KR102157150B1 - Battery Cell Comprising Inner Surface Coated with Electrical Insulating Material - Google Patents

Abstract

The present invention is an electrode assembly having a positive electrode, a negative electrode, and a separator structure interposed between the positive electrode and the negative electrode; A first battery case in which a storage unit in which the electrode assembly is embedded is formed; And a second battery case mounted on the first battery case so as to surround the receiving part, wherein the first battery case is made of a metal material, and the inner surface is coated with an electrical insulating material. Provides.

Description

Battery Cell Comprising Inner Surface Coated with Electrical Insulating Material {Battery Cell Comprising Inner Surface Coated with Electrical Insulating Material}

The present invention relates to a battery cell in which the inner surface of the battery case is coated with an electrically insulating material.

In recent years, interest in environmental pollution and rising prices of energy sources due to depletion of fossil fuels are amplified, and the demand for eco-friendly alternative energy sources is becoming an indispensable factor for future life. Accordingly, research on various power generation technologies such as nuclear power, solar power, wind power, and tidal power is continuing, and power storage devices for more efficient use of the energy produced in this way are also receiving great interest.

In particular, as technology development and demand for mobile devices increase, the demand for batteries as an energy source is rapidly increasing, and accordingly, many studies on batteries that can meet various demands have been conducted.

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

In addition, secondary batteries are classified according to the structure of an electrode assembly in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are stacked. Typically, long sheet-shaped positive electrodes and negative electrodes are used. A jelly-roll type (wound type) electrode assembly wound with a separator interposed therebetween, a stacked (stacked) electrode assembly in which a plurality of anodes and cathodes cut into units of a predetermined size are sequentially stacked with a separator interposed therebetween In recent years, in order to solve the problems of the jelly-roll type electrode assembly and the stack type electrode assembly, as an electrode assembly having an advanced structure, which is a mixture of the jelly-roll type and the stack type, A stack/folding electrode assembly having a structure in which the unit cells stacked with the anode and the cathode interposed between the separator and the unit cells stacked on the separation film were sequentially wound up was developed.

In addition, secondary batteries are cylindrical and prismatic batteries in which an electrode assembly is built into a cylindrical or square metal can, and a pouch-type battery in which the electrode assembly is built into a pouch-shaped case of an aluminum laminate sheet, depending on the shape of the battery case. Classified.

In particular, in recent years, a pouch-type battery having a structure in which a stack-type or stack/folding-type electrode assembly is embedded in a pouch-type battery case of an aluminum laminate sheet has attracted a lot of attention due to low manufacturing cost, small weight, and easy shape transformation. And also its usage is gradually increasing.

1 is an exploded perspective view schematically showing the structure of a conventional pouch-type battery cell.

Referring to FIG. 1, a pouch-type battery cell 100 includes an electrode assembly 130, electrode tabs 131 and 132 extending from the electrode assembly 130, and electrodes welded to the electrode tabs 131 and 132. It is configured to include a battery case 120 accommodating the leads 140 and 141 and the electrode assembly 130.

The electrode assembly 130 is a power plant in which an anode and a cathode are sequentially stacked with a separator interposed therebetween, and has a stacked or stacked/folded structure. The electrode tabs 131 and 132 extend from each electrode plate of the electrode assembly 130, and the electrode leads 140 and 141 are formed with a plurality of electrode tabs 131 and 132 extending from each electrode plate, for example, Each is electrically connected by welding, and a part of the battery case 120 is exposed to the outside. In addition, an insulating film 150 is attached to a portion of the upper and lower surfaces of the electrode leads 140 and 141 in order to increase the degree of sealing with the battery case 120 and at the same time secure an electrical insulation state.

The battery case 120 is composed of a case body 122 including a concave storage unit 123 in which the electrode assembly 130 can be seated and a cover 121 integrally connected to the body 122 In addition, a battery is completed by combining the both side portions 124 and the upper end 125, which are contact portions, in a state in which the electrode assembly 130 is accommodated in the storage unit 123. The battery case 120 is made of an aluminum laminate structure of a resin outer layer/barrier metal layer/thermal meltable resin sealant layer, so that the cover 121 and both sides 124 and upper end 125 of the cover 121 and the main body 122 are in contact with each other. Heat and pressure are applied to the resin layers to form a bonded sealing surplus by fusing each other. Both side portions 124 are in direct contact with the same resin layers of the upper and lower battery cases 120, so that uniform sealing is possible by melting. On the other hand, since the electrode leads 140 and 141 protrude from the upper end 125, the electrode leads 140, 141 and the thickness of the electrode leads 140 and 141 and the heterogeneity with the material of the battery case 120 are considered to increase the sealing property. Thermal fusion is performed with the insulating film 150 interposed between the leads 140 and 141.

In general, the pouch-type battery cell of this structure removes gas generated in the aging process, the process of storing the electrode assembly and the electrolyte solution to the battery case, the sealing process of the battery case by thermal fusion, the aging process through charge and discharge, and the aging process. It is manufactured through various processes, such as a degas process.

At this time, each of the processes is performed in a state in which the pouch-type battery cell is fixed to a jig or tool by a predetermined vacuum adsorption, and the pouch-type battery cell is due to the material characteristics of the battery case, At the portion where the vacuum is adsorbed, the appearance of the battery case may be deformed, and in the process of repeating the bonding and separation of the jig or the tool in each process, it is difficult to uniform positioning, and defects due to the positioning deviation There is a problem that occurs.

In addition, since the pouch-type battery cell has a weak rigidity of the battery case made of an aluminum laminate sheet, there is a limit to forming the receiving part in a shape and size corresponding to the external shape of the electrode assembly, and it is relatively difficult to protect the electrode assembly from external impact. Is disadvantageous.

Therefore, there is a high need for a technology that can fundamentally solve this problem.

An object of the present invention is to solve the problems of the prior art and technical problems that have been requested from the past.

After repeated in-depth research and various experiments, the inventors of the present application formed the first battery case in which the storage part was formed of a metal material, as described later, and configured the inner surface to be coated with an electrical insulating material. Uniform positioning is possible when a jig or tool is combined between manufacturing processes of the cell, and external deformation due to vacuum adsorption can be prevented, thus minimizing the defect rate of the product and improving the overall structural stability of the battery cell, It was confirmed that the battery cell can be more safely protected from external impacts, insulation properties can be secured, and the sealing power of the battery case can be improved by heat fusion, and the present invention has been completed.

The battery cell according to the present invention for achieving this object includes an electrode assembly having a positive electrode, a negative electrode, and a separator structure interposed between the positive electrode and the negative electrode, a first battery case having a storage unit in which the electrode assembly is built, and the storage Includes a second battery case mounted on the first battery case to surround the part, the first battery case is made of a metal material, the inner surface is coated with an electrical insulating material, and the second battery case is a resin outer layer , A barrier metal layer, and a laminate sheet including a heat-melt resin sealant layer, the electrical insulating material is the same as the material of the heat-melt resin sealant layer of the second battery case, the second battery case When the outer peripheries of the first battery case and the second battery case are pressed while being heated and pressurized in a state that surrounds the storage part of the first battery case, the first battery case and the second battery case are formed by the heat-melt resin sealant layer. The outer periphery facing the battery case may be bonded and sealed.

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Therefore, uniform positioning is possible when the jig or tool is combined between the manufacturing processes of the battery cell, and external deformation due to vacuum adsorption can be prevented, thereby minimizing the defect rate of the product, and the overall structural stability of the battery cell. As a result, it is possible to more safely protect the battery cell from external impacts, secure insulation, and improve the sealing power of the battery case by thermal fusion.

In addition, since the inner surface of the first case is coated with an electrical insulating material, it is possible to secure electrical insulation by preventing direct contact between the first battery case made of a metal material and the electrode assembly.

In one specific example, the first battery case may be formed of a metal plate, and may have a structure in which the receiving portion is recessed corresponding to the shape of the electrode assembly.

Therefore, the first battery case may have fewer or no restrictions in configuring the size and shape of the storage unit compared to the conventional pouch-type battery case made of an aluminum laminate sheet, and by providing higher strength, the structural Stability can be improved.

In this case, the receiving portion of the first battery case is formed by processing a metal plate, and in detail, it may be formed by a deep drawing method.

The deep drawing process is a typical molding method for making a hollow container without a joint from a flat plate. It refers to a molding method in which a material plate placed on the surface of a die is pressed with a punch to perform plastic processing.

However, the method of forming the receiving unit is not limited thereto, and if a method capable of forming the receiving unit in a desired size and shape without damaging the first battery case made of a metal plate, the method is greatly limited. It is not.

On the other hand, if the first battery case is a metal capable of easily forming the shape and size of the storage unit while exhibiting desired strength and structural stability, the material is not largely limited, and in detail, from the outside. It may be a structure made of aluminum or an aluminum alloy that can prevent the inflow of moisture.

In addition, the second battery case may have a plate-shaped sheet structure.

That is, unlike the first battery case, the second battery case does not include a separate storage unit, and is a plate-shaped sheet structure mounted on the first battery case so as to surround the storage unit of the first battery case. Compared to the battery case, there may be less risk of damage or deformation due to processing.

Accordingly, the second battery case may be a pouch-shaped case made of the same aluminum laminate sheet as in the prior art, and in detail, the second battery case is, from an outer direction, a resin outer layer, a barrier metal layer, and a heat melting property. It may be a structure consisting of a laminate sheet including a resin sealant layer.

More specifically, the outer layer of the resin exhibits excellent tensile strength and weather resistance compared to the thickness so as to protect the battery from the outside, and in detail, may be made of ONy (stretched nylon film). The barrier metal layer serves to prevent air, moisture, and the like from flowing into the battery, and in detail, may be made of aluminum (Al). The heat-melting resin sealant layer is heat-sealed by applied heat and pressure in a state in which the electrode assembly is embedded to provide sealing properties, and in detail, may be made of a polyolefin-based resin such as polyethylene or polypropylene. .

In addition, the second battery case may have a structure in which the outer periphery of the second battery case is mounted by being heated and pressurized by a press while facing a structure surrounding the storage part of the first battery case, thereby being bonded and sealed.

That is, the second battery case may have a structure in which the outer periphery is heat-sealed, thereby being bonded to and sealed with the first battery case.

At this time, the electrical insulating material coated on the inner surface of the first battery case may be the same as the material of the heat-melting resin sealant layer of the second battery case, and in detail, the electrical insulating material may be a polyolefin resin. have.

Accordingly, since the electrical insulating material of the first battery case and the heat-melting resin sealant layer of the second battery case are bonded to each other by thermal fusion at each outer periphery, a more improved sealing force can be provided.

Meanwhile, the electrical insulating material may have a structure coated with a thickness of 10 micrometers to 100 micrometers.

If the coating thickness of the electrical insulating material is less than 10 micrometers, the coating thickness of the electrical insulating material is too thin to exhibit the desired insulating property, or it is damaged by direct contact with the electrode assembly and does not exhibit insulation. By doing so, electrical stability may deteriorate.

Conversely, when the coating thickness of the electrical insulating material exceeds 100 micrometers, the coating thickness of the electrical insulating material becomes too thick compared to the thickness required to exhibit the desired insulating property, rather the number of first battery cases Since the payment space may be reduced, it may result in a decrease in the capacity of the electrode assembly included in the receiving unit.

In one specific example, the electrical insulating material may have a structure coated on the entire inner surface including the receiving portion and the outer peripheral portion of the first battery case.

Therefore, at the outer periphery, it is heat-sealed with the heat-melting inner sealant layer of the second battery case, thereby exhibiting improved sealing power.

In another specific example, the electrical insulating material may have a structure coated only on the inner surface of the receiving portion excluding the outer periphery of the first battery case.

More specifically, the electrode assembly is mounted on the receiving unit of the first battery case, and thus, in the first battery case, the portion requiring insulation from the electrode assembly is only the inner surface of the receiving unit, and thus the electrical insulating material is 1 By coating only the inner surface of the storage unit excluding the outer periphery of the battery case, it is possible to save time and cost required for coating the electrical insulating material.

In this case, the surface of the metallic material coated with the electrically insulating material at the outer periphery of the first battery case may have a structure in which the surface is treated to form irregularities.

More specifically, when the electrical insulating material is coated only on the inner surface of the storage unit excluding the outer periphery of the first battery case, the outer periphery of the first battery case is made of a metal material that has the thermal melting properties of the second battery case. The inner sealant layer is bonded to each other by heat fusion, and accordingly, the surface of the outer peripheral portion of the first battery case is surface-treated to form irregularities, thereby improving bonding strength between different materials.

In addition, when the electrically insulating material is coated on the entire inner surface including the storage portion and the outer peripheral portion of the first battery case, the surface of the outer peripheral portion of the first battery case is surface-treated to form irregularities, It is possible to improve the sealing force by combining the first battery case and the second battery case.

At this time, the surface treatment is not limited as long as it is capable of forming irregularities on the surface of a metal material at the outer periphery of the first battery case, and in detail, sand blast or etching It can be done by (etching).

Here, the sand blast is a method for processing the surface of a metallic material, and by pressing and accelerating fine sand with compressed air and spraying, contaminants on the surface may be removed and fine irregularities may be formed.

In addition, the etching is a method of corroding the surface of a metallic material with an acidic or basic chemical, and the surface can be polished and irregularities having a desired shape and size can be formed more easily.

On the other hand, despite the above structure, the second battery case is made of aluminum or aluminum alloy so as to exhibit the same structural stability as the first battery case and prevent the penetration of moisture, and secure insulation for the electrode assembly. , In order to improve adhesion and sealing power with the first battery case, the inner surface facing the first battery case may be coated with the same material as the electrical insulating material coated on the inner surface of the first battery case.

In other words, the second battery case may also be made of the same material as the first battery case, not an aluminum laminate sheet.

At this time, the electrical insulating material is a structure coated on the entire inner surface of the second battery case, similar to the coating structure of the electrical insulating material of the first battery case, or the first battery case excluding the outer periphery of the second battery case It may have a structure coated only on the inner surface corresponding to the receiving part of the.

However, in this case, of the first battery case and the second battery case, an electrical insulating material must be coated on the outer periphery of at least one battery case to exert adhesive and sealing effects by thermal fusion.

In addition, in this case, the surface of the metal material coated with the electrical insulating material at the outer periphery of the second battery case is also surface-treated to form irregularities in order to improve the bonding force and sealing power to the first battery case. It can be a structure that is there.

On the other hand, the electrode assembly is not greatly limited as long as it is capable of exhibiting a desired capacity and electrical characteristics in a state embedded in the storage unit of the first battery case, and in detail, a folding type structure or a stack It may have a type structure, a stack/folding type structure, or a lamination/stack type structure.

In one specific example, the type of the battery cell is not particularly limited, but as a specific example, a lithium secondary battery such as a lithium ion battery or a lithium ion polymer battery having advantages such as high energy density, discharge voltage, and output stability. It can be a battery.

In general, a 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 coating a mixture of a positive electrode active material, a conductive material, and a binder on a positive electrode current collector, followed by drying, and if necessary, a filler may be further added to the mixture.

The positive electrode 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; Lithium manganese oxides such as formula Li _1+x Mn _2-x O ₄ (wherein x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , and LiMnO ₂ ; 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 ; Ni site-type lithium nickel oxide represented by the formula LiNi _1-x M _x O ₂ (here, 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, Zn or Ta, and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (where M = Fe, Co, A lithium manganese composite oxide represented by Ni, Cu or Zn); LiMn ₂ O _{4 wherein} part of Li in the formula is substituted with alkaline earth metal ions; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ and the like may be mentioned, but the present invention is not limited thereto.

The conductive material is typically added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the battery, and examples thereof include graphite such as natural graphite or artificial graphite; Carbon blacks such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fibers and metal fibers; 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 may be used.

The binder is a component that aids in bonding of an active material and a conductive material and bonding to a current collector, and is typically added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, recycled cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, and various copolymers.

The filler is selectively used as a component that suppresses the expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing chemical changes to the battery, and examples thereof include olefin-based polymers such as polyethylene and polypropylene; Fibrous materials such as glass fiber and carbon fiber are used.

The negative electrode is manufactured by coating and drying a negative electrode active material on a negative electrode current collector, and if necessary, components as described above may be optionally further included.

Examples of the negative active material include carbon such as non-graphitized carbon and graphite-based 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' : Al, B, P, Si, elements of groups 1, 2 and 3 of the periodic table, halogen, metal complex oxides such as 0<x≦1;1≦y≦3;1≦z≦8); Lithium metal; Lithium alloy; Silicon-based alloys; Tin-based alloys; 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 metal oxides such as Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The separator and the separation film are 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 μm, and the thickness is generally 5 to 130 μm. Examples of such separation membranes include olefin-based polymers such as polypropylene having chemical resistance and hydrophobicity; Sheets or non-woven fabrics made of glass fiber or polyethylene are used. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as a separator.

In addition, in one specific example, in order to improve the safety of the battery, the separator and/or the separation film may be an organic/inorganic composite porous SRS (Safety-Reinforcing Separators) separator.

The SRS separator is manufactured by using inorganic particles and a binder polymer as active layer components on a polyolefin-based separator substrate, and at this time, the pore structure included in the separator substrate itself and the interstitial volume between inorganic particles as the active layer component It has a uniform pore structure formed.

In the case of using such an organic/inorganic composite porous separator, compared to the case of using a conventional separator, there is an advantage in that it is possible to suppress an increase in the thickness of the battery due to swelling during the formation process. When a polymer that can be gelled when impregnated with a liquid electrolyte is used, it can be used as an electrolyte at the same time.

In addition, since the organic/inorganic composite porous separator can exhibit excellent adhesion characteristics by controlling the content of inorganic particles and binder polymers as active layer components in the separator, the battery assembly process can be easily performed.

The inorganic particles are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as the oxidation and/or reduction reaction does not occur in the operating voltage range (eg, 0 to 5V based on Li/Li+) of the applied battery. Particularly, in the case of using inorganic particles having ion transfer capability, it is possible to improve the performance by increasing the ionic conductivity in the electrochemical device, so it is preferable that the ion conductivity is as high as possible. In addition, when the inorganic particles have a high density, it is difficult to disperse during coating, as well as a problem of weight increase during battery manufacturing, so it is preferable that the density is as small as possible. Further, in the case of an inorganic material having a high dielectric constant, the ionic conductivity of the electrolyte may be improved by contributing to an increase in the degree of dissociation of an electrolyte salt, such as a lithium salt, in a liquid electrolyte.

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

As the non-aqueous liquid electrolyte, for example, N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyl lactone, 1,2-dimethoxy ethane, tetrahydroxy franc (franc), 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolone, formamide, dimethylformamide, dioxolone , Acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid tryster, trimethoxymethane, dioxolone derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbo Aprotic organic solvents such as nate derivatives, tetrahydrofuran derivatives, ethers, methyl pyropionate and ethyl propionate may be used.

As the organic solid electrolyte, for example, a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, a poly agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, A polymer or the like containing an ionic dissociating group may be used.

As the inorganic solid electrolyte, for example, 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 may be used.

The lithium salt is a material 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.

In addition, non-aqueous electrolytes include pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexaphosphate triamide for the purpose of improving charge/discharge properties and flame retardancy, etc. , Nitrobenzene derivative, sulfur, quinone imine dye, N-substituted oxazolidinone, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxy ethanol, aluminum trichloride, etc. May be. In some cases, in order to impart non-flammability, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further included, and carbon dioxide gas may be further included in order to improve high-temperature storage characteristics.

The present invention also provides a battery pack including the battery cell and a device including the battery pack as a power source, wherein the device includes a mobile phone, a tablet computer, a notebook computer, a power tool, a wearable electronic device, and an electric vehicle. , Hybrid electric vehicle, plug-in hybrid electric vehicle, and may be any one selected from the group consisting of a power storage device.

Since such devices or devices are known in the art, detailed descriptions thereof will be omitted in this specification.

As described above, in the battery cell according to the present invention, the first battery case in which the receiving part is formed is formed of a metal material, and the inner surface is formed to be coated with an electrical insulating material. When combined with the battery, uniform positioning is possible and external deformation due to vacuum adsorption can be prevented, thereby minimizing the defect rate of the product, and improving the overall structural stability of the battery cell, thereby preventing the battery cell from external impact. It is possible to protect more safely, secure insulation, and at the same time improve the sealing power of the battery case by heat fusion.

1 is an exploded perspective view schematically showing the structure of a conventional pouch-type battery cell;
2 is a schematic diagram schematically showing the structure of a battery case constituting a battery cell according to an embodiment of the present invention;
3 to 5 are schematic diagrams schematically showing the structure of a battery case according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings according to an embodiment of the present invention, but the scope of the present invention is not limited thereto.

2 is a schematic diagram schematically showing the structure of a battery case according to an embodiment of the present invention.

Referring to FIG. 2, the battery case 200 includes a first battery case 210 and a second battery case 220.

The first battery case 210 is formed in a structure in which the storage part 213 in which the electrode assembly is embedded is recessed, and the second battery case 220 surrounds the storage part 213 of the first battery case 210. So, it consists of a plate-shaped structure mounted on the upper surface of the first battery case 210.

The first battery case 210 is made of an aluminum plate 211.

Therefore, during the manufacturing process of the battery cell, even if the first battery case 210 is fixed to the jig or tool by vacuum, the outer shape of the first battery case 210 is not deformed, and it is combined with the jig or tool in each process. And in the process of repeating the separation, uniform positioning is possible, so that defects that may be caused by the positioning deviation can be minimized.

An electrical insulating material 212 is coated on the inner and outer peripheral portions 214 of the receiving portion 213 of the first battery case 210 in which the electrode assembly is accommodated.

Accordingly, the electrode assembly mounted on the receiving portion 213 of the first battery case 210 and the aluminum plate 211 forming the first battery case 210 are electrically insulated, thereby improving safety.

The second battery case 220 is made of a laminate sheet including a resin outer layer 221, a barrier metal layer 222, and a heat-melt resin sealant layer 223 from the outside.

The electrically insulating material 212 coated on the first battery case 210 is made of the same material as the heat-melting resin sealant layer 223 of the second battery case 220.

Therefore, when the outer peripheral portions 214 and 224 of the first battery case 210 and the second battery case 220 are pressed by a press, the electrical insulating material 212 and the first battery case 210 2 The heat-melt resin sealant layer 223 of the battery case 220 is melted and adhered to each other and sealed.

3 to 5 are schematic diagrams schematically showing the structure of a battery case according to another embodiment of the present invention.

First, referring to FIG. 3, the battery case 300 covers the first battery case 310 in which the storage part 313 is formed and the storage part 313 of the first battery case 310. It includes a second battery case 320 mounted on.

The first battery case 310 is coated with an electrically insulating material 312 only on the inner surface of the receiving portion 313 except for the outer peripheral portion 314.

An irregularity 315 is formed in the outer periphery of the first battery case 310.

Therefore, when the outer peripheral portions 314 and 324 of the first battery case 310 and the second battery case 320 are pressed by a press, the heat-melting resin sealant layer 323 of the second battery case 320 ) Melts and adheres to a wider surface, so it can exhibit a higher sealing power.

Structures other than the above structure are the same as those of the battery case of FIG. 2 (200 of FIG. 2), and detailed descriptions thereof will be omitted.

Referring to FIG. 4, the battery case 400 includes a first battery case 410 in which a storage part is formed and a second battery mounted on the upper surface in a form surrounding the storage part 413 of the first battery case 410. It includes a case 420.

The second battery case 420 is made of an aluminum plate 421 and has a structure in which an electrical insulating material 423 is coated on an inner surface of the first battery case 410 facing the receiving part 413.

Accordingly, the second battery case 420 can exhibit relatively high strength compared to a structure made of a laminate sheet, thereby improving structural stability of the battery cell.

In addition, the second battery case 420 has an inner surface coated with an electrical insulating material 423 of the same material as the electrical insulating material 412 coated on the inner surface of the first battery case 410. The electrode assembly mounted on the receiving part 413 of the case 410 and the aluminum plate 421 constituting the second battery case 420 are electrically insulated, thereby improving safety, and the first battery case 410 ) And the outer peripheral portions 414 and 424 of the second battery case 420 are pressed by a press, electricity of the electrical insulating material 412 of the first battery case 410 and the second battery case 420 The insulating material 423 is melted and bonded and sealed to each other.

The rest of the structure except for the second battery case 420 is the same as that of the battery case 200 of FIG. 2, and a detailed description thereof will be omitted.

Referring to FIG. 5, the battery case 500 includes a first battery case 510 in which a storage part is formed and a second battery mounted on the upper surface in a form surrounding the storage part 513 of the first battery case 510. It includes a case 520.

The first battery case 510 has the same structure as the first battery case of FIG. 2 (210 of FIG. 2 ).

The second battery case 520 is made of an aluminum plate 521 and has a structure in which an electrical insulating material 523 is coated on an inner surface of the first battery case 510 facing the receiving part 513.

The electrically insulating material 523 coated on the inner surface of the second battery case 520 is stored in the receiving portion 513 of the first battery case 510 except for the outer peripheral portion 524 of the second battery case 520. It is coated only on the corresponding area.

An irregularity 525 is formed in the outer peripheral portion 524 of the second battery case 520.

Accordingly, when the overall strength of the battery case 500 is improved and the outer peripheral portions 514 and 524 of the first battery case 510 and the second battery case 520 are pressed by a press, the first battery Since the electrical insulating material 512 of the case 510 is melted and adhered to a wider surface at the outer peripheral portion 524 of the second battery case 520, a higher sealing force can be exhibited.

Those of ordinary skill in the field to which the present invention belongs will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

Claims (22)

An electrode assembly having an anode, a cathode, and a separator structure interposed between the anode and the cathode;
A first battery case in which a storage unit in which the electrode assembly is embedded is formed; And
A second battery case mounted on the first battery case to surround the receiving part;
Including,
The first battery case is made of a metal plate, the inner surface is coated with an electrical insulating material,
The second battery case is made of a laminate sheet including a resin outer layer, a barrier metal layer, and a heat-melt resin sealant layer,
The electrical insulating material is the same as the material of the heat-melting resin sealant layer of the second battery case,
The first battery case enables uniform positioning during bonding to a jig or tool between manufacturing processes of a battery cell, prevents external deformation due to vacuum adsorption, and has a higher strength than the second battery case,
When the second battery case is heated and pressurized by pressing the outer peripheries of the first battery case and the second battery case while facing each other in a structure surrounding the storage part of the first battery case, the heat-melting resin sealant layer and the A battery cell, characterized in that the outer peripheries of the first battery case and the second battery case facing each other are adhered and sealed by an electrically insulating material. The battery cell according to claim 1, wherein the first battery case has a structure in which the receiving portion is recessed corresponding to the shape of the electrode assembly. The battery cell according to claim 1, wherein the first battery case is made of aluminum or an aluminum alloy. The battery cell according to claim 1, wherein the second battery case has a plate-shaped sheet structure. delete delete delete The battery cell according to claim 1, wherein the electrical insulating material is a polyolefin-based resin. The battery cell according to claim 1, wherein the electrically insulating material is coated to a thickness of 10 micrometers to 100 micrometers. The battery cell according to claim 1, wherein the electrically insulating material is coated on the entire inner surface including the receiving portion and the outer peripheral portion of the first battery case. The battery cell according to claim 1, wherein the electrically insulating material is coated only on the inner surface of the receiving part excluding the outer periphery of the first battery case. The battery cell according to claim 10 or 11, wherein the surface of the metallic material coated with the electrically insulating material at the outer periphery of the first battery case is surface-treated to form irregularities. The battery cell according to claim 12, wherein the surface treatment is performed by sand blasting or etching. delete delete delete delete The battery cell according to claim 1, wherein the electrode assembly has a folding type structure, a stack type structure, or a stack/folding type structure, or a lamination/stack type structure. The battery cell according to claim 1, wherein the battery cell is a lithium secondary battery. A battery pack comprising the battery cell according to claim 1. A device comprising the battery pack according to claim 20 as a power source. The method of claim 21, wherein the device is any one selected from the group consisting of a mobile phone, a tablet computer, a notebook computer, a power tool, a wearable electronic device, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device. A device, characterized in that.

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