KR20180034953A - Fiber shaped inorganic solid electrolyte and the manufacturing method of the same and cell using the same - Google Patents

Abstract

The present invention relates to a fibrous inorganic solid electrolyte and a preparing method thereof, and more particularly, to a preparing method of a fibrous inorganic solid electrolyte, and a solid electrolyte formed in a woven body or non-woven fabric shape by a fibrous inorganic material, prepared by the method. The preparing method of the present invention comprises the steps of: preparing a mixture by mixing start materials for preparing an inorganic electrolyte; preparing a molten inorganic material by heating, stirring, and melting the mixture; extruding the molten inorganic material in air from a spinning nozzle, and cooling and solidifying the same to form an inorganic fiber; and forming a porous woven body or manufacturing a non-woven fabric, by using the fiber. Accordingly, the present invention can be used as a separation membrane in addition to a solid electrolyte, and thus greatly simplifies the structure of a fuel cell, and the effect of increasing the production speed of a fuel cell is expected.

Description

TECHNICAL FIELD [0001] The present invention relates to a fibrous inorganic solid electrolyte, a production method thereof, and a battery including the same.

The present invention relates to a fibrous inorganic solid electrolyte, a method for producing the same, and a battery including the same. More particularly, the present invention relates to a method for producing a fibrous inorganic solid electrolyte comprising: preparing a mixture by mixing starting materials for preparing an inorganic electrolyte; Heating the mixture to melt while stirring to produce a molten inorganic material; And extruding the molten inorganic material into air from a spinning nozzle to cool and solidify the inorganic fiber to form an inorganic fiber; Forming a porous woven fabric using the fiber or fabricating a nonwoven fabric, and a process for producing a fibrous inorganic solid electrolyte, which comprises the step of forming a woven fabric or a nonwoven fabric And a battery using the solid electrolyte.

The secondary battery is an energy storage device that utilizes the transfer phenomenon of electrons due to the reversible redox reaction through the electrolyte of the two electrodes having a large difference in ionization tendency. For example, a lithium ion battery utilizes a chemical reaction to move lithium ions from the cathode material through the electrolyte to a carbon-based cathode that forms a layered structure during charging, and the discharging process proceeds to the reverse of the charging process. That is, lithium ion is a typical secondary battery technology capable of charging and discharging many times by using the principle of going between the anode and the cathode.

Most commercialized secondary batteries have a potential risk of explosion because they use an organic liquid electrolyte in which a lithium salt is dissolved in an organic solvent. According to this recognition, the use of a solid electrolyte instead of an organic liquid electrolyte has attracted attention as an alternative to overcome the safety problem.

Korean Patent Laid-Open Publication No. 2000-0018387 "Lithium ion secondary battery using a polymer electrolyte and a production method thereof" has been disclosed in connection with an electrolyte. This is because a polymer gel having high ion conductivity and a polymer fiber are mixed with a reinforcing agent The present invention relates to a method for producing a lithium ion battery using a polymer electrolyte prepared from a gel / fiber polymer complex.

The polymer used in the gel preparation is poly (acrylonitrile) (PAN), poly (vinylchloride) (PVC), poly (meta methyl acrylate) (PMMA), poly (vinyl cholide) Or a mixture of two or more components is mixed with a carbonate-based organic solvent and a lithium salt. As a reinforcing fiber, a polymer electrolyte of a film is prepared by impregnating or coating a woven or non-woven polypropylene, polyethylene, polypropylene, glass fiber, or the like.

These composites have sufficient mechanical properties to prevent shorting between electrodes and to facilitate lamination in the form of anode / polymer electrolyte / cathode sandwich to simplify battery assembly process. In particular, the polymer electrolyte can be easily prepared by coating or impregnating the polymer gel with the woven or non-woven fabric of the reinforcing fiber, thereby greatly simplifying the production process of the polymer electrolyte film as compared with the case where the gel electrolyte is used alone There is an advantage to be able to do.

However, the solid polymer electrolyte is a material composed only of a polymer having a polar group and a salt, without using a solvent, and is easily processed and flexible as an electrolyte film of a thin film, but has a very low ionic conductivity at room temperature and low chemical stability , The synthesis process is very complicated.

In addition, although the inorganic solid electrolyte has high ionic conductivity and chemical stability, the sheet is produced through molding or casting of the ion conductive powder, followed by densification through sintering, There is a problem that it is not flexible, is fragile, and is difficult to manufacture in a large area. In addition, due to difficulties inherent in processing of ceramics, the production cost is very high, and it is difficult to manufacture complicated shapes, which limits the applications.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an inorganic solid electrolyte which not only facilitates the large-scale production of an inorganic solid electrolyte but also can be easily produced with a thickness of several tens of micrometers, An electrolyte and a method of manufacturing the same are provided.

In addition, the present invention provides a fibrous inorganic solid electrolyte having a higher ionic conductivity and being reinforced with fibrous phase alone, compared to conventional polymer solid electrolytes, and a method for producing the same.

The present invention also provides a fibrous inorganic solid electrolyte having a level of flexibility similar to that of a conventional solid electrolyte, and a method for producing the same.

In addition, the present invention provides a fiber-like inorganic solid electrolyte which can easily be made large in size even in a simple manufacturing process, and can freely adjust its area if necessary, and a method for producing the same.

In order to achieve the above object, the present invention provides a method for producing an inorganic electrolyte, comprising: mixing a starting material for preparing an inorganic electrolyte to prepare a mixture; Heating the mixture to melt while stirring to produce a molten inorganic material; And extruding the molten inorganic material into air from a spinning nozzle to cool and solidify the inorganic fiber to form an inorganic fiber; And forming a porous woven fabric or fabricating a nonwoven fabric by using the fibers. The present invention also provides a method for producing a fibrous inorganic solid electrolyte.

The inorganic fibers preferably have an average diameter in the cross-section of micrometer, sub-micrometer, or nanometer unit.

The inorganic fibers preferably have an average cross-sectional diameter of 1 to 20 mu m.

The porous woven fabric or nonwoven fabric preferably has pores having a size of 0.1 to 15 탆.

The step of fabricating the nonwoven fabric may include the steps of winding unit fibers from the inorganic fibers wound on the bobbin; Cutting the woven unit fiber into a desired length and size using a cutter to produce a chopped strand; And the inorganic strand is sprayed together with a binder and heated to fix the strand on the nonwoven fabric, or the inorganic strand is immersed in a binder and solidified into a sheet form to produce a nonwoven fabric-type inorganic solid electrolyte (140) The method comprising the steps of:

The inorganic solid electrolyte is preferably used as a separator at the same time.

The present invention also provides a fibrous inorganic solid electrolyte characterized in that a plurality of fibrous inorganic materials are formed as a woven fabric or nonwoven fabric.

Further, the present invention is a battery comprising the inorganic solid electrolyte as a constitution.

According to the present invention as described above, it is possible to easily manufacture a large-area inorganic solid electrolyte with a thickness of several tens of micrometers, and it is expected that the production efficiency can be improved.

Further, since the electrolytic material can be produced even if the high-purity process such as sintering and processing of the ceramic material is not performed, an action effect highly suitable for mass production is expected.

In addition, according to the present invention, a high level of flexibility is obtained compared to conventional inorganic solid electrolytes, and thus it is anticipated that the advantages of both polymer solid electrolytes and inorganic solid electrolytes can be shared.

In addition, according to the present invention, in manufacturing a solid electrolyte with a large area, it is possible to easily realize a large-sized surface by a simple manufacturing process as well as an effect that the area can be freely adjusted as needed.

1 is a schematic view showing an apparatus for producing an inorganic solid electrolyte according to an embodiment of the present invention.
2 shows a fabric type inorganic solid electrolyte produced according to an embodiment of the present invention.
Fig. 3 shows a fabric type inorganic solid electrolyte produced according to another embodiment of the present invention.
4 shows a non-woven inorganic solid electrolyte produced according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail based on the accompanying drawings and preferred embodiments. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the present invention, the defined terms are defined in consideration of the function of the present invention, and it can be changed according to the intention or custom of the technician working in the field, and the definition is based on the contents throughout this specification It should be reduced.

Here, the inorganic material radiator manufactured by the present invention can be fabricated either in the form of a weave or a nonwoven fabric, and its application is not limited.

1 is a schematic view of an apparatus for producing an inorganic solid electrolyte according to an embodiment of the present invention.

As shown in FIG. 1, the inorganic solid electrolyte according to the present invention may be manufactured as a woven fabric according to an embodiment. In this case, a conventional melt spinning apparatus may be used for melt spinning.

Fig. 1 shows such a melt spinning apparatus. Of course, there are a variety of devices other than the disclosed devices, and thus it is to be understood that the present invention is not solely made by the disclosed device.

The apparatus for producing an inorganic solid electrolyte according to the present invention comprises a batch chamber 110, a raw material reservoir 120, a melting furnace 130, and a plurality of bushings (nozzles) 131, And the inorganic fibers formed through the cooling process are wound around the bobbin. The wound fiber is drawn and processed to produce a nonwoven fabric or woven inorganic electrolyte.

When a La, Li, or Si based composite is used as a solid electrolyte, depending on the material of the solid electrolyte, it is necessary to melt at a high temperature of 1500 ° C or higher. Therefore, the melt receptacle of the bushing (nozzle) It must be a material that can withstand high temperatures.

Methods for producing inorganic fibers will be described in more detail as follows. Some processes form a common factor in the manufacturing process of woven fabric and nonwoven fabric.

First, the inorganic raw material in powder form is conveyed from the batch chamber 110 of the apparatus to the melting furnace 130. The inorganic raw material may be preliminarily placed in the raw material storage tank 120. When the raw materials contained in the batch chamber 110 of the apparatus are two or more kinds of raw material mixtures, they are used in a state in which they are mixed in advance. However, the arrangement chamber 110 may be provided with an apparatus for mixing such as an impeller (not shown).

Thereafter, the inorganic raw material in powder form carried in the melting furnace 130 is heated to the melting point. The method of melting is not particularly limited, but a method of heating at a high frequency will be simple. In addition, the inorganic raw material includes all known materials that can be used as a solid electrolyte. In other words, inorganic raw materials which can not be used as a solid electrolyte are excluded.

Such a melting point differs depending on the inorganic raw material, and it is preferable that the condition for the melting point is controlled by the input control unit. These inorganic raw materials may include amorphous mixed with inorganic raw materials.

Then, the molten inorganic raw material is radiated through the bushing 131. At this time, after spinning the filament of the unit radiator in the form of a very thin filament, the organic compound is coated as necessary to give flexibility.

Thereafter, as necessary, a plurality of filaments coated with the organic compound are twisted and wound on the bobbins 141 and 151-1 to 151-n, respectively, and the fabrics 150 are manufactured After that, crystallization is carried out through a heat treatment process.

As a result, a solid electrolyte in the form of an inorganic fabric or a nonwoven fabric can be produced.

The process for fabricating such a fabric or nonwoven fabric is as follows.

First, the manufacturing method of the nonwoven fabric is the same as the step S110. The unit fibers 143 are drawn from the inorganic fibers 141 wound on the bobbin, and the inorganic nonwoven fabric 140 is produced from the unit fibers 143. More specifically, the woven unit fiber 143 is cut into a desired length and size by using a cutter 147 to produce a chopped strand 145. The cut strand is then spun onto a nonwoven fabric, Or may be immersed in a binder and then solidified into a sheet form to prepare a nonwoven fabric-like inorganic solid electrolyte 140.

The fabrication method of the fabric is the same as that of step S120. The inorganic fiber wound around the bobbins 151-1 to 151-n is taken out and weaving is performed through the weaving machine 153 to fabricate the fabric-type inorganic solid electrolyte 150 . The weaving process is a well-known technique, and a detailed description thereof will be omitted.

FIG. 2 shows a woven solid type inorganic solid electrolyte. The solid electrolyte shown is a lattice type that can be expressed theoretically and is not actually expressed in this way, but rather forms a somewhat random form. That is, in the case of weaving in a lattice form, the unit lattice does not form a square or a rectangle.

Here, the thickness of the fiber can be controlled by controlling the parameters such as the thickness of the nozzle, the spinning speed, and the preferable thickness should be less than the micrometer unit. Particularly, when the fiber has a thickness of 1 to 20 μm Non-woven fabric or the like can be easily adjusted.

In addition, it is preferable that the woven fabric produced therefrom has a porosity of 10 to 30% and a pore size of 0.1 to 15 μm. In this case, a short circuit does not occur during charging and discharging of the secondary battery. Particularly, it is preferable to have the above-mentioned porosity for use with a separator.

On the other hand, although the method is somewhat different from the above method, it is also possible to consider a method of randomly arranging melt-spinning inorganic materials and using them as a fabric. This is characterized in that it is random compared to the case of using a fabric or a loom 153. [

As shown in FIG. 3, the heat resistant plate 170 is placed so that the inorganic fibers radiated in the melt spinning process are seated, the inorganic fibers are directly radiated directly on the heat resistant plate, cooled and solidified Thereafter, the inorganic fibers may be separated from the heat resistant plate 170 to obtain an inorganic solid electrolyte 180 similar to a fabric.

When the various types of inorganic solid electrolytes are used as a separator in a primary cell, it is preferable that the porosity is 85% to 95%, which is excellent in electrolyte impregnability and low in polarization resistance, .

4 shows a non-woven inorganic solid electrolyte produced according to an embodiment of the present invention.

That is, the inorganic yarn strands are seated on the nonwoven fabric, and are fixed on the nonwoven fabric by the binder. It is preferable that the strand is cut to a length of 9 to 13 mm, but it is not limited to the length.

In addition, it is also possible to produce a non-woven inorganic solid electrolyte by the above-described impregnation method. The inorganic solid strand is dispersed in a water tank, the water is sucked and removed, and then impregnated and cured with a curable organic compound mixture. The mixed solution of the organic compound to be used at this time is referred to as a "binder ". In the impregnation and curing process, the binder requires excellent impregnation property and work stability, and also has an important influence on the physical properties of the final product.

Such a nonwoven fabric can also easily control the porosity, the pore size, the pore distribution, and the like, and thus an inorganic porous article having various physical properties can be obtained.

On the other hand, although not shown, fabrics and nonwoven fabrics made from inorganic raw materials have a certain degree of flexibility, and therefore, they are easily made large-sized, and proper durability can be maintained without being damaged against impact.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (8)

Mixing a starting material for producing an inorganic solid electrolyte to prepare a mixture;
Heating the mixture to melt while stirring to produce a molten inorganic material; And
Extruding the molten inorganic material from the spinning nozzle into air to cool and solidify the inorganic fiber to form inorganic fibers;
Fabricating a porous inorganic or nonwoven fabric using the fibers;
Wherein the inorganic solid electrolyte is formed of a fibrous inorganic solid electrolyte. The method according to claim 1,
Wherein the inorganic fibers have an average diameter in the cross-section of micrometer, sub-micrometer, or nanometer unit. The method according to claim 1,
Wherein the inorganic fibers have an average diameter in the cross section of 1 to 20 占 퐉. The method according to claim 1,
Wherein the porous woven fabric or the nonwoven fabric has pores having a size of 0.1 to 15 占 퐉. The method according to claim 1,
Wherein the inorganic solid electrolyte is used as a separator at the same time. The method according to claim 1,
The step of fabricating the non-
Winding unit fibers out of the inorganic fibers wound on the bobbin;
Cutting the woven unit fiber into a desired length and size using a cutter to produce a chopped strand; And
The inorganic strands are sprayed together with a binder and heated to fix the strands on the nonwoven fabric, or the inorganic strands are immersed in a binder and solidified into a sheet form to produce a nonwoven fabric-type inorganic solid electrolyte (140) ;
Wherein the inorganic solid electrolyte is formed of a fibrous inorganic solid electrolyte. A process for the preparation of a compound according to any one of claims 1 to 6,
A fibrous inorganic solid electrolyte characterized in that a plurality of fibrous inorganic materials form a fabric or a nonwoven fabric. A battery characterized by comprising the inorganic solid electrolyte of claim 6 as one constituent.

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