KR102253784B1 - Battery Module with Improved Stability in Long-Term Use - Google Patents

Abstract

The present invention is a structure in which first and second end plates are supported respectively at the top and bottom of a module stack, in which a plurality of cell modules in which a battery cell is mounted on a cartridge are stacked; First through holes to which compression springs are mounted are formed at corners of the first and second end plates; The cartridge has second through holes formed at positions in communication with the first through holes; The rod-shaped fastening member is continuously inserted into the first through holes and the second through holes and coupled to the bolt, while the module stack and the first and second ends in the form via a compression spring mounted on the first through holes. Integrally joining the plates; When the volume of the battery cells in the module stack is expanded, the compression spring is elastically deformed to offset an increase in the thickness of the module stack in the stacking direction.

Description

Battery Module with Improved Stability in Long-Term Use}

The present invention relates to a battery module with improved structural stability against long-term use.

Recently, a secondary battery capable of charging and discharging has been widely used as an energy source or auxiliary power device of a wireless mobile device. 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).

In small mobile devices, one or two or three battery cells per device are used, whereas in medium- to large-sized devices such as auxiliary power devices or automobiles, due to the necessity of high power and large capacity, a battery module in which a plurality of battery cells are electrically connected is used. .

Since the battery module is preferably manufactured with a small size and weight as much as possible, prismatic batteries and pouch-type batteries that can be charged with a high degree of integration and have a small weight to capacity are mainly used as battery cells (unit cells) of medium and large battery modules. . In particular, pouch-type batteries using an aluminum laminate sheet or the like as an exterior member are attracting a lot of attention due to advantages such as low weight, low manufacturing cost, and easy shape transformation.

The battery module may be used alone, but two or more may be combined to form a battery pack. In this case, it is important that each battery module is manufactured with uniform dimensions.

When each battery module does not have uniform dimensions, that is, when dimensional stability is not maintained, when a strong shock or vibration is applied from the outside, the battery module is not fixed inside the battery pack, so there is a problem in the durability or safety of the battery pack. Can cause.

If such dimensional stability is maintained, it is possible to achieve durability or safety of the battery pack from external shock or vibration by configuring to fit each dimension.

In general, battery modules have used a method of stacking a plurality of battery cells and fixing them using a rod-shaped fastening member.

This will be described in detail with reference to the structure of the battery module according to the prior art in FIG. The battery module 10 according to FIG. 1 includes end plates 2 and 3 for reinforcing rigidity at the top and bottom of the stack in a state in which battery cells (not shown) mounted on the cartridge 1 are stacked. These are arranged, and the end plates 2 and 3 and the cartridge 1 are integrally coupled to each other by a rod-shaped fastening member 4.

However, in the case of a battery cell, a so-called swelling phenomenon in which the volume of the battery cell swells is caused by repeated charging and discharging, and accordingly, the battery module according to FIG. 1 is deformed in a form in which the stacking height of the battery cells is increased.

In this case, there is a problem in that the pressure due to the expansion is concentrated to the rest of the end plate except for the portion fixed by the fastening member, that is, the central portion of the end plate, and the end plate is distorted.

Therefore, there is a high need for developing a battery module having a new assembly structure to solve 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 based on a structure in which a rod-shaped fastening member connects a module stack and end plates in a form via a compression spring, and the compression spring is elastically deformed even if the volume of the battery cells is expanded, and the stacking direction By offsetting the increase in the thickness of the module stack, it is to provide a battery module having a structure in which deformation and damage of the end plates are prevented.

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

A structure in which first and second end plates are supported respectively at the top and bottom of the module stack, in which a plurality of cell modules in which the battery cells are mounted on the cartridge are stacked;

First through holes to which compression springs are mounted are formed at corners of the first and second end plates;

The cartridge has second through holes formed at positions in communication with the first through holes;

The rod-shaped fastening member is continuously inserted into the first through holes and the second through holes and coupled to the bolt, while the module stack and the first and second ends in the form via a compression spring mounted on the first through holes. Integrally joining the plates;

When the volume of the battery cells in the module stack is expanded, the compression spring is elastically deformed to offset an increase in the thickness of the module stack in the stacking direction.

That is, the battery module according to the present invention is based on a structure in which a rod-shaped fastening member connects the module stack and end plates in a form via a compression spring, and the compression spring is elastically deformed even if the volume of the battery cells expands. It is a structure in which deformation and damage of the end plates can be prevented by offsetting the increase in the thickness of the module stack in the stacking direction.

In the present invention, the compression spring may be a conical spring having a conical shape. This structure has the advantage that the compression spring can be easily contracted when the fastening member is fastened. Conversely, when the thickness of the module stack is increased, the compression spring is easily elastically deformed.

The compression spring may also have a structure in which steel is wound more than once to less than 3 times.

When the compression spring is wound less than one time, it is difficult to achieve the intended effect of the present invention because it cannot be viewed as a spring capable of substantially elasticity and restoration. Since the elastic modulus formed for each winding radius is small, it is easy to shrink, but the force pressing the end plate together with the fastening member in a normal state is low, making it difficult to maintain a firmly coupled state of the module stack and the end plates. There is.

In addition, when the elastic modulus of the compression spring is excessively large, the pressure of the compression spring forcibly contracted by the fastening member is applied to the cartridge and the end plate, and when the volume of the battery cells expands, the first through hole and the second penetrate Not only the periphery of the sphere may be deformed, but the shrinkage does not proceed smoothly, so it is difficult to offset the increase in the thickness of the module stack when the battery cell is expanded in volume.

On the other hand, when the elastic modulus of the compression spring is too small, as described above, the force pressing the end plate together with the fastening member in a normal state is low, making it difficult to maintain a firmly coupled state of the module stack and the end plates. there is a problem.

In consideration of this, the elastic modulus of the compression spring in the present invention may be (400/n) N/mm to (1300/n) N/mm. Wherein n is the total number of compression springs mounted on the battery module, the number can be appropriately selected according to the structure of the battery module, as an example, 2 or more to 30 or less, in detail 4 or more to 12 It may be less than or equal to 4, more specifically 4 or more to 8 or less.

The fastening member may integrally couple the cell module stack and the first and second end plates in a state in which the compression spring is pressed to a height of 10% to 60% of the height of the compression spring in an uncompressed state.

If the fastening member is less than the minimum value of the range, which can be seen in a state in which the compression spring is excessively pressed, when the volume of the battery cell expands, the compression spring is elastically deformed to offset the increase in the thickness of the module stack in the stacking direction. Since the degree is small, it is difficult to achieve the intended effect in the present invention.

On the other hand, when the fastening member exceeds the maximum value of the range that can be seen in a state in which the compression spring is pressed loosely, it is difficult to maintain a firm coupling state of the module stack and the first and second end plates, for example, During vibration or impact, cartridges or end plates of the module stack may flow within the height of the compression spring. This is undesirable in that direct shock and vibration can be applied to the battery cells constituting the module stack.

The compression spring may be mounted on the first through hole in a form integral with the periphery of the first through hole. Alternatively, the compression spring may be mounted in a form detachable from the first through hole.

On the other hand, the fastening member is a taper bolt;

The maximum inner diameter of the compression spring may be 100% to 105% of the maximum outer diameter of the tapered bolt.

If it is less than the minimum value of the above range, it is difficult to sufficiently perform elastic deformation while the compression spring is fixed to the tapered bolt.It is not preferable, and if it exceeds the maximum value of the above range, the fastening member is fastened, due to deformation, etc. It is not desirable because the compression spring may pass through the fastening member and disengage from the fastening member.

In one specific example, each of the first end plate and the second end plate may have a planar shape and have a rectangular shape, and have a structure in which a corner in which the first through hole is formed protrudes outward.

The first end plate and the second end plate may allow air to flow, and a plurality of beads may be formed to reinforce the rigidity of the plate.

In one specific example, the cartridge may be formed in a planar shape, in a rectangular shape, and a corner in which a second through hole is formed protrudes outward.

Here, the cartridge is a ring-shaped open cartridge including an outer circumferential fixing portion fixed along the outer circumference of the battery cell;

The outer surface of the battery cell is exposed through the cartridge while the battery cell is mounted on the cartridge;

A radiating fin may be mounted on the exposed outer surface of the battery cell.

At least one of the cell modules constituting the module stack has a fastening protrusion formed on its cartridge;

The battery module may be mounted to another battery module or device through a fastening protrusion.

In addition, a third through hole may be formed in the fastening protrusion, and another fastening member such as screws, bolts, rivets, etc. may be fastened to the third through hole.

In the module stack, the electrode terminals of the battery cells may be arranged on one side of the module stack, and the battery module includes an insulating member having an opening through which the electrode terminals arranged as described above can pass, and an insulating member arranged on the insulating member. It may further include a bus bar assembly electrically connected to the electrode terminals.

In the present invention, the battery cell is a lithium ion (Li-ion) secondary battery, a lithium polymer (Li-polymer) secondary battery, or a lithium ion polymer having advantages such as high energy density, discharge voltage, and output stability. (Li-ion polymer) It may be a lithium secondary battery such as a secondary battery.

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 current collector is generally made to have a thickness of 3 to 500 micrometers. These positive electrode current collectors and extended current collectors are not particularly limited as long as they have high conductivity without causing chemical changes to the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum Surface treatment of carbon, nickel, titanium, silver, etc. on the surface of stainless steel may be used. The positive electrode current collector and the extended current collector may increase the adhesion of the positive electrode active material by forming fine irregularities on the surface thereof, and various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics are possible.

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.

The negative electrode current collector is generally made to have a thickness of 3 to 500 micrometers. Such a negative electrode current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel For the surface treatment with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloys, etc. may be used. In addition, like the positive electrode current collector, it is possible to enhance the bonding strength of the negative electrode active material by forming fine irregularities on the surface thereof, and it may be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics.

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 is 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 micrometers, and the thickness is generally 5 to 300 micrometers. Examples of such a separation membrane include olefin-based polymers such as polypropylene having chemical resistance and hydrophobic properties; 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.

The electrolyte may be a lithium salt-containing non-aqueous electrolyte, and consists of a non-aqueous electrolyte and a lithium salt. As the non-aqueous electrolyte, a non-aqueous organic solvent, an organic solid electrolyte, an inorganic solid electrolyte, or the like is used, but is not limited thereto.

As the non-aqueous organic solvent, 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 and Li ₃ PO ₄ -Li ₂ S-SiS _{2 may be used.}

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

In addition, in the non-aqueous electrolyte solution, for the purpose of improving charge/discharge characteristics and flame retardancy, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexaphosphate triamide, Nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinone, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxy ethanol, aluminum trichloride, etc. may be added. have. In some cases, in order to impart non-flammability, a halogen-containing solvent such as carbon tetrachloride and ethylene trifluoride may be further included, and carbon dioxide gas may be further included to improve high-temperature storage characteristics, and FEC (Fluoro-Ethylene Carbonate), PRS (Propene sultone), and the like may be further included.

In one specific example, _{lithium salts such as LiPF 6} , LiClO ₄ , LiBF ₄ , LiN(SO ₂ CF ₃ ) ₂ are used in the cyclic carbonate of EC or PC as a highly dielectric solvent and DEC, DMC or EMC as a low viscosity solvent. The lithium salt-containing non-aqueous electrolyte can be prepared by adding it to a mixed solvent of linear carbonate.

As described above, the battery module according to the present invention is based on a structure in which a rod-shaped fastening member connects the module stack and end plates in a form via a compression spring, and the compression spring This elastic deformation offsets the increase in the thickness of the module stack in the stacking direction, thereby preventing the end plates from being deformed and damaged.

1 is a schematic diagram of a battery module according to the prior art;
2 is a schematic diagram of a battery module according to an embodiment of the present invention;
3 is a schematic diagram of a compression spring.

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

2 is a schematic diagram of a battery module 100 according to an embodiment of the present invention.

2, the battery module 100 includes a battery cell 140, a cartridge 130, a first end plate 110, a second end plate 120, a compression spring 160, and a fastening member 170. ).

The battery cell 140 is mounted on the cartridge 130 and is defined as a cell module 140. The cell modules 140 are stacked upward with respect to the ground to form a module stack.

A first end plate 110 and a second end plate 120 are arranged at the top and bottom of the module stack, respectively.

Each of the first end plate 110 and the second end plate 120 has a planar shape, has a rectangular shape, and has a structure with a corner protruding outward, and a first through hole 101 is formed at the protruding corner. have. Compression springs 160 are mounted in the first through holes 101.

The first end plate 110 and the second end plate 120 also allow air to flow and include a plurality of beads 103 for reinforcing the rigidity of the end plates 110 and 120.

The cartridge 130 has a planar shape, has a rectangular shape, and has a structure with a corner protruding outward. Here, second through holes 102 are formed at the corners of the cartridge 130.

The corners of the second through hole 102 and the cartridge 130 are located at a position corresponding to the corners of the first end plate 110 and the second end plate 120 and the first through hole 101, that is, in a vertical direction. Is formed at a position forming a line in, and as shown in FIG. 2, when the cartridges 130 and the end plates 110 and 120 are arranged, the first through hole 101 and the second through hole 102 are They are located up and down and communicate with each other.

Meanwhile, of the cartridges 130 constituting the module stack, two cartridges have a fastening protrusion 180 formed therein, and a third through hole 182 is formed in the fastening protrusion 180. The third through hole 182 is for fastening to another battery module 100 or device.

Although not shown in the drawing, the cartridge 130 is a ring-shaped open cartridge 130 including an outer circumferential fixing portion fixed along the outer circumference of the battery cell 140.

Accordingly, while the battery cell 140 is mounted on the cartridge 130, the outer surface of the battery cell 140 is exposed through the cartridge 130, and a radiating fin is mounted on the exposed outer surface of the battery cell 140.

The module stack including the cartridges of the above structure is fastened together with the end plates 110 and 120 by a rod-shaped fastening member.

Specifically, the tapered bolt 170, which is a rod-shaped fastening member, is continuously inserted into the first through holes 101 and the second through holes 102 so that the second end plate 120 is positioned at the bottom of the second end plate. When passing through the through hole 102, the tapered bolt 170 is fastened to the nut 172 and integrally couples the module stack and the first and second end plates 120 to each other.

Here, the battery pack according to the present invention includes a compression spring 160, in a state in which the tapered bolt 170 passes through the compression spring 160 mounted to the first through holes 101, the first The first through holes 101 of the end plate 110, the second through holes 102 of the cartridges, and the first through holes 101 of the second end plate 120 are sequentially passed through. Thereafter, the tapered bolt 170 is fastened to the nut 172 while passing through the compression spring 160 mounted on the first through hole 101 of the second end plate 120, The first and second end plates 110 and 120 are integrally coupled.

The advantage of this structure is that, compared to the battery module 10 of FIG. 1 according to the prior art, even if the volume of the battery cells 140 forming the module stack is expanded, the pressure applied to the end plates 110 and 120 The compression spring 160 is also applied, and as a result, as the compression spring 160 contracts, the pressure applied to the end plates 110 and 120 may be reduced.

In other words, in the present invention, the compression spring 160 is elastically deformed by the pressure caused by the expansion of the battery cell 140, thereby offsetting the increase in the thickness of the module stack in the stacking direction, thereby increasing the thickness of the plates 110 and 120. You should pay attention to what you can withstand.

In addition, this is because the pressure due to the expansion is distributed to the compression spring 160 located at each corner of the battery module 100, a problem in which one part of the end plates 110, 120, for example, only the center is deformed. Can be resolved.

3 is a schematic diagram of a compression spring 160 according to an embodiment of the present invention.

Referring to FIG. 3, the compression spring 160 is made of a conical spring in the shape of a cone whose inner diameter of the winding is reduced from the top to the bottom. Compression spring 160 also consists of a structure wound approximately 2.5 times.

Such a conical spring is suitable for achieving the intended effect in the present invention because it is easy to contract and elastically deform when an external force is applied.

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

Claims (15)

As a battery module,
A structure in which first and second end plates are supported respectively at the top and bottom of the module stack, in which a plurality of cell modules in which the battery cells are mounted on the cartridge are stacked;
First through holes to which compression springs are mounted are formed at corners of the first and second end plates;
The cartridge has second through-holes formed at positions in communication with the first through-holes;
The rod-shaped fastening member is continuously inserted into the first through holes and the second through holes and coupled to the bolt, while the module stack and the first and second ends in the form via a compression spring mounted on the first through holes. Integrally joining the plates;
When the volume of the battery cells in the module stack is expanded, the compression spring is elastically deformed to offset an increase in the thickness of the module stack in the stacking direction,
The battery module, characterized in that the compression spring is a conical spring. As a battery module,
A structure in which first and second end plates are supported respectively at the top and bottom of the module stack, in which a plurality of cell modules in which the battery cells are mounted on the cartridge are stacked;
First through holes to which compression springs are mounted are formed at corners of the first and second end plates;
The cartridge has second through holes formed at positions in communication with the first through holes;
The rod-shaped fastening member is continuously inserted into the first through holes and the second through holes and coupled to the bolt, while the module stack and the first and second ends in the form via a compression spring mounted on the first through holes. Integrally joining the plates;
When the volume of the battery cells in the module stack is expanded, the compression spring is elastically deformed to offset an increase in the thickness of the module stack in the stacking direction,
The fastening member is characterized in that in an uncompressed state, the cell module stack and the first and second end plates are integrally coupled with the compression spring pressed to a height of 10% to 60% of the height of the compression spring. Battery module. As a battery module,
A structure in which first and second end plates are supported respectively at the top and bottom of the module stack, in which a plurality of cell modules in which the battery cells are mounted on the cartridge are stacked;
First through holes to which compression springs are mounted are formed at corners of the first and second end plates;
The cartridge has second through holes formed at positions in communication with the first through holes;
The rod-shaped fastening member is continuously inserted into the first through holes and the second through holes and coupled to the bolt, while the module stack and the first and second ends in the form via a compression spring mounted on the first through holes. Integrally joining the plates;
When the volume of the battery cells in the module stack is expanded, the compression spring is elastically deformed to offset an increase in the thickness of the module stack in the stacking direction,
The fastening member is a tapered bolt;
Battery module, characterized in that the maximum inner diameter of the compression spring is 100% to 105% of the maximum outer diameter of the tapered bolt. The battery module according to claim 1, wherein the compression spring has an elastic modulus of (400/n) N/mm to (1300/n) N/mm, and n is the total number of compression springs. The battery module according to claim 1, wherein each of the first end plate and the second end plate has a planar shape and a rectangular shape, and a corner in which the first through hole is formed protrudes outward. . The battery module according to claim 1, wherein the compression spring is mounted on the first through hole in a form integral with the periphery of the first through hole. The battery module according to claim 1, wherein the compression spring is mounted in a form detachable from the first through hole. The battery module according to claim 1, wherein the compression spring has a structure in which steel is wound more than once to less than 3 times. delete The battery module according to claim 1, wherein a plurality of beads are formed on the first end plate and the second end plate. The battery module according to claim 1, wherein the cartridge has a planar shape, a rectangular shape, and a corner having a second through hole protruding outward. The method of claim 11,
The cartridge is a ring-shaped open cartridge including an outer circumferential fixing portion fixed along the outer circumference of the battery cell;
The outer surface of the battery cell is exposed through the cartridge while the battery cell is mounted on the cartridge;
A battery module, characterized in that a heat dissipation fin is mounted on an outer surface of the exposed battery cell. The method of claim 1,
At least one of the cell modules constituting the module stack has a fastening protrusion formed on its cartridge;
The battery module is a battery module, characterized in that mounted to another battery cell or device through a fastening protrusion. The battery module according to claim 13, wherein a third through hole is formed in the fastening protrusion. The battery module according to claim 1, wherein the electrode terminals of the battery cells in the module stack are arranged on one side of the module stack.

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