KR101713102B1 - Electrode Sheet Rolling Device for Secondary Battery Comprising Cleaning Roller - Google Patents

Abstract

The present invention relates to an electrode sheet rolling apparatus for a secondary battery including a cleaning roller, and more particularly, to an electrode sheet rolling apparatus for a secondary battery that rolls an electrode sheet coated with an electrode compound on one surface or both surfaces of a current collector, A pair of rolling rollers rotating at a position spaced apart from each other by a width narrower than the thickness of the electrode sheet so that the sheet can be rolled while passing therethrough, and a cleaning member disposed adjacent to the rolling rollers and carrying a rust- The electrode sheet rolling apparatus for a secondary battery is characterized by comprising a roller.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electrode sheet rolling apparatus for a secondary battery including a cleaning roller,

The present invention relates to an electrode sheet rolling apparatus for a secondary battery including a cleaning roller, and more particularly, to an electrode sheet rolling apparatus for a secondary battery that rolls an electrode sheet coated with an electrode compound on one surface or both surfaces of a current collector, A pair of rolling rollers rotating at a position spaced apart from each other by a width narrower than the thickness of the electrode sheet so that the sheet can be rolled while passing therethrough, and a cleaning member disposed adjacent to the rolling rollers and carrying a rust- And an electrode sheet rolling apparatus for a secondary battery.

Lithium secondary batteries have been used not only as energy sources for mobile devices but also as power sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs) in recent years. In addition, they are also used as power assist power sources through grid- The use area is expanding.

The manufacturing process of such a lithium secondary battery is roughly classified into an electrode process, a granulation process, and a chemical process. The electrode process may be divided into an active material mixing process, an electrode coating process, a rolling process, a slitting process, and a winding process.

Among these processes, the rolling process involves passing the electrode through two rolling rolls heated at high temperature to increase the capacity density by reducing the thickness of the coated electrode and increasing the adhesion between the electrode current collector and the electrode active material, .

When such a rolling roller is subjected to a rolling process for a predetermined period of time, a thickness step is generated on the surface of the rolling roller which is in contact with the edge of the electrode sheet on which the active material is not applied or the non-coated portion due to wear of the electrode sheet and the rolling roller . In addition, when changing the type of the battery to be produced, the width of the electrode sheet to be rolled by each kind (for example, cylindrical battery, prismatic battery, polymer battery, etc.) There is a problem in that the thickness variation of the electrode sheets produced due to the increase in thickness is increased.

That is, when the electrode sheet is manufactured using such a worn rolling roller, the electrochemical performance and safety of the battery cell is deteriorated due to the thickness variation of the electrode sheet continuously generated.

Therefore, in order to prevent abrasion of the rolling roller, a technique of increasing the hardness of the surface of the rolling roller through a coating process has been applied. Particularly, hard chrome plating is inexpensive, It is widely used and has been widely used because it has the advantage of being easily provided with services.

However, since the hard chrome-plated rolling roller has a relatively low surface hardness, there has been a problem that the productivity is lowered and the manufacturing cost is increased according to the short replacement period of the rolling roller.

In addition, in the rolling process, serious contamination occurs on the surface of the rolling roller due to the electrode active material, so that the worker may stop the operation for cleaning the rolling roller by hand, or the new rolling roller may be replaced, .

Therefore, there is a great need for a technique that can fundamentally solve the above problems.

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

An object of the present invention is to provide a cleaning roller which is capable of preventing contamination of the surface of a rolling roller that occurs during a rolling process of an electrode sheet by further including a cleaning roller including a cleaning member carrying rust- The present invention provides an electrode sheet rolling apparatus for a secondary battery which can shorten the overall manufacturing time of the battery and is easy to manufacture because the rolling roller can be cleaned while the process is being carried out.

In order to achieve the above object, an electrode sheet rolling apparatus for a secondary battery according to the present invention is an electrode sheet rolling apparatus for a secondary battery for rolling an electrode sheet coated with an electrode mixture on one surface or both surfaces of a current collector,

At least one pair of rolling rollers rotating at a position spaced apart from each other by a width narrower than the thickness of the electrode sheet so that the electrode sheet can be rolled while passing therethrough; And

A cleaning roller disposed adjacent to the rolling rollers and including a cleaning member carrying anti-rust oil;

As shown in FIG.

Therefore, the electrode sheet rolling apparatus for a secondary battery according to the present invention can further prevent contamination of the surface of the rolling roller, which occurs in the rolling process of the electrode sheet, by including the cleaning roller including the cleaning member bearing the anti- , The rolling roller can be cleaned simultaneously with the progress of the process without having to stop the operation for cleaning the rolling roller, thereby shortening the overall manufacturing time of the battery and facilitating the manufacturing process.

In one specific example, the rolling rollers and the cleaning roller may be of a structure made of a metal material, and the periphery of the cleaning roller may further include a jetting portion for jetting rust-preventive oil onto the cleaning member, It may be a structure for continuously spraying rust preventive oil between the rinsing member of the roller and the rolling roller.

Further, in order to prevent the surface of the rolling roller from being worn, chromium (Cr) may be coated on the surface thereof, and the electrode sheet rolling apparatus for a secondary battery according to the present invention further includes a power unit for rotating the rolling rollers Structure.

Meanwhile, the cleaning member has a shape that directly contacts the outer surface of the rolling roller, and more specifically, a cylindrical shape surrounding the outer surface of the cleaning roller.

The cleaning member is not particularly limited as long as it is a material capable of supporting rust preventive oil, and may be preferably made of a nonwoven fabric material. Specifically, the nonwoven fabric material may be composed of one or more materials selected from the group consisting of polyester resins, nylon resins, polysulfone resins, polylactic acid, chitosan, collagen, cellulose, fibrinogen, and copolymers of two or more thereof , But are not limited thereto.

The rust preventive oil is not particularly limited as long as it is a solution containing a component capable of preventing and cleaning the surface of the rolling roller, and specifically, it is preferably a mixed solution of acetone and naphtha.

The present invention also provides an electrode sheet produced by using the above rolling apparatus, wherein the electrode sheet has an electrode mixture coating layer including an electrode active material, a binder, a conductive material, and a filler on one surface or both surfaces of the current collector An electrode sheet for a secondary battery is provided.

In one specific example, the electrode sheet is a negative electrode sheet and may include lithium titanium oxide as a negative electrode active material.

The lithium titanium oxide is preferably a compound expressed by the following composition formula (1), for example, Li _0.8 Ti _2.2 O ₄ , Li _2.67 Ti _1.33 O ₄ , LiTi ₂ O ₄ , Li _1.33 Ti _1.67 O ₄ , Li _1.14 Ti _1.71 O ₄ , but are not limited to these. More preferably, it may be Li _1.33 Ti _1.67 O ₄ having a spinel structure with a small change in crystal structure during charge and discharge and having excellent reversibility, and may be a secondary particle in which primary particles are aggregated, May be 200 nm to 30 탆.

Li _x Ti _y O ₄ (0.5? _X? 3; 1? Y? 2.5) (1)

The method for producing the lithium titanium oxide is well known in the art. For example, a lithium salt such as lithium hydroxide, lithium oxide, or lithium carbonate is dissolved in water as a lithium source, And then titanium oxide or the like is added as a titanium source, followed by stirring and drying to prepare a precursor and then calcining the precursor.

The present invention provides a secondary battery including the electrode sheet, and the secondary battery can be variously applied regardless of the type and external shape of the battery cell, and can be preferably a lithium secondary battery.

For reference, a typical lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt.

The positive electrode is prepared, for example, by applying a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector in the form of a slurry and then drying the mixture. Optionally, 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 ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; 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); 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. However, the present invention is not limited to these.

The conductive material is usually added in an amount of 1 to 30% 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.

The binder is a component which 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 30% by weight 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 negative electrode may be formed by applying a negative electrode active material on the negative electrode collector in the form of a slurry and drying the positive electrode active material. Optionally, the negative electrode may further include the components as described above.

Examples of the negative electrode active material include lithium titanium oxide, carbon such as non-graphitized carbon and graphite carbon; B, P, Si, Group 1 of the periodic table, LixFe2O3 (0? X? 1), LixWO2 (0? X? 1), SnxMe1-xMe'yOz (Me: Mn, Fe, Pb, 2 < / RTI > group III element, halogen, 0 < x < Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; Metal oxides such as SnO 2, 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 ₂ , 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 and the like may be used, but the present invention is not limited thereto.

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 non-aqueous electrolyte solution containing a lithium salt is composed of a polar organic electrolyte and a lithium salt. As the electrolytic solution, a non-aqueous liquid electrolytic solution, an organic solid electrolyte, an inorganic solid electrolyte and the like are used.

Examples of the nonaqueous liquid electrolytic solution 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, Polymers containing ionic dissociation groups, and the like can 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 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

For the purpose of improving the charge-discharge characteristics and the flame retardancy, the non-aqueous liquid electrolyte may contain, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like are added It is possible. In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

The present invention also provides a device using the lithium secondary battery as a power source or a power source.

Preferred examples of the device include a notebook, a mobile phone, a PDP, a PMP, an MP3 player, a DSC (Digital Still Camera), a DVR, a smart phone, a GPS system, a camcorder, an electric vehicle, a hybrid electric vehicle, a plug- Power storage devices, and the like, but the present invention is not limited thereto.

The structure of these devices and their fabrication methods are well known in the art, and a detailed description thereof will be omitted herein.

INDUSTRIAL APPLICABILITY As described above, the electrode sheet rolling apparatus for a secondary battery according to the present invention further comprises a cleaning roller provided with a cleaning member carrying anti-rust oil, thereby preventing contamination of the surface of the rolling roller, Since the rolling roller can be cleaned simultaneously with the progress of the process without having to stop the operation for cleaning the rolling roller, the overall manufacturing time of the battery can be shortened and the manufacturing process can be facilitated.

1 is a schematic diagram of an electrode sheet rolling apparatus according to one embodiment of the present invention;
Fig. 2 is a side view of the region A in Fig. 1; Fig.

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.

Fig. 1 schematically shows a structure of an electrode sheet rolling apparatus according to one embodiment of the present invention.

1, an electrode sheet rolling apparatus 100 according to the present invention includes a cylindrical upper end rolling roller 101, a lower end rolling roller 102, an upper housing 111 for fixing the upper end rolling roller 101, A lower end housing 112 for fixing the rolling roller 102, an upper cleaning roller 121 located adjacent to the upper rolling roller 101 and including a cleaning member carrying anti-rust oil, An upper spray portion 131 connected to the upper housing 111 and a lower spray portion 132 connected to the lower housing 112. The lower cleaning roller 122 includes a cleaning member, Lt; / RTI >

The upper rolling roller 101 and the lower rolling roller 102 are fixed by an upper housing 111 and a lower housing 112 respectively and are coated with chromium to prevent abrasion on the surface. And is rotated at a position spaced apart from each other by a width smaller than the thickness of the electrode sheet so as to be rolled.

Fig. 2 schematically shows a side view of the region A in Fig.

2, the upper cleaning roller 121 includes a cylindrical upper cleaning member 141 that surrounds the outer surface and supports a mixed solution of acetone and naphtha as anti-rust oil, and the lower cleaning roller 122 also has an outer surface And a cylindrical bottom stage cleaning member 142 which carries a mixed solution of acetone and naphtha as rust preventive oil.

The upper and lower cleaning members 141 and 142 are positioned so as to face the upper and lower rolling rollers 101 and 102 respectively so that the upper and lower cleaning members 141 and 142 The cleaning operation can be simultaneously performed on the surfaces of the upper and lower rolling rollers 101 and 102 through the rust preventive oil carried on the cleaning member 142. [

The upper and lower spray members 131 and 132 connected to the upper housing 111 and the lower housing 112 are connected to the upper and lower cleaning members 141 and 142, It is possible to clean the rolling rollers 101 and 102 at the same time while performing the process without having to stop the process in order to spray the rust preventive oil manually or to replace the cleaning members 141 and 142, The manufacturing time can be shortened and the manufacturing process can be easily performed.

Although it has been described that the cleaning rollers are formed at each of the lengths corresponding to the upper and lower rolling rollers of the electrode sheet rolling apparatus according to the present invention shown in FIGS. 1 and 2, It is needless to say that the number, the size, the shape, and the number of the electrode sheets may be varied according to the number of the electrode sheets.

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)

An electrode sheet rolling apparatus for a secondary battery for rolling an electrode sheet coated with an electrode mixture on one surface or both surfaces of a current collector,
At least one pair of rolling rollers rotating at a position spaced apart from each other by a width narrower than the thickness of the electrode sheet so that the electrode sheet can be rolled while passing therethrough; And
A cleaning roller disposed adjacent to the rolling rollers and including a cleaning member carrying anti-rust oil;
And the electrode sheet rolling apparatus for a secondary battery. The electrode sheet rolling apparatus for a secondary battery according to claim 1, further comprising a jetting portion located around the cleaning roller and jetting rust-preventive oil onto the cleaning member. The electrode sheet rolling apparatus for a secondary battery according to claim 1, wherein the rolling rollers and the cleaning roller are made of a metal material. The electrode sheet rolling apparatus for a secondary battery according to claim 1, wherein the rolling rollers are coated with chromium (Cr) on their surfaces. The electrode sheet rolling apparatus for a secondary battery according to claim 1, further comprising a power section for rotating the rolling rollers. The electrode sheet rolling apparatus for a secondary battery according to claim 1, wherein the cleaning member has a cylindrical shape surrounding the outer surface of the cleaning roller. The electrode sheet rolling apparatus for a secondary battery according to claim 1, wherein the cleaning member is made of a nonwoven fabric material. The nonwoven fabric according to claim 7, wherein the nonwoven fabric material is composed of one or more materials selected from the group consisting of polyester resin, nylon resin, polysulfone resin, polylactic acid, chitosan, collagen, cellulose, fibrinogen and copolymers of two or more thereof Wherein said electrode sheet rolling apparatus for a secondary battery comprises: The electrode sheet rolling apparatus for a secondary battery according to claim 1, wherein the anti-rust oil is a mixed solution of acetone and naphtha. The electrode sheet rolling apparatus for a secondary battery according to claim 1, wherein the electrode material mixture is an electrode material mixture in the form of a slurry. delete delete delete delete delete delete delete delete delete

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