KR20180065096A - Battery Module Comprising Cell Frames of Standardized Structure - Google Patents

Abstract

The present invention provides a battery module. The battery module includes: a battery cell laminate where the sides of a plurality of battery cells are arranged adjacent to each other; and a pair of cell frames mounted on both ends of the battery cell laminate and coupled to each other and having the same structure. The plurality of battery cells are electrically connected to each other by a structure of 2m-1S x nP (where m and n are natural numbers of 1 or more). Manufacturing costs can be reduced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery module including a cell frame of a standardized structure,

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

BACKGROUND ART [0002] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. In addition, the secondary battery is attracting attention as an energy source for electric vehicles, hybrid electric vehicles, and electric bicycles, which are proposed as solutions for air pollution in conventional gasoline vehicles and diesel vehicles using fossil fuels. Therefore, 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 many fields and products in the future.

Such a secondary battery may be classified as a lithium ion battery, a lithium ion polymer battery, or a lithium polymer battery depending on the configuration of an electrode and an electrolytic solution. The amount of the lithium ion polymer battery Is growing.

2. Description of the Related Art Generally, a secondary battery includes a cylindrical battery and a prismatic battery in which an electrode assembly is embedded in a cylindrical or rectangular metal can according to the shape of a battery case, and a pouch type battery in which an electrode assembly is embedded in a pouch- .

Such a secondary battery comprises a battery module or a battery pack by connecting a plurality of secondary batteries according to a capacity of a device in which the battery is mounted.

1 is a perspective view of a battery module in which a plurality of conventional secondary batteries are electrically connected to each other.

1, the battery module 10 includes a plurality of battery cells 11 arranged side by side so that the frames 12 are mounted on both ends of the battery cells 11, Are electrically connected to each other by the terminal plate 13.

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

As a result, the frame 12 can not be manufactured with one mold in the manufacturing process of the frame 12 because the pair of frames 12 have to be formed differently from each other, There is a problem that the manufacturing cost is increased.

Therefore, a battery pack capable of solving the above problems is very necessary.

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

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

According to an aspect of the present invention,

A battery cell stack comprising a plurality of battery cells arranged side by side adjacent to each other; And

A pair of cell frames mounted on opposite ends of the battery cell stack body and coupled to each other and having the same structure;

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The plurality of battery cells may have a structure in which they are electrically connected to each other by a structure of 2m-1S x nP (where m and n are natural numbers of 1 or more). 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.

Therefore, the battery module according to the present invention has a structure in which a pair of cell frames mounted from both side ends of the battery cell stack body are mutually coupled, and a plurality of battery cells are electrically connected in an odd number of series A pair of cell frames can be manufactured by a single mold at the time of manufacturing a slit frame in order to constitute a high capacity / high output battery module, so that the 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.

The jelly-roll type electrode assembly may be manufactured by coating a mixture containing an electrode active material on each metal current collector, placing the separator sheet between the anode and the cathode in the form of a sheet dried and pressed, and winding the sheet.

In one specific embodiment of the present invention, the battery cells may have a structure in which they are electrically connected to each other by a 7S × 9P structure. The electrical connection structure of the battery cells may be changed according to a desired battery standard.

As one specific example of the cell frame, the cell frames may include a first cell frame mounted from one end of the battery cell stack to accommodate a portion of the cell stack, and a second cell frame mounted from the other end of the battery cell stack And a second cell frame for receiving the remaining portion of the battery cell stack body, and the first cell frame and the second cell frame may be connected to each other while being in contact with each other.

Specifically, each of the first cell frame and the second cell frame is formed with 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 the electrode terminals of the battery cells are exposed May be formed on the outer surface.

More specifically, at least one through-hole through which refrigerant can flow may be formed between the battery cell receivers of the first cell frame and the second cell frame.

The first cell frame and the second cell frame may have a symmetrical structure with respect to a center point of the battery module. Specifically, the first cell frame may have a point symmetrical structure in which the first cell frame 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.

At least one battery cell support portion may be formed on the outer surface of the cell frame to expose the electrode terminal of the battery cell to fix the battery cells.

In one specific example, the battery cell support portion may be located between four unit 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 the lateral direction from one side of the cell frame to the other side.

The battery cell support portions of different shapes may be formed on each of the outer surfaces of the cell frame at the same time.

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

As one specific example of the terminal plate, the terminal plate is formed in a bar shape having a width larger than a thickness, and a first connection portion for electrically connecting to an adjacent terminal plate is protruded at one end portion Can be.

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, at the top of the terminal plate mounted on the battery cells located in the uppermost heat and the lowermost row in a plane on the battery cell stack, external input / And a second connection part for electrically connecting the first connection part and the second connection part to each other.

In one specific example, the type of the battery cell is not particularly limited, but specific examples thereof include a lithium ion battery having advantages such as a high energy density, a discharge voltage, and an output stability, a lithium secondary battery such as a lithium ion polymer battery, Battery.

Generally, 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, and then drying the mixture. Optionally, a filler may be further added to the mixture.

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

The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

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

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

The negative electrode is manufactured by applying and drying a negative electrode active material on a negative electrode collector, and if necessary, the above-described components may be selectively included.

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

The separation membrane 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 mu m, and the thickness is generally 5 to 130 mu m. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

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

The SRS separator is manufactured by using inorganic particles and a binder polymer on the polyolefin-based separator substrate as an active layer component. In addition to the pore structure contained in the separator substrate itself, the SRS separator is formed by interstitial volume between inorganic particles And has a uniform pore structure.

The use of such an organic / inorganic composite porous separator has the advantage of suppressing an increase in thickness of the cell due to swelling at the time of chemical conversion compared with the case of using a conventional separator, When a gelable polymer is used when liquid electrolyte is impregnated, it can also be used as an electrolyte.

In addition, the organic / inorganic composite porous separator can exhibit excellent adhesion characteristics by controlling the contents of the inorganic particles and the binder polymer in the separator, so that the cell 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 usable 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 of the applied battery (for example, 0 to 5 V based on Li / Li +). Particularly, when inorganic particles having an ion-transporting ability are used, the ion conductivity in the electrochemical device can be increased and the performance can be improved. Therefore, 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 the particles at the time of coating, and there is a problem of an increase in weight during the production of the battery. In the case of an inorganic substance having a high dielectric constant, dissociation of an electrolyte salt, for example, a lithium salt, in the liquid electrolyte also contributes to increase ionic conductivity of the electrolyte.

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

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

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

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

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

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

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

The present invention also provides a device characterized by 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.

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

As described above, the battery module according to the present invention includes the terminal plate receiving portion in which the terminal plates are inserted and fixed in the pair of cell frames, so that in the process of electrically connecting the plurality of battery cells, A separate jig for arranging and welding can be excluded, thereby reducing manufacturing cost and time.

1 is a perspective view of a battery module in which a plurality of conventional secondary batteries are electrically connected to each other;
2 is a perspective view of a battery module according to one embodiment of the present invention;
Figure 3 is an exploded view of the battery module of Figure 2; And
Fig. 4 is a top view of the battery module of Fig. 2;

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

FIG. 2 is a perspective view of a battery module according to an embodiment of the present invention. FIG. 3 is an exploded view of the battery module of FIG. 2, Is schematically shown.

Referring to FIGS. 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 in a state where their sides are adjacent to each other. The battery cells 101 are electrically connected to each other by a 7S × 9P structure.

The cell frames 120 and 130 include a first cell frame 120 mounted from one end of the battery cell stack 110 to receive a portion of the battery cell stack 110, And a second cell frame 130 mounted from the other end of the battery cell stack 110 to receive the remaining portion of the battery cell stack 110. The first cell frame 120 and the second cell frame 130 are in contact with each other And the structure is coupled in the state.

Each of the first cell frame 120 and the second cell frame 130 is formed with a battery cell receiving portion 121 having a shape corresponding to one end portion and the other end portion of the battery cells 101, Openings 122 for exposing the electrode terminals of the battery cells 101 are formed on the outer surface.

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

The battery cell supporting portions 140 and 150 are formed on the outer surfaces of the cell frames 120 and 130 where the electrode terminals of the battery cells 101 are exposed.

The first battery cell support part 140 is disposed between the battery cells 101 of four units and has a rectangular shape on a horizontal plane and the second battery cell support part 150 is formed from a side of the cell frames 120, And extending in the lateral direction to the other side.

A first terminal plate 160 for electrically connecting the battery cells 101 is mounted between the battery cell supporting portions 140 and 150.

The first terminal plate 160 is formed in a bar shape and has a first connection part 161 protruding from one end of the first terminal plate 160 to be electrically connected to the adjacent first terminal plate 160.

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

The first terminal plate 170 is mounted on the battery cells 101 located in the uppermost and lowermost rows in the plan view of the battery cell stack 110. The external terminal input / And a second connection portion 171 for electrically connecting to the terminal.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (15)

A battery cell stack comprising a plurality of battery cells arranged side by side adjacent to each other; And
A pair of cell frames mounted on opposite ends of the battery cell stack body and coupled to each other and having the same structure;
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Wherein the plurality of battery cells are electrically connected to each other by a structure of 2m-1S x nP (where m and n are natural numbers of 1 or more). The battery module according to claim 1, wherein the battery cell is a cylindrical battery cell. The battery module according to claim 1, wherein the battery cells are electrically connected by a 7S × 9P structure. The method according to claim 1,
The cell frames include a first cell frame mounted from one end of the battery cell stack to receive a portion of the battery cell stack, and a second cell frame mounted from the other end of the battery cell stack to receive the remaining portion of the battery cell stack And a second cell frame for performing a second operation;
Wherein the first cell frame and the second cell frame are coupled while being in contact with each other. The battery cell of claim 4, wherein each of the first cell frame and the second cell frame is formed with a battery cell housing part having a shape corresponding to one end portion and the other end portion of the battery cells, Wherein openings for exposing the battery module are formed on the outer surface. The battery module according to claim 5, wherein at least one through-hole through which refrigerant can flow is formed between the battery cell receivers 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. The battery module according to claim 4, wherein at least one battery cell supporting part is formed on an outer surface of the cell frame, on which an electrode terminal of the battery cell is exposed, so as to fix the battery cells. The battery module according to claim 8, wherein the battery cell support part is disposed between the battery cells of four units and has a rectangular shape on a horizontal plane. The battery module according to claim 8, wherein the battery cell support portion extends from one side of the cell frame to the other side in a lateral direction. The battery module according to claim 8, wherein a terminal plate for electrically connecting the battery cells is mounted between the battery cell supporting portions in the longitudinal direction. The terminal plate according to claim 11, wherein the terminal plate is formed in a bar shape having a width larger than a thickness, and a first connection part for electrically connecting to the adjacent terminal plate protrudes at one end thereof Battery module. 13. The battery module according to claim 12, wherein the terminal plate is electrically connected to an adjacent terminal plate through a bus bar assembly mounted on one side of the cell frame. 14. The battery pack according to claim 13, wherein a top surface of the terminal plate mounted on the battery cells located on the uppermost and lowermost rows in a plane on the battery cell stack body is electrically connected to an external input / output terminal formed on the bus bar assembly And a second connection part for the battery module is protruded. A battery pack comprising the battery module according to any one of claims 1 to 14.

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