KR20150015387A - Individual Electrolyte Injection Device - Google Patents

Abstract

The present invention relates to an electrolyte injecting device, capable of injecting electrolyte into a cell case fast while stably maintaining a shape of a pouch-type secondary cell. More specifically, the electrolyte injecting device comprises: a chamber to individually inject cells having an electrode assembly embedded in a pouch-type cell case; a water activated pipe which is installed to be connected to an electrolyte injection hole of the cell via a portion of the chamber; and a pressurization vacuum pipe which is connected to the chamber to form a vacuum pressure in the chamber.

Description

[0002] Individual Electrolyte Injection Device [

The present invention relates to an apparatus for injecting an individual electrolytic solution.

As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among such secondary batteries, lithium secondary batteries having high energy density and voltage, long cycle life and low self- It has been commercialized and widely used.

Typically, in terms of the shape of a battery, there is a high demand for a prismatic secondary battery and a pouch-type secondary battery which can be applied to products such as mobile phones with a small thickness, and has advantages such as high energy density, discharge voltage, There is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries.

Generally, the secondary battery is fabricated by sealing an electrode assembly in a state of being impregnated with an electrolyte solution in a battery case. In the electrolyte injection process of the secondary battery, after a secondary battery is charged into a predetermined chamber in the device, The battery case is evacuated and the electrolytic solution is supplied to a cylindrical container such as a liquid hopper connected to a nozzle for supplying an electrolyte to the battery case and connected to the main liquid port of the case, And in some cases, the electrolytic solution is injected into the battery case by pressurization on the side of the injection hopper.

However, in the case of the pouch type secondary battery, the shape is deformed by a small pressure difference between the inside and the outside of the case due to the thin thickness of the battery case and the weak mechanical strength, and the deformation causes the device It can not be fixed accurately in the storage portion of the housing.

Also, the electrolyte injection process of the pouch type secondary battery is performed by charging a plurality of secondary batteries into the same chamber of the electrolyte injection device. Even if the electrolyte can be injected by vacuum, the shape of the secondary battery can not be fixed , It is impossible to inject the electrolytic solution by pressurization, so that it is difficult to stably maintain the shape of the pouch type secondary battery during the electrolyte injection process.

Therefore, a need exists for a technique capable of solving such a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments and have completed an electrolyte injection device capable of injecting an electrolyte solution into the battery case more quickly while maintaining the shape of the pouch type secondary battery stably as described later It came to the following.

Therefore, the electrolyte injector according to the present invention comprises: a chamber into which a battery cell having an electrode assembly built in a pouch-type battery case is individually inserted; a liquid injection pipe (not shown) installed to be connected to an electrolyte injection port of the battery cell through a part of the chamber; pipe); And a pressurized vacuum pipe connected to the chamber and forming a vacuum pressure in the chamber.

In one specific example, the chamber may include a pressing jig for holding the shape of the battery cell, and the pressing jig may be a structure composed of a pair of members facing each other to press both side surfaces of the battery cell .

The inventors of the present application have found that the battery cells injected into the chamber of the electrolyte injecting apparatus are fixed by the pressing jig located on both sides of the chamber so that the shape of the pouch type secondary battery can be stably maintained even when the electrolyte is injected by vacuum and pressurization, It was confirmed that the electrolytic solution could be injected into the case.

In one specific example, the pair of members constituting the pressure jig may be movable so as to adjust the position thereof in accordance with the size of the battery cell.

Therefore, the pressing jig can adjust the position and fix the secondary battery according to the size of the pouch-type secondary battery inserted into the chamber of the electrolyte injection device.

In one specific example, the chamber may be a structure including a chamber body in which the battery cell is housed and an upper portion is opened, and a chamber door that covers and seals the upper portion of the chamber body.

Meanwhile, the injection tube is connected to an electrolyte tank containing an electrolyte, and the pressurized vacuum pipe may be connected to a vacuum pump for maintaining the chamber in a vacuum state and a pressurizing pump for providing a pressing force.

In this case, the injection tube may include a juice nozzle directly connected to an electrolyte injection hole of the battery cell, a juice hopper coupled to the juice nozzle, and an on-off valve for opening and closing the juice nozzle.

The pressure provided in the chamber may be from 0.10 bar to 0.99 bar.

If the pressure provided in the chamber is excessively low or high outside the above range, excessive pressure difference between the inside and outside of the case of the battery cell may cause deformation of the case.

According to the present invention, there is provided a method of injecting an electrolyte solution into a battery cell using the electrolyte injection device,

(i) a process of putting the battery cells individually into a chamber and connecting a fluid pipe to the battery cell;

(ii) sealing the chamber;

(iii) switching the inside of the chamber to vacuum using a vacuum pump;

(iv) pressing the inside of the chamber formed with the vacuum atmosphere into a pressurized atmosphere to inject an electrolyte;

The electrolyte solution injecting method of the present invention includes:

In this case, the pressurization of the process (iv) can be performed at a pressure of not less than 1.0 bar and not more than 5.0 bar.

If the pressure is 1.0 bar, the electrolyte can not be easily injected into the chamber due to the excessively low pressure. If the pressure is more than 5.0 bar, due to the excessively high pressure, It may be difficult to precisely control the amount.

The present invention also provides a secondary battery manufactured using the electrolyte injection device.

In this case, the secondary battery may have a structure in which an electrode assembly including a cathode, a cathode, and a separator interposed between the anode and the cathode is embedded in the pouch-shaped battery case and the electrolyte is impregnated, And a lithium transition metal oxide represented by the following general formula (1) or (2) as a cathode active material.

Li _x M _y Mn _{2 - y} O _{4 - z z} (1)

In this formula,

M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, ;

A is one or more anions of -1 or -2;

0.9? X? 1.2, 0 <y <2, 0? Z <0.2.

(1-x) LiM'O _2-y A _y -xLi ₂ MnO _{3 -y '} A _y' (2)

In this formula,

M 'is Mn _a M _b ;

M is one or more selected from the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and two period transition metals;

A is at least one selected from the group consisting of anions of PO ₄ , BO ₃ , CO ₃ , F and NO ₃ ;

0 <x <1, 0 <y? 0.02, 0 <y? 0.02, 0.5? A? 1.0, 0 b? 0.5, a + b =

Generally, the positive electrode is prepared by applying an electrode mixture, which is a mixture of a positive electrode active material, a conductive material and a binder, on a positive electrode collector, followed by drying. If necessary, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ) or lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals, in addition to the lithium transition metal oxide represented by Formula 1 or 2. Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); A lithium manganese composite oxide having a spinel structure represented by LiNi _x Mn _2-x O ₄ ; LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like, but is not limited thereto.

The cathode current collector generally has a thickness of 3 to 500 mu m. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, titanium, sintered carbon, aluminum or stainless steel A surface treated with carbon, nickel, titanium, silver or the like may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

The conductive material is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

On the other hand, the graphite-based material having elasticity may be used as a conductive material, and may be used together with the materials.

The binder is a component that assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 50 wt% based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for suppressing the expansion of the anode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. Examples of the filler include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The secondary batteries including the lithium-transition metal oxide generally include an anode, a cathode, a separator interposed between the anode and the cathode, and a non-aqueous electrolyte containing a lithium salt, and other components of the lithium secondary battery will be described below .

The negative electrode is prepared by applying, drying and pressing an anode active material on an anode current collector, and may optionally further include a conductive material, a binder, a filler, and the like as described above.

The negative electrode active material may include, for example, carbon such as non-graphitized carbon or graphite carbon; _{Li x Fe 2 O 3 (0≤x≤1} ), Li x WO 2 (0≤x≤1), Sn x Me 1-x Me 'y O z (Me: Mn, Fe, Pb, Ge; Me' : Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen, 0 &lt; x &lt; Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Titanium oxide; Lithium titanium oxide and the like can be used, and in particular, a carbon-based material and / or Si can be included.

The negative electrode current collector is generally made to have a thickness of 3 to 500 mu m. Such an anode current collector is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, and examples of the anode current collector include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, a surface of copper or stainless steel A surface treated with carbon, nickel, titanium, silver or the like, an aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

The separation membrane is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 300 mu m. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

The lithium salt-containing nonaqueous electrolyte is composed of a nonaqueous electrolyte and lithium. Nonaqueous organic solvents, organic solid electrolytes, inorganic solid electrolytes, and the like are used as the nonaqueous electrolyte, but the present invention is not limited thereto.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyrolactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane , Acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate Nonionic organic solvents such as tetrahydrofuran derivatives, ethers, methyl pyrophosphate, ethyl propionate and the like can be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, A polymer containing an ionic dissociation group and the like may be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide.

The lithium salt-containing non-aqueous electrolyte may further contain, for the purpose of improving charge / discharge characteristics, flame retardancy, etc., for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride, etc. May be added. In some cases, halogen-containing solvents such as carbon tetrachloride and ethylene trifluoride may be further added to impart nonflammability. In order to improve the high-temperature storage characteristics, carbon dioxide gas may be further added. FEC (Fluoro-Ethylene Carbonate, PRS (Propene sultone), and the like.

In one specific _{example, LiPF 6, LiClO 4, LiBF} 4, LiN (SO 2 CF 3) 2 , such as a lithium salt, a highly dielectric solvent of DEC, DMC or EMC Fig solvent cyclic carbonate and a low viscosity of the EC or PC of And then adding it to a mixed solvent of linear carbonate to prepare a lithium salt-containing non-aqueous electrolyte.

Meanwhile, the pouch-shaped battery case may be a battery case of a laminate sheet including a resin layer and a metal layer, but is not limited thereto.

The present invention provides a battery module including the secondary battery as a unit cell, a battery pack including the battery module, and a device including the battery pack as a power source.

At this time, specific examples of the device may be, but not limited to, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage system.

As described above, in the apparatus for injecting an electrolyte according to the present invention, since the battery cells are individually introduced into the chamber and both side surfaces of the battery cells are pressed by the pressing jig, the shape of the pouch type secondary battery can be stably maintained, There is an effect that the electrolytic solution can be injected into the battery case quickly.

1 is a schematic view schematically showing the structure of an electrolyte injection device according to one embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

1 is a schematic view schematically showing the structure of an electrolyte injection device according to one embodiment of the present invention.

1, the electrolyte injection device 100 includes a chamber 110 into which battery cells are individually charged, a liquid injection pipe 120 connected to an electrolyte injection port of the battery cell, And a pressurized vacuum pipe 130.

The injection pipe 120 is connected to an electrolyte tank 140 containing an electrolyte and the pressurized vacuum pipe 130 is connected to a vacuum pump 150 for maintaining the inside of the chamber 110 in a vacuum state, And is connected to a pressurizing pump 160 provided.

The pressure jig 170 for holding the shape of the battery cell is included in the chamber 110. The pressing jig 170 is formed of a pair of members facing each other on both sides of the battery cell, The battery cells in the chamber 110 are fixed and the shape is maintained during the electrolyte injection process.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (19)

A chamber in which a battery cell in which an electrode assembly is embedded in a pouch-shaped battery case is separately inserted;
A fluid pipe installed to be connected to an electrolyte injection port of the battery cell through a part of the chamber; And
A pressurized vacuum pipe connected to the chamber and forming a vacuum pressure in the chamber;
Wherein the electrolyte solution is injected into the electrolyte solution. 2. The electrolyte injection device according to claim 1, wherein a pressure jig for holding the shape of the battery cell is included in the chamber. The apparatus according to claim 2, wherein the pressing jig is made of a pair of members facing each other to press both side surfaces of the battery cell. 4. The apparatus according to claim 3, wherein the pair of members constituting the pressing jig are movable so as to adjust the position in accordance with the size of the battery cell. 2. The electrolyte injection device according to claim 1, wherein the chamber includes a chamber body accommodating a battery cell and having an upper portion opened, and a chamber door covering and sealing the upper portion of the chamber body. The pressurized vacuum pipe according to claim 1, wherein the liquid injection pipe is connected to an electrolyte tank containing an electrolyte, and the pressurized vacuum pipe is connected to a vacuum pump for maintaining the chamber in a vacuum state and a pressurizing pump for providing a pressing force Wherein the electrolytic solution injecting device comprises: 2. The electrolyte injection device according to claim 1, wherein the injection pipe comprises an injection nozzle directly connected to an electrolyte injection hole of the battery cell, a injection hopper coupled to the injection nozzle, and an opening / closing valve for opening / . The apparatus of claim 1, wherein the pressure provided in the chamber is greater than or equal to 0.10 bar and less than or equal to 0.99 bar. A method for injecting an electrolyte solution into a battery cell using the electrolyte injection device according to claim 1,
(i) a process of putting the battery cells individually into a chamber and connecting a fluid pipe to the battery cell;
(ii) sealing the chamber;
(iii) switching the inside of the chamber to vacuum using a vacuum pump;
(iv) pressing the inside of the chamber formed with the vacuum atmosphere into a pressurized atmosphere to inject an electrolyte;
Wherein the electrolyte solution is injected into the electrolyte solution. 10. The method according to claim 9, wherein the step (iv) is performed at a pressure of not less than 1.0 bar and not more than 5.0 bar. A secondary battery according to claim 1, wherein the secondary battery is manufactured using the electrolyte injection device. 12. The secondary battery according to claim 11, wherein the secondary battery includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the electrode assembly is embedded in the pouch- battery. 13. The secondary battery according to claim 12, wherein the anode comprises a lithium transition metal oxide represented by the following general formula (1) or (2) as a cathode active material:
Li _x M _y Mn _{2 - y} O _{4 - z z} (1)
In this formula,
M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, ;
A is one or more anions of -1 or -2;
0.9? X? 1.2, 0 <y <2, 0? Z <0.2.


(1-x) LiM'O _2-y A _y -xLi ₂ MnO _{3 -y '} A _y' (2)
In this formula,
M 'is Mn _a M _b ;
M is one or more selected from the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and two period transition metals;
A is at least one selected from the group consisting of anions of PO ₄ , BO ₃ , CO ₃ , F and NO ₃ ;
0 <x <1, 0 <y? 0.02, 0 <y? 0.02, 0.5? A? 1.0, 0 b? 0.5, a + b = 13. The secondary battery according to claim 12, wherein the negative electrode comprises a carbonaceous material and / or Si as an anode active material. 13. The secondary battery according to claim 12, wherein the pouch-shaped battery case is a battery case of a laminate sheet including a resin layer and a metal layer. 12. A battery module comprising a secondary battery according to claim 11 as a unit cell. A battery pack comprising the battery module according to claim 16. A device according to claim 17, comprising a battery pack as a power source. 19. The device of claim 18, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a system for power storage.

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