KR102211576B1 - Battery Module Comprising Cell Frames of Standardized Structure - Google Patents

Abstract

The present invention is a battery cell stack in which a plurality of battery cells are arranged in a state in which side surfaces are adjacent to each other; And a pair of cell frames mounted from both ends of the battery cell stack and coupled to each other and having the same structure, wherein the plurality of battery cells are 2m-1 S × nP (m, n is a natural number of 1 or more) provides a battery module, characterized in that the structure is electrically connected.

Description

Battery Module Comprising Cell Frames of Standardized Structure

The present invention relates to a battery module including cell frames of a standardized structure.

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.

1 is a perspective view of a battery module configured by electrically connecting a plurality of conventional secondary batteries.

Referring to FIG. 1, in the battery module 10, a plurality of battery cells 11 are arranged with side surfaces adjacent to each other, and frames 12 are mounted at both ends of the battery cells 11, and the battery cells 11 The electrode terminals located at both ends of the) are electrically connected by the terminal plate 13.

The battery cells 11 are electrically connected in a 10S×2P structure. As the battery cells 11 are connected in series in an even number, both a positive terminal and a negative terminal must be formed in one of the frames 12 on which the battery cells 11 are mounted.

Accordingly, since the frame 12 of the pair is inevitably formed differently from each other, the frame 12 cannot be manufactured with one mold in the manufacturing process of the frame 12, and each of the frames 12 There is a problem in that manufacturing cost increases because a plurality of molds suitable for it are required.

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, an object of the present invention is to provide a battery module capable of reducing manufacturing cost by improving a structure for electrically connecting a plurality of battery cells in order to construct a high capacity/high output battery module.

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

A battery cell stack in which a plurality of battery cells are arranged with side surfaces adjacent to each other; And

A pair of cell frames mounted from both ends of the battery cell stack, coupled to each other, and having the same structure;

Contains,

The plurality of battery cells may have a structure electrically connected in a 2m-1 S × nP (m, n is a natural number of 1 or more) structure. That is, in the battery module according to the present invention, a plurality of battery cells may have an odd number of series connection structures.

Accordingly, in the battery module according to the present invention, a pair of cell frames mounted from both ends of the battery cell stack and coupled to each other have the same structure, and a plurality of battery cells are electrically connected in series with an odd number. As a result, in order to construct a high-capacity/high-output battery module, a pair of cell frames can be manufactured by a single mold when manufacturing a sling frame, so manufacturing cost can be reduced.

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 specific embodiment of the present invention, the battery cells may be made of a structure that is electrically connected in a 7S × 9P structure. Of course, the electrical connection structure of the battery cells may be changed according to a desired battery standard.

As a specific example of the cell frame, the cell frames are mounted from one end of the battery cell stack to accommodate a part of the battery cell stack, and a first cell frame mounted from the other end of the battery cell stack As a result, the second cell frame may be configured to accommodate the remaining portion of the battery cell stack, and the first cell frame and the second cell frame may be combined in a state of contact with each other.

Specifically, in each of the first cell frame and the second cell frame, a battery cell receiving portion having a shape corresponding to each of one end portion and the other end portion of the battery cells is formed inside, and the electrode terminals of the battery cells are exposed. It may be of a structure in which the openings are formed on the outer surface.

More specifically, one or more through passages through which refrigerant can flow may be formed between the battery cell receiving portions of each of the first cell frame and the second cell frame.

In addition, the first cell frame and the second cell frame may have a structure having a symmetrical structure with respect to the center point of the battery module. Specifically, the first cell frame may have a point symmetric structure that is positioned in the same shape as the second cell frame when rotated 180 degrees with respect to the center point of the battery module.

One or more battery cell support portions may be formed on an outer surface of the cell frame to which the electrode terminals of the battery cells are exposed so as to fix the battery cells.

As a specific example, the battery cell support part may be positioned between 4 units of battery cells and may have a rectangular shape on a horizontal plane.

As another specific example, the battery cell support portion may be formed to extend in a horizontal direction from one side of the cell frame to the other side.

Each of the battery cell support portions of different shapes may be simultaneously formed at least one of each of the outer surfaces of the cell frame.

In addition, a terminal plate for electrically connecting the battery cells may be mounted between the battery cell support portions in the vertical direction. The vertical direction may mean a direction in which a plurality of battery cells connected in parallel are arranged to be connected in series.

As a specific example of the terminal plate, the terminal plate has a bar shape having a width higher than that of the thickness, and a first connection portion for electrically connecting with an adjacent terminal plate protrudes at one end thereof. There may be.

In addition, the terminal plate may be electrically connected to an adjacent terminal plate through a bus bar assembly mounted on one side of the cell frame.

As another specific example of the terminal plate, an external input/output terminal formed in the bus bar assembly on the upper side of the terminal plate mounted on the battery cells located in the top and bottom insulation in the plane of the battery cell stack A second connection portion for electrically connecting to and protruding may be formed.

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 include 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 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, the ionic conductivity in the electrochemical device can be increased to improve performance, so it is preferable that the ionic 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 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 a terminal plate receiving unit in which terminal plates are inserted into a pair of cell frames to be fixed in place, so that the terminal plates are electrically connected in the process of electrically connecting a plurality of battery cells. Since a separate jig for arranging and welding can be excluded, manufacturing cost and time can be reduced.

1 is a perspective view of a battery module configured by electrically connecting a plurality of conventional secondary batteries;
2 is a perspective view of a battery module according to an embodiment of the present invention;
Figure 3 is an exploded view of the battery module of Figure 2; And
4 is a top view of the battery module of FIG. 2.

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. 2 schematically shows a perspective view of a battery module according to an embodiment of the present invention, and FIG. 3 schematically shows an exploded view of the battery module of FIG. 2, and FIG. 4 shows the battery module of FIG. The top view of is schematically shown.

2 to 4, the battery module 100 includes a battery cell stack 110 and cell frames 120 and 130.

The battery cell stack 110 has a structure in which a plurality of cylindrical battery cells 101 are arranged with side surfaces adjacent to each other, and the battery cells 101 are electrically connected in a 7S×9P structure.

The cell frames 120 and 130 are mounted from one end of the battery cell stack 110 to accommodate a portion of the battery cell stack 110 and a first cell frame 120 and a battery cell stack 110 ) Is mounted from the other end of the battery cell stack 110 to accommodate the rest of the cell frame 130, the first cell frame 120 and the second cell frame 130 in contact with each other It consists of a structure that is joined in a state.

Each of the first cell frame 120 and the second cell frame 130 has a battery cell accommodating portion 121 having a shape corresponding to each of one end portion and the other end portion of the battery cells 101 is formed inside, Openings 122 through which the electrode terminals of the battery cells 101 are exposed are formed on the outer surface.

In addition, one or more through passages 123 through which refrigerant can flow are formed between the battery cell receiving portions 121 of each of the first cell frame 120 and the second cell frame 130.

Battery cell support portions 140 and 150 are formed on the outer surfaces of the cell frames 120 and 130 to which the electrode terminals of the battery cells 101 are exposed to fix the battery cells 101.

The first battery cell support 140 is located between the battery cells 101 of 4 units and has a rectangular shape on a horizontal plane, and the second battery cell support 150 is formed from one side of the cell frames 120 and 130. It consists of a structure extending in the horizontal direction to the other side.

In addition, a first terminal plate 160 for electrically connecting the battery cells 101 is mounted between the battery cell support portions 140 and 150.

The first terminal plate 160 has a bar shape, and a first connection part 161 for electrically connecting the adjacent first terminal plate 160 is formed to protrude at one end thereof.

The first terminal plate 160 is electrically connected to the adjacent first terminal plate 160 through a bus bar assembly 180 mounted on one side of the cell frames 120 and 130.

On the upper side of the second terminal plate 170 mounted on the battery cells 101 located in the uppermost row and the lowermost row in the plane of the battery cell stack 110, the bus bar assembly 180 A second connection part 171 for electrically connecting to the external input/output terminal is formed to protrude. The second connecting portions of the upper and lower portions of the battery cell stack form electrode terminal portions having different polarities, respectively. Thus, unlike the prior art, the positive and negative terminals of the present invention are not all formed on one side of the battery cell stack 110, but are formed on the opposite side, respectively.

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 (15)

A battery cell stack in which a plurality of cylindrical battery cells are arranged with side surfaces adjacent to each other; And
A pair of cell frames mounted from both ends of the battery cell stack, coupled to each other, and having the same structure;
Contains,
The plurality of battery cells are

(m,n are natural numbers of 1 or more, S: series, P: parallel)
One or more battery cell support portions are formed on an outer surface of the cell frame to which the electrode terminals of the battery cells are exposed to fix the battery cells,
Between the battery cell support portions, a terminal plate for connecting two rows of battery cells in parallel in a row direction and in series in a column direction is mounted,
The terminal plate,
It is electrically connected to the adjacent terminal plate through a bus bar assembly mounted on one side of the cell frame,
It consists of a bar shape having a width higher than that of the thickness, and a first connection portion for electrically connecting to the bus bar assembly is protruded at one end thereof,
A second connection part for electrically connecting to an external input/output terminal protrudes as a positive terminal or a negative terminal on the upper side of the terminal plate mounted on the battery cells located at the uppermost end of the battery cell stack,
On the upper side of the terminal plate mounted on the battery cells located at the lowermost end of the battery cell stack,
A second connection portion for electrically connecting to an external input/output terminal formed in the bus bar assembly is formed to protrude as a negative terminal or a positive terminal,
A battery module, characterized in that the positive terminal and the negative terminal are formed on the corresponding other side of the battery cell stack.
delete The battery module of claim 1, wherein the battery cells are electrically connected in a 7S×9P structure. The method of claim 1,
The cell frames are mounted from one end of the battery cell stack to accommodate a part of the battery cell stack, and the first cell frame is mounted from the other end of the battery cell stack to accommodate the rest of the battery cell stack. Consisting of a second cell frame;
The battery module, characterized in that the first cell frame and the second cell frame are coupled in contact with each other. The battery cell according to claim 4, wherein each of the first cell frame and the second cell frame includes a battery cell receiving portion having a shape corresponding to each of one end portion and the other end portion of the battery cells, and electrode terminals of the battery cells A battery module, characterized in that the openings for exposing them are formed on the outer surface. The battery module according to claim 5, wherein at least one through passage through which the refrigerant flows is formed between the battery cell receiving portions of each of the first cell frame and the second cell frame. The battery module according to claim 4, wherein the first cell frame and the second cell frame have a symmetrical structure with respect to a center point of the battery module. delete The battery module according to claim 1, wherein the battery cell support part is positioned between four units of battery cells and has a rectangular shape on a horizontal plane. The battery module according to claim 1, wherein the battery cell support part extends in a horizontal direction from one side of the cell frame to the other side.
delete delete delete delete A battery pack comprising the battery module according to any one of claims 1, 3 to 7, 9, and 10.

Images