JP4608721B2 - Non-aqueous electrolyte secondary battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-aqueous electrolyte secondary battery.
[0002]
[Prior art]
In recent years, portable information devices such as laptop computers and word processors, AV tape devices such as camera-integrated video tape recorders, liquid crystal televisions, and mobile communication devices such as mobile phones have been remarkably developed. Therefore, a secondary battery having a small size, light weight and high energy density is required. Up to now, aqueous secondary batteries such as lead batteries, nickel cadmium batteries, and nickel metal hydride batteries have been used, but this is not sufficient for demands such as weight reduction and high energy density.
[0003]
Recently, as a clean battery having a high energy density, there has been great interest and expectation in a non-aqueous electrolyte secondary battery.
Here, a conventional non-aqueous electrolyte secondary battery will be described with reference to FIGS.
[0004]
FIG. 4A is a cross-sectional view of a conventional non-aqueous electrolyte secondary battery. In this non-aqueous electrolyte secondary battery, an electrode element 2 is accommodated in a cylindrical bottomed outer can 1, and a non-aqueous electrolyte (not shown) is injected into the outer can 1. The electrode element 2 is impregnated with the electrolytic solution.
[0005]
The electrode element 2 is formed by laminating a film-like positive electrode and a negative electrode via a film-like separator, and the laminated film is wound around, for example, a cylindrical core.
[0006]
Insulating thin plates are arranged on both sides of the electrode element 2, and the free ends of the leads 9 and 10 of the electrode element 2 are led out to the outside. The free end of the negative electrode lead 10 is welded to the bottom surface of the outer can 1 serving as an electrode terminal lead-out portion.
[0007]
The lid 7, the PTC element 3, and the safety valve 6 are caulked on one end side of the outer can 1 via a gasket 8 and sealed. Thereby, the cover body 7, the PTC element 3, and the safety valve 6 are electrically connected.
[0008]
The safety valve 6 is formed with a protrusion 6a at the center thereof that protrudes toward the electrode element 2 side. The protrusion 6 a is welded to the sub disk 4 through the center hole 11 c of the disk 11. As a result, the protrusion 6 a is electrically connected to the sub disk 4.
[0009]
The disk 11 is fixed inside the safety valve 6 via a disk holder 12.
Here, the shape of the disk 11 will be described in detail. FIG. 4B is a plan view of a disk used in a conventional nonaqueous electrolyte secondary battery.
[0010]
In FIG. 4B, the outer edge portion 11a is a belt-like plate that is a part of the disk 11 and whose outer side forms a circle. Further, the outer edge portion 11 a itself is fixed to the gasket 8 to support the entire disk 11.
[0011]
The concave portion 11b is a part of the disk 11, and the shape thereof is a flat plate and is continuous with the outer edge portion 11a.
The disk 11 has a center hole 11c. The center hole 11 c is a circular hole centered on the symmetry point of the disk 11.
The outer peripheral hole 11d is a substantially rectangular hole having a semicircular portion on the side of the central hole 11c, and the central axis thereof faces the radial direction.
[0012]
The sub disk 4 shown in FIG. 4A is a thin disk, and is welded to the center of the disk 11 and the electrode element 2 side of the disk 11.
A positive electrode lead 9 is welded to the electrode element 2 side of the sub disk 4.
Thereby, the sub disk 4 and the positive electrode lead 9 are electrically connected.
[0013]
Next, the operation of the safety valve used in the conventional nonaqueous electrolyte secondary battery will be described with reference to FIG. Here, the safety valve has two mechanisms, a current interruption mechanism and a cleavage mechanism.
First, before explaining the current interruption mechanism and the cleavage mechanism, the normal state of the safety valve will be explained. FIG. 2A is a cross-sectional view showing the state of the safety valve 6 in a normal state for a conventional nonaqueous electrolyte secondary battery.
[0014]
In FIG. 2A, although the sub disk 4 blocks the center hole 11c of the disk 11, the diameter of the sub disk 4 is small, so that the outer hole 11d provided near the outer periphery of the disk 11 is not blocked. Thus, since the outer peripheral hole 11d of the disk 11 is not blocked, the gas present in the battery can pass through. On the other hand, since the safety valve 6 does not have a hole, the gas present in the battery cannot be discharged to the outside and is kept airtight.
[0015]
Next, the operation of the current cutoff mechanism of the safety valve will be described. FIG. 5B is a cross-sectional view showing the function of the safety valve in a current interruption state for a conventional nonaqueous electrolyte secondary battery.
[0016]
When gas is generated in the outer can 1 for some reason, the internal pressure increases. At this time, the generated gas passes through the outer peripheral hole 11 d of the disk 11 and applies pressure to the inner surface of the safety valve 6. As a result, the safety valve 6 is deformed outward.
[0017]
Due to the deformation of the safety valve 6, in the welded portion between the projection 6 a of the safety valve 6 and the subdisk 4, the subdisk 4 existing around the welded portion is torn off by the shearing force. Thus, the electrical connection between the positive electrode lead 9 and the lid body 7 is cut by separating the protrusion 6a and the sub disk 4 from each other.
[0018]
Next, the operation of the safety valve tearing mechanism will be described. FIG. 2C is a cross-sectional view showing the operation of the safety valve in a cleaved state for a conventional nonaqueous electrolyte secondary battery.
When the pressure in the outer can 1 becomes higher than the pressure in the above-described current interruption state, the safety valve 6 itself is cleaved. Thus, when the safety valve 6 is cleaved, the gas generated inside the battery first passes through the outer peripheral hole 11d of the disk 11, then passes through the cleaving portion 6b of the safety valve 6, and further passes through the vent hole 7a of the lid body 7. Passed and released to the outside.
[0019]
[Problems to be solved by the invention]
Here, the generated gas can easily pass through the cleavage portion 6 b of the safety valve 6. However, in the disk 11, only the outer peripheral hole 11d can pass gas, and it is difficult to pass gas.
[0020]
As a solution to this, it is conceivable to increase the opening area of the outer peripheral hole 11d. However, if the opening area is increased, it becomes difficult to ensure the mechanical strength of the disk 11 itself. In order to ensure this mechanical strength, it is conceivable to increase the thickness of the disk 11, but the capacity of the battery must be reduced by increasing the thickness. Therefore, it is practically difficult to increase the opening area of the outer peripheral hole 11d.
[0021]
As a result, when gas is generated in the outer can 1, the conventionally used disk has a problem that the generated gas cannot be released to the outside in a short time.
[0022]
This invention is made | formed in view of such a subject, and it aims at providing the nonaqueous electrolyte secondary battery which can release gas in a short time at the time of cleavage of a safety valve.
[0023]
[Means for Solving the Problems]
Nonaqueous electrolyte secondary battery of the present invention, an electrode element, a cylindrical outer can in which the electrode element is housed,
A safety valve provided on one end side of the cylindrical outer can and a thin plate-like disk fixed inside the safety valve via a disk holder. The safety valve has a protrusion at the center, and the protrusion is connected to the lead of the electrode element through the center hole of the disk. The disc is an outer peripheral hole made up of a plurality of cutout holes provided on the outer periphery of the disc, and is thinner than the other portions in the disc, and continues through the outer peripheral hole along the circumference centering on the central hole. And a thin portion formed in a linear shape. A separation portion surrounded by the thin portion and the outer peripheral hole is provided in the disc, and the disc and the separation portion can be opened in the outer peripheral hole continuous with the thin portion and the thin portion.
[0024]
The non-aqueous electrolyte secondary battery of the present invention includes a thin disk-shaped sub-disk welded to the center of the disk on the electrode element side. The sub disk has a safety valve protrusion welded to the disk side surface and a lead free end welded to the electrode element side surface .
[0025]
According to the non-aqueous electrolyte secondary battery of the present invention, since the disk has a linear thin portion, the gas passage area when the safety valve is opened increases.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the invention relating to a non-aqueous electrolyte secondary battery will be described with reference to FIGS.
First, the configuration of the nonaqueous electrolyte secondary battery according to the present embodiment will be described. FIG. 1A is a cross-sectional view of the nonaqueous electrolyte secondary battery according to the present embodiment. This embodiment is a case where a lithium-doped lithium secondary battery comprising a non-aqueous electrolyte comprising a material capable of doping and undoping lithium in a positive electrode and / or a negative electrode and a non-aqueous electrolyte is provided. The present invention is not limited to this embodiment and the example of FIG. 1A.
[0027]
In this embodiment, an electrode element 2 is accommodated in an iron cylindrical bottomed outer can 1 plated with nickel (Ni), and a nonaqueous electrolyte (not shown) is contained in the outer can 1. The electrode element 2 is impregnated with this nonaqueous electrolytic solution.
The outer can 1 is not limited to a cylindrical one as described above. In addition, other cylindrical batteries such as a square may be used.
[0028]
The electrode element 2 is formed by laminating a film-like positive electrode and a negative electrode via a film-like separator, and the laminated film is wound around, for example, a cylindrical core.
[0029]
The positive electrode and the negative electrode of the electrode element 2 are respectively formed by applying a positive electrode active material and a negative electrode active material on both surfaces of a strip-shaped current collector foil made of, for example, an aluminum (Al) foil and a copper (Cu) foil.
[0030]
One end of the positive electrode lead 9 made of Al and the negative electrode lead 10 made of Ni is welded from the opposite ends of the respective current collector foils of each positive electrode and negative electrode, and as shown in FIG. A positive electrode lead 9 is led out from the electrode element 2 from the center of the element 2, and a negative electrode lead 10 is led out from the outer peripheral side of the electrode element 2.
[0031]
The electrode element 2 is inserted into the outer can 1 with the lead-out side of the negative electrode lead 10 being the bottom side of the outer can 1.
Insulating thin plates are arranged on both sides of the electrode element 2, and the free ends of the leads 9 and 10 of the electrode element 2 are led out to the outside. And the free end of the negative electrode lead 10 is welded to the bottom face of the armored can 1 used as an electrode terminal derivation | leading-out part, for example.
[0032]
In the electrode element 2 described above, the positive electrode active material of the positive electrode is, for example, a material that can be dedoped or redoped with Li, for example, an active material Li _x MO ₂ (M is Co, Ni, Mn Of these, at least one kind of transition metal is preferably a complex oxide represented by 0.4 ≦ x ≦ 1.1), among which LiCoO ₂ , LiNiO ₂ , LiMn ₂ O _{4 and the} like are preferable. Such a lithium transition metal oxide is prepared by mixing, for example, Li, Co, Ni, Mn carbonates, nitrates, oxides, hydroxides, and the like in amounts corresponding to the composition, It is obtained by firing in a temperature range of 1000 ° C.
[0033]
The negative electrode active material of the negative electrode is, for example, a material that can be doped or dedoped with Li, for example, a low crystalline carbon material obtained by firing at a relatively low temperature of 2000 ° C. or less, or a material that is easily crystallized, and is close to 3000 ° C. Highly crystalline materials such as artificial graphite and natural graphite processed at a high temperature are used. For example, pyrolytic carbons, cokes, graphites, glassy carbons, organic polymer compound fired bodies (furan resin etc. fired at a suitable temperature and carbonized), carbon fiber, activated carbon, etc. can be used. is there.
[0034]
The low crystalline carbon material is preferably carbonized by firing furan resin or petroleum pitch at less than 1500 ° C., and has a (002) plane spacing of 3.70 angstroms or more by the wide angle X-ray diffraction method. A carbonaceous material having a density of less than 1.70 g / cm ³ and having no exothermic peak at 700 ° C. or higher by differential thermal analysis in an air stream is used. As the graphite powder, a carbonaceous material having a (002) plane spacing of less than 3.42 angstroms by wide angle X-ray diffraction is preferably used. These carbonaceous materials are materials that have a large amount of Li doping and dedoping and have excellent charge / discharge cycle life performance, and the negative electrode material is most suitable for the equipment to be used in combination with the positive electrode material. A combination can be selected.
[0035]
The separator can be composed of, for example, a microporous film of polyethylene, polypropylene, or Teflon.
[0036]
The nonaqueous electrolytic solution is composed of an organic solvent and an electrolyte dissolved in the organic solvent. Alternatively, a so-called polymer electrolyte in which a nonaqueous electrolytic solution is mixed with a polymer compound, or a polymer electrolyte in which an electrolyte is mixed or bonded to a polymer compound can also be used.
Examples of the organic solvent include cyclic carbonates such as ethylene carbonate and propylene carbonate, chain carbonates such as dimethyl carbonate and diethyl carbonate, cyclic esters such as γ-butyrolactone and γ-parerolactone, and chain esters such as ethyl acetate and methyl propionate. One or more of ethers such as tetrahydrofuran, 1,2-dimethoxyethane and the like can be used.
As the electrolyte, lithium salts that dissolve in the solvent to be used and exhibit ionic conductivity, such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ 1 or more types can be used.
[0037]
The lid 7, the PTC element 3, and the safety valve 6 are caulked on one end side of the outer can 1 via a gasket 8 and sealed. That is, for example, a lid 7 serving as a positive electrode side terminal lead portion made of stainless steel, Ni, Fe, for example, a ring-shaped PTC element 3 having a positive temperature characteristic, and a safety valve 6 made of Al, for example, disposed inside the gasket 8 Is sealed by being crimped to the open end of the outer can 1. Thereby, the cover body 7, the PTC element 3, and the safety valve 6 are electrically connected.
[0038]
The safety valve 6 is formed with a protrusion 6a at the center thereof that protrudes toward the electrode element 2 side. The protrusion 6a is welded to the sub disk 4 (detailed later) through a center hole 11c of the disk 11 (detailed later). As a result, the protrusion 6 a is electrically connected to the sub disk 4.
[0039]
The disk 11 is fixed inside the safety valve 6 via a disk holder 12. The disk 11 is made of a metal plate such as Al. The disc holder 12 has a function of electrically insulating the safety valve 6 and the disc 11.
[0040]
Here, the shape of the disk 11 will be described in detail. FIG. 1B is a plan view of a disk used in the nonaqueous electrolyte secondary battery according to the present embodiment.
The outer edge portion 11a of the disk 11 is a strip-shaped plate that is a part of the disk 11 and whose outer side forms a circle. Further, the outer edge portion 11 a itself is fixed to the gasket 8 to support the entire disk 11.
[0041]
The outer peripheral part 11f and the separating part 11g are a part of the disk 11, and are continuous plates via a thin part 11e (described in detail later). Moreover, this outer peripheral part 11f and the isolation | separation part 11g are following the outer edge part 11a, and form the recessed part in the electrode element 2 side from the outer edge part 11a.
[0042]
The disk 11 has a center hole 11c. The center hole 11 c is a circular hole centered on the symmetry point of the disk 11, and is formed in the separation part 11 g of the disk 11. Further, the center hole 11c has a function of allowing the protrusion 6a of the safety valve 6 to pass through.
[0043]
11 d of outer peripheral holes are formed in six places over the outer peripheral part 11f, the thin part 11e, and the isolation | separation part 11g. The outer peripheral hole 11d is a substantially rectangular hole having a semicircular portion on the center hole 11c side, and the center axis thereof is directed in the radial direction. Further, the outer peripheral hole 11d has a function of allowing gas generated in the battery (described in detail later) to pass therethrough.
[0044]
The disk 11 has a linear thin portion 11e. The thin portion 11e is substantially along a circle centered on the symmetry point of the center hole 11c. The thin portion 11e intersects the outer peripheral hole 11d.
[0045]
In addition, the position of the thin part 11e is not necessarily limited to the above-mentioned position. That is, it is preferable that the thin part 11e is outside the sub-disk 4 and inside the outermost part of the outer peripheral part 11f. This is because if the thin portion 11e is inside the sub-disk 4, shearing of the thin portion 11e is impossible, and if the thin portion 11e is outside the outermost periphery of the outer peripheral portion 11f, the thin portion 11e is sheared. Because it becomes impossible.
[0046]
Moreover, it does not ask | require whether the thin part 11e itself has crossed the outer peripheral hole 11d as mentioned above, or has formed the perfect circle without intersecting with the outer peripheral hole. Further, the thin portion 11e is not limited to the circular shape as described above. In short, any shape can be adopted as long as the separating portion 11g can be separated from the outer peripheral portion 11f.
[0047]
Moreover, the thickness of the thin part 11e is 0.2 mm. On the other hand, the thickness of the outer peripheral part 11f and the separation part 11g is 0.4 mm. In addition, although 0.2 mm was employ | adopted as the thickness of the thin part 11e here, it is not necessarily limited to this thickness. Of course, the thickness can be appropriately changed depending on the value of the pressure to be cleaved. Furthermore, the thickness of the thin portion 11e is not only uniform over the entire thin portion, but also by making the thickness different for a part of the thin portion, it is possible to provide a portion where cleavage is likely to occur.
[0048]
Next, the sub disk 4 will be described with reference to FIG. 1A. The sub disk 4 is a thin disk having a thin shape, and is made of a metal such as Al. The sub disk 4 is welded to the center of the disk 11 and to the electrode element 2 side of the disk 11.
The free end of the positive electrode lead 9 is welded to the surface of the sub disk 4 on the electrode element 2 side. Thereby, the sub disk 4 and the positive electrode lead 9 are electrically connected. As a result, the protrusion 6 a of the safety valve 6 is electrically connected to the positive electrode lead 9.
[0049]
Next, the operation of the safety valve and the disk used in the nonaqueous electrolyte secondary battery according to the present embodiment will be described. Here, the safety valve has two mechanisms, a current interruption mechanism and a cleavage mechanism. The disc also has a cleavage mechanism.
[0050]
First, before explaining the current interruption mechanism and the cleavage mechanism, the normal state of the safety valve and the disc will be explained. FIG. 2A is a cross-sectional view showing the state of the safety valve 6 and the disk 11 in a normal state for the non-aqueous electrolyte secondary battery according to the present embodiment. FIG. 2A shows the upper part of FIG. 1A.
[0051]
In FIG. 2A, although the sub disk 4 blocks the center hole 11c of the disk 11, the diameter of the sub disk 4 is small, so that the outer hole 11d provided near the outer periphery of the disk 11 is not blocked. Further, since the outer peripheral hole 11d of the disk 11 is not blocked as described above, the gas present in the battery can pass through. On the other hand, since the safety valve 6 does not have a hole, the gas present in the battery cannot be discharged to the outside and is kept airtight. This state is the normal state of FIG. 2A.
[0052]
Next, the operation of the current cutoff mechanism of the safety valve will be described. FIG. 2B is a cross-sectional view showing the operation of the safety valve in the current interruption state for the nonaqueous electrolyte secondary battery according to the present embodiment.
[0053]
When gas is generated in the outer can 1 for some reason, the internal pressure increases. At this time, the generated gas passes through the outer peripheral hole 11 d of the disk 11 and applies pressure to the inner surface of the safety valve 6. As a result, the safety valve 6 is pushed outward and bulges outward and deforms. Due to this deformation, the internal volume of the battery increases, and the internal pressure can be relaxed accordingly.
[0054]
Due to the deformation of the safety valve 6, in the welded portion between the projection 6 a of the safety valve 6 and the subdisk 4, the subdisk 4 existing around the welded portion is torn off by the shearing force. Thus, the electrical connection between the positive electrode lead 9 of the electrode element 2 and the lid body 7 is cut by separating the protrusion 6a from the sub disk 4. That is, the positive electrode lead 9 is electrically connected to the safety valve 6 through the sub disk 4 and the protrusion 6a, and further through the PTC element 3 and the lid 7, but the sub disk 4 and the protrusion 6a are connected as described above. By separating, the electrical connection between the positive electrode lead 9 and the lid 7 is also disconnected.
[0055]
Here, the deformation of the safety valve 6 will be described in more detail. As can be seen from FIG. 2B, when the safety valve 6 deforms, it deforms greatly at 6k and 6l. That is, it is 6k which is the outermost periphery of the flat area inside the safety valve 6, and 6l very close to the projection part 6a. The portions other than these, that is, the protruding portion 6a are hardly deformed, and the flat portion outside the protruding portion 6s is only slightly deformed.
[0056]
Further, as can be seen from FIG. 2B, the distance between the bending points 6k and 6l is large. Therefore, the protrusion 6 a is greatly separated from the sub disk 4 due to the deformation of the safety valve 6. As described above, since the protruding portion 6a and the sub disk 4 are largely separated from each other, there is an effect that current interruption can be reliably performed.
[0057]
Next, the operation of the safety valve tearing mechanism will be described. FIG. 2C is a cross-sectional view showing the functions of the safety valve and the disc in the cleaved state of the nonaqueous electrolyte secondary battery according to the present embodiment.
When the pressure in the outer can 1 becomes higher than the pressure in the above-described current interruption state, the safety valve 6 itself is cleaved.
As described above, when the safety valve 6 is cleaved but the disk 11 is not cleaved, the gas generated inside the battery first passes through the outer peripheral hole 11d of the disk 11 and then the cleaved portion of the safety valve 6. 6 b passes through the vent hole 7 a of the lid 7 and is released to the outside.
[0058]
Next, the operation of the disc tearing mechanism will be described with reference to FIG. 2C.
When the pressure becomes higher than the pressure at which the safety valve tearing mechanism operates, the disk 11 tearing mechanism operates. That is, the separation part 11 g of the disk 11 is separated from the disk 11. Thereby, the separation part 11g floats, and the cleavage part 11h is made around this separation part 11g. As a result, the gas generated inside the battery can simultaneously pass through the cleaved portion 11h of the disk 11 in addition to the outer peripheral hole 11d of the disk. Further, the generated gas passes through the cleaving portion 6b of the safety valve 6, and then passes through the vent hole 7a of the lid 7 and is released to the outside.
[0059]
Here, how the disk 11 is cleaved will be described in detail with reference to FIG. FIG. 3 is a plan view showing a state of the disc used in the nonaqueous electrolyte secondary battery according to the present embodiment in a cleaved state.
When gas is generated inside the battery, the gas first passes through the outer peripheral hole 11 d of the disk 11. Furthermore, when the gas pressure increases, a large pressure acts on the surface of the separation portion 11g on the electrode element 2 side. When such a large pressure acts, a large shear stress acts on the thin portion 11 e of the disk 11. Here, since the thin part 11e is mechanically weakest, it is easily sheared by this shearing force. As a result, the separation unit 11g is separated from the disk 11 in the state shown in FIG. 3B. And the cleavage part 11h is formed in the part which was the thin part 11e among the circumference | surroundings of this isolation | separation part 11g.
[0060]
As described above, when the disk 11 is cleaved, the gas passage area when the safety valve is cleaved increases. In the above description, the disc is cleaved after the safety valve is cleaved, but the order is not limited. In other words, depending on the state of pressure generation inside the battery, the disc may be cleaved simultaneously with the cleaving of the safety valve. In any of these states, the disk cleaving mechanism works effectively, and the gas passage area can be increased. As a result, the gas can be released in a short time when the safety valve is opened.
[0061]
When the disk is torn, the separation part of the disk may come into contact with the safety valve and be electrically connected by rising from the disk. However, when gas is released to the outside from the battery, the battery itself is in a state where it cannot function as a battery, so a problem arises even if the separation part and the safety valve are electrically connected. Absent.
Moreover, although the above-mentioned embodiment demonstrated the cylindrical non-aqueous electrolyte secondary battery, the application range of this invention is not limited to this cylindrical non-aqueous electrolyte secondary battery. That is, of course, the present invention can be applied to other batteries having a pressure release mechanism.
Further, the present invention is not limited to the above-described embodiments, and various other configurations can be adopted without departing from the gist of the present invention.
[0062]
【The invention's effect】
The present invention has the following effects.
Since the disc has a linear thin portion, the gas can be released in a short time when the safety valve is opened.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a non-aqueous electrolyte secondary battery according to the present invention and a plan view of a disk used in the non-aqueous electrolyte secondary battery.
FIG. 2 is a cross-sectional view showing the functions of a safety valve and a disk in a normal state, a current interruption state, and a cleavage state for a nonaqueous electrolyte secondary battery according to the present invention.
FIG. 3 is a plan view showing a state of a disk used in the nonaqueous electrolyte secondary battery according to the present invention in a cleaved state.
FIG. 4 is a cross-sectional view of a conventional non-aqueous electrolyte secondary battery and a plan view of a disk used in the non-aqueous electrolyte secondary battery.
FIG. 5 is a cross-sectional view showing the function of a safety valve in a normal state, a current interruption state, and a cleavage state, for a conventional nonaqueous electrolyte secondary battery.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Exterior can, 2 ... Electrode element, 3 ... PTC element, 4 ... Sub disk, 6 ... Safety valve, 6a ... Projection part, 6b ... Cleavage part, 7 ... Cover, 7a ... Vent hole, 8 ... Gasket, 9 ... Positive electrode lead, 10 ... Negative electrode lead, 11 ... Disc, 11a ... Outer edge, 11b ... Recess, 11c ... Center hole, 11d ... Outer hole, 11e ... ... Thin part, 11f ... Outer peripheral part, 11g ... Separation part, 11h cleavage part, 12 ... Disc holder

Claims (7)

An electrode element;
A cylindrical outer can containing the electrode element;
A safety valve provided on one end of the cylindrical outer can,
A thin plate-like disc fixed to the inside of the safety valve via a disc holder,
The safety valve has a protrusion at the center,
The protrusion is connected to the lead of the electrode element through the center hole of the disk;
The disc has an outer peripheral hole composed of a plurality of cutout holes provided on the outer periphery of the disc;
A thin part formed in a linear shape through the outer peripheral hole along the circumference centered on the central hole, thinner than other parts in the disk,
A separation part surrounded by the thin part and the outer peripheral hole is provided in the disk,
The disk and the separating portion can be opened in the thin hole and the outer peripheral hole continuous with the thin portion.
Non-aqueous electrolyte secondary battery. The non-aqueous electrolyte secondary battery according to claim 1, wherein the outer peripheral hole is a substantially rectangular hole having a semicircular portion on the side of the center hole, and the center axis faces the radial direction. A thin disk-shaped sub-disk welded to the center of the disk on the electrode element side of the disk, the sub-disk being welded with the protrusion of the safety valve on the disk-side surface; The non-aqueous electrolyte secondary battery according to claim 1, wherein a free end of the lead is welded to the battery. The non-aqueous electrolyte secondary battery according to claim 3, wherein the sub disk has a smaller diameter than the disk. The non-aqueous electrolyte secondary battery according to claim 4, wherein the thin portion is provided outside a portion where the sub disk is welded. The nonaqueous electrolyte secondary battery according to claim 5, wherein a sub-disk existing around the welded portion is configured to be openable at a welded portion between the protrusion of the safety valve and the sub-disk. 2. The nonaqueous electrolyte secondary battery according to claim 1, wherein an outer edge portion of a circular belt-like plate is provided outside the disk, and the outer edge portion is fixed to a gasket .

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