KR101631124B1 - Secondary Battery Having Member for Temperature Measurement - Google Patents

Abstract

The present invention provides a secondary battery in which an electrode assembly is mounted inside a battery case, and a temperature measuring member for measuring a temperature of the secondary battery is mounted.

Description

[0001] The present invention relates to a secondary battery having a temperature measurement member,

[0001] The present invention relates to a secondary battery including a temperature measuring member, and more particularly to a temperature measuring member for measuring the temperature of the secondary battery, wherein the electrode assembly is mounted inside the battery case To a secondary battery.

As the secondary battery, there is a high demand for a prismatic secondary battery and a pouch-type secondary battery that can be applied to products such as cellular phones with a thin thickness in terms of the shape of the battery, and a high energy density, a discharge voltage, There is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries.

The secondary battery has a structure in which an electrode assembly composed of a positive electrode / separator / negative electrode is embedded in a battery case in a sealed state. The electrode assembly includes a jelly-roll type electrode assembly formed by winding a separator between an anode and a cathode formed by applying an electrode active material to a metal foil, and a plurality of anodes formed by coating the electrode active material on a metal foil of a predetermined size A stacked electrode assembly in which a cathode and a cathode are sequentially stacked with a separator interposed therebetween, and a stack / folding type electrode assembly in which the stacked electrode assembly is combined. In general, a pouch-shaped battery is referred to as a cylindrical battery in which such an electrode assembly is housed in a cylindrical case, a prismatic battery in which a rectangular battery is housed in a rectangular case, and a pouch-shaped battery in which an aluminum laminate sheet is housed in a pouch case.

In such a secondary battery, one of the biggest problems is a safety problem. For example, the lithium secondary battery is composed of a lithium transition metal oxide-based cathode active material, a carbon-based anode active material, a lithium salt-containing electrolyte, and the like. In the case of overcharging, overcurrent, external impact, dropping, Resulting in heat generation and expansion. Therefore, when this phenomenon accelerates, the battery may ignite or explode.

Generally, a lithium secondary battery is activated during the manufacturing process of a battery, and the activation process includes applying a current to a predetermined voltage to an electrode assembly impregnated with an electrolyte. The initial charge and discharge process for this activation generates heat, and in some cases, such a heat may cause deterioration of performance of the secondary battery.

In addition, the secondary batteries repeatedly charge and discharge repeatedly during operation, and a large amount of heat may be generated in this process, 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.

Therefore, in order to ensure the optimal operating condition and safety for the battery, many tests are conducted before the production stage of the product. During such tests, the electrochemical operating state of the test specimen such as the voltage and current, And measuring the state.

Typical tests for evaluating the performance of batteries in general are temperature measurement and voltage measurement. Generally, the temperature change changes the state of the battery and necessarily involves a change in the voltage. Therefore, for accurate testing of battery performance, voltage measurements at specific temperatures are required, for which temperature and voltage measurements need to be made at the same time.

The temperature measurement is performed by attaching a temperature sensor to the surface of the battery, and the voltage measurement is performed by bringing the voltage measurement probe into contact with the positive terminal and the negative terminal respectively. Therefore, when the temperature and the voltage of the specimen cell are to be measured at the same time, a plurality of measuring means must be attached to or contacted with the corresponding portion, so that the measuring process is very troublesome.

Therefore, a need exists for a technique for measuring an effective temperature at various temperature measurement sites of a test sample through a simple operation.

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.

That is, an object of the present invention is to provide a secondary battery in which the electrode assembly is mounted inside the battery case and includes a temperature measuring member for measuring the temperature of the secondary battery, The present invention provides a secondary battery capable of simply measuring the temperature of the secondary battery without complicated processes of attaching or contacting a plurality of measurement means to a corresponding portion of the secondary battery during a test process.

In order to attain the above object, the secondary battery according to the present invention has a structure in which an electrode assembly is mounted inside a battery case, and a temperature measuring member for measuring a temperature of the secondary battery is mounted.

That is, according to the present invention, since the electrode assembly is mounted inside the battery case and includes a temperature measuring member for measuring the temperature of the secondary battery, the test process such as initial charging and discharging for activating the battery in the manufacturing process of the secondary battery It is possible to provide a secondary battery capable of simply measuring the temperature of the secondary battery without complicated processes of attaching or contacting a plurality of measurement means to a corresponding portion of the secondary battery.

In one specific example, the temperature measuring member may have a built-in structure at one side of the battery case, and may be a temperature sensor for measuring the temperature of the secondary battery or a built-in chip for temperature measurement.

In another specific example, the temperature measuring member may be attached to the inner surface of the battery case or embedded in the battery case.

Further, the temperature measuring member may further include an RF antenna for wireless communication with the outside, so that the temperature of the secondary battery measured by the temperature measuring member through the RF antenna can be measured without an additional connection terminal for electrical connection with the outside Can be transmitted to the outside.

In some cases, the temperature measuring member may be attached to the outer surface of the battery case with the connection terminal exposed.

The present invention also provides a secondary battery test apparatus including a temperature display unit receiving and displaying measurement information from a temperature measuring member of the secondary battery and the secondary battery by wire or wireless.

Therefore, the secondary battery test apparatus according to the present invention can confirm the temperature of the secondary battery in real time through the temperature display unit included in the desk-top computer. Therefore, during the manufacturing process of the secondary battery, It is possible to easily measure the temperature of the secondary battery without complicated process of attaching or contacting a plurality of measurement means to a corresponding portion of the secondary battery in a test process.

The electrode assembly is not particularly limited in its structure, and preferably includes a folding structure, a stacking structure, and a stacking / folding structure. In one specific example, the tabs extending from the electrode plates of the electrode assembly are coupled to one electrode lead, and the plate-shaped electrode terminals are formed by the electrode leads.

Details of the stacked / folded structure of the electrode assembly are disclosed in Korean Patent Application Laid-Open Nos. 2001-0082058, 2001-0082059 and 2001-0082060, the contents of which are incorporated herein by reference. As a reference.

The battery case may be, for example, a square metal can, and the prismatic secondary battery includes a jelly-roll having a positive electrode sheet and a negative electrode sheet wound with a separator interposed therebetween, Inserting it into a rectangular can, impregnating the electrolytic solution, and sealing the can.

In addition, the secondary battery according to the present invention can be suitably applied to a pouch-type secondary battery in which an electrode assembly is embedded in a storage portion of a pouch-type case of a laminate sheet including a metal layer and a resin layer, for example, an aluminum laminate sheet have.

The battery according to the present invention is preferably a lithium ion secondary battery in which a lithium-containing electrolyte is impregnated in an electrode assembly, a lithium secondary battery such as a so-called lithium ion polymer battery in which an electrode assembly is impregnated with a lithium- Can be applied.

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 < 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 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 device including the secondary battery as a power source.

The device according to the present invention can be preferably used for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device, as well as a mobile device such as a mobile phone and a portable computer, as well as excellent lifetime characteristics and safety.

As described above, the secondary battery according to the present invention includes the electrode assembly mounted inside the battery case and includes a temperature measuring member for measuring the temperature of the secondary battery. Thus, in the manufacturing process of the secondary battery, It is possible to provide a secondary battery which can easily measure the temperature of the secondary battery without complicated process of attaching or contacting a plurality of measurement means to a corresponding portion of the secondary battery in a test process such as initial charging and discharging.

1 is a schematic view of a secondary battery according to an embodiment of the present invention;
2 is a schematic view of a secondary battery according to another embodiment of the present invention;
3 is a schematic view of a secondary battery according to another embodiment of the present invention.

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 of a secondary battery according to an embodiment of the present invention.

Referring to FIG. 1, a secondary battery 100 according to the present invention includes an electrode assembly 180 in which an anode and a cathode are stacked with a separator interposed therebetween. The electrode assembly 180 is housed in a square can 130, And a top cap 140 having an electrode terminal (for example, an anode terminal 144) formed at the open upper end of the square can 130 is assembled.

The negative electrode of the electrode assembly 180 is electrically connected to the negative terminal 144 on the top cap 140 via the negative electrode tab 181 such that the negative electrode terminal 144 is electrically connected to the top cap 140 ). On the other hand, another electrode (for example, an anode) of the electrode assembly 180 is electrically connected to the top cap 140 whose cathode tab 182 is made of a conductive metal material such as aluminum, To form a bipolar terminal.

In addition, a sheet-like insulating member 150 (not shown) is interposed between the top cap 140 and the electrode assembly 180 to assure the insulation state between the electrode assembly 180 and the top cap 140 except for the electrode tabs 181, The temperature measuring member 110 is mounted thereon and then the top cap 140 is covered and the contact surfaces of the top cap 140 and the square can 130 are welded together.

2 and 3 are schematic views of a secondary battery according to another embodiment of the present invention.

Referring to FIG. 2, the secondary battery 200 is manufactured by assembling an insulating top cap 240 to a square can 230 in which an electrode assembly (not shown) is mounted.

A temperature measuring member 210 is embedded in the square can 130. The temperature measuring member 210 has a structure including an RF antenna for wireless communication with the outside and is separately provided for electrical connection with the outside The temperature of the secondary battery 200 measured by the temperature measuring member 210 can be transmitted to the outside through the RF antenna without the connection terminal of the secondary battery 200. [

3, a temperature measuring member 310 is attached to an outer surface of the square can 330 in a state where connection terminals are exposed on one side surface of the square can 330. As shown in FIG.

The secondary batteries 200 and 300 incorporating the temperature measuring members 210 and 310 include a temperature display unit for receiving and displaying measurement information from the temperature measuring members 210 and 310 of the secondary battery by wire or wireless, The temperature of the secondary batteries 200 and 300 can be confirmed in real time by the test apparatus.

As shown in FIGS. 1 to 3, according to the present invention, since the electrode assembly is mounted inside the battery case and includes the temperature measuring member for measuring the temperature of the secondary battery, It is possible to provide a secondary battery capable of easily measuring the temperature of the secondary battery without complicated processes of attaching or contacting a plurality of measurement means to a corresponding portion of the secondary battery in a test process such as initial charging and discharging for the secondary battery.

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 (15)

The electrode assembly is mounted inside the battery case, and a temperature measuring member for measuring the temperature of the secondary battery is mounted,
The battery case is a rectangular metal can,
Wherein the temperature measuring member is embedded in the battery case,
And an RF antenna for external wireless communication of the temperature measuring member is further included. The secondary battery according to claim 1, wherein the electrode assembly is a folding structure, a stacking structure, or a stacking / folding structure. delete delete delete The secondary battery according to claim 1, wherein the secondary battery is a lithium secondary battery. delete The secondary battery according to claim 1, wherein the temperature measuring member is a temperature sensor or a temperature measuring chip. delete delete delete A device as claimed in any one of claims 1, 2, 6 and 8 as a power source. 13. The device of claim 12, wherein the device is selected from a cell phone, a tablet computer, a notebook computer, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device. A secondary battery according to any one of claims 1, 2, 6, and 8; and a temperature display unit for receiving and displaying measurement information from a temperature measuring member of the secondary battery by wire or wireless And a secondary battery. 15. The secondary battery test apparatus according to claim 14, wherein the temperature indicator is included in a desk-top computer.

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