KR102248869B1 - Battery Module Comprising Battery Cell Assembly of Oblique Line Arrangement Structure - Google Patents

Abstract

The present invention is a battery module mounted under a heat transfer sheet or a rear heat sheet of an electric vehicle, and plate-shaped unit cells having a relatively large width and length compared to the thickness are electrically connected, and both sides of each unit cell are connected to the ground. A battery cell assembly in which a plurality of unit cells are arranged adjacent to each other in a state inclined at a predetermined angle to form a diagonal arrangement structure; And a module case in which an assembly receiving part in which the battery cell assembly is mounted is formed.

Description

Battery Module Comprising Battery Cell Assembly of Oblique Line Arrangement Structure

The present invention relates to a battery module including a battery cell assembly of a diagonal arrangement structure.

In recent years, as technology development and demand for mobile devices increase, the demand for rechargeable and dischargeable secondary batteries as an energy source is rapidly increasing, and accordingly, many studies on secondary batteries that can meet various demands have been conducted. In addition, the secondary battery is an electric vehicle (EV), hybrid electric vehicle (HEV), and plug-in hybrid electric vehicle that is proposed as a solution to the air pollution of conventional gasoline vehicles and diesel vehicles that use fossil fuels. It is also attracting attention as a power source such as (PLUG-IN HEV).

Accordingly, an electric vehicle (EV) that can be operated with only a battery, a hybrid electric vehicle (HEV) that uses a battery and an existing engine together have been developed, and some are commercially available. Secondary batteries as power sources such as EVs and HEVs are mainly nickel hydride metal (Ni-MH) secondary batteries, but in recent years, studies using lithium secondary batteries with high energy density, high discharge voltage, and output stability are actively progressing. And are in the stage of commercialization.

In the case of an electric vehicle using such a secondary battery as a power source, a battery module or a battery pack composed of a plurality of battery cells is usually mounted on a heat transfer sheet or a rear heat sheet of the vehicle.

Such a battery module or battery pack has a hexahedral structure by stacking battery cells horizontally or vertically at 90 degrees. Conventionally, in order to reduce the height of a battery module or battery pack having such a structure, it is necessary to change the dimensions of the battery cell, or to change the location and design of the mechanical part of other electronic components mounted in the module or pack. There is a problem in that the process is complicated and the manufacturing time is increased.

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.

Specifically, an object of the present invention is to provide a battery module with increased space utilization as a battery mounted as a power source of an electric vehicle.

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

As a battery module mounted on the lower portion of the electric vehicle's heat transfer sheet or rear heat sheet,

Plate-shaped unit cells having a relatively large width and length compared to the thickness are electrically connected, and with both sides of each unit cell inclined at a predetermined angle with respect to the ground, a plurality of unit cells are arranged adjacent to each other and arranged diagonally. A battery cell assembly constituting a structure; And

A module case in which an assembly receiving part in which the battery cell assembly is mounted is formed;

It may consist of a structure including.

Accordingly, the battery module according to the present invention includes a battery cell assembly in which a plurality of unit cells are arranged adjacent to each other to form a diagonal arrangement structure with both sides of the unit cells inclined at a predetermined angle with respect to the ground. It can increase the space utilization within.

In one embodiment of the present invention, in the diagonal arrangement structure, both sides of the unit cell may be inclined at an angle of 20 degrees to 80 degrees with respect to the ground. When the unit cell is inclined at an angle of less than 20 degrees with respect to the ground, it may be difficult to arrange and fix the battery cells. On the other hand, when the unit cell is inclined at an angle of more than 80 degrees with respect to the ground, space utilization may be degraded because a desired amount of space may not be sufficiently secured.

In one embodiment of the present invention, the unit cell may have a structure in which plate-shaped battery cells are mounted in a cartridge in which a battery cell receiving part is formed in two units.

In a specific embodiment, an end plate for maintaining the adjacent arrangement of the unit cells may be mounted on outer surfaces of the unit cells located at the outermost of the unit cells.

In addition, a heat dissipation sheet may be interposed between the unit cells for cooling the battery module.

Specifically, a heat dissipation pad may be mounted at the lower end of the heat dissipation sheets in a thermal contact state. Accordingly, heat generated from the unit cell may be radiated to the outside of the battery module through the heat radiation sheet and the heat radiation pad.

In addition, a strap band may be mounted at the lower end of the battery cell assembly in the direction of the arrangement of the unit cells to fix the arrangement of the battery cells and cartridges constituting the unit cells.

In one embodiment of the present invention, positive terminals and negative terminals of the battery cells in the unit cells may be positioned equally toward the first side of the battery cell assembly.

In addition, a bus bar assembly for electrical connection may be mounted on the first side of the battery cell assembly in which the electrode terminals of the battery cells are located.

In one embodiment of the module case, the module case may have a hexahedral structure having a trapezoidal shape on a vertical cross section.

The module case includes a first side on which electrode terminals of the battery cell assembly are positioned, a second side opposite to the first side, and a third side adjacent to the first side and the second side and inclined diagonally. The side surface may be exposed to the outside, and may have a structure in which an open portion is formed.

Specifically, in the upper and lower portions of the first side and the upper and lower portions of the second side of the module case for setting the opening portion, a plurality of ventilation holes are perforated to allow the refrigerant to flow to the upper and lower portions of the battery cell assembly. Can be.

In addition, a BMS mounting portion on which a battery management system (BMS) is mounted may be formed at a portion facing the third side of the battery cell assembly inside the module case.

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 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 the active material and the conductive material and bonding to the 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 butyrene 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 a separation membrane 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 separator 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 the 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 formation, and as a binder polymer component. When a polymer capable of gelling 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 of the applied battery (eg, 0 to 5V based on Li/Li+). 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 the liquid electrolyte.

The lithium salt-containing non-aqueous electrolytic solution is composed of a polar organic electrolytic solution 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, trimethoxy methane, 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.

Examples of the organic solid electrolyte include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, poly agitation lysine, polyester sulfide, polyvinyl alcohol, 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, 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 one or more of the battery modules.

In one embodiment of the battery pack,

The battery pack includes a first battery module and a second battery module;

The second battery module has the same shape as the first battery module;

In a state in which the first battery module is upright and the second battery module is inverted, the inclined outer surface of the first battery module and the inclined outer surface of the second battery module may be arranged to face each other.

Specifically, the battery pack is a battery pack, characterized in that it has an external structure of a rectangular parallelepiped or a regular cube.

The present invention also provides an electric vehicle including the battery pack as a power source.

As described above, the battery module according to the present invention includes a battery cell assembly in which a plurality of unit cells are arranged adjacent to each other to form a diagonal arrangement structure with both sides of the unit cells inclined at a predetermined angle with respect to the ground. By doing so, it is possible to increase the space utilization in the electric vehicle.

1 is a perspective view of a battery module according to an embodiment of the present invention;
Figure 2 is an exploded view of the battery module of Figure 1;
Figure 3 is a side view of the battery module of Figure 1;
Figure 4 is a top view of the battery module of Figure 1;
Figure 5 is a front view of the battery module of Figure 1; And
6 is a side view of the battery module of FIG. 1.

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.

1 schematically shows a perspective view of a battery module according to an embodiment of the present invention, and FIG. 2 schematically shows an exploded view of the battery module of FIG. 1, and FIG. A side view is schematically shown, FIG. 4 schematically shows a top view of the battery module of FIG. 1, and FIG. 5 schematically shows a front view of the battery module of FIG. 1.

1 to 5, the battery module 100 includes a battery cell assembly 110 and a module case 120.

The battery cell assembly 110 is electrically connected to unit cells 101 in a plate shape having a relatively large width and length compared to the thickness, and both sides of each unit cell 101 are inclined at an angle of 45 degrees to the ground. In a state, a plurality of unit cells 101 are arranged adjacent to each other to form a diagonal arrangement structure.

The unit cell 101 has a structure in which the plate-shaped battery cells 102 are mounted in a cartridge 104 in which the battery cell accommodating part 103 is formed in two units.

An end plate 105 for maintaining the adjacent arrangement of the unit cells 101 is mounted on the outer surfaces of the unit cells 101 located at the outermost of the unit cells 101.

For cooling the battery module 100, a heat dissipation sheet 106 is interposed between the unit cells 101, and a heat dissipation pad 107 is mounted at a lower end of the heat dissipation sheets 106 in a thermal contact state.

In order to fix the arrangement of the battery cells 102 and the cartridges 104 constituting the unit cells 101, a strap in the direction of the arrangement of the unit cells 101 at the lower end of the battery cell 102 assembly 110 A band 108 is attached.

In the unit cells 101, the positive and negative terminals of the battery cells 102 are positioned equally toward the first side 10 of the battery cell 102 assembly 110.

A bus bar assembly 130 for electrical connection is mounted on the first side 10 of the battery cell 102 assembly 110 in which the electrode terminals of the battery cells 102 are located.

The module case 120 has a hexahedral structure having a trapezoidal shape in a vertical cross section, and has a first side 10 on which the electrode terminals of the battery cell 102 assembly 110 are located, and the first side 10 Opposing second side surfaces 20 and a third side surface 30 adjacent to the first side 10 and the second side 20 and inclined diagonally are exposed to the outside. ) Is formed.

In addition, in the upper and lower portions of the first side 10 and the second side 20 and the upper and lower portions of the module case 120 for setting the opening portion 40, the battery cell 102 assembly 110 A plurality of ventilation holes 121 are perforated to allow the refrigerant to flow to the upper and lower ends of the.

Inside the module case 120, a BMS mounting portion 122 to which the BMS 140 is mounted is formed at a portion facing the third side surface 30 of the battery cell 102 assembly 110.

6 schematically shows a side view of a battery pack according to an embodiment of the present invention.

6, the battery pack 200 includes a first battery module 210 and a second battery module 220, and the second battery module 220 has the same shape as the first battery module 210 Consists of.

The battery pack 200 includes an inclined outer surface of the first battery module 210 and the second battery module 220 in a state in which the first battery module 210 is erected and the second battery module 220 is inverted. The inclined outer surfaces of are arranged in a structure facing each other.

The battery pack 200 has an external structure of a rectangular parallelepiped.

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 (17)

As a battery module mounted on the lower portion of the electric vehicle's heat transfer sheet or rear heat sheet,
Plate-shaped unit cells having a relatively large width and length compared to the thickness are electrically connected, and with both sides of each unit cell inclined at a predetermined angle with respect to the ground, a plurality of unit cells are arranged adjacent to each other and arranged diagonally. A battery cell assembly constituting a structure; And
Including; a module case in which an assembly receiving portion in which the battery cell assembly is mounted is formed,
The module case,
A first side on which electrode terminals of the battery cell assembly are located,
A second side opposite to the first side,
Including a third side that is adjacent to the first side and the second side and is inclined diagonally to be parallel to both sides of the unit cells, and is provided with an opening in a structure exposed to the outside,
A battery module, characterized in that the vertical section is made of a hexahedral structure having a trapezoidal shape. The battery module according to claim 1, wherein in the diagonal arrangement structure, both surfaces of the unit cells are inclined at an angle of 20 degrees to 80 degrees with respect to the ground. The battery module according to claim 1, wherein the unit cell has a structure in which plate-shaped battery cells are mounted in a cartridge in which a battery cell receiving part is formed in two units. The battery module according to claim 3, wherein an end plate for maintaining the adjacent arrangement of the unit cells is mounted on outer surfaces of the unit cells located at the outermost of the unit cells. The battery module according to claim 3, wherein a heat dissipation sheet is interposed between the unit cells. The battery module according to claim 5, wherein a heat dissipation pad is mounted at the lower end of the heat dissipation sheets in a thermal contact state. The method of claim 3, wherein a strap band is mounted at a lower end of the battery cell assembly in an arrangement direction of the unit cells to fix the arrangement of the battery cells and cartridges constituting the unit cells. Battery module. The battery module according to claim 3, wherein positive terminals and negative terminals of the battery cells in the unit cells are positioned equally toward the first side of the battery cell assembly. The battery module of claim 4, wherein a bus bar assembly for electrical connection is mounted on the first side of the battery cell assembly in which the electrode terminals of the battery cells are located. delete delete The method of claim 1, wherein the upper and lower portions of the first side and the upper and lower portions of the second side of the module case for setting the opening portion are provided with a plurality of refrigerant to flow to the upper and lower portions of the battery cell assembly. Battery module, characterized in that the ventilation holes are perforated. The battery module according to claim 1, wherein a BMS mounting portion is formed on a portion of the module case facing the third side surface of the battery cell assembly to which a battery management system (BMS) is mounted. A battery pack comprising at least one battery module according to any one of claims 1 to 9, 12, and 13. The method of claim 14,
The battery pack includes a first battery module and a second battery module;
The second battery module has the same shape as the first battery module;
In a state in which the first battery module is upright and the second battery module is inverted, the inclined outer surface of the first battery module and the inclined outer surface of the second battery module are arranged in a structure facing each other. Battery pack. The battery pack according to claim 15, wherein the battery pack has an external structure of a rectangular parallelepiped or a regular cube. An electric vehicle comprising another battery pack as a power source according to claim 14.

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