporous separators or membranes (with or without high temperature fillers or particles); alternatively, a bagIncludes at least one high T _g A polymeric microporous layer (with or without high temperature fillers or particles).

Preferably, the battery separator comprises a single or double sided high T of an electrostatic silk-coated coating applied to a microporous substrate film or membrane _g A polymeric microporous coating or consisting of said microporous coating. Preferably, the separator is a high melting temperature battery separator composed of a porous film having a high T on at least one side thereof _g Electrostatic silk-deposited nanofiber coating of polymer, and preferably having a coating on both sides, said high T _g The polymer is preferably Polybenzimidazole (PBI) or a blend of PBI with other polymer or polymers. Although PBI is preferred, blends of PBI with another polymer or polymers such as polyaramid, polyimide, polyamideimide, polyvinylidene fluoride, copolymers of polyvinylidene fluoride, and blends, mixtures, and/or combinations thereof may also be used.

It is at least one object of the present utility model to provide a high melting temperature coated or electrostatic wire-coated microporous lithium ion rechargeable battery separator or membrane that can maintain its physical structure in a lithium ion rechargeable battery (cell, stack, battery, accumulator, capacitor, etc.) up to 250 ℃ for at least a short period of time.

Preferably, the separator or membrane has an electrostatic silk-deposited nanofiber coating of Polybenzimidazole (PBI) or a blend of PBI with another polymer or polymers applied to at least one side thereof, and preferably has a coating on both sides of the microporous substrate membrane.

Preferably, the electrostatic silk nanofiber coating is comprised of nanoscale PBI fibers having diameters ranging from 10 to 2,000 nanometers, from 20 to 1,000 nanometers, from 25 to 800 nanometers, or from 30 to 600 nanometers. The target basis weight of the nano-grade PBI electrostatic deposition wire coating of the high melting temperature microporous lithium ion rechargeable battery diaphragm is 1.0 to 8.0g/m ² 2.0 to 6.0g/m ² 2.2 to 5.0g/m ² Or 2.5 to 5.0g/m ² 。

Preferably, the electrostatic silk nanofiber is flat and non-porous when viewed by SEM at 5,000x magnification. The electrostatic filament process can deposit nanoscale PBI fibers on the surface of a microporous film of a substrate in a random fashion, similar to spaghetti strands dispersed on the surface.

The electrostatic filament coating system can be used for coating high T _g The polymer is coated onto the microporous porous membrane without adversely affecting the pore structure or porosity of the porous base membrane, said high T _g The polymer may be PBI or a blend of PBI with another polymer or polymers, which may be polyaramid, polyimide, polyamideimide, and blends, mixtures and/or combinations thereof, i.e.: the nanoscale electrostatic silk-accumulating fibers do not block the pores of the substrate film. The electrostatic filament deposition process will take the form of nano-sized fibers with high T _g The polymer is applied to the microporous substrate membrane and the nanofibers themselves need not be porous. The interstices between the electrostatic filament nanofibers provide the desired openings or porosity. Does not need to be in electrostatic silk accumulating nanometer level high T _g Holes are formed in the polymer fibers. In the electrostatic filament deposition process, the high T is _g The polymer or polymers are dissolved in a solvent or solvents. The solvent evaporates during the formation of the electrostatic filament deposition fibers.

In general, dip coating or gravure coating of the polymer applied to the microporous substrate film may require immersing the coated film in a bath for removing the polymer solvent. Will be high T _g The application of the polymer to the microporous film or electrostatic filament deposition for forming a free standing film is simpler because no impregnation or extraction is required to remove the solvent in order to form the porous structure in the coating. The electrostatic deposition wire can be used for increasing the T level of the nanometer level _g The polymer fibers are applied to microporous films to produce high melting temperature microporous lithium ion rechargeable battery separators or membranes at a relatively low cost.

In one embodiment, the high T _g The polymer is dissolved in at least one moderately volatile solvent to form a polymer having a high T _g The polymer is coated onto a microporous substrate film made from a thermoplastic polymer. Thermoplastic polymers include, but are not limited to, polyolefins such as polyethylene, polypropylene, polymethylpentene, and/or blends, mixtures, or combinations thereof. PolyolefinThe hydrocarbon microporous substrate film may be derived from Celgard, LLC of charlotte, north carolina. Microporous substrate films can be made by Celgard, LLC of Charlotte, north Carolina

A dry stretching process or a wet process (i.e., a phase separation or extraction process) by korean Celgard Korea Inc, asahi of japan and Tonen of japan. The substrate film may be a single or multiple layer polypropylene or polyethylene, or a multiple layer film, such as a three layer film, for example polypropylene/polyethylene/polypropylene (PP/PE/PP) or polyethylene/polypropylene/polyethylene (PE/PP/PE), a double layer film (PP/PE or PE/PP), or the like.

Some base films or films such as polypropylene may require pretreatment to alter the surface properties of the film and increase the high T _g Adhesion of polymer coating or nanoscale electrostatic filament fibers to one or both sides of the substrate film. Pretreatment may include, but is not limited to, priming, stretching, corona treatment, plasma treatment, and/or coating, such as a surfactant coating on one or both sides thereof.

The battery separator according to the present utility model has a heat insulating surface layer (thermal insulating barrier layer), so that the base material is not dissolved even at high temperatures higher than its melting point, and insulation between the anode and the cathode is maintained to ensure the normal operation of the battery.

The coating according to the utility model is a three-dimensional structure of a gel coating, a precipitate coating, or a porous air-saturated structure formed by electrospinning, and is not a two-dimensional coating formed by solvent evaporation, drying, which determines its adiabatic function.

According to the utility model, the separator second layer forms a thermally inert protective structure for the separator first layer, whereby the separator first layer remains unmelted above its melting temperature, remains dimensionally and structurally intact, and is still ensured to be formed independently of each other between the separator first layer and the separator second layer, such that the cell continues to operate at least partially for at least 5 minutes, at least 15 minutes, or at least 60 minutes.

Drawings

FIG. 1 is a side view of one embodiment of the present coating process and film path.

Fig. 2 is a typical thermal resistance thermogram.

Fig. 3 is a schematic view of the structural principle of a polymer solution being spun into electrospun fibers by an electrostatic filament fiber forming apparatus.

Fig. 4 is a side view of a hot tip hole propagation testing device.

FIG. 5 is a surface SEM micrograph of a PBI electrostatic filament coating showing 5,000Xmagnification.

FIG. 6 is a surface SEM micrograph of a PBI electrostatic filament coating showing 20,000Xmagnification.

FIG. 7 is an uncoated control sample, 1-sided and 2-sided electrodeposited wire coated PBI

Thermal resistance thermogram of M824 membrane.

FIG. 8 is an uncoated control sample, 1-sided and 2-sided electrodeposited wire coated PBI

Expansion e-TMA thermogram of M824 membrane.

FIG. 9 is a thermal profile of the expansion thermodynamic analysis (e-TMA) of 13 μm control substrate film (uncoated) and film examples 1-5 (coated).

FIG. 10 is thermal resistance thermograms of 13 μm control and examples 1-4.

FIG. 11 is a surface SEM micrograph of 5,000Xmagnification according to example 4.

FIG. 12 is a cross-sectional SEM micrograph of 10,000Xmagnification according to example 4.

Fig. 13 is a surface SEM micrograph at 5,000x magnification according to example 3.

Fig. 14 is a cross-sectional SEM micrograph at 5,000x magnification according to example 3.

Fig. 15 is a 5,200x magnification SEM micrograph of a cross-section of the coating according to example 5.

FIG. 16 is a thermal profile of the expansion thermodynamic analysis (e-TMA) of the 16 μm control example, example 6 and example 2.

FIG. 17 is a thermal resistance test thermogram of 16 μm control example, example 6 and example 2.

Fig. 18 is a surface SEM micrograph at 20,000x magnification according to example 6.

Fig. 19 is a corresponding cross-sectional SEM micrograph at 830x magnification (left panel) and 2,440x magnification (right panel) according to example 6.

FIG. 20 is a surface SEM micrograph of 20,000Xmagnification according to example 2.

Fig. 21 is a corresponding cross-sectional SEM micrograph at 2,480 x magnification (left panel) and 13,300x magnification (right panel) according to example 2.

Fig. 22 is a corresponding cross-sectional SEM micrograph at 4,380 magnification (left panel) and at 12,100x magnification (right panel) according to example 2.

FIG. 23 is a control sample coated with surfactant and a 2-sided PBI coated

Thermal resistance thermogram of 3401 film.

FIG. 24 is a control sample coated with surfactant and a 2-sided PBI coated

Expansion e-TMA thermogram of 3401 film.

Detailed Description

In the present utility model, each of the related terms is defined as follows:

the term "high melting temperature" refers to temperatures >160 ℃, even >250 ℃.

The term "high melting temperature microporous battery separator" refers to a battery separator whose coating comprises a high glass transition temperature polymer (i.e., the temperature T of the glass transition of the polymer _g High), has a sufficient degree of dimensional or structural integrity to permit the battery to be placed in a battery>When maintained at a temperature of 160 ℃ for at least 5 minutes, short circuits between the anode and cathode are prevented and the cell is allowed to function at least partially normally at that temperature and the first and second layers are formed independently of each other. Preferably, said T _g The polymer has a T of greater than 165 ℃, greater than 180 ℃, or at least 250 DEG C _g The method comprises the steps of carrying out a first treatment on the surface of the The T is _g The polymer is soluble in at least one moderately volatile solvent; the T is _g The polymer is selected from: focusing microphoneOxazole, polybenzimidazole (PBI), polyimide, polyamideimide, polyaramid, polysulfone, aromatic polyester, polyketone, and combinations thereof; preferably said T _g The polymer is Polybenzimidazole (PBI). The high melting temperature microporous battery separator is closed at about 130 ℃, still maintaining the anode and cathode physically separated at about 160 ℃, still without any portion melting, and allowing the battery to at least partially function properly at that temperature.

The term "coating" refers to a high T _g A gelled or precipitated coating of a polymer, or an electrostatically deposited layer of filaments. Preferably, the coating further comprises vapor phase alumina; the coating is applied as a coating solution or slurry of PBI, alumina particles, and DMAc.

The term "microporous film" is a thermoplastic polymer which is a polyolefin selected from the group consisting of: polyethylene, polypropylene, polymethylpentene, and combinations thereof; preferably, the microporous film is manufactured by a dry stretching process or a wet process. The microporous film is at least one of the following: polyolefin film, polypropylene film, polyethylene film, and three-layer separator; the microporous film comprises a high T _g Polymers, or containing high T _g Blends of polymers.

The term "pretreatment" refers to altering the surface properties of the microporous film and increasing the high T _g Adhesion of a polymer coating to the microporous film, the pretreatment is performed on one or both sides of the microporous film, including priming, stretching, corona treatment, plasma treatment, coating such as surfactants, and combinations thereof.

The term "coating" means that the high T _g A polymer coating is applied to the microporous film by a coating step followed by a dipping step, wherein a high T is applied _g Immersing the coating film in a gelling bath to precipitate a high T _g The polymer is again removed for high T _g Solvents for polymers to form high T _g A porous coating or layer; or will be high T _g Immersing the coating film in a bath to precipitate a high T _g A polymer.

The term'The term "electrodeposited filament layer" refers to a layer/layers of high T _g A coating of polymer electrostatic silk-deposited nanofibers onto at least one side of the microporous film; preferably, the diameter of the nanofibers is in the range of 30-600 nanometers; the coating has a basis weight of 2.0-6.0g/m ² Within the range; and the continuous resistance of the separator is up to 200 ℃.

The term "coating liquid application device" refers to a device that applies a coating liquid on at least one surface of a microporous film by a doctor blade, a coating die, a meyer rod, or a direct/reverse gravure roll; the solvent of the coating liquid is dissolved with high T _g A polymer; the solvent may be dimethylacetamide (DMAc), 1, 4-dioxane, acetone, N-methylpyrrolidone, etc.; the coating liquid can also contain: for a high T _g A non-solvent for the polymer; crosslinking agents, such as dihalides, dialdehydes or acid dichlorides; a surfactant to improve coating uniformity; inorganic particles, e.g. A1 ₂ O ₃ 、TiO ₂ 、CaCO ₃ 、BaSO ₄ Silicon carbide, boron nitride; and/or organic polymers, such as powdered PTFE, which are chemically inert and have a small particle size<2 micrometers or<1 micron), drying and high melting temperature.

The term "gel impregnation cell" may consist of a single cell consisting of a mixture of non-solvents or non-solvents, or a series of cells; instead of the last series of cells having a series of mixtures comprising a solvent and one or more non-solvents, the last series of cells is made up of a mixture of non-solvents or non-solvents.

As shown in fig. 1, a back web 1 of a microporous battery separator according to the present utility model has a thermally inert protective structure 2. The battery separator includes: a separator first layer 1 which is a microporous membrane 11; and a separator second layer 2 which is a three-dimensional porous skin structure deposited on at least one side of the microporous membrane 11, the separator second layer 2 being a gel coat 2, a precipitate coat 2, or an electrostatic filigree deposit layer 2 comprising a high glass transition temperature polymer, being saturated with air bubbles, constituting a thermally inert protective structure 2, forming a thermally inert protective structure 2 for the separator first layer 1, whereby the separator first layer 1 remains unmelted above its melting temperature, remains dimensional and structural integrity, and is still ensured to be formed independently of each other between the separator first layer 1 and the separator second layer 2, such that the battery continues to operate at least partially for at least 5 minutes, at least 15 minutes, and even at least 60 minutes.

Diameter of heat propagation hole of the battery separator

The method meets the following conditions: />

Preferably, the method comprises the steps of,

more preferably, the process is carried out,

whereas in the prior art->

Thus, according to the microporous battery separator of the present utility model, the diameter of the heat spreading holes

Also the maximum value of (2) is significantly smaller than the minimum value of the prior art.

In one embodiment, the microporous membrane 11 is a pre-treated membrane to improve the bond strength and reliability between the separator first layer 1 and the separator second layer 2 of the illustrated battery separator. In one embodiment, the coating 2 of the microporous membrane 11 is a coating applied to form a three-dimensional bubble-saturated insulating structure. In one embodiment, the microporous membrane 11 may itself be a single layer membrane, a double layer membrane, a three layer membrane, or a multi-layer membrane to make a composite structure of multiple materials as desired. In one embodiment, the microporous battery separator is a high melt temperature microporous battery separator; and/or the microporous membrane 11 is a self-supporting high glass transition temperature polymer membrane so that the battery separator can still continue to operate for at least some time in extremely high temperature environments.

The microporous battery separator may be used in a lithium ion rechargeable battery, a battery cell, a battery pack, a battery, a storage battery, a lead acid battery, or a capacitor according to the present utility model.

In one embodiment, a microporous inner wall coating is disposed within a plurality of micropores in the microporous battery. The material of the microporous inner wall coating is different from the material of the second layer of the separator. Alternatively, the material of the microporous inner wall coating is the same as the material of the second layer of the separator.

In one embodiment, both surfaces of the separator first layer 1 have positive electrode ribs a12, B12 and negative electrode ribs a13, B13, respectively.

In one embodiment, the negative electrode rib has at least one bubble rising channel disposed in the up-down direction in the left-right direction; the rising channel is positioned between the two areas; alternatively, the rising channel is a straight channel or a curved channel.

In one embodiment, at least one region is provided with ribs that are at least partially non-parallel to the left-right direction and also non-parallel to the up-down direction. In one embodiment, at least one region is provided with at least partially intermittent ribs. In one embodiment, at least one region has a continuous rib at least partially notched. In one embodiment, at least one region is provided with parallel ribs of at least partially different height. In one embodiment, at least one region is provided with ribs having at least a portion of a cross-section that is narrower at the top and wider at the bottom. In one embodiment, at least one region is provided with ribs having at least part of the cross-sectional sides curved or straight. In one embodiment, at least one region is provided with at least partially curved or undulating ribs.

In one embodiment, at least one region is provided with ribs arranged at least partially in a matrix; at least one area is internally provided with a rib array which is at least partially arranged in bilateral symmetry; and/or at least one area is provided with a rib array with at least part of row spacing changing.

As shown in fig. 1, an apparatus for manufacturing a microporous battery separator according to one embodiment of the present utility model includes:

a coating liquid applying device 10 for applying a solution 12 containing a high glass transition temperature polymer on an advancing microporous film 11;

at least one successive gel impregnation cell 20, having a sealing cap 21, placed downstream of said applicator 10; and

a drying box 30, wherein the microporous film 11 moving out of the gel impregnation tank 20 continues to advance, and enters the drying box 30 to be dried;

the distance between the applicator 10 and the nearest gel dipping bath 20 is as small as possible; the applicator 10 operates in a vacuum environment 22; and/or the inlet 24 and outlet 23 of the microporous membrane 11 and the gel impregnation tank 20 are provided with

seals

24, 23.

In one embodiment, the apparatus for manufacturing a microporous battery separator further comprises: a tenter which further dries the microporous film moving out of the drying box and prevents shrinkage or curling thereof.

In one embodiment, the apparatus for manufacturing a microporous battery separator further comprises: the direction of advance guides 25, 26, 27, 28 of the microporous film 11.

In one embodiment, the apparatus for manufacturing a microporous battery separator further comprises: vacuum sealing means 21, 23, 24 of gel impregnation cell 20 to provide a high glass transition temperature polymer precipitation and desolventizing process space 22 under vacuum.

According to the present utility model, during the advancing of the microporous film 11 from the upstream extrusion device 13, rolling device 14 or unwinding device (not shown), the high glass transition temperature polymer is precipitated onto the microporous film 11, and the solvent of the coating liquid is removed, thereby creating a three-dimensional porous structure in the high glass transition temperature polymer coating layer, forming the heat insulating deposition layer 2 of the microporous film.

According to the utility model, the thermally insulating deposited layer 2 forms a thermally inert protective structure 2 for the first separator layer 1, whereby the first separator layer 1 is still not melted above its melting temperature, remains dimensional and structural integrity, and is still ensured to be shaped independently of each other between said first separator layer 1 and said second separator layer 2, so that the cell continues to operate at least partially for at least 5 minutes, at least 15 minutes, and even at least 60 minutes.

In one embodiment, the extrusion device 13 extrudes a flat film a11 without ribs or the microporous film with longitudinal ribs a12 and/or with transverse ribs a13, the longitudinal ribs a12 being formed by longitudinal grooves 131 of the extrusion device 13 and the transverse ribs a13 being formed by roll surface grooves 133 of extrusion rolls 132 of the extrusion device 13. In another embodiment, the roll press device 14 extrudes the flat film B11 without ribs or the microporous film with longitudinal ribs B12 and/or with transverse ribs B13, the longitudinal ribs B12 being formed by circumferential grooves 141 of extrusion rolls 143 of the roll press device 14, and the transverse ribs B13 being formed by roll face axial grooves 142 of extrusion rolls 144 of the roll press device 14.

According to another aspect of the present utility model, there is provided an apparatus for manufacturing a microporous battery separator comprising:

The microporous battery separator according to the utility model is obtained directly from the manufacturing apparatus according to the utility model, the separator second layer of which forms a thermally inert protective structure for the separator first layer, whereby the separator first layer is still not melted above its melting temperature, remains dimensional and structural integrity, and is still ensured to be shaped independently of each other, so that the battery continues to operate at least partly for at least 5 minutes, at least 15 minutes, and even at least 60 minutes.

According to the technical conception disclosed in the specification, various parts which are not discussed in detail can be adopted in the prior art, and redundant description is not needed.

According to one embodiment, the high T is applied in the coating liquid by a coating slot die (see FIG. 1), doctor blade, meyer rod, or direct or reverse gravure roll _g A polymer. By combining a high T _g The polymer is dissolved in a suitable solvent, which may be dimethylacetamide (DMAc), N-methylpyrrolidone, 1, 4-dioxane, acetone, etc., to prepare a coating solution. The coating liquid may further contain: 1) For a high T _g A non-solvent for the polymer; 2) Crosslinking agents, such as dihalides, dialdehydes or acid dichlorides; 3) A surfactant to improve coating uniformity; 4) Inorganic particles, e.g. A1 ₂ O ₃ 、TiO ₂ 、CaCO ₃ 、BaSO ₄ Silicon carbide, boron nitride; or 5) organic polymers, such as powdered PTFE or other chemically inert, small [ ] organic polymers<2 micrometers or<1 micron), drying, and high melting temperature.

Applying a high T _g After the polymer, the film may be immersed in a gelling bath (see fig. 1). The gelling bath may be comprised of a single bath comprised of a mixture of non-solvents or non-solvents, or a series of baths comprised of a mixture of solvents and one or more non-solvents. In the case where the coating operation consists of a series of baths, the final bath consists of a non-solvent or a mixture of non-solvents. The distance between the coating die and the gelling bath should be minimized to prevent the coating mixture from contacting air. The bath may be at room temperature, below room temperature, or at an elevated temperature.

The gel bath step was used to set a high T _g Precipitation of polymer onto the substrate film, removal of the polymer solvent (or solvents) and at high T _g A porous structure is created in the polymer coating or layer. The composition of the bath and the temperature of the bath control the rate of precipitation of the polymer, as well as the porosity of the porous coating or layer formed on the substrate film, film or supportAnd a pore structure.

The coated film, film or support may then be dried in an oven and may be dried on a tenter frame to prevent shrinkage or curling of the film. Final high T _g The polymer coating or layer thickness is 1-20 μm and the total thickness of the coated microporous film or separator is 5-40 μm. Preferably, the polyolefin microporous film has a coating on one or both sides of at least about 4 μm, at least about 6 μm, or at least about 8 μm to form an HTMI separator.

In another embodiment, a microporous battery separator is coated with an electrostatic wire to form a high glass transition temperature (T _g ) Electrostatic filamented nanofiber coating of polymer, said high glass transition temperature (T _g ) The polymer is Polybenzimidazole (PBI) and is preferably coated on both sides (on both sides of the porous base membrane). Although PBI is preferred, blends of PBI with other polymers or polymers, such as polyaramids, polyimides, polyamideimides, copolymers of polyvinylidene fluoride and polyvinylidene fluoride, and blends, mixtures, and/or combinations thereof, may also be used.

The electrostatic filament process can produce polymer nanofibers in the range of 40-2,000 nm. The electrostatic filament process uses an electric field to pull the polymer solution from the capillary tip to the collector. Fig. 3 is a schematic view of an electrostatic filament nozzle type apparatus. A voltage is applied to the polymer solution such that a thin stream of polymer solution is pulled toward a grounded collector. The trickle dries to form polymeric fibers that accumulate on the collector to form a three-dimensional fibrous web structure. The electrostatic filaments apply a nanofiber polymer coating to a substrate such as a microporous film.

The present utility model provides high melting temperature electrostatic filament coated microporous lithium ion rechargeable battery separators or membranes that can maintain their physical structure in lithium ion rechargeable batteries (cells, batteries, cells, accumulators, capacitors, etc.) up to 250 ℃ for at least a short period of time. The separator or membrane preferably has an electrostatic silk nanofiber coating of Polybenzimidazole (PBI) or a blend of PBI with another polymer or polymers applied to at least one side thereof, and preferably has a coating on both sides of the microporous substrate membrane. Electrostatic dischargeThe filamentized nanofiber coating is preferably comprised of nanoscale PBI fibers having diameters in the range of 10 to 2,000 nanometers, 20 to 1000 nanometers, 25 to 800 nanometers, or 30 to 600 nanometers, as shown in the Scanning Electron Microscope (SEM) micrographs of fig. 5 and 6. The target basis weight of the nano-sized PBI electrostatic filament coating of the high melting temperature microporous lithium ion rechargeable battery separator is at least 1.0 to 8.0g/m ² Preferably 2.0 to 6.0g/m ² 2.2 to 5.0g/m ² Or 2.5 to 5.0g/m ² 。

The results of the thermal resistance test, the expansion-thermogravimetric analysis (e-TMA) test, and the hot tip hole propagation test were used to determine the high melt temperature integrity (HTMI) performance of the electrostatic filament coated microporous lithium ion rechargeable battery separator film.

Figure 2 shows a thermal spectrum of a typical thermal resistance showing the initial closure of a test sample as represented by a sharp increase in resistance and shows the closure integrity window as a flat portion of the thermal spectrum where the resistance remains at a high level. Fig. 7 shows the thermal resistance test results of the separator coated with PBI on one side and the test results of the separator coated with PBI on both sides. At about 135 c,

the pores in the PE layer of the M824PP/PE/PP multilayer substrate film melt and close, and the substrate film thermally closes. Thermal resistance testing indicated that thermal closure had occurred in the base film with a sharp increase in resistance. As the temperature increases in the thermal resistance test, the PBI coated M824 film on one and both sides has a continuously increasing resistance at temperatures up to 200 ℃, showing the high melt temperature integrity of the separator. The high level of continuously increasing resistance indicates that the separator can prevent shorting of the electrodes in the cell beyond 200 ℃.

FIG. 8 shows the results of an expansion-thermogravimetric analysis (e-TMA) test on an electrodeposited wire coated separator, wherein the separator was coated with a multilayer PP/PE/PP base film

Melting of the PP layer in M824, the base film ruptures approximately in the range 160-170℃and the film sample size remains at 250℃up to an increase in temperature 100%. Maintaining the dimensions of the test sample at 100% means that the PBI layer is thermally stable up to 250 ℃. This e-TMA performance indicates that the separator has High Temperature Melt Integrity (HTMI) up to 250 ℃.

The results of the hot tip well propagation test showed that the diameter of the well size of the one-side electrostatic wire coated PBI and the two-side coated PBI samples after contact with the hot tip probe at 450 ℃ was 0.6-0.7mm in size, while the diameter of the well size of the uncoated control sample was 2.96mm. The hot tip hole propagation results indicate that the PBI electrostatic silk-coated separator has high temperature stability in the X, Y and Z directions. The minimal pore propagation in response to contact with the hot tip probe simulates the response of the separator to local hot spots that may occur during internal shorts in Li-ion battery cells.

The electrostatic filament deposition process may deposit nanoscale PBI fibers onto a substrate microporous film, membrane, or composite in a random fashion, creating a three-dimensional nanoscale fibrous network structure on the substrate microporous film. When viewed by SEM at 5,000x magnification, the fibers had a smooth surface appearance and were non-porous, that is, the fibers did not have any holes or voids.

Electrostatic filament coating will be high T _g Coating a polymer onto a microporous porous membrane, said high T _g A polymer such as PBI or a blend of PBI with another polymer or polymers such as polyaramid, polyimide and polyamideimide, and blends, mixtures and/or combinations thereof, without adversely affecting the pore structure or porosity of the porous substrate film, i.e.: the nanoscale electrostatic silk-accumulating fibers do not block the pores of the basement membrane. The electrostatic filament process applies the high Tg polymer in the form of nano-sized fibers to the microporous substrate film without the nano-sized fibers themselves being porous. The spaces between the fibers may provide the desired porosity. Therefore, there is no need to increase T in the electrostatic filament nano-scale _g And a further step of forming pores in the polymer fibers. In the electrostatic filament deposition process, the high T is _g The polymer or polymers are dissolved in a solvent or solvents. The solvent evaporates during the formation of the electrostatic filament.

Typically, the impregnation of the polymer onto the microporous substrate filmThe coating or gravure coating process may require immersing the coated film in a bath for removing or extracting the polymer solvent. This impregnation step forms a porous structure in the coating. From the viewpoint of manufacture, will be high T _g The electrostatic deposition of polymer onto microporous films is simpler because there is virtually no need for extraction or impregnation steps to remove solvent and form pores in the coating. The electrostatic deposition wire has a nanometer level high T _g The polymer fibers are applied to microporous films, membranes, composites or supports to make microporous lithium ion rechargeable battery separators, membranes, composites, etc. at relatively low cost and high melting temperature.

Example 1:

will be 13 μm

The EK1321PE microporous film was coated with a 4 μm coating layer consisting of polybenzimidazole (PBI Performance Products available from RockHill, SC, 26% coating in DMAc) and Degussa vapor phase alumina 20nm diameter particles. In the preparation of the coating solution, the alumina particles were first dried overnight in an oven at 180 ℃ to remove moisture. A slurry of 25 wt.% dry alumina particles in DMAc was then prepared. The final coating composition was 7% Polybenzimidazole (PBI), 28% alumina and 65% dmac. The coating was applied as a single sided coating using a slot die and the coated film was dried in an oven at 80-100 ℃ for less than 15 minutes.

Example 2:

will be 13 μm

The EK1321PE microporous film was coated with a 7 μm coating layer consisting of polybenzimidazole (PBI Performance Products available from Rock Hill, SC) and Degussa vapor phase alumina 20nm diameter particles. In the preparation of the coating solution, the alumina particles were first dried overnight in an oven at 180 ℃ to remove moisture. Then, a 25 wt.% slurry of dry alumina particles in DMAc was prepared. The final coating composition was 7% Polybenzimidazole (PBI), 28% alumina and 65% dmac. The coating was applied as a single-sided coating using a slot die and the coated film was dried in an oven at 80-100 ℃ for less than 15 minutes. / >

Example 3:

the 13.3% pbi coating was diluted to 7% with DMAc. The coating liquid is applied to 13 mu m by reverse gravure coating

The EK1321PE microporous film was then immersed in a room temperature water bath. The film was dried in an oven at 80-100 ℃ for 6-10 minutes. The water bath is a circulating bath to minimize DMAc concentration. The film coating path is designed so that the coated side of the film does not come into contact with the roller while in the bath. The immersion time in the bath was at least 1 minute.

Example 4:

the 13.3% pbi coating was diluted to 7% with DMAc. The coating liquid was applied to 13 μm by the reverse gravure process

The EK1321PE microporous film was then immersed in a room temperature bath of 33% propylene glycol in water. The film was dried in an oven at 80-100 ℃ for 6-10 minutes. The film coating path is designed so that the coated side of the film does not come into contact with the roller while in the bath. The immersion time in the bath was at least 1 minute.

Example 5:

26% PBI coating was diluted to 10% in DMAc. The coating liquid was applied to 13 μm using a doctor blade

The EK1321PE microporous film was then immersed in an acetone bath at room temperature for 3-5 minutes. The film was dried in an oven at 100 ℃ for 5 minutes.

Example 6:

coating 16 μm polyethylene with a slurry of polyaramid dissolved in DMAc mixed with Degussa vapor phase alumina 20nm particles

A diaphragm. The coating is applied using a gravure coating procedure.

TABLE 1 13 μm control sample and separator properties of examples 1-5

	Control	Example 1	Example 2	Example 3	Example 4	Example 5
							Thickness of substrate film (μm)		13	13	13	13	13
Type of base film	PE	PE	PE	PE	PE	PE
							Coating thickness (μm)		4	7	6	6	7
Total thickness (μm)	13	17	20	19	20	20
							JIS Gurley value(s)	212	237	261	437	1106
Puncture strength (g)	329	502	502	542	563
							MD tensile Strength (kgf/cm) ² )	1824	1251	1262	1449	1568
TD tensile Strength (kgf/cm) ² )	996	951	809	948	909
							ER (ohm-cm) ² )	1.1-1.3	1.7	1.9	2.5	2.9
MD shrinkage at 120 ℃/1hr	8.61	6.22	5.28	2.97	2.41
							TD shrink at 120deg.C/1 hr	3.4	0	0.45	0.78	1.37
MD shrinkage at 130 ℃/1hr	20.91	11.87	9.76	3.54	3.6
							TD shrink at 130 ℃/1hr	16.53	6.45	4.39	1.16	2.14
Thermal tip propagation diameter (mm)	2.43	2.8	3.5	0.63	0.7	<1
							E-TMA rupture temperature (. Degree. C.)	145	154	154	215	220	>250

TABLE 2 control samples of 16 μm and 13 μm and separator properties of example 6 and example 2

Performance of	PE control (16 μm)	Example 6	Example 2	PE control (13 μm)
					Thickness (μm)	16	24	17 (13 μm base film)	13
Dielectric breakdown (V)	2057	2893	2141	1178
					Puncture strength (g)	516	581	502	329
Tensile Strength-MD kgf/cm ²	1355	1023	1262	1824
					Tensile Strength-TD kgf/cm ²	1145	1056	809	996

Example 7:

in the presence of dimethylacetamide (DMAc) as solvent, a 15% solution of Polybenzimidazole (PBI) (PBI Performance products,26% paint available from RockHill, SC) was used

The M824 three layer microporous film was electro-static wire coated on one side. The coating was performed by using a nozzle type electrostatic wire deposition apparatus, the applied voltage was 15kV, the flow rate was 0.5ml/h, the gauge of the needle was 7"ID, 0.025" OD, and the distance between the tip of the needle and the collector was 25cm. The thickness of the coating applied to one side of the M824 substrate film was 7-8 μm. The total thickness of the coated samples was 20 μm.

Example 8:

The M824 three layer microporous film was electro-static wire coated on both sides. The coating process used a nozzle-type electrostatic filament apparatus in which the applied voltage was 15kV, the flow rate was 0.5ml/h, the gauge of the needle was 7"ID, 0.025" OD, and the distance between the needle tip and the collector was 25cm. The basis weight of the coated sample was 0.94mg/cm ² . A coating 3-4 μm thick was applied to each side of the M824 substrate film. The total thickness of the coated samples was 20 μm.

Example 9:

by two (two)Methylacetamide (DMAc) as solvent was prepared with a 15% solution of Polybenzimidazole (PBI) (PBI Performance products,26% paint available from RockHill, SC)

3401 surfactant coated monolayer polypropylene microporous film was electrostatic silk coated on both sides. The coating process used a nozzle-type electrostatic wire device with an applied voltage of 15kV, a flow rate of 0.5ml/h, a needle gauge of 7"ID, 0.025" OD and a distance between the needle tip and the collector of 25cm. The total thickness of the coated samples was 55 μm.

TABLE 3 HTMI test data for control three layer M824 samples and 1-sided PBI-coated and 2-sided PBI-coated Celgard three layer substrate films

TABLE 4 control three layers

3401 sample and 2-sided PBI coated +.>

3401 HTMI test data

	3401 control monolayer PP	2-side coated PBI
			Thickness, μm	26	55
Basis weight mg/cm ²	1.56	2.22
			Thermal tip, μm Point 1	3.8	1.6
Point 2	4.2	1.3
			Point 3	3.7	0.5
Thermal resistor	The base PP film was melted at 165 DEG C	The substrate PP film melts at 165 ℃ and the PBI layer maintains resistance up to 200 DEG C
			e-TMA	Rupture of the base PP film at 165-170 DEG C	The substrate PP film breaks at 165-170deg.C, and the PBI layer does not break up to 250deg.C

The test result of the diameter of the heat-spreading hole of the 13 μm control (uncoated) of the present invention was 2.6mm;

the heat-spreading hole diameter test result of the coated base film of example 1 of the present invention was 2.7mm;

the heat-spreading hole diameter test result of the coated base film of example 2 of the present invention was 3.0mm;

example 3 of the present invention the heat propagation hole diameter test result of the coated base film was 0.63mm;

example 4 of the present invention the heat propagation hole diameter test result of the coated base film was 0.63mm;

example 5 of the present invention the heat spreading hole diameter test result of the coated base film was 0.73mm.

The hole size of the hot tip hole propagation image of the 16 μm control of the present invention was 3.4mm;

the aperture size of the hot tip aperture propagation image of example 6 of the present invention is 2.3mm;

the aperture size of the hot tip aperture propagation image of example 2 of the present invention was 2.4mm.

In the hot tip hole propagation control image, hole diameter = 2.96mm.

Thermal tip hole propagation 1-sided PBI coated sample image, hole diameter = 0.68mm.

Thermal tip well propagation in 2-sided PBI coated sample images, well diameter = 0.595mm.

Thermal tip hole propagation

3401 surfactant coated sample image, pore diameter = 3.7mm.

Hot tip hole propagation PBI electrostatic silk coated sample image, hole diameter = 0.596mm.

Test program

Thickness of (L)：

Thickness was measured according to ASTM D374 using an Emveco Microgage210-a precision micrometer. Thickness values are recorded in micrometers (μm).

Gurley value：

Gurley is defined as Japanese Industrial Standard (JIS Gurley) and is measured using an OHKEN breathability tester. JIS Gurley is defined as the number of seconds required for 100cc of air to pass through a one square inch membrane at a constant pressure of 4.9 inches of water.

Tensile Properties：

Machine Direction (MD) and Transverse Direction (TD) tensile strengths were measured according to the ASTM-882 procedure using an Instron Model 4201.

Puncture strength：

Puncture strength was measured using an Instron Model 4442 based on ASTM D3763. The measurement is made across the width of the microporous stretched product and the average puncture strength is defined as the force required to puncture the test sample.

Shrinkage of：

Shrinkage was measured at two temperatures by placing one sample in a 120 ℃ oven for 1 hour and a second sample in a 130 ℃ oven for 1 hour. Shrinkage is measured in the Machine Direction (MD) and the Transverse Direction (TD).

Basis weight：

Basis weight in mg/cm using ASTM D3776 ² 。

Testing of heat propagation pore size：

In the hot tip hole propagation test, a hot tip probe at 450 ℃ with a tip diameter of 0.5mm was made to touch the surface of the diaphragm. The hot tip probe was brought into proximity with the membrane at a speed of 10 mm/min and brought into contact with the surface of the membrane for a period of 10 seconds. The results of the hot tip test (i.e., the heat propagation hole diameter) are given in digital images taken with an optical microscope, which shows the hole shape formed as a result of the diaphragm reacting to the 450 ℃ hot tip probe, and the hole diameter in the diaphragm after removal of the hot tip probe. The minimal propagation of pores in the separator from contact with the hot tip probe mimics the response of the separator to localized hot spots that may occur during internal shorts in Li-ion cells.

ER (resistance)：

The unit of resistance is ohm-cm ² . The separator resistance was characterized by cutting a small piece of separator from the finished material and then placing it between two barrier electrodes. The separator was saturated with battery electrolyte having 1.0M LiPF in 3:7 volume ratio EC/EMC solvent ₆ And (3) salt. The resistance R of the separator was measured by a 4-probe AC impedance technique and is expressed in ohms (Ω). In order to reduce measurement errors at the electrode/separator interface, multiple measurements need to be made by adding more layers.

Based on the multilayer measurement, then represented by formula R _s ＝p _s l/A calculating the electrical (ionic) resistance R of an electrolyte saturated separator _s (Ω) where p _s Is expressed as omegaIon resistivity of the separator expressed in cm, A being expressed in cm ² Electrode area is expressed and l is separator thickness in cm. Ratio p _s Slope calculated for separator resistance (AR) as a function of multilayer (Δδ), from slope=p _s A=Δr/Δδ.

e-TMA：

The expansion-thermodynamic analysis method measures the dimensional change of the diaphragm under load conditions in the X (longitudinal) and Y (transverse) directions as a function of temperature. Samples of length 5-10mm and width 5cm size were held in a mini Instron-type clamp, with the samples under a constant 1 gram tension load. The temperature was ramped up at 5 c/min until the film reached its melt fracture temperature. Typically, the separator held under tension exhibits shrinkage upon temperature elevation, then begins to elongate and eventually breaks. A sharp downward drop in the curve indicates shrinkage of the separator. The increase in size indicates a softening temperature, and the temperature at which the separator breaks apart is a breaking temperature.

Thermal resistor：

Thermal resistance is a measure of the resistance of a diaphragm as the temperature increases linearly. The rise in resistance measured as impedance corresponds to the collapse of the pore structure caused by melting or "closing" of the diaphragm. The drop in resistance corresponds to separator opening caused by coalescence of the polymer; this phenomenon is known as loss of "melt integrity". When the separator has a continuously high level of resistance at more than 200 ℃, this indicates that the separator can prevent electrode short-circuiting in a battery at more than 200 ℃.

In accordance with the present utility model, the tests and/or properties of tables 1 and 2 above may be utilized to measure or test potential high temperature separators or composites to see if they may be or may become High Temperature Melt Integrity (HTMI) separators. If it passes the above test, the separator may be tested in a battery, cell or stack to determine that it is a High Temperature Melt Integrity (HTMI) separator and that it at least maintains the electrodes apart at a temperature of at least about 160 ℃, at least 180 ℃, at least 200 ℃, at least 220 ℃, or at least 250 ℃.

According to the present utility model, if the high temperature separator passes the test in tables 1 and 2 above, this well indicates that the separator may be or may become a High Temperature Melt Integrity (HTMI) separator.

In accordance with the present utility model, a good indicator or initial test procedure for knowing whether a separator can be used as or is likely to be a High Temperature Melt Integrity (HTMI) battery separator comprises the steps of:

1) The separator was subjected to the separator thickness, gurley, tensile, puncture, shrinkage, hot tip, ER, e-TMA and thermal resistance tests described above, if passed

2) The separator is subjected to a cell or battery test to determine.

According to the present utility model, the high temperature polymer, filler, coating, layer or separator may be measured or tested to see if it may be or may be used as a high temperature separator or as a High Temperature Melt Integrity (HTMI) coating, layer or separator by:

1) The polymer (or polymers) and filler (or fillers, if any) of the high temperature coating, layer or freestanding separator are inspected to confirm that they each have a melting temperature or degradation temperature of at least about 160 ℃, 180 ℃, 200 ℃, 220 ℃, or at least 250 ℃;

2) The polymer (or polymers) and filler (if any) of the high temperature coating, layer or freestanding separator are inspected to confirm that each is insoluble in the electrolyte of the cell intended for the separator;

3) Shrinkage of the freestanding or intact separator (including high temperature coatings or layers) is measured to ensure that it is less than about 15%, less than 10%, less than 7.5% or less than 5% at 150 ℃; and

4) If the high temperature coating, layer, freestanding separator and complete separator pass the three tests, then the freestanding or complete separator is tested in a battery, cell or battery to determine it to be a high melt temperature separator or a High Temperature Melt Integrity (HTMI) separator and will at least keep the electrodes apart at a temperature of at least about 160 ℃, at least 180 ℃, at least 200 ℃, at least 220 ℃ or at least 250 ℃.

If the high temperature coating, layer, freestanding separator and complete separator pass the three tests, this well indicates that the freestanding or complete separator (including the high temperature coating or layer) may be or may become a high melt temperature separator or a High Temperature Melt Integrity (HTMI) separator, but for the sake of certainty, the freestanding or complete separator should be tested in a battery, cell or stack.

In accordance with the present utility model, a good indicator or initial test to see if a high temperature coating, layer or freestanding high temperature separator is available, can be used in, or is likely to be a high melting temperature separator or a High Temperature Melt Integrity (HTMI) coating, layer or separator comprises the steps of:

1) The polymer (or polymers) and filler (if any) of the high temperature coating, layer or freestanding separator are inspected to confirm that they each have a melting temperature, degradation temperature, melting point, decomposition temperature or T of about 180 ℃, 200 ℃, 220 ℃ or at least 250 °c _g ；

2) The polymer (or polymers) and filler (if any) of the high temperature coating, layer or freestanding separator are inspected to confirm that each is insoluble in the electrolyte of the cell intended for the separator; and

3) Shrinkage of free standing or intact separators (including high temperature coatings or layers) was measured to ensure shrinkage of less than about 15%, less than 10%, less than 7.5%, or less than 5% at 150 ℃.

If the high temperature coating, layer, freestanding separator and complete separator pass the three tests described above, this is a good indicator or initial test, indicating that the high temperature coating, layer, freestanding separator or complete separator can be used, or can become a high melting temperature separator or a High Temperature Melting Integrity (HTMI) coating, layer or separator, and that the separator can at least maintain the electrodes apart at a temperature of at least about 160 ℃, at least 180 ℃, at least 200 ℃, at least 220 ℃, or at least 250 ℃. For the purpose of this determination, freestanding or intact separators should be tested in a battery, cell or stack.

The addition of fillers or particles to the high temperature polymer coating or layer may make it easier to form pores because the spaces or voids between the fillers or particles help to form pores, may reduce costs, and the like. However, the addition of fillers or particles to high temperature polymer coating materials or batches can make the polymer more difficult to handle. It is therefore preferred to dispense with fillers or particles to keep the treatment relatively simple and to use a bath (see fig. 1) to form the holes.

Since the HTMI separator only needs to keep the electrodes apart for a short period of time, a high T can be used in accordance with the utility model _g Polymers, non-melting polymers or materials, melting or slow-flowing polymers or materials, cross-linked polymers or materials or other materials, blends or mixtures that will keep the electrodes apart long enough to allow the battery control circuitry to shut down the battery.

In one embodiment, a method is provided having>160 ℃ or>A 180 ℃ high melting temperature separator having the desired height dimension and/or structural integrity to still prevent shorting between anode and cathode when the cell is at an extremely high temperature for a period of time. Separators having such high levels of dimensional and structural integrity are known as High Temperature Melt Integrity (HTMI) separators, which are coated with a high glass transition temperature (T _g ) High melt temperature battery separators of porous films, membranes or substrates of polymers (also referred to as "binders"). In another embodiment, a high T is provided _g A freestanding porous membrane made of a polymer. The high temperature separator has>160 ℃ or>A high melting temperature of 180 ℃ has the high degree of size and/or structural integrity required to still prevent shorting between anode and cathode when the cell is at extremely high temperatures for a period of time, and to shut down or allow ion flow between anode and cathode when the cell is at extremely high temperatures for a period of time, such separators with high degree of size and structural integrity are known as High Temperature Melt Integrity (HTMI) separators with or without closure. The separator does not melt or fuse away and ensures that the cell continues to function partially or fully at high temperatures.

The present utility model provides:

high T _g Microporous lithium ion rechargeable battery separators, and separators can still prevent shorting between the anode and cathode when the battery is at extremely high temperatures for a period of time.

High T _g Microporous lithium ion rechargeable battery separator, separator manufacturing or use system, T _g The microporous lithium ion rechargeable battery separator and separator can still prevent shorting between the anode and cathode when the battery is at extremely high temperatures for a period of time.

A lithium ion rechargeable battery includes one or more high melting temperature microporous lithium ion rechargeable battery separators, membranes, etc. (with or without closure) that remain protected from shorting between anode and cathode when the battery is at extremely high temperatures for a period of time.

A closed lithium ion rechargeable battery separator that prevents shorting between the anode and cathode when the battery is at extremely high temperatures for a period of time.

A lithium ion rechargeable battery, cell, stack, accumulator or capacitor comprising one or more high melting temperature separators, membranes that still prevent shorting between anode and cathode when the battery is at extremely high temperatures for a period of time, the battery, cell, stack, etc. may have any shape, size and/or configuration, such as cylindrical, flat, rectangular, large scale Electric Vehicles (EVs), prismatic, button, envelope, box, etc.

A separator, separator for a lithium ion rechargeable battery, capable of at least partially functioning properly, including maintaining the battery anode and cathode physically separated, at high temperatures (e.g., at least about 160 ℃, at least about 180 ℃ or higher) for short periods of time.

A high melting temperature separator that closes at about 130 ℃ but keeps the cell anode and cathode physically separated at about 160 ℃.

A microporous battery separator comprising at least one layer or component having a high melting temperature.

A high temperature separator having a high melting temperature of >160 ℃ or >180 ℃ and having the high dimensions or structural integrity required to still prevent shorting between anode and cathode when the cell is at extremely high temperatures for a period of time.

A High Temperature Melt Integrity (HTMI) separator having a high degree of dimensional or structural integrity.

A high melting temperature battery separator includesThe less surface is coated with high glass transition temperature (T) _g ) Porous membranes of polymers or blends (also referred to as binders).

With high T _g A free standing monolayer or multilayer porous film made of a polymer or blend.

A high melting temperature microporous lithium ion rechargeable battery separator or membrane that maintains its physical structure up to 250 ℃ in lithium ion rechargeable batteries (cells, batteries, accumulators, capacitors, etc.).

Preferably, the separator or membrane according to the utility model consists of one or more polymers having a glass transition temperature (T _g ) Greater than 165 ℃, greater than 180 ℃, at least 250 ℃, and is soluble in at least one moderately volatile solvent.

Preferably, the separator or membrane according to the utility model consists of a single-sided or double-sided high Tg polymer coating applied to a microporous base membrane or of a self-supporting high T _g A polymeric microporous separator or membrane.

Preferably, the separator or membrane according to the utility model has a high T coated onto a microporous base membrane made of thermoplastic polymer _g Polymers including polyolefins such as polyethylene, polypropylene, polymethylpentene, and blends, mixtures or combinations thereof.

Preferably, the separator or membrane according to the utility model is produced by

A dry stretching process, a wet process also known as a phase separation or extraction process, or a particle stretching process, etc.

Preferably, the separator or film according to the present utility model, the base film may be a single-layer or multi-layer film such as a polypropylene/polyethylene/polypropylene (PP/PE/PP) or a polyethylene/polypropylene/polyethylene (PE/PP/PE) three-layer film, a double-layer film (PP/PE or PE/PP), or the like.

Preferably, the separator or membrane according to the utility model, a base membrane or membrane such as polypropylene, may be pretreated to alter the surface properties of the membrane and improve the height T _g Adhesion of the polymer coating to the substrate film.

Preferably, the separator or film according to the present utility model, the pretreatment may include priming, stretching, corona treatment, plasma treatment, and/or coating, such as a surfactant coating on one or both sides thereof.

Preferably, the separator or membrane according to the utility model can be applied with a high T by a coating step followed by a dipping step _g Polymers, and will have a high T _g Immersing the coated film in a gelling bath to precipitate a high T _g Polymer and removal for high T _g Solvent for the polymer to form a high T _g Porous coatings or layers.

Preferably, the separator or membrane according to the utility model can be applied with a high T by a coating step followed by a dipping step _g Polymers, to be high T _g Immersing the coating film in a bath to precipitate a high T _g A polymer.

Preferably, the separator or membrane according to the utility model has a height T _g The polymer is Polybenzimidazole (PBI).

Preferably, the separator or membrane according to the utility model, the high temperature coating or layer comprises Polybenzimidazole (PBI) and vapor phase alumina.

Preferably, the separator or membrane according to the utility model is coated with a solution or slurry of PBI, alumina particles and DMAc.

A high melting temperature electrostatic wire coated microporous lithium ion rechargeable battery separator, which prevents shorting between anode and cathode when the battery is at extremely high temperatures for a period of time.

A system for manufacturing or using high melting temperature electrostatic filament coated microporous lithium ion rechargeable battery separators, membranes, etc., that remain resistant to shorting between anode and cathode for a period of time when the battery is at extremely high temperatures.

A lithium ion rechargeable battery includes one or more high melting temperature electrostatic filament coated microporous lithium ion rechargeable battery separators, membranes, etc., that remain protected from shorting between anode and cathode when the battery is at extremely high temperatures for a period of time.

A lithium ion rechargeable battery capable of operating normally at high temperatures includes components such as an electrostatic wire coated microporous battery separator or diaphragm that can operate normally at high temperatures.

An improved electrostatic wire battery separator for at least some high temperature applications, for high melting temperature electrostatic wire coated microporous lithium ion rechargeable battery separators, membranes, etc., which still prevent shorting between anode and cathode when the battery is at extremely high temperatures for a period of time; systems for making and/or using such separators, diaphragms, and the like; and/or for lithium ion rechargeable batteries including one or more such separators, membranes, etc.

A lithium ion rechargeable battery, cell, battery pack, accumulator or capacitor comprising one or more high temperature electrostatic filament coated separators or membranes, wherein the lithium ion rechargeable battery, cell, battery pack, etc. can have any shape, size and/or configuration, such as cylindrical, flat, rectangular, large scale Electric Vehicle (EV), prismatic, button, envelope, box, etc.

An electrostatically wire-coated separator, membrane, etc. for a lithium ion rechargeable battery that can function properly at high temperatures (e.g., at least about 160 ℃ or at least about 180 ℃) for at least a short period of time, where "normal operation" can include maintaining the battery anode and cathode physically separate, allowing ionic flow between the electrodes, or both.

An electrostatically wire-coated high temperature separator that is closed at about 130 ℃, but maintains the cell anode and cathode physically separated at about 160 ℃, allows ion flow between the electrodes at about 160 ℃ (not closed at 130 ℃), or a combination of the above.

An electrostatically wire-coated microporous battery separator that operates normally at high temperatures, does not melt at high temperatures, has a high melting temperature, includes at least one layer or component having a high melting temperature, and the like.

An electrostatically wire-coated high temperature separator has a high melting temperature of >160 ℃ or >180 ℃ and has a high degree of dimensional or structural integrity required to prevent shorting between anode and cathode when the battery is at extremely high temperatures for a period of time.

An electrostatically deposited filament coated High Temperature Melt Integrity (HTMI) separator having a high degree of dimensional or structural integrity.

A high melting temperature microporous lithium ion rechargeable battery separator or membrane is coated on at least one side with PBI electrostatic filament deposition.

According to the separator or membrane, consists of a single-sided or double-sided PBI electrostatic filament coating applied to a microporous substrate membrane.

The electrostatic filament coating is composed of PBI or a blend of PBI and one or more polymers including polyamides, polyaramides, polyimides, polyamideimides, polyvinylidene fluoride or copolymers of polyvinylidene fluoride, and blends, mixtures and/or combinations thereof.

According to the electrostatic filament coating, it consists of a PBI having a thickness of at least 4 μm, at least 5 μm, at least 6 μm or at least 7 μm.

The electrostatic filament coating consists of PBI or blends of PBI with one or more polymers including polyamides, polyaramides, polyimides, polyamideimides, polyvinylidene fluoride or copolymers of polyvinylidene fluoride, and blends, mixtures and/or combinations thereof, having a thickness of at least 4 μm, at least 5 μm, at least 6 μm, or at least 7 μm.

The electrostatic filament coating consists of PBI or a blend of PBI and one or more polymers, including polyamides, polyaramides, polyimides, polyamideimides, polyvinylidene fluoride or copolymers of polyvinylidene fluoride, and blends, mixtures and/or combinations thereof, having a weight of 2.0 to 6.0g/m ² 2.2 to 5.0g/m ² Or 2.5 to 5.0g/m ² An increment of (Add-on).

Preferably, the separator or film according to the present utility model, the PBI electrostatic deposition filaments are coated onto a microporous substrate film made of a thermoplastic polymer, including a polyolefin, such as polyethylene, polypropylene, polymethylpentene, and blends, mixtures, or combinations thereof.

Dry stretching processes, wet processes by what is also known as phase separation or extraction processes, by particle stretching processes, and the like.

Preferably, the separator or film according to the present utility model may be a single-layer polypropylene or polyethylene or a multi-layer film, such as a polypropylene/polyethylene/polypropylene (PP/PE/PP) or a polyethylene/polypropylene/polyethylene (PE/PP/PE) three-layer film, a double-layer film (PP/PE or PE/PP), or the like.

Preferably, the separator or membrane according to the utility model, such as a base membrane or membrane of polypropylene, may be pretreated in order to alter the surface properties of the membrane and improve the adhesion of the electrostatic filament PBI coating to the base membrane.

Preferably, the separator or film according to the present utility model, the pretreatment may comprise priming, stretching, corona treatment, plasma treatment and/or coating, such as surfactant coating(s) on one or both sides thereof.

In summary, the present utility model provides: a high melting temperature microporous lithium ion rechargeable battery separator, a closed high melting temperature battery separator, a membrane, a composite, etc., that still prevents shorting between the anode and cathode when the battery is at extremely high temperatures for a period of time; systems for manufacturing, testing and/or using such separators, membranes, composites, and the like; and/or batteries, lithium ion rechargeable batteries, etc. comprising one or more such separators, membranes, composites, etc.

The utility model is not limited to the embodiments disclosed in the above specification.

Claims

1. A battery separator having a thermally inert protective structure, said battery separator comprising: a separator first layer which is a microporous membrane; and a separator second layer which is a three-dimensional porous surface layer structure deposited on at least one side of the microporous film, the separator second layer being a gel coating, a precipitation coating, or an electrostatic filament deposition layer comprising a high glass transition temperature polymer, saturated with air bubbles, forming a thermally inert protective structure for the separator first layer,

Thereby, the separator first layer remains unmelted above its melting temperature, remains dimensionally and structurally intact, and remains molded independently of each other between the separator first layer and the separator second layer, such that the battery continues to operate at least partially for at least 5 minutes;

the diameter phi of the heat propagation hole of the battery separator satisfies: the maximum value is also smaller than the minimum value in the prior art.

2. The battery separator as in claim 1 wherein,

phi is more than or equal to 0.500mm and less than or equal to 2.700mm; phi is more than 2.9mm in the prior art;

the microporous membrane is a pretreatment membrane; the coating is a coating; the microporous film itself is a single layer film, a double layer film, a three layer film, or a multilayer film; the battery separator is a high melting temperature microporous battery separator; and/or the microporous film is a self-sustaining high glass transition temperature polymer film.

3. The battery separator of claim 1 wherein the microporous membrane has a PP/PE/PP, PE/PP/PE, PP/PE or PE/PP structure for use in a lithium ion rechargeable battery, cell, battery, accumulator, lead acid battery, or capacitor.

4. The battery separator according to claim 1, wherein a microporous inner wall coating is provided within a plurality of micropores in said microporous film; and/or the material of the microporous inner wall coating is different from or the same as the material of the second layer of the separator.

5. The battery separator according to claim 1, wherein both surfaces of the separator first layer have a positive electrode rib and a negative electrode rib, respectively, the negative electrode rib having at least one bubble rising channel provided in the up-down direction in the left-right direction; the rising channel is positioned between the two areas; the ascending channel is a straight channel or a curve channel; at least one area is internally provided with ribs which are at least partially not parallel to the left-right direction and the up-down direction; at least one region is provided with at least partially intermittent ribs; at least one region having a continuous rib at least partially notched therein; at least one area is internally provided with parallel ribs with at least part of different heights; at least one area is provided with ribs with at least part of cross sections being narrow at the upper part and wide at the lower part; at least one area is provided with ribs with at least part of cross-section side surfaces being curved or straight; at least one region is provided with at least partially curved or wavy ribs; at least one area is internally provided with ribs which are at least partially arranged in a matrix; at least one area is internally provided with a rib array which is at least partially arranged in bilateral symmetry; and/or at least one area is provided with a rib array with at least part of row spacing changing.

6. A manufacturing apparatus of a battery separator having a thermally inert protective structure, the manufacturing apparatus comprising: a coating liquid applying device (10) for applying a solution (12) containing a high glass transition temperature polymer onto an advancing microporous film (11); at least one sequentially arranged gel dipping bath (20) disposed downstream of said applicator (10); and a drying box (30), wherein the microporous film (11) moving out of the gelation dipping tank (20) continues to advance, and enters the drying box (30) to be dried;

the distance between the applicator (10) and the nearest gel dipping bath (20) is as small as possible; the coating liquid applying device (10) operates in a vacuum environment; and/or the inlet and outlet of the microporous membrane (11) and the gel impregnation tank (20) are provided with seals such that the microporous membrane (11) from the upstream extrusion means (13), rolling means (14) or unwinding means is precipitated onto the microporous membrane (11) during the advancing process and the solvent of the coating solution is removed, thereby creating a three-dimensional porous structure in the high glass transition temperature polymer coating, forming an insulating deposition layer (2) of the microporous membrane, forming a thermally inert protective structure for the separator first layer (1), whereby the separator first layer remains unmelted above its melting temperature, remains dimensional and structurally intact, still ensures that the separator first layer and the separator second layer are formed independently of each other, and allows the battery to continue to operate at least partially for at least 5 minutes.

7. The apparatus for manufacturing a battery separator according to claim 6, further comprising: a tenter which further dries the microporous film moved out of the drying box and prevents shrinkage or curling thereof; a direction of advance guide for the microporous film; and/or a vacuum sealing apparatus for the gel impregnation cell.

8. A manufacturing apparatus of a battery separator having a thermally inert protective structure, the manufacturing apparatus comprising:

an electric field retainer disposed between the injector and the electric field ground plate such that the noodle-type deposition surface layer solution is deposited as long as possible on the surface of the microporous film as the separator first layer as the noodle-type deposition surface layer is deposited with filaments as long as possible, forming a separator second layer which forms a thermally inert protective structure to the separator first layer, thereby allowing the separator first layer to remain unmelted above its melting temperature, remain dimensional and structural integrity, and remain secured to be formed independently of each other between the separator first layer and the separator second layer, such that the battery continues to operate at least partially for at least 5 minutes.

9. The manufacturing apparatus of a battery separator according to claim 6 or 8, wherein the extrusion device (13) extrudes a flat film (a 11) without ribs or the microporous film with longitudinal ribs (a 12) and/or with transverse ribs (a 13), the longitudinal ribs (a 12) being formed by longitudinal grooves (131) of the extrusion device (13) and the transverse ribs (a 13) being formed by roll surface axial grooves (133) of an extrusion roll (132) of the extrusion device (13).

10. The manufacturing apparatus of a battery separator according to claim 6 or 8, wherein the rolling device (14) forms a flat film (B11) without ribs or the microporous film with longitudinal ribs (B12) and/or with transverse ribs (B13), the longitudinal ribs (B12) being formed by circumferential grooves (141) of an extrusion roll (143) of the rolling device (14), and the transverse ribs (B13) being formed by roll surface axial grooves (142) of an extrusion roll (144) of the rolling device (14).