KR102205313B1 - Battery Module Including Elastic Frame for Fixing Battery Cells - Google Patents

Abstract

The present invention is a battery cell assembly in which a plurality of battery cells are arranged adjacent to each other; A pair of cell frames mounted from both ends of the battery cell assembly; And an elastic frame mounted between the cell frames so that the battery cell can be fixed by preventing a gap between the battery cell and the cell frame.

Description

Battery Module Including Elastic Frame for Fixing Battery Cells {Battery Module Including Elastic Frame for Fixing Battery Cells}

The present invention relates to a battery module including an elastic frame for fixing the battery cell.

Recently, secondary batteries capable of charging and discharging have been widely used as an energy source for wireless mobile devices. In addition, secondary batteries are attracting attention as energy sources such as electric vehicles, hybrid electric vehicles, and electric bicycles, which have been suggested as a solution to air pollution such as existing gasoline vehicles and diesel vehicles using fossil fuels. Accordingly, the types of applications using secondary batteries are diversifying due to the advantages of secondary batteries, and it is expected that secondary batteries will be applied to more fields and products than now.

These secondary batteries are also classified into lithium-ion batteries, lithium-ion polymer batteries, and lithium polymer batteries, depending on the composition of electrodes and electrolytes, among which there is little possibility of electrolyte leakage, and the amount of use of lithium-ion polymer batteries that are easy to manufacture is low. Is increasing.

In general, secondary batteries are cylindrical and prismatic batteries in which an electrode assembly is embedded in a cylindrical or rectangular metal can, and a pouch-type battery in which the electrode assembly is embedded in a pouch-shaped case of an aluminum laminate sheet, depending on the shape of the battery case. It is classified as

These secondary batteries are configured as a battery module or battery pack by connecting a plurality of secondary batteries according to the capacity required by the device in which the battery is mounted.

FIG. 1 is a perspective view of a battery module configured by electrically connecting a plurality of conventional secondary batteries, and FIG. 2 is a horizontal cross-sectional view of a cell frame of the battery module of FIG. 1, and FIG. An enlarged view of the A'region is shown.

1 to 3, in the battery module 10, a plurality of battery cells 11 are arranged with side surfaces adjacent to each other, and cell frames 12 are mounted at both ends of the battery cells 11 .

The cell frame 12 has battery cell accommodating portions 13 in which the battery cells 11 are mounted.

The battery cells 11 have a small difference in diameter (R1), respectively, depending on the manufacturing environment, and the diameter (R2) of the battery cell accommodating part 13 may also have a small difference from the diameter (R1) of the battery cells (11). Therefore, there is a problem that a gap occurs between the battery cell 11 and the cell frame 12.

Therefore, there is a very need for a battery pack capable of solving the above problems.

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.

Specifically, it is an object of the present invention to provide a battery module capable of preventing a gap between the battery cell and the cell frame when a plurality of battery cells are mounted on a cell frame in order to construct a high capacity/high output battery module. will be.

The battery module according to the present invention for achieving this purpose,

A battery cell assembly in which a plurality of battery cells are arranged adjacent to each other;

A pair of cell frames mounted from both ends of the battery cell assembly; And

An elastic frame mounted between the cell frames so that the battery cell can be fixed by preventing a gap between the battery cell and the cell frame;

It may be composed of a structure including.

Accordingly, the battery module according to the present invention includes an elastic frame mounted between the cell frames, thereby preventing a gap between the battery cell and the cell frame, thereby fixing the battery cell.

In one embodiment of the present invention, the battery cell may be a cylindrical battery cell.

The cylindrical battery cell may have a structure in which a jelly-roll type electrode assembly is embedded in a metal can together with an electrolyte, and a cap assembly is mounted on the top of the metal can to be sealed.

The jelly-roll type electrode assembly can be prepared by coating a mixture containing an electrode active material on each metal current collector, placing a separator sheet between the positive electrode and the negative electrode in the form of a dried and pressed sheet, and winding it.

In one embodiment of the present invention, each of the cell frames and the elastic frame may have battery cell accommodating portions having a hollow structure corresponding to the battery cells so that the battery cells can be inserted and fixed. .

In one specific example, on the inner surface of the battery cell receiving portion of the elastic frame, at least one elastic protrusion from the inner wall of the battery cell receiving portion to prevent a gap between the battery cell and the elastic frame to fix the battery cell. It may be protruding.

Specifically, the elastic protrusion may be formed in the longitudinal direction of the battery cell, but may be formed in the circumferential direction of the battery cell.

More specifically, the elastic protrusion may have a structure in which the thickness increases toward the center of the elastic protrusion. Accordingly, as the battery cell enters the battery cell receiving portion, the elastic protrusion may pressurize the battery cell to fix it.

The thickness at the center of the elastic protrusion may be 0.1% to 5% of the diameter of the battery cell. When the thickness of the elastic protrusion is less than 0.1% of the diameter of the battery cell, the force of the elastic protrusion pressing the battery cell is weak, so that the battery cell may not be fixed. On the other hand, when the thickness of the elastic protrusion exceeds 5% of the diameter of the battery cell, it may be difficult to insert the battery cell into the battery cell receiving unit due to the thickness of the elastic protrusion.

In one embodiment of the present invention, the size of the outer periphery of the elastic frame may be of a relatively larger structure than the outer periphery of the cell frame.

In one specific example, the cell frame insertion portions to which the outer peripheral partition walls of the cell frames are inserted and coupled to the outer peripheral partition walls of the elastic frame may be formed at upper and lower portions, respectively.

In addition, on the outer surfaces of the outer peripheral partition walls located on both sides of the elastic frame, one or more first fastening portions are formed to protrude outward for additional fastening with the cell frame;

On the outer surfaces of the outer periphery partition walls located on both sides of the cell frame, a second fastening part is formed to protrude outward at a position corresponding to the first fastening part;

The second fastening part may have a structure mounted inside the first fastening part.

In one embodiment of the present invention, one or more through passages through which refrigerant can flow may be formed between the battery cell receiving portions of the cell frames and the elastic frames.

Specifically, in the through-path of the elastic frame, a through-hole through which an end is inserted and mounted in the through-path of the cell frames may be formed to protrude outward. Accordingly, the through part may be inserted into the through passages of the cell frames to solidify the coupling between the cell frame and the elastic frame.

In one embodiment of the present invention, the elastic frame may be made of rubber, but it is not limited thereto if it is a material having elasticity.

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 (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, 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 in} which 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 a binder 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, 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. In addition, 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 that is easily 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, and hexaphosphate triamide for the purpose of improving charge/discharge properties and flame retardancy. , 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 module.

The present invention also provides a battery pack including the battery module.

The present invention also provides a device comprising the battery pack as a power source.

The device may be selected from an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device.

Since the structure of these devices and a method of manufacturing them are known in the art, detailed descriptions thereof will be omitted in the present specification.

As described above, the battery module according to the present invention includes an elastic frame mounted between the cell frames, thereby preventing a gap between the battery cell and the cell frame, thereby fixing the battery cell.

1 is a perspective view of a battery module configured by electrically connecting a plurality of conventional secondary batteries;
2 is a horizontal cross-sectional view of a cell frame of the battery module of FIG. 1;
3 is an enlarged view of portion'A' of FIG. 2;
4 is a perspective view of a battery module according to an embodiment of the present invention;
Figure 5 is an exploded view of the battery module of Figure 4;
6 is an enlarged view of the battery cell accommodating part of FIG. 4;
7 is a vertical cross-sectional view of a state in which the cell frame and the elastic frame of FIG. 4 are combined.

Hereinafter, it will be described with reference to the drawings according to an embodiment of the present invention, but this is for an easier understanding of the present invention, and the scope of the present invention is not limited thereto.

FIG. 4 is a perspective view of a battery module according to an embodiment of the present invention, and FIG. 5 is an exploded view of the battery module of FIG. 4, and FIG. 6 is an enlarged view of the battery cell receiving part of FIG. 4. 7 is a vertical cross-sectional view of the cell frame and the elastic frame of FIG. 4 in a combined state.

4 to 7, the battery module 100 includes a battery cell assembly 110, cell frames 120 and elastic frames 130.

The battery cell assembly 110 has a structure in which a plurality of cylindrical battery cells 101 are arranged with side surfaces adjacent to each other.

The cell frames 120 are mounted from both ends of the battery cell assembly 110, and an elastic frame 130 is mounted between the cell frames 120.

In the cell frames 120 and the elastic frame 130, the battery cell receiving portions 121 having a hollow structure corresponding to the battery cells 101 are formed so that the battery cells 101 can be inserted and fixed. have.

On the inner surface of the battery cell accommodating portion 121 of the elastic frame 130, four elastic protrusions (4 elastic protrusions) to prevent the gap between the battery cell 101 and the elastic frame 130 to fix the battery cell 101 ( 131 is formed to protrude from the inner wall of the battery cell accommodating part 121.

The elastic protrusion 131 is formed in the longitudinal direction of the battery cell 101 and has a structure in which the thickness increases toward the center of the elastic protrusion 131.

The thickness at the center of the elastic protrusion 131 is 1% of the diameter R3 of the battery cell 101.

The size of the outer periphery of the elastic frame 130 is made of a structure relatively larger than the outer periphery of the cell frame 120, and the outer periphery partition walls of the cell frames 120 are inserted into the outer periphery partition walls of the elastic frame 130 Cell frame insertion portions 132 to be coupled are formed at the upper and lower portions, respectively.

In addition, on the outer surface of the outer peripheral partition walls located on both sides of the elastic frame 130, for additional fastening with the cell frame 120, at least one first fastening portion 133 is formed in a structure protruding outward. In the cell frame 120, on the outer surfaces of the outer periphery partition walls located on both sides of the cell frame 120, the second fastening part 123 is formed in a structure that protrudes outward at a position corresponding to the first fastening part 133, The second fastening part 123 is mounted to the inside of the first fastening part 133.

Between the cell frames 120 and the elastic frame 130, each of the battery cell receiving portions 121 are formed through passages 124, 134 through which the refrigerant can flow, and the through passages of the elastic frame 130 In 134, a through portion 135, through which an end portion is inserted and mounted, in the through passage 124 of the cell frames 120 is formed to protrude outwardly.

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

Claims (14)

A battery cell assembly in which a plurality of battery cells are arranged adjacent to each other;
A pair of cell frames mounted from both ends of the battery cell assembly and having battery cell accommodating portions having a hollow structure corresponding to the battery cells so that the battery cells can be inserted and fixed; And
The battery cell storage portions are mounted between the pair of cell frames and have a hollow structure having a shape corresponding to the battery cells so that the battery cells can be inserted and fixed. An elastic protrusion made of an elastic material protruding from an inner wall thereof in a longitudinal direction of the battery cell to fix the inserted battery cell; An elastic frame provided with four in the east-west, north-south direction, to prevent a gap between the battery cell and the cell frame to stably fix the battery cell to the cell frame;
Consists of including,
The elastic protrusion has a structure in which the thickness increases toward the center of the elastic protrusion. As the battery cell enters the battery cell receiving unit, the battery cell is pressed to stably fix the battery cell to the cell frame and the elastic frame. A battery module, characterized in that. The battery module according to claim 1, wherein the battery cell is a cylindrical battery cell. delete delete delete delete The battery module according to claim 1, wherein the thickness at the center of the elastic protrusion is 0.1% to 5% of the diameter of the battery cell. The battery module according to claim 1, wherein the size of the outer periphery of the elastic frame is relatively larger than the outer periphery of the cell frame. The battery module according to claim 8, wherein a cell frame insertion portion is formed on an outer periphery of the elastic frame by inserting and connecting the outer periphery of the cell frames to each other. The method of claim 1,
On the outer surfaces of the outer peripheral partition walls located on both sides of the elastic frame, at least one first fastening portion is formed to protrude outward for additional fastening with the cell frame;
On the outer surfaces of the outer periphery partition walls located on both sides of the cell frame, a second fastening part is formed to protrude outward at a position corresponding to the first fastening part;
Battery module, characterized in that consisting of a structure in which the second fastening part is mounted inside the first fastening part. The battery module according to claim 1, wherein at least one through passage through which the refrigerant flows is formed between the battery cell receiving portions of each of the cell frames and the elastic frame. The battery module according to claim 11, wherein the through-path of the elastic frame is formed with a through-part protruding outwardly into the through-path of the cell frames. The battery module according to claim 1, wherein the elastic frame is made of rubber. A battery pack comprising a battery module according to any one of claims 1, 2, and 7 to 13.

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