KR20130103106A - Separator structure used in electrochemical device - Google Patents

Abstract

PURPOSE: A separating structure for an electrochemical diode is provided to maintain the primary function of a safety device by the shielding function of a separating film and to suppress the short circuit between a positive electrode and a negative electrode due to the increase of a short circuit temperature even when high heat is generated. CONSTITUTION: A separating structure for an electrochemical diode comprises a separating film (10) which has a first melting point; a heat resistant protection layer (20) which is located at one side of the separating film and has a higher melting point than the first melting point; an adhesive layer (30) in a fiber web shape with pores, which attaches the separating film and the heat resistant protection layer. The separating film is formed of a polyolefin-based resin. At least one of the heat resistant protection layer and the adhesive layer is formed of electrospun fiber. The heat resistant protection layer has a reduced thickens due to a hot-pressing.

Description

[0001] SEPARATOR STRUCTURE USED IN ELECTROCHEMICAL DEVICE [0002]

The present disclosure relates generally to a separator structure for electrochemical devices, and more particularly to a separator structure for an electrochemical device using a web-like adhesive layer formed from fibers to have porosity.

Herein, the background art relating to the present disclosure is provided, and these are not necessarily meant to be known arts.

A separator which can be used in an electrochemical device such as a lithium secondary battery is required to have a high short-circuit temperature while having a shut-down function together with a basic function of a separator. That is, the separator is disposed between the anode and the cathode of the battery to provide insulation, maintains the electrolyte to provide a path for ion conduction, and when the temperature of the battery becomes excessively high, a part of the separator melts to block the current, And has a closing function. When the temperature rises further and the separator melts, a large hole is formed and a short circuit occurs between the anode and the cathode. This temperature is referred to as the short-circuit temperature. In general, the separator should have a lower closure temperature and a higher short-circuit temperature. In the case of the polyethylene separator, when the battery is abnormally heated, the electrode shrinks due to heat shrinkage at 150 ° C or higher, which may cause a short circuit. Therefore, it is very important to have both a closing function and a heat resistance for a high energy density, large-sized secondary battery. That is, a separator having excellent heat resistance and small heat shrinkage and excellent cycle performance according to high ion conductivity is required. To this end, a separator structure having a high melting point applied or laminated on the separator has been proposed.

U.S. Patent Publication No. 2010-0304205 discloses a separator structure in which a heat resistant protective layer made of a polymer resin having a melting point of 180 ° C or higher or a melting point is electrospun laminated on a separator. However, the separator structure thus fabricated has a problem of insufficient physical strength to be used in an actual cell assembly process, which is difficult to industrialize.

This will be described later in the Specification for Implementation of the Invention.

SUMMARY OF THE INVENTION Herein, a general summary of the present disclosure is provided, which should not be construed as limiting the scope of the present disclosure. of its features).

According to one aspect of the present disclosure, there is provided a separator structure for an electrochemical device, comprising: a separator having a first melting point; A heat resistant protective layer located on at least one side of the separator and not soluble at the first melting point; A separator structure for an electrochemical device is provided, which comprises a web-shaped adhesive layer that combines the separator and the heat-resistant protective layer and has pores so as to have fibers.

This will be described later in the Specification for Implementation of the Invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram showing an example of a membrane structure according to the present disclosure,
2 is a diagram showing an example of an electrospinning apparatus that can be used in the present disclosure,
3 is a table showing the results of measurement of thickness, air permeability, heat shrinkage, adhesion, hot box,
4 is a view showing a battery performance evaluation,
5 is a SEM photograph showing the surface of the adhesive layer electrospun to the separation membrane,
6 is a SEM photograph showing the surface of the heat resistant protective layer,
7 is a SEM photograph showing the surface of the heat-treated separator structure,
8 is a photograph showing Example 1 (A), Example 2 (B), Comparative Example 1 (C) and Comparative Example 2 (D) after heat shrinkage.

The present disclosure will now be described in detail with reference to the accompanying drawing (s).

1 is a view showing an example of a separation membrane structure according to the present disclosure. The separation membrane structure includes a separation membrane 10, heat-resistant protection layers 20 and 20 located on both sides of the separation membrane 10, (30, 30) formed of a fiber so as to have porosity while improving the bonding force of the layers (20, 20). For example, such fibers can be produced by electrospinning or electrospraying. The electrospinning process should be understood as a broad electrospinning process involving a meltblow-spinning process, a force-spinning process, and a process in which these processes add blowing systems and high-current systems . Melt blowing is a process of producing fibers by blowing high-temperature, high-pressure air to a conventional melt spinning process in which a raw polymer is heated-melted and extruded from a spinning nozzle into air to form fibers while cooling. In the force-spinning process, a polymer solution is dropped onto a rotating spinneret (spin coating), and the polymer is ejected out of the polymer by centrifugal force to produce fibers. The main components of this system are spinner, collector, environmental control room, control system, motor and brake. In the multiple spinnerets, the polymer in the cavity is continuously supplied, and the solution or the melt is ejected through the orifice by the centrifugal force to become the nanofiber. Solution, and molten phase materials.

2 shows an example of an electrospinning apparatus that can be used in the present disclosure. The electrospinning apparatus 40 includes a feeding unit 110 for feeding a polymer material for a fiber material in a molten state, a feeding unit 110 A plurality of spinning nozzles 122 for discharging the polymer solution supplied from the spinning unit 120 in the form of charged filaments or fibers; A control unit 140 disposed on at least both sides of the radiation unit 120 and a control unit 140 and a collector 130 for surrounding the filament stream, And an air conditioning unit 160 for injecting air into the space between the radiation unit 120 and the collector 130 and evaporating the solvent in the space to discharge the air to the outside . The supply unit 110 is a storage container 112 for storing a solution in which a polymer material as a fiber raw material is dissolved, and a pump 114 for pressurizing and supplying the solution stored in the storage container 112 to the spinning unit 120. ) And a distributor 116 and a delivery tube 118 for dispensing the solution to the respective nozzles. The spinning unit 120 performs a function of spinning in the direction of the collector 130 in the form of fine filaments in a state in which the fiber raw material solution supplied from the supply unit 110 is charged. The radiation unit 120 has at least one radiation nozzle pack 126 in which a plurality of radiation nozzles 122 are disposed. The number of the spinning nozzles 122 constituting the spinning nozzle pack 126 or the number of the spinning nozzle packs 126 constituting the spinning unit 120 is determined in consideration of the size, . When a plurality of polymer materials are emitted, a separate spinning nozzle pack may be provided. The collector 130 may be grounded to have a potential difference with respect to a voltage applied to the radiation unit 120, or may be applied with a negative voltage. The collector 130 is for accumulating the charged filaments discharged from the spinning unit 120, and may be configured to continuously move in a conveyor belt manner through a transfer means such as a roller 132, for example. The control unit 140 is for preventing a case in which the filament stream radiated from each of the spinning nozzles 122 rebounds from each other and spreads out from the path, and the control unit 140 includes at least a portion of the spinning nozzle pack 126. It is provided on both sides of the longitudinal direction. The voltage of the same polarity as that of the control unit 140 is applied to the induction unit 150. [ The induction unit 150 is installed around the elongated charged filament stream to guide the traveling direction of the stream. Induction unit 150 is provided in the form of a conductor plate or a conductor rod. The induction unit 150 is charged with the same polarity as the charged filament to induce the filament to be integrated in a limited area of the upper surface of the collector 130. The air conditioning unit 160 is to volatilize the solvent dissolved in the charged filament in the space between the spinning unit 120 and the collector 130 to exhaust it to the outside, for example, to absorb the solvent such as a suction fan and an exhaust fan. , Exhaust means and a plurality of air inlet slots 162. The positive voltage is excited by the output voltage of the high voltage unit 170. The high voltage unit 170 outputs a DC voltage in the range of 10 kV to 120 kV. When the raw material solution stored in the supply unit 110 is supplied to the radiation unit 120 through the pump 114 and the distributor 116 in a fixed amount, the current passing portion inside each radiation nozzle pack 126 of the radiation unit 120 The solution is charged. Subsequently, the charged solution is discharged toward the collector 130 in the form of fine filaments while passing through the capillary tube of the spinning nozzle 122. Here, the filaments are radiated while being stretched to a nanoscale diameter by a strong electric field formed between the collector 130 and the charged filaments. In this spinning process, due to the repulsive force between the filaments, the stream to be spread out of the traveling path to the outside is returned to the original position by the control unit 140 to maintain the correct traveling path. On the other hand, the induction unit 150 is installed above the collector 130 to surround the discharged stream, so that the stream which is about to go out of the path by the induction unit 150 is guided to the limited integration region on the collector 130. The filaments derived as described above are continuously integrated on the collector 130 in the form of a conveyor belt or a rotating drum or on the upper surface of the substrate 182 such as a film, a mock paper, or a nonwoven fabric conveyed by the roller 180. Thus, a porous web is formed of nanofibers. An example of such an electrospinning apparatus is shown in US Patent No. 7,351,052.

The separator 10 mainly uses a polyolefin base film. The polyolefin-based substrate is widely used as a conventional separator, and examples thereof include polyethylene, polypropylene, polybutylene, and polypentene. Porous materials such as a copolymer or a mixture thereof (blending) Membranes can be used. The above-described separation membrane may be used alone or in combination. The separation membrane 10 having a thickness of 1 to 50 占 퐉, a pore size of 0.001 to 300 占 퐉 and a porosity of 10 to 95% is mainly used.

The heat-resistant protective layer 20 can be produced by various conventional methods, but it is preferably formed by electrospinning, taking into consideration the adhesive layer 30 in the form of a web formed from the electrospun fiber described later. As the heat-resistant protective layer 20 suitable for electrospinning, a polymer resin which can be dissolved in an organic solvent and has a melting point of 180 DEG C or higher and no melting point is used, for example, polyacrylonitrile, polyethylene terephthalate, Aromatic polyesters such as polyethylene terephthalate, polyethylene naphthalate, and the like; aromatic polyesters such as polyamide, polycarbonate, polyethylene oxide, polyisothiketone, polyphenylene oxide, polyphenylenesulfone, polysulfone, polyisosulfone, polyimide, polyetherimide, poly Amide imide, polybenzimidazole, polybenzoxazole, cellulose acetate, poly (meta-phenylene isophthalamide), polydiphenoxipospasogen, polyphosphazene, and an adhesive layer 30 ) Adhesive property and a swelling polymer resin can be used. The thickness of the heat resistant protective layer 20 is preferably 1 to 30 占 퐉, and the weight per unit area is preferably 0.05 to 20 g / m2. If the thickness is too thick, the ion movement distance will be distant to deteriorate the performance of the cell, and it will be disadvantageous to the high density and high integration design. If the thickness is too thin, the function of the microfibre film can not be exhibited and the heat resistance effect is also reduced.

The adhesive layer 30 is formed in the form of a web formed from fibers by electrospinning, and increases interfacial adhesion. By introducing the adhesive layer 30, an adhesive force can be exerted without severely setting the heat and pressure applied in the process of bonding the separation membrane 10 and the heat-resistant protective layer 20, and a separation membrane 10 made of polyolefin- And the adhesion between the separator 10 and the heat-resistant protective layer 20 is improved. Thus, the interlayer separation phenomenon can be suppressed in the winding process and the cell assembly process, and the process efficiency can be improved. Further, by forming the adhesive layer 30 in the form of a web formed from fibers by electrospinning, the impregnation rate, content and wettability of the electrolyte solution are improved by the porous morphology structure and the property of gelation when impregnated into the electrolyte, The battery performance is improved. As the material of the adhesive layer 30, a polymer resin which can be formed into a fiber by electrospinning and has good adhesion and swelling property is suitable. For example, polyvinylidene fluoride (PVDF), poly (vinylidene fluoride- (Vinylidene fluoride) -co- (hexafluoropropylene), P (VdF-HFP), poly (vinylidene fluoride-chlorotrifluoroethylene) (VdF-CTFE) copolymer, polymethylene oxide, polyethylene oxide, polyvinyl acetate, polystyrene, polyacrylonitrile, polyacrylamide, polymethyl acrylate, polymethyl methacrylate, polyvinyl pyrrolidone, Can also be used as a mixture of two or more. The adhesive layer 30 may be electrospinned directly to the separation membrane 10 or may be electrospinned directly to the heat resistant protective layer 20. At this time, the concentration of the solution, the composition ratio of the solvent, the discharge amount, and the temperature and humidity in the electrospinning chamber are adjusted so that the adhesion property is given on the substrate. Generally, the ultrafine fiber web produced by electrospinning has an already solidified fibrous phase when it is integrated on a substrate, and since its phase change is deteriorated on the substrate itself, the drying degree is controlled until the surface is integrated on the substrate, . These conditions vary depending on the raw materials used and are not limited to specific conditions. The thickness of the adhesive layer 30 is preferably 0.1 to 30 占 퐉, and the weight per unit area is preferably 0.05 to 20.0 g / m2. If the thickness is too thick, the fibers are melted by the non-dried solvent and proceed to the film-like film, which adversely affects the porosity. If the thickness is too small, it becomes difficult to impart the adhesive force to the separation membrane 10 and the heat- .

In the case of forming the heat resistant protective layer 20 by using electrospinning, the heat resistant protective layer 20 can be obtained by integrating through electrospinning on a substrate such as a film, a nonwoven fabric, and a parchment, and then peeling off. The heat resistant protective layer 20 can also be obtained by electrospinning directly on the separating film 10 on which the adhesive layer 30 is formed. At this time, the separation membrane 10 may be transported together with the collector 130, or may be accumulated while passing through the collector 130. The adhesive layer 30 may be electrospun to the heat resistant protective layer 20 and the heat resistant protective layer 20 may be formed on the adhesive layer 30. [

The heat resistant protective layer 20 constituting the separator structure is preferably subjected to a thermal compression process in order to impart mechanical strength and shape stability. This can be done in the process of laminating the separator 10, the adhesive layer 30 and the heat-resistant protective layer 20, and then joining the separator structure by applying heat and pressure using a roll. Further, the heat-resistant protective layer 20 integrated by electrospinning is peeled off from the substrate such as a film, a nonwoven fabric, or an imitation, and heat and pressure are applied to the heat-resistant protective layer 20 in advance through the calender roll, ) Thickness can be reduced and the overall thickness after lamination can be minimized. It is possible to combine them with the separation membrane 10 through the minimum pressure during the coupling process. This reduces the possibility of pore collapse of the separator 10 during the thermocompression process and eliminates the bulky characteristics of the heat resistant protection layer 20 and minimizes the damage of the separator 10 by the minimum pressure during the bonding process There are advantages to be able to.

Since the pores of the membrane 10 may be damaged in the thermocompression process, a stretching process may be added to the membrane structure to restore the porosity or readjust the thickness of the membrane structure. The stretching is uniaxial or biaxial stretching.

The separator structure according to the present disclosure is not limited to Fig. 1, and the following separator structure is possible.

A three-layer separation membrane structure made of the heat-resistant protective layer 20 / the adhesive layer 30 / the separation membrane 10

Layer structure (Fig. 1 structure) composed of the heat-resistant protective layer 20 / the adhesive layer 30 / the separator 10 / the adhesive layer 30 / the heat-

At this time, the adhesive layer 30 may be provided on the separator 10, on the heat-resistant protective layer 20, or separately. Likewise, the heat-resistant protective layer 20 may be provided separately or may be bonded to the adhesive layer 30 or to the separator 10 bonded to the adhesive layer 30.

The porosity of the membrane structure is preferably 20% or more. If the porosity is low, the impregnation rate of the electrolyte is low, which is not suitable for use as a separator for high performance cells. The total thickness of the membrane structure is preferably 5 to 70 mu m. If the thickness is thinner than 5 탆, the strength is weak, which may lead to a problem in the manufacturing process of the battery, and the production cost rises sharply. If it is thicker than 70 탆, the ion conductivity may be deteriorated. A more preferable thickness is 10 to 40 占 퐉.

The separator structure manufactured by the above-described method is used for manufacturing an electrochemical device such as a lithium secondary battery or a supercapacitor device. The separator structure is an electrode structure in which an electrode and a separator structure are integrated through a lamination process, which is interposed between an anode and a cathode, is inserted into a battery case, and an organic electrolyte is injected and sealed to manufacture an electrochemical device. The organic electrolytic solution is injected into an organic solvent in the form of lithium phosphohexafluoride (LiPF 6), lithium perchlorate (LiClO 4), lithium tetrafluoroborate (LiBF 4), lithium trifluoromethane sulfonate (Lithium trifluoromethanesulfonate) (LiCF 3 SO 3). The organic solvent may be selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, Ethylmethyl carbonate (EMC), gamma-butyrolactone, or a combination of such solvents.

Example 1

- Production of heat resistant protective layer (20)

15% by weight of PEI (Polyehter imide) and dimethylacetamide (DMAc, Dimethylacetamide) were mixed at a weight ratio of 15:85 to prepare a 15wt% electrolytic solution. Then, the electrolytic solution was added to the storage container 112 of the electrospinning device 40 The fibers were prepared by injection. The spinning nozzle pack 126 and the collector 130 are vertically connected to the electrospinning device 40 and used as a base material for collecting the fibers. The collector 130 is placed on the upper surface of the collector 130, Roll-to-roll facility in which the substrate was passed through, and the fibers by electrospinning were only accumulated on the top of the substrate. The electrospinning device 40 was provided with eight spinning nozzle packs 126 in which 60 spinning nozzles 122 were arranged. The applied voltage was 30 kV and the discharge amount was 20 μL / min.hole. The heat-resistant protective layer 20 having a thickness of 9 mu m was manufactured by maintaining the distance between the collector 130 and the ends of the spinning nozzles 122 at 20 cm.

- Preparation of the adhesive layer (30)

The PVDF-CTFE copolymer was dissolved in a mixed solvent of acetone and dimethylacetamide (DMAc) in a weight ratio of 6: 4 to prepare an electrospinning solution of 15% by weight. Then, the electrospinning device 40 ) Into the storage container 112 of the fabric. The electrospinning device 40 includes a spinneret nozzle pack 126 and a collector 130 which are vertically connected to each other and which are made of polypropylene (PP) Roll facility in which the separator 10 is arranged to pass on the collector 130 on the collector 130 and the fibers by the electrospinning are used as the separator 10, And then directly integrated on the upper and lower surfaces. The electrospinning device 40 was provided with eight spinneret nozzle packs 126 each having 60 spinning nozzles 122 arranged at the upper and lower ends thereof, respectively. The applied voltage was 28 kV and the discharge amount was 50 μL / min.hole. The distance between the collector 130 and the end of the spinning nozzles 122 was maintained at 20 cm. The thickness of the adhesive layer (30) Respectively.

- Preparation of Membrane Structure

The heat resistant protective layer 20 was laminated on both sides of the separation membrane 10 on which the adhesive layer 30 was electrospun and the laminate was passed through a laminator (Model: EXCEL AM-655Q) at a temperature of 50 캜 and a linear pressure of 30 kg / To prepare a separator structure. The total thickness of the prepared membrane structure was measured to be 26 탆. The thickness of each layer after delamination was measured to be 3.5 탆 after thermocompression, and the thickness of the heat resistant protective layer 20 of 9 탆 was 61% The separation membrane 10 with a thickness of 탆 was 19 탆 after thermal compression and showed a 5% reduction in thickness. The decrease in thickness due to thermocompression showed a significant decrease in the thickness of the heat resistant protective layer 20 having a high porosity (75% or more) and a relatively low porosity (45%) of the polypropylene separator 10 Thickness reduction was small.

Example 2

The separation membrane 10 and the adhesive layer 30 were prepared in the same manner as in Example 1 and directly bonded to the heat resistant protective layer 20 by electrospinning using the same as the base material. To prepare a membrane structure. The thickness was measured to be 25 mu m.

Example 3

After the adhesive layer 30 was electrospun each of the heat resistant protective layers 20, a heat-resistant microfine fiber porous film having microfine fiber coating was prepared. The polyolefin porous membrane was used without coating. The remaining conditions were the same as in Example 1, and a composite membrane was prepared. The thickness was measured to be 26 탆.

Comparative Example 1

Only the separation membrane used in Example 1 was used as the separation membrane structure.

Comparative Example 2

Except that the separation membrane 10 and the heat-resistant protection layer 20 were bonded to each other without the adhesive layer 30 to prepare a separation membrane structure.

Comparative Example 3

Was used in the same manner as in Example 1, except that the separation membrane 10 applied by a dip coating method in which a PVdF-CTFE copolymer was dissolved in a concentration of 10% by weight was impregnated with the separation membrane 10.

The thickness, the air permeability, the heat shrinkage and the adhesion were measured using the separator structure prepared in Examples and Comparative Examples, and the cell was fabricated with each separator structure, and the stability test was performed. The results are shown in FIG.

In Comparative Example 3, the air permeability was not measured, because the dip coating material blocked the pores of the separator and the porosity of the separator was largely deteriorated to thereby greatly deteriorate the performance of the battery. It is also confirmed in Fig. In the case of Examples 1-3 and Comparative Example 2, lamination through thermocompression bonding was performed on the separator 10 as a base material, and the influence on the air permeability was examined. As a result, the numerical value was improved as compared with Comparative Example 1, . As a result of the adhesive force, in Comparative Example 2 in which the adhesive layer 30 is not provided, the bonding force is too low to be used as a separator, and laminating is required through more severe thermocompression but the collapse of the pores of the separator 10 can be predicted. The adhesive layer 30 exhibited an adhesive strength sufficient for use when the adhesive layer 30 or the adhesive layer 30 material was dip-coated. As a result, the thermal stability of the heat-resistant protective layer (20) was verified in all cases except for Comparative Example 1, and at the same time, the same results were obtained in the heat shrinkage test of FIG. 8 (Example 1 (A), Example 2 (B), Comparative Example 1 (C), and Comparative Example 2 (D)). The heat shrinkage of Comparative Example 1 exposed at 150 ° C for 1 hour was 38%, whereas the heat shrinkage rate of the separator structure having (20) heat resistant protective layer under the same conditions was greatly improved to 4 to 11.5% Respectively. Particularly, in Examples 1 and 2, it can be seen from Fig.

Thickness measurements were used TESA-μhite gage, air permeability was measured the number of seconds it takes to pass through the air 100mL using a Toyoseiki Co. Gurley type Densometer (No.158), the adhesive force is the tensile strength measuring equipment (LLOYD LR5K PLUS ) After separating, the separator (10) was attached to the glass plate with the width of 2.5 cm and the length of 7 cm. The glass plate was fixed to the lower grip and the end of the heat-resistant protective layer (20) Respectively. The heat shrinkage was determined to stand for one hour at 150 ℃ were fixed covered with the metal plate of the material fixing the same on a specimen of metal (SUS304) plate after altar the membrane structure to 5cm x 5cm standard, hot box (Hot box) is The thermal stability of the battery was evaluated by heating at 160 ° C for 1 hour in a fully charged state. The safety pass is a state in which there is no flame, smoke and explosion.

6 is a SEM photograph showing the surface of the heat-resistant protective layer, FIG. 7 is a SEM photograph showing the surface of the heat-treated separation membrane structure, and FIG. 8 is a cross- (A), Example 2 (B), Comparative Example 1 (C), and Comparative Example 2 (D) after heat shrinkage.

Various embodiments of the present disclosure will be described below.

(1) According to the separation membrane structure for an electrochemical device according to the present disclosure, a separation membrane having a first melting point; A heat resistant protective layer located on at least one side of the separator and not soluble at the first melting point; The separator structure for electrochemical devices according to any one of claims 1 to 3, further comprising a web-shaped adhesive layer which combines the separator and the heat-resistant protective layer and has pores. A representative example of an electrochemical device is a lithium secondary battery. By using the heat-resistant protective layer that is not melted at the first melting point, the primary safety device function is maintained by the sealing function by the separating function, so that short circuit between the two countries and the cathode can be suppressed have. Further, by introducing an adhesive layer in the form of a fibrous web, it is possible to maintain the porosity at a certain level while enhancing the bonding between the heat resistant protective layer and the separator.

(2) The separator structure for an electrochemical device, wherein at least one of the heat resistant protective layer and the adhesive layer is formed of electrospun fiber. If the adhesive layer can be made into a web of fibers, the method is not limited to electrospinning. However, by using electrospinning, it is a preferred embodiment to use this method because it can easily make a web of fibers that maintains porosity suitable for a separator structure for an electrochemical device. Further, both the heat-resistant protective layer and the adhesive layer are electrospun, thereby enhancing the similarity in the structure between them, and controlling the porosity and improving the bonding strength.

(3) The separator structure for an electrochemical device, characterized in that the heat resistant protective layer has a reduced thickness due to thermal pressurization.

(4) The separator structure for an electrochemical device according to any one of the above items (1) to (4), wherein the heat resistant protective layer has a thickness reduced by heat pressing before the separator and the heat resistant protective layer are bonded. This can reduce the thickness reduction to heat pressurization in the bond, so this should be understood as a limitation of structural features, not simply methodological techniques.

 Separator (10) Heat-resistant protective layer (20) Adhesive layer (30)

Claims (12)

In a separator structure for an electrochemical device,
A separation membrane having a first melting point;
A heat resistant protective layer located on at least one side of the separator and not soluble at the first melting point; And,
And a web-shaped adhesive layer of a fiber, which combines the separator and the heat-resistant protective layer and has pores. The method according to claim 1,
Wherein the separation membrane is formed of a polyolefin-based resin. The method according to claim 1,
Wherein at least one of the heat resistant protective layer and the adhesive layer is formed of an electrospun fiber. The method according to claim 1,
Wherein the adhesive layer is formed of electrospun fiber. The method according to claim 1,
Wherein the heat resistant protective layer has a reduced thickness due to thermal pressurization. The method according to claim 1,
Wherein the heat resistant protective layer has a reduced thickness due to thermal pressurization before bonding the separator and the heat resistant protective layer. The method according to claim 1,
The adhesive layer may be formed of at least one of polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-hexafluoropropylene), poly (vinylidene fluoride-chlorotrifluoroethylene) copolymer, polymethylene oxide, polyethylene oxide, polyvinyl acetate , At least one of polystyrene, polyacrylonitrile, polyacrylamide, polymethyl acrylate, polymethyl methacrylate, polyvinyl pyrrolidone, and polyurethane. The method according to claim 1,
The heat resistant protective layer may be formed of a material which forms an adhesive layer or a material which forms an adhesive layer or a material which forms an adhesive layer or a material which forms an adhesive layer or a material which forms an adhesive layer, At least one of polyamideimide, polyimide, polyimide, polyamideimide, polybenzimidazole, polybenzoxazole, cellulose acetate, poly (meta-phenylene isophthalamide), polydiphenoxaphospazene, polyphosphazene Wherein the separation membrane structure for an electrochemical device according to claim 1, The method according to claim 1,
Wherein the adhesive layer has a thickness of 0.1 to 30 μm and a weight per unit area of 0.05 to 20.0 g / m 2. The method according to claim 1,
Wherein the heat resistant protective layer has a thickness of 1 to 30 μm and a weight per unit area of 0.05 to 20 g / m 2. The method according to claim 1,
The separator is formed of a polyolefin resin,
The heat-resistant protective layer and the adhesive layer are formed of electrospun fiber,
Wherein the heat resistant protective layer has a reduced thickness due to thermal pressurization. The method of claim 11,
Wherein the heat resistant protective layer has a reduced thickness due to thermal pressurization before bonding the separator and the heat resistant protective layer.

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