JP2012151032A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery capable of preventing a short circuit.SOLUTION: A nonaqueous electrolyte secondary battery 10 comprises an insulating member 4 between a wound body 1 and a lid 6. The insulating member 4 is composed of low-density polyethylene or an ionomer resin, and has a melting point around 100°C. When the temperature of the nonaqueous electrolyte secondary battery 10 reaches 100°C at which a separator in the wound body 1 starts to shrink, the insulating member 4 melts to form an insulating body between a positive electrode and a negative electrode in the wound body 1. As a result, the positive electrode in the wound body 1 is kept from coming in contact with the negative electrode.

Description

  The present invention relates to a non-aqueous electrolyte secondary battery.

  Conventionally, a non-aqueous electrolyte battery that can prevent a short circuit even when the temperature of the battery rises abnormally is known (Patent Document 1).

  This non-aqueous electrolyte battery includes an electrode body produced by winding or laminating a positive electrode, a negative electrode, and a separator. The separator exposed from the end face of the electrode body on the lid side of the battery can of the nonaqueous electrolyte battery is used as a short-circuit prevention allowance, and the separator as the short-circuit prevention allowance is pressed against the end face direction of the electrode body by the insulating plate. Yes. The insulating plate is heat-sealed with the separator.

Japanese Patent Laid-Open No. 5-74443

  However, in the conventional non-aqueous electrolyte battery, the insulating plate is made of the same material as the separator. Therefore, when the separator starts to shrink, the insulating plate also begins to shrink. That is, at the temperature at which the separator starts to shrink, the insulating plate shrinks without being thermally fused with the separator. As a result, there is a problem that the electrode is exposed and short-circuited.

  Accordingly, the present invention has been made to solve such a problem, and an object thereof is to provide a non-aqueous electrolyte secondary battery capable of preventing a short circuit.

  According to the embodiment of the present invention, the non-aqueous electrolyte secondary battery includes a metal can, a wound body, and an insulating member. The battery can is made of metal. The wound body is housed in a battery can and includes a positive electrode, a negative electrode, and a separator. The insulating member is disposed between the wound body and the lid of the battery can, and melts when reaching a first temperature at which the separator starts to shrink.

  In the non-aqueous electrolyte secondary battery according to the embodiment of the present invention, when the first temperature is reached, the separator of the wound body shrinks, but the insulating member melts and reaches the portion where the separator shrinks, and the wound body On the lid side, an insulator is formed between the positive electrode and the negative electrode. As a result, the positive electrode is not in contact with the negative electrode.

  Therefore, a short circuit can be prevented.

FIG. 1 is a perspective view of a non-aqueous electrolyte secondary battery according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the wound body taken along the line II-II shown in FIG. FIG. 3 is a cross-sectional view of the wound body at a high temperature of 130 ° C. or higher. FIG. 4 is a process diagram showing a method for manufacturing the non-aqueous electrolyte secondary battery shown in FIG. FIG. 5 is a perspective view of another nonaqueous electrolyte secondary battery according to an embodiment of the present invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a perspective view of a non-aqueous electrolyte secondary battery according to an embodiment of the present invention. In FIG. 1, the positive electrode can 5 is illustrated so that the inside thereof can be seen.

  Referring to FIG. 1, a nonaqueous electrolyte secondary battery 10 according to an embodiment of the present invention includes a wound body 1, a positive electrode tab 2, a negative electrode tab 3, an insulating member 4, a positive electrode can 5, A lid 6, a vent 7, a negative electrode terminal 8, and an inlet 9 are provided.

  The nonaqueous electrolyte secondary battery 10 is, for example, a lithium ion battery.

  The wound body 1 has a structure in which a positive electrode and a negative electrode are wound through a separator. In addition, the wound body 1 has a generally flat plate shape, and has a planar shape that is formed by the shape of a track of a sports field on a plane parallel to the bottom surface of the positive electrode can 5. The wound body 1 contains an electrolytic solution and is accommodated in the positive electrode can 5.

  The positive electrode tab 2 is made of, for example, aluminum (Al) having a thickness of 0.08 mm, and has a strip shape. One end of the positive electrode tab 2 is welded to the positive electrode of the wound body 1. Further, the positive electrode tab 2 is disposed between the wound body 1 and the lid body 6 through the through hole 41 of the insulating member 4 on the other end side. In this case, the positive electrode tab 2 is curved between the wound body 1 and the lid body 6 and disposed in the positive electrode can 5. The other end of the positive electrode tab 2 is welded to the lid 6.

  The negative electrode tab 3 is made of, for example, a nickel (Ni) -copper (Cu) clad steel plate having a thickness of 0.08 mm, and has a strip shape. One end of the negative electrode tab 3 is welded to the negative electrode of the wound body 1. The other end side of the negative electrode tab 3 is disposed between the wound body 1 and the negative electrode terminal 8 through the through hole 42 of the insulating member 4. In this case, the negative electrode tab 3 is curved between the wound body 1 and the negative electrode terminal 8 and disposed in the positive electrode can 5. The negative electrode tab 3 is welded to the negative electrode terminal 8 at the other end.

  The insulating member 4 is made of, for example, low density polyethylene (LDPE: Low Density Polyethylene) or ionomer resin. Low density polyethylene is a synthetic resin belonging to a crystalline thermoplastic resin in which ethylene as a repeating unit is randomly bonded with branches. The low density polyethylene is polymerized using a multistage gas compressor in an environment of 1000 to 4000 atmospheres and 100 to 350 ° C. using a radical initiator such as oxygen or peroxide in the air as a catalyst. Thereafter, the residual monomer is separated and manufactured by cooling. Thus, since low density polyethylene is polymerized under high pressure and high temperature conditions, ethylene does not bond in a simple chain, and has many long chain branches and short chain branches. Therefore, this structure reduces the density. And low density polyethylene has melting | fusing point of 100-115 degreeC, and practical temperature is about 90 degreeC at the maximum.

  The ionomer resin is a resin having a special structure in which an ethylene-methacrylic acid copolymer or an ethylene-acrylic acid copolymer is intermolecularly bonded with a metal ion such as sodium or zinc. The ionomer resin has a melting point of 96 ° C. for injection molding and has a melting point of 88 ° C. for film.

  Thus, the insulating member 4 has a melting point of about 100 ° C. The insulating member 4 has through holes 41 and 42. The insulating member 4 is disposed between the wound body 1 and the lid body 6.

  The positive electrode can 5 is made of, for example, Al. In addition, the positive electrode can 5 has a generally flat plate shape, and has a planar shape formed by the shape of a track of a motion field on a plane parallel to the bottom surface. The positive electrode can 5 accommodates the wound body 1, the positive electrode tab 2, the negative electrode tab 3, and the insulating member 4.

  The lid body 6 is made of, for example, Al and has an outer shape made up of the shape of a track on the sports field. Then, the lid 6 is fitted to the open end of the positive electrode can 5.

  The vent 7 is provided on the lid body 6. The vent 7 is used for extracting gas from the positive electrode can 5. The negative electrode terminal 8 is provided on the lid body 6 via an insulator (not shown), and is connected to the other end of the negative electrode tab 3. The injection port 9 is provided in the lid body 6. The injection port 9 is a port for injecting the electrolytic solution into the wound body 1.

  FIG. 2 is a cross-sectional view of the wound body 1 taken along the line II-II shown in FIG. Referring to FIG. 2, wound body 1 includes a positive electrode 11, a negative electrode 12, and a separator 13.

  The negative electrode 12 has a wider width than the positive electrode 11, and the separator 13 has a wider width than the negative electrode 12. The positive electrode 11 is disposed such that both ends are located inside the both ends of the negative electrode 12. The negative electrode 12 is arranged such that both ends are located inside the both ends of the separator 13. A separator 13 is disposed on the outermost periphery of the wound body 1. And the positive electrode 11 and the negative electrode 12 are wound through the separator 13, and the wound body 1 is produced. A tape 20 is attached to the bottom surface of the wound body 1.

  The positive electrode 11 includes a positive electrode current collector and a positive electrode active material layer. The positive electrode current collector is made of, for example, an Al foil and has a strip shape.

  The positive electrode active material layer is formed by, for example, applying a slurry prepared by mixing a positive electrode active material and a binder to the surface of the positive electrode current collector, drying the applied slurry, and then pressing in the thickness direction. It is formed. The slurry is applied by, for example, a doctor blade method or a spray method. Moreover, the slurry may further contain a conductive material as necessary.

The positive electrode active material is composed of, for example, LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiNi _1/3 Co _1/3 Mn _1/3 O, LiFePo _4, or the like.

  Binders include fluorine resins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF), rubber resins such as styrene butadiene rubber (SBR) and ethylene propylene diene multiblock polymer, and cellulose such as carboxymethyl cellulose (CMC). It consists of a resin.

  The conductive material is made of a carbon material such as acetylene black (AB), ketjen black (KB), graphite, and amorphous carbon. These conductive materials may be used alone or in combination.

  The negative electrode 12 includes a negative electrode current collector and a negative electrode active material layer. The negative electrode current collector is made of, for example, Cu foil and has a strip shape.

  The negative electrode active material layer is formed, for example, by applying a slurry obtained by mixing a negative electrode active material and a binder into a paint onto the surface of the negative electrode current collector, drying the applied slurry, and then pressing in the thickness direction. It is formed. The slurry is applied by the above-described doctor blade method, spray method, or the like. Moreover, the slurry may further contain a conductive material as necessary.

The negative electrode active material occludes and releases lithium (Li) such as metals that can be alloyed with Li, such as Sn and Si, metallic lithium, LiAl alloys, amorphous carbon, artificial graphite, natural graphite, fullerene, and nanotubes. It consists of lithium titanate that can occlude and release Li, such as a possible carbon-based material, Li ₄ Ti ₅ O ₁₂ and Li ₂ Ti ₃ O ₇ .

  The binder is made of any one of PTFE, PVDF, SBR, carboxymethylcellulose (CMC), and the like. These binders may be used alone or in combination.

  The conductive material is made of a carbon material such as AB, KB, and amorphous carbon. These conductive materials may be used alone or in combination.

  There is no restriction | limiting in particular about the separator 13, A conventionally well-known thing is applied as the separator 13. FIG. For example, a microporous polyethylene film or a microporous polypropylene film having a thickness of 5 to 30 μm and a porosity of 30 to 70%, a polyethylene polypropylene composite film, or the like is preferably used as the separator 13. And when the separator 13 consists of a microporous polyethylene film, it will begin to shrink at 100 degreeC (1st temperature), and a shrinkage rate larger than the shrinkage rate in 1st temperature at 125-130 degreeC (2nd temperature). Shrink at.

  Here, the first temperature is a temperature at which the shrinkage rate of the separator 13 reaches 2% or more and less than 5%, and the second temperature is a shrinkage rate of the separator 13 of 5% or more (= first temperature). The shrinkage rate is larger than the shrinkage rate of the separator 13).

Further, the shrinkage rate is defined as follows. The separator is cut into 10 cm × 10 cm in the winding direction × winding axis direction of the wound body 1 and stored in a commercially available envelope, and left in a thermostat set at, for example, T ° C. for 1 hour. Then, a separator is taken out from a thermostat and the dimension x of a winding axis direction is measured. Then, the shrinkage rate is defined by the following equation using the measured dimension x and the dimension before being left in the thermostatic chamber.
Shrinkage rate (%) = 100 × (10−x) / 10 (1)
The temperature T is a temperature detected as a temperature at which the shrinkage rate of the separator 13 becomes 2% or more by repeating the experiment in which the separator 13 is left in the thermostatic bath for 1 hour while changing the temperature of the thermostatic bath.

  The first temperature (100 ° C.) and the second temperature (125 to 130 ° C.) described above are temperatures when the separator 13 is made of a microporous polyethylene film, and the separator 13 is other than the microporous polyethylene film. In the case of the material, the first temperature is a temperature different from 100 ° C., and the second temperature is a temperature different from 125 to 130 ° C. However, even when the separator 13 is made of a material other than the microporous polyethylene film, the first temperature and the second temperature can be determined according to the above-described definition using the shrinkage rate described above. Therefore, regardless of the material, the separator 13 starts to shrink at the first shrinkage rate (shrinkage rate of 2% or more and less than 5%) when reaching the first temperature, and reaches the second temperature when reaching the second temperature. Shrinkage at a shrinkage ratio (shrinkage ratio of 5% or more).

The electrolytic solution is made of, for example, a Li salt dissolved in an organic solvent. As the Li salt, a salt that can be dissociated in an organic solvent to generate Li ⁺ ions and does not cause a side reaction such as decomposition in the voltage range of a battery having an electrolytic solution as a constituent element is used.

Li salts include, for example, inorganic compounds such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , and LiClCO ₄ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiN (SO ₂ CF _{3) (SO 2 C 4 F} 9), LiC (SO 2 CF 2) 3, LiC (SO 2 C 2 F 5) 3, LiPF 6-n (C 2 F 5) n (n is an integer from 1 to 6 ), LiSO ₃ CF ₃ , LiSO ₃ C ₂ F ₅ , and organic compounds such as LiSO ₃ C ₄ F ₈ .

  The organic solvent is not limited as long as it can dissolve the Li salt and does not cause side reactions such as decomposition in the voltage range of the battery. Examples of the organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate, chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, cyclic esters such as γ-butyrolactone, and dimethoxyethane. Chain ethers such as diglyme, triglyme, and tetraglyme, cyclic ethers such as dioxane, tetrahydrofuran, and 2-methyltetrahydrofuran, and nitriles such as acetonitrile, propionitrile, methoxypropionitrile, and ethoxypropionitrile. Can be mentioned. These organic solvents can be used alone or in combination.

  Among these, the organic solvent is preferably a mixed solvent of ethylene carbonate and chain carbonate. If this mixed solvent is used, high electrical conductivity can be obtained and good battery characteristics can be realized.

  For the purpose of improving characteristics such as safety, cycleability, and high-temperature storage stability, the electrolyte solution is appropriately vinylene carbonates, 1,3-propane sultone, diphenyl disulfide, cyclohexane, biphenyl, fluorobenzene, and t- Additives such as butylbenzene may be included.

  In addition, instead of the organic solvent, the electrolyte solution is ethyl-methylimidazolium trifluoromethylsulfonium imide, heptyl-trimethylammonium trifluoromethylsulfonium imide, pyridinium trifluoromethylsulfonium imide, and guanidinium trifluoromethylsulfonium imide. Ordinary room temperature molten salt may be included.

  Furthermore, the electrolytic solution may be gelled with the following host polymer. As the host polymer, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyethylene oxide, polypropylene oxide, ethylene oxide-propylene oxide copolymer, a crosslinked polymer containing an ethylene oxide chain in the main chain or side chain, Examples include (meth) acrylate copolymers that can be cross-linked by light and heat and have an oxetane compound or an alicyclic epoxy compound in the side chain.

  FIG. 3 is a cross-sectional view of the wound body 1 at a high temperature of 130 ° C. or higher. As described above, the insulating member 4 has a melting point of about 100 ° C., and when the separator 13 reaches about 100 ° C., the insulating member 4 starts to shrink at a first shrinkage rate (= 2% or more and less than 5% shrinkage rate). When it reaches ˜130 ° C., it shrinks at the second shrinkage (shrinkage of 5% or more).

  Therefore, when the temperature of the nonaqueous electrolyte secondary battery 10 rises to 130 ° C. or higher, the separator 13 contracts on the lid 6 side, but reaches the portion where the insulating member 4 melts and the separator 13 contracts, and the positive electrode 11 and the negative electrode Insulators 21 to 23 are formed between the two. That is, the insulating member 4 makes the insulators 21 to 23 between the positive electrode 11 and the negative electrode 12 not only in the outer peripheral portion of the wound body 1 but also in the entire region. As a result, the positive electrode 11 is not in contact with the negative electrode 12. Therefore, a short circuit can be prevented.

  Since the tape 20 is attached to the bottom surface of the wound body 1, the separator 13 does not shrink on the bottom surface side of the wound body 1, and the positive electrode 11 and the negative electrode 12 on the bottom surface side of the wound body 1. Is not exposed. Therefore, on the bottom surface side of the wound body 1, there is no problem of short circuit due to the exposure of the positive electrode 11 and the negative electrode 12.

  When the insulating member 4 is made of an ionomer resin, the insulating member 4 has a melting point of 88 to 96 ° C. Therefore, when the insulating member 4 is made of an ionomer resin, when the temperature of the nonaqueous electrolyte secondary battery 10 is raised to 100 ° C. at which the separator 13 begins to shrink, the insulating member 4 melts, and the insulators 21 to 23 become the positive electrode 11 and the negative electrode. 12 is formed. As a result, a short circuit can be prevented even at 100 ° C. at which the separator 13 starts to shrink.

  Further, when the insulating member 4 is made of low density polyethylene, it has a melting point of 100 to 115 ° C. Therefore, when the temperature of the non-aqueous electrolyte secondary battery 10 is raised to the temperature of the heating test (= 130 ° C.), the insulating member 4 melts regardless of whether it is made of an ionomer resin or low-density polyethylene. The insulators 21 to 23 are formed between the positive electrode 11 and the negative electrode 12. As a result, a short circuit can be prevented even at the temperature during the heating test of the nonaqueous electrolyte secondary battery 10.

  Therefore, the nonaqueous electrolyte secondary battery 10 according to the embodiment of the present invention may include the insulating member 4 that melts when the separator 13 reaches the first temperature (= 100 ° C.) at which the separator 13 starts to shrink. You may provide the insulating member 4 which melt | dissolves when it reaches 2nd temperature (= 130 degreeC) higher than temperature (= 100 degreeC).

  FIG. 4 is a process diagram showing a method for manufacturing the non-aqueous electrolyte secondary battery 10 shown in FIG. Referring to FIG. 4, when the production of non-aqueous electrolyte secondary battery 10 is started, positive electrode 11, negative electrode 12 and separator 13 are produced (step S1).

  Then, one end of the tape-shaped aluminum foil is welded to the positive electrode current collector of the positive electrode 11 using a welding machine, and the tape-shaped aluminum foil is cut with a cutter at a position of a predetermined length L1 from the one end (step) S2). As a result, the positive electrode tab 2 is connected to the positive electrode 11.

  Thereafter, one end of the tape-like Ni—Cu clad steel plate is welded to the negative electrode current collector of the negative electrode 12 using a welding machine, and the tape-like Ni—Cu clad steel plate is placed at a predetermined length L1 from the one end. Cutting with a cutter (step S3). As a result, the negative electrode tab 3 is connected to the negative electrode 12.

  Subsequently, the positive electrode 11 with the positive electrode tab 2, the separator 13, and the negative electrode 12 with the negative electrode tab 3 are laminated, and the positive electrode 11 and the negative electrode 12 are wound by the winding machine through the separator 13, and tape is applied to the bottom surface of the wound body 1. 20 is pasted (step S4). Thereby, the wound body 1 is produced.

  And the winding body 1 produced in step S4 is accommodated in the positive electrode can 5 (step S5).

  Thereafter, the insulating member 4 is installed on the wound body 1 in the positive electrode can 5 so that the positive electrode tab 2 and the negative electrode tab 3 pass through the through holes 41 and 42, respectively (step S6).

  Then, the other ends of the positive electrode tab 2 and the negative electrode tab 3 respectively connected to the positive electrode 11 and the negative electrode 12 of the wound body 1 housed in the positive electrode can 5 are trimmed, and the other end of the positive electrode tab 2 is welded to the lid body 6. Then, the other end of the negative electrode tab 3 is welded to the negative electrode terminal 8 (step S7). In this case, the surface of the negative electrode tab 3 made of copper (Cu) is welded to the negative electrode terminal 8. This is because the negative electrode tab 3 is welded to the negative electrode terminal 8 by laser welding, and in laser welding, the laser cannot be applied to the surface made of copper (Cu), and the laser is applied to the surface made of nickel (Ni). This is because it is necessary to irradiate.

  Thereafter, the lid 6 is fitted into the opening of the positive electrode can 5 (step S8). Accordingly, a portion of the positive electrode tab 2 between the wound body 1 and the lid body 6 is curved, and a portion of the negative electrode tab 3 between the wound body 1 and the lid body 6 is the positive electrode can 5. It is bent so as not to contact the inner wall.

  And electrolyte solution is inject | poured into the winding body 1 from the injection port 9 (step S9). Thereby, the non-aqueous electrolyte secondary battery 10 is completed.

  FIG. 5 is a schematic view of another nonaqueous electrolyte secondary battery according to the embodiment of the present invention. The nonaqueous electrolyte secondary battery according to the embodiment of the present invention may be a nonaqueous electrolyte secondary battery 10A shown in FIG.

  Referring to FIG. 5, a non-aqueous electrolyte secondary battery 10A is obtained by adding an insulating plate 30 to the non-aqueous electrolyte secondary battery 10 shown in FIG. 1, and the other is a non-aqueous electrolyte secondary battery. 10 is the same.

  The insulating plate 30 has a melting point higher than that of the insulating member 4 and does not melt in the heating test at 130 ° C. The insulating plate 30 has through holes 301 and 302. The insulating plate 30 is disposed between the insulating member 4 and the lid body 6.

  In the non-aqueous electrolyte secondary battery 10A, the positive electrode tab 2 is connected to the lid 6 through the through hole 41 of the insulating member 4 and the through hole 301 of the insulating plate 30, and the negative electrode tab 3 is formed of the insulating member. 4 and the through hole 302 of the insulating plate 30 are connected to the negative electrode terminal 8.

  When the temperature of the nonaqueous electrolyte secondary battery 10A is raised to 130 ° C., the separator 13 of the wound body 1 contracts on the lid 6 side, the insulating member 4 melts, and the insulators 21 to 23 become the positive electrode 11. And the negative electrode 12.

  And since the insulating plate 30 does not melt even if the insulating member 4 melts, the contact between the negative electrode tab 3 and the positive electrode can 5 is suppressed.

  Therefore, in the nonaqueous electrolyte secondary battery 10A, a short circuit can be further prevented.

  In the process diagram shown in FIG. 4, the non-aqueous electrolyte secondary battery 10 </ b> A includes an insulating plate 30 between the insulating member 4 and the lid body 6 so that the positive electrode tab 2 and the negative electrode tab 3 pass through the through holes 301 and 302, respectively. Is manufactured according to the process diagram in which the step of arranging in step S6 is added between step S6 and step S7.

  The description of the other parts of the non-aqueous electrolyte secondary battery 10A is the same as the description of the non-aqueous electrolyte secondary battery 10 described above.

  In the embodiment of the present invention, the insulating member 4 may be provided also in the laminated nonaqueous electrolyte secondary battery. The laminate-type non-aqueous electrolyte secondary battery may include a wound body in which a positive electrode and a negative electrode are wound through a separator, and a laminated body in which the positive electrode and the negative electrode are stacked through a separator. May be provided.

  In the embodiment of the present invention, positive electrode can 5 and lid 6 constitute a “battery can”.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a non-aqueous electrolyte secondary battery.

  DESCRIPTION OF SYMBOLS 1 Winding body, 2 Positive electrode tab, 3 Negative electrode tab, 4 Insulating member, 5 Positive electrode can, 6 Lid body, 7 Vent, 8 Negative electrode terminal, 9 Inlet, 10,10A Nonaqueous electrolyte secondary battery, 11 Positive electrode, 12 Negative electrode, 13 separator, 20 tape, 21-23 insulator, 30 insulating plate, 41, 42, 301, 302 through hole.

Claims (4)

A battery can made of metal,
A wound body that is housed in the battery can and includes a positive electrode, a negative electrode, and a separator;
A non-aqueous electrolyte secondary battery comprising an insulating member that is disposed between the wound body and the lid of the battery can and that melts when reaching a first temperature at which the separator starts to shrink.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the insulating member melts when reaching a second temperature higher than the first temperature.   The non-aqueous electrolysis according to claim 2, wherein the second temperature is a temperature at which the shrinkage rate of the separator reaches a second shrinkage rate that is larger than the first shrinkage rate of the separator at the first temperature. Liquid secondary battery.   The insulating plate having a melting point higher than the melting point of the insulating member and further having a through hole that is disposed between the insulating member and the lid and passes through a negative electrode tab connected to the negative electrode. The nonaqueous electrolyte secondary battery according to claim 1.

Images