KR101750489B1 - Temperature Sensor for Battery Module and Battery Module Having the Same - Google Patents

Abstract

The present invention relates to a temperature sensor for measuring the temperature of a battery cell, the temperature sensor comprising: a flexible printed circuit board (FPCB) having a structure in which a circuit is printed on a board of an electrically insulating material, A temperature sensing unit located at one end of the FPCB and including a temperature sensing element; And a connection insertion part located at the other end of the FPCB and including a connection terminal inserted into a connector provided in the temperature detector and electrically connected to the connector.

Description

TECHNICAL FIELD [0001] The present invention relates to a temperature sensor for a battery module,

The present invention relates to a temperature sensor for a battery module and a battery module including the same.

2. Description of the Related Art As technology development and demand for mobile devices have increased, the demand for secondary batteries as energy sources has been rapidly increasing, and a lot of research has been conducted on secondary batteries that can meet various demands.

When the secondary battery is classified into a cylindrical secondary battery, a prismatic secondary battery, and a pouch-type secondary battery depending on the shape, it is preferable to use a lithium secondary battery such as a lithium ion battery or a lithium ion polymer battery having high energy density, discharge voltage, Demand is high.

The secondary batteries are repeatedly charged and discharged repeatedly during the operation. In this process, a large amount of heat is generated and the output voltage state of the battery may be changed. The temperature rise due to such heat generation and the change in the output voltage cause a malfunction of a device using the battery, deteriorate the operating efficiency, and shorten the life of the battery.

In addition, since the battery pack includes a battery module structure in which a plurality of battery cells are embedded in the pack case, when the battery cells are over-voltage, over-current and over-heating, There is a need for a means to do this. Accordingly, a temperature sensor or the like is connected to the battery cells to check the operation state at real time or at regular intervals.

Generally, such a temperature sensor is mounted in a state of being electrically connected to a connector provided in a temperature detector, and has a structure for connecting to a connector, and has a connector connecting portion, a contact portion extending to a contact portion of a battery cell, A printed circuit board coupled through soldering or the like at the end of the wire portion, and a temperature sensor element disposed on the printed circuit board.

Since the mounting or connection of the temperature sensor is configured to have a somewhat complicated structure including a plurality of members as described above, the assembling process of the battery pack becomes complicated, which is an obstacle to improvement in productivity.

Further, in a battery pack structure used as a power source for an electric vehicle (EV), a hybrid electric vehicle (HEV) using a battery and an existing engine in combination, when an external force in the forward or backward direction or in an upward direction is applied, There is a problem that disconnection may occur at the soldering portion of the semiconductor device.

Accordingly, there is a great need for a temperature sensor structure for shortening the manufacturing process of the battery module and the battery pack and improving the productivity while easily solving the above problems.

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, the object of the present invention is to simplify the manufacturing process and the assembling process by including the temperature sensor having a simplified structure as the structure including the temperature sensor element and the connection terminal on the printed circuit board composed of the bendable material A temperature sensor having a structure capable of reducing manufacturing costs, and a battery module including the same.

According to an aspect of the present invention, there is provided a temperature sensor for measuring a temperature of a battery cell,

An FPCB (Flexible Printed Circuit board) having a structure in which a circuit is printed on a board of an electrically insulating material and is elongated in a rectangular shape to be bent;

A temperature sensing unit located at one end of the FPCB and including a temperature sensing element; And

A connection insertion portion located at the other end of the FPCB and including a connection terminal inserted into a connector provided in the temperature detector and electrically connected thereto;

As shown in FIG.

Accordingly, the temperature sensor according to the present invention includes a temperature sensor having a simplified structure as a structure including a temperature sensor element and a connection terminal in an FPCB made of a material capable of bending, so that the manufacturing process of the temperature sensor and the assembling It is possible to provide a temperature sensor with a structure that can greatly simplify the process and reduce the manufacturing cost.

In addition, it is possible to provide an effect of solving the problems such as disconnection of the connection part due to a simplified structure compared to a temperature sensor structure in which a plurality of members such as a wire, a connector and a printed circuit board are electrically connected by soldering or the like .

The temperature sensing element is for measuring the temperature of the battery cell. Examples of the temperature sensing element include a thermocouple or a thermistor. However, the temperature sensing element is not limited thereto, Lt; / RTI >

The thermistor is a temperature measuring sensor that uses a principle that the resistance greatly changes even in a minute temperature change. The temperature of the battery cell can be measured in real time through a thermistor provided on the outer surface of the battery cell.

Preferably, the temperature sensing part is molded of a polymer resin at one end of the FPCB. The polymer resin may include, for example, an acrylic polymer, a silicone resin, an epoxy resin, and the like. , And may be used in combination of two or more in some cases.

The connection inserting unit may further include a reinforcing member for stably inserting into the connector provided in the temperature detector. Specifically, the reinforcing member may have a shape corresponding to the connection terminal of the connection inserting unit, Shaped member to be attached to the connector, and may be a structure that facilitates connection to the connector.

Also, the temperature detector may be a temperature sensing assembly having a structure mounted on one upper end of the battery module.

The present invention also relates to a battery module including the temperature sensor, comprising: at least two battery cells in which electrode terminals are sequentially arranged in a state of being electrically connected;

A sensing board assembly mounted on one side of the secondary battery cells to detect voltage and / or temperature of the battery cells; And

A temperature sensor inserted and electrically connected to a connector provided at one side of the sensing board assembly;

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Wherein the temperature sensor comprises: an FPCB having a circuit printed on a board of an electrically insulating material and having a rectangular shape and being elongated and foldable; a temperature sensing unit located at one end of the FPCB and including a temperature sensing element; And a connection inserting portion having a connection terminal for inserting into the connector of the sensing board assembly and electrically connected to the other end portion of the battery module and having a structure in which the temperature sensing portion is in contact with the outer surface of the battery cell. have.

The battery cell may be a plate-shaped battery cell having a thin thickness and a relatively wide width and a length so as to minimize the overall size of the battery cell when the battery cell is constructed.

A preferable example thereof is a secondary battery having a structure in which an electrode assembly is embedded in a battery case of a laminate sheet including a resin layer and a metal layer, and electrode terminals protrude from both upper and lower ends. More specifically, It may be a structure in which an electrode assembly is built in the case. The secondary battery having such a structure may also be referred to as a pouch-shaped battery cell.

The plate-shaped battery cell may have a structure in which a positive terminal and a negative terminal are protruded, and the positive terminal and the negative terminal protrude from one end of the battery cell.

The electrode terminals of the battery cells may be connected in series or in parallel. Specifically, the battery cells may be directly connected to the adjacent battery cells in a stacked state to provide an electrical connection. In this case, the temperature sensing unit may be in contact with the outer surfaces of the sequentially arranged battery cells. And may be in contact with the outer surface of the battery cell located at the outermost one of the battery cells for ease of mounting and detachment.

The temperature sensor includes an FPCB extending from the sensing board assembly to a position where the battery cell is located. Specifically, the FPCB of the temperature sensor detects the temperature of the battery cell And a straight section formed by a length reaching the center of the outer surface.

In addition, in order to facilitate insertion of the connection insertion portion into the connector of the sensing board assembly, the connection insertion portion includes a bending section extending from the linear section and being bent toward the sensing board assembly, And can be stably mounted.

The battery cell is not particularly limited as long as it is a rechargeable secondary battery. For example, a lithium ion battery cell or a lithium polymer battery cell that provides a high output relative to weight can be used.

For reference, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte solution 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 < 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 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 mu m and the thickness is generally 5 to 300 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.

The non-aqueous 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, etc. 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, wherein the battery pack has a structure in which a battery module assembly having a structure in which two or more battery modules are closely arranged is mounted on an upper surface of a tray assembly And a temperature sensor may be mounted on the battery modules constituting the battery pack.

The present invention also provides a device comprising one or more of the battery packs, wherein the device is selected from the group consisting of a power tool, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device It can be one.

Since the devices are well known in the art, a detailed description thereof will be omitted herein.

As described above, the temperature sensor according to the present invention includes a temperature sensor having a simplified structure as a structure including a temperature sensor element and a connection terminal in an FPCB composed of a flexible material, It is possible to greatly simplify the assembly process of the battery module and to provide a temperature sensor having a structure capable of reducing the manufacturing cost

1 is a schematic view schematically showing the structure of a battery module according to an embodiment of the present invention;
2 is a schematic diagram showing the structure of the temperature sensor of Fig.

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. 1 is a schematic view schematically showing the structure of a battery module according to an embodiment of the present invention, and FIG. 2 is a schematic view showing the structure of the temperature sensor of FIG.

Referring to FIGS. 1 and 2, the battery module 100 includes at least two battery cells 110 in which electrode terminals are sequentially connected in an electrically connected state. On the upper surface of the battery module 100, A sensing board assembly 120 for detecting the voltage and / or temperature of the battery 110 is mounted in the direction of the electrode terminal connection (not shown) from the upper end of the battery cell 110.

One side of the sensing board assembly 120 includes a connector 121 electrically connected to the temperature sensor 130. The temperature sensor 130 has one side connected to the connector 121 of the sensing board assembly 120, And the other side thereof is in contact with the outer surface of the battery cell 110.

The temperature sensor 130 includes a FPCB 140 having a structure in which a circuit is printed on a board of an electrically insulating material and is elongated in a rectangular shape and is capable of bending. A temperature sensing element 151 ) Is molded with an epoxy resin.

The FPCB 140 includes a connection insertion portion 160 having a connection terminal for inserting and electrically connecting the connector 121 of the sensing board assembly 120 to the other end of the FPCB 140, Like reinforcing reinforcement 161 added to a shape corresponding to the connection terminal of the connection inserting portion 160 as a reinforcing member to be stably inserted into the connector 121 of the sensing board assembly 120. [

The FPCB 140 of the temperature sensor is configured to be stably mounted on the outer surface of the connector 121 of the sensing board assembly 120 and the battery cells 110 along the outer surface of the battery module 100, A straight section 141 and a connection inserting section 160 formed to have a length reaching the center of the outer surface of the battery cells 110 in order for the sensing element 151 to stably contact the outer surface of the battery cells 110, And a bending section 142 extending from the straight line section 141 and bent in the direction of the sensing board assembly 120 for ease of insertion into the connector 121 of the sensing board assembly 120.

Accordingly, such a temperature sensor structure is formed in a simplified structure as a structure including a temperature sensor element and a connection terminal in an FPCB having a structure that is elongated in a rectangular shape and is capable of bending, so that a manufacturing process of a temperature sensor, It is possible to greatly simplify the assembling process and provide a structure capable of reducing the manufacturing cost.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

1. A battery module comprising a temperature sensor,
At least two battery cells in which electrode terminals are sequentially arranged in an electrically connected state;
A sensing board assembly mounted on one side of the sequentially arranged battery cells to detect voltage and temperature of the battery cells; And
A temperature sensor inserted and electrically connected to a connector provided at one side of the sensing board assembly;
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A temperature sensor for measuring the temperature of the battery cell,
An FPCB (Flexible Printed Circuit board) having a structure in which a circuit is printed on a board of an electrically insulating material and is elongated in a rectangular shape to be bent;
A temperature sensing unit located at one end of the FPCB and including a temperature sensing element; And
A connection insertion portion located at the other end of the FPCB and including a connection terminal inserted into a connector provided in the temperature detector and electrically connected thereto;
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The temperature sensing portion is mounted in a structure in which it is in contact with the outer surface of the battery cell,
The FPCB of the temperature sensor includes a straight section formed to have a length reaching the center of the outer surface of the battery cell so that the temperature sensor stably contacts the outer surface of the battery cell,
Wherein the FPCB of the temperature sensor includes a bending section extending from the linear section and bent in the direction of the sensing board assembly for ease of inserting the connection inserting section into the connector of the sensing board assembly. The battery module according to claim 1, wherein the temperature sensing element is a thermistor. The battery module according to claim 1, wherein the temperature sensing unit is molded of a polymer resin at one end of the FPCB. The battery module according to claim 3, wherein the polymer resin is at least one material selected from the group consisting of an acrylic resin, a silicone resin, and an epoxy resin. The battery module according to claim 1, wherein the connection insertion portion further comprises a reinforcing member for stably inserting the connection terminal into the connector. The battery module according to claim 5, wherein the reinforcing member is a plate-shaped member attached to the connection terminal in a shape corresponding to the connection terminal of the connection insertion portion. The battery module of claim 1, wherein the temperature sensor is a temperature sensing assembly of the battery module. delete The battery module according to claim 1, wherein the battery cell is a plate-shaped battery cell. The battery module according to claim 1, wherein the battery cell is a pouch-shaped battery cell having an electrode assembly embedded in a case of a laminate sheet including a metal layer and a resin layer. The battery module according to claim 9, wherein the plate-shaped battery cell has a structure in which a positive terminal and a negative terminal protrude from one end. The battery module according to claim 1, wherein the electrode terminals of the battery cells are connected in series or in parallel. The battery module according to claim 1, wherein the temperature sensing unit is in contact with an outer surface of a battery cell located at an outermost one of the sequentially arranged battery cells. delete delete A battery pack comprising the battery module according to any one of claims 1 to 7 and 9 to 13, wherein a battery module assembly having a structure in which two or more battery modules are closely arranged is disposed in a tray assembly Is mounted on an upper surface of the battery pack. A device comprising at least one battery pack according to claim 16. 18. The device of claim 17, wherein the device is any one selected from the group consisting of a power tool, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device.

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