JPH10172528A - Non-aqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a non-aqueous electrolyte battery whose safety valve occupies a smaller space, the electrical contact between the safety valve and the positive pole terminal is good, and the leakage-resistance is excellent due to the compression of the gasket by the safety valve. SOLUTION: The safety valve 2 is composed of a cap plate 5 provided with a penetrating hole 5, a torn-open film 6 plugging the penetrating hole 5a of this cap plate 5, and a reinforcement ring 7. At least two steps 5b and 5c are provided around the penetrating hole 5a in the cap plate 5, and the torn-open film 6 and the reinforcement ring 7 are stored on the step 5b which is the first step from the penetrating hole side in the cap plate 5. The step 5c of far-outer periphery of the cap plate 5b is brought into contact with a flat periphery 3c of the positive pole terminal 3, and the positive pole terminal 3 is electrically connected with a safety valve 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-aqueous electrolyte battery, and more particularly to an improvement of a safety valve for releasing an internal pressure when the internal pressure of the battery generated during an abnormal reaction increases.

[0002]

2. Description of the Related Art In recent years, non-aqueous electrolyte batteries have been used as a power supply for various electronic devices, particularly portable electronic devices, because of their light weight, high potential, high performance, and long life. It has become.

This non-aqueous electrolyte battery uses a lithium salt as an electrolyte salt. As an example, a lithium manganese dioxide battery using lithium or a lithium alloy as a negative electrode active material and manganese dioxide as a positive electrode active material is known. Have been. This lithium manganese dioxide battery is used, for example, as a cylindrical battery in a camera or the like.

In such a non-aqueous electrolyte battery, if the battery is used improperly, such as charging at a high voltage, an abnormal reaction occurs in the battery, and the battery temperature and internal pressure rise. I will. If this temperature rise and internal pressure rise are left unchecked, the battery can may expand or even burst.

Therefore, in such a non-aqueous electrolyte battery,
In order to prevent the internal pressure of the battery from excessively rising, a safety valve for releasing the internal pressure when the internal pressure of the battery exceeds a predetermined internal pressure is usually provided.

The safety valve has a through-hole 11a as shown in FIG. 7 (a), and a tear film 12 for closing the through-hole 11a of the cover plate 11 is provided on a cover plate 11 whose outer peripheral side stands upright.
7B, the outer peripheral edge of the cover plate 11 is folded inward, as shown in FIG. 7B, so that the outer peripheral edges of the split membrane 12 and the reinforcing ring 13 are covered with the cover plate. 11 is pressed down. The cleavage membrane 1
Reference numeral 2 denotes a laminated film in which a plastic is coated on the surface of a metal foil, and has a strength such that the film is split when a predetermined pressure is applied.

[0007] In order to incorporate such a safety valve into a cylindrical battery, an opening of a cylindrical battery can accommodating a power generating element is provided.
The safety valve and the positive electrode terminal provided with the exhaust hole are applied via an insulating gasket, and caulked and hermetically sealed.

In the cylindrical battery incorporating the safety valve, when the internal pressure of the battery rises, the cleavage membrane 12 expands toward the positive electrode terminal and breaks when the pressure exceeds a predetermined pressure. As a result, the gas in the battery can passes through the through hole of the cover plate and the exhaust hole of the positive electrode terminal and is exhausted to the outside, so that the battery can is prevented from being ruptured due to an increase in internal pressure.

[0009]

However, when such a safety valve is incorporated in a battery, the safety valve occupies a large volume in the battery can, and the effective volume in which the electrode can be accommodated decreases accordingly. This is disadvantageous in improving the battery capacity.

In such a battery, the positive electrode in the battery can is connected to the positive terminal via the cover plate 11 of the safety valve, and the connection between the cover plate 11 and the positive terminal is made by the folded portion 11b of the cover plate 11. And the outer peripheral edge of the positive electrode terminal. In the case of contact between the folded portion 11b and the outer peripheral edge of the positive electrode terminal, a sufficient contact area cannot be obtained, which causes a reduction in load characteristics of the battery.

In addition, in this safety valve, the step of turning back the cover plate 11 is very complicated, and the turn-back portion 11
Since a is curved, the gasket cannot be sufficiently compressed during the caulking step. For this reason, there is a problem that the hermeticity of the battery is reduced, and the electrolyte is likely to leak.

In view of the above, the present invention has been proposed in view of such a conventional situation, and the volume occupied by the safety valve is small, and the contact area between the cover plate of the safety valve and the positive electrode terminal is sufficiently ensured. Still another object of the present invention is to provide a non-aqueous electrolyte battery in which a gasket is sufficiently compressed by a safety valve and has excellent liquid leakage resistance.

[0013]

In order to achieve the above-mentioned object, a nonaqueous electrolyte battery according to the present invention has a negative electrode and a positive electrode housed in a battery can having an opening. At the end, a safety valve that closes the opening of the battery can and releases the internal pressure when the battery can exceeds a predetermined internal pressure,
A non-aqueous electrolyte battery in which a positive electrode terminal having an exhaust hole is attached via an insulating gasket, wherein the safety valve includes a cover plate having a through hole, and a cleaving plug for closing the through hole of the cover plate. The cover plate has at least two steps around the through hole, and the cleaved membrane and the reinforcing ring are located on the first step from the through hole side of the cover plate. It is characterized by being stored in.

In this non-aqueous electrolyte battery, at least two steps are formed on the cover plate of the safety valve, so that the strength is obtained as compared with a cover plate having a small step. Therefore, even when the thickness of the lid plate is reduced to some extent, the external force applied at the time of caulking of the battery can be sufficiently endured, and the occupied volume of the safety valve is reduced by such a thin plate thickness.

Further, in this safety valve, the cleavage membrane and the reinforcing ring are accommodated in the first step of the cover plate, and the step on the outer peripheral side thereof and the positive electrode terminal are joined to each other so that the cover plate and the reinforcing plate are joined together. The positive terminal is conducted.

That is, in this safety valve, conduction with the positive electrode terminal can be achieved without turning the peripheral portion of the lid plate, so that a complicated turning step is unnecessary and the manufacturing process of the safety valve can be simplified. In addition, the occupied volume is reduced by the absence of the folded portion.

Further, in such an electrical contact between the stepped portion of the cover plate and the flat portion of the positive electrode terminal, a good contact state can be obtained, and the electrical resistance can be easily reduced by controlling these contact areas. Can be Therefore, the load characteristics of the battery are improved.

[0018]

Embodiments of the present invention will be described below.

The non-aqueous electrolyte battery of this embodiment is shown in FIG.
As shown in FIG. 1, a spiral electrode element 4 is accommodated in a battery can 1 having an opening, and the opening of the battery can 1 is
And sealed by the positive electrode terminal 3.

The battery can 1 is formed in a cylindrical shape, one end of the cylinder is closed, and the other end is an opening. The battery can 1 is made of, for example, iron plated with nickel or the like having high thermal conductivity, and the outer peripheral surface of the cylinder is covered with an insulating outer label.

In this battery can 1, a spiral electrode element 4 composed of a negative electrode and a positive electrode is accommodated.

For the negative electrode, a belt-like lithium foil or lithium alloy foil is used. One end of a negative electrode lead (not shown) is welded to the negative electrode, and the other end of the negative electrode lead is welded to the battery can.

For the positive electrode, MnO _{2 or the} like is used as an active material. In order to form a positive electrode using this active material, a positive electrode mixture comprising MnO ₂ , a conductive agent and a binder is disposed on both sides of a belt-shaped current collector and molded. One end of a positive electrode lead 9 is welded to the positive electrode, and the other end of the positive electrode lead 9 is welded to a cover plate 5 of the safety valve 2 described later.

The negative electrode and the positive electrode are stacked with a separator interposed therebetween, and housed in the battery can 1 in a spirally wound form.

Further, a non-aqueous electrolyte is injected into the battery can 1. This non-aqueous electrolyte is obtained by dissolving a lithium salt serving as an electrolyte salt in an organic solvent.

Examples of the organic solvent include esters such as propylene carbonate, ethylene carbonate, γ-butyrolactone, diethyl ether, tetrahydrofuran, and the like.
Substituted tetrahydrofuran, dioxolane, pyran and derivatives thereof, ethers such as dimethoxyethane and diethoxyethane, and 3 such as 3-methyl-2-oxazolidinone.
Substituted-2-oxazolidinone, sulfolane, methylsulfolane, acetonitrile, propionitrile and the like. These organic solvents may be used alone or in combination of two or more.

As the electrolyte, lithium perchlorate, lithium borofluoride, lithium phosphofluoride, lithium aluminate, lithium halide, lithium trifluoromethanesulfonate and the like are used.

The opening of such a battery can 1 is provided with a safety valve 2
And the positive electrode terminal 3.

As shown in FIG. 2, the safety valve 2 includes a cover plate 5 having a through hole 5a formed therein, and a through hole 5a formed in the cover plate 5.
And a reinforcing ring 7.

The cover plate 5 is made of a metal material such as stainless steel and is formed in a circular shape with the through hole 5a substantially at the center. As shown in FIG. At least 2 so that the height position is higher on the side
Step portions 5b and 5c of the step are formed.

The cleavage membrane 6 and the reinforcing ring 7
Are housed and welded on the first step portion 5b from the through hole 5a side.

The cleavable film 6 is a film having such a strength as to be cleaved when a predetermined pressure is applied. As the cleavage film 6, for example, a laminated film in which a polymer resin is coated on the surface of a metal foil is used. In this laminated film, an aluminum foil or the like is used as the metal foil, and polypropylene or polyethylene or the like is used as the polymer resin. The cleavage membrane 6 has a circular shape slightly smaller in diameter than the outer diameter of the first step 5b from the through hole 5a side of the cover plate 5.

The reinforcing ring 7 is for reinforcing the peripheral edge of the cleavage membrane. The reinforcing ring 7 has the same outer diameter as that of the cleavage film 6, and is formed in a ring shape by forming a through hole 7a at a substantially central portion.

The positive terminal 3 is made of iron or the like. As shown in FIG. 1, the positive electrode terminal 3 is formed in a circular shape having an outer diameter substantially equal to that of the cover plate 5 of the safety valve 2, and has a protruding portion 3b protruding outside the battery at a substantially central portion. The periphery of 3b is a flat portion 3c. Note that an exhaust hole 3a is formed on the peripheral surface of the protruding portion 3b.

The safety valve 2 and the positive electrode terminal 3 are flattened on the outermost step (in this case, the second step from the through hole side) 5c of the cover plate 5 constituting the safety valve 2. The portion 3c is joined, and in this state, the opening is applied to the opening of the battery can 1 via the insulating gasket 8. Then, the inside of the battery can 1 is sealed by caulking the end of the battery can 1 on the opening side, and a battery is configured.

In such a battery, the safety valve operates as follows.

That is, when an abnormal reaction occurs in the battery due to misuse and the internal pressure of the battery rises, the cleavage film 6 of the safety valve 2 expands toward the positive electrode terminal 3 and breaks when the pressure exceeds a predetermined pressure. . Thereby, the gas in the battery can 1 is exhausted to the outside through the through holes 5a and 7a of the cover plate 5, the reinforcing ring 7, and the exhaust hole 3a of the positive electrode terminal 3, and the rupture of the battery can 1 due to an increase in internal pressure is prevented. Will be avoided.

Here, the safety valve 2 has such a function, but in the nonaqueous electrolyte battery of this embodiment, the safety valve 2
Since at least two step portions 5b and 5c are formed on the cover plate 5, the strength can be obtained as compared with a cover plate having a small step. Therefore, even when the thickness of the cover plate 5 is reduced to some extent, the cover plate 5 can sufficiently withstand the external force applied at the time of caulking of the battery. With such a thin plate thickness, the occupied volume of the safety valve 2 can be reduced. is there.

In the safety valve 2, the cleavage film 6 and the reinforcing ring 7 are accommodated in the first step 5 b of the cover plate 5, and the step 5 c on the outer peripheral side of the first step 5 c and the flattening of the positive electrode terminal 3. By joining the portion 3c, the lid plate 5 and the positive electrode terminal 3 are conducted.

That is, in the safety valve 2, since conduction with the positive electrode terminal 3 can be achieved without turning the peripheral portion of the cover plate 5, a complicated turning step is not required, and the manufacturing process of the safety valve 2 can be simplified. Also, because there is no folded part,
The occupied volume is reduced.

Moreover, since the peripheral edge of the cover plate 5 is not folded back, the insulating gasket is directly compressed by the right-angled peripheral portion of the cover plate 5, and the sealing performance of the battery is improved.

Further, in such an electrical contact between the stepped portion 5c of the cover plate 5 and the flat portion 3c of the positive electrode terminal 3, a good contact state can be obtained. Is easily lowered. Therefore, the load characteristics of the battery are improved.

Incidentally, in such a safety valve 2, when the outer diameter of the reinforcing ring 7 is a and the inner diameter of the flat portion 3c of the positive electrode terminal 3 is b, the relationship a> b is satisfied, and FIG. As shown, before the caulking of the battery can, the height position of the upper surface of the reinforcing ring 7 is smaller than the height position of the outermost step portion 5c of the cover plate 5 by a height difference h of less than 0.2 mm. It is desirable that it be made higher in the range. a> b is satisfied, that is, the flat portion 3c of the positive electrode terminal 3 and the reinforcing ring 7 are partially overlapped, and the height position of the upper surface of the reinforcing ring 7 is When the height is slightly higher than the height of the step 5c on the outer periphery, the reinforcing ring 7 is pressed downward by the flat portion 3c of the positive electrode terminal 3.
Thereby, the reliability of the thermal welding of the reinforcing ring 7 and the cleavage film 6 is improved, and the sealing performance of the battery is improved. If the height position of the upper surface of the reinforcing ring 7 is higher than this, the cover plate 5
A space is left between the outermost step portion 5c and the flat portion 3c of the positive electrode terminal 3, so that electrical contact cannot be obtained.

The reinforcing ring 7 has a through hole 7a.
However, as shown in FIG. 5, it is desirable that the shape of the through-hole 7a is such that it has a leading portion 7b protruding inward of the through-hole 7a. In this example, the through hole 7a has a shape as if two circles are partially overlapped, and has two leading portions 7b protruding inward. When such a leading portion 7b is formed, when the cleaved film 6 expands toward the positive electrode terminal 3 due to an increase in battery internal pressure, the cleaved film 6 comes into contact with the leading portion 7b of the through hole 7a and quickly. To break. In other words, since the safety valve operates at a relatively early stage after the internal pressure of the battery starts to increase, the safety of the battery is further improved.

The above is the basic structure of the battery. As shown in FIG.
May be interposed between the outermost step portion 5c and the flat portion 3c of the positive electrode terminal 3.

The temperature-sensitive resistance element 10 exhibits conductivity under normal use conditions of the battery, and the lid plate 5 and the positive electrode terminal 3 are conducted through the temperature-sensitive resistance element 10. On the other hand, when the battery temperature rises abnormally, the resistance value of the temperature-sensitive resistance element 10 rises, and the current is cut off between the cover plate 5 and the positive electrode terminal 3.
Thereby, the abnormal reaction in the battery is stopped.

However, it is desirable that the temperature-sensitive resistance element 10 satisfies the relationship a> c when the outer diameter of the reinforcing ring 7 is a and the inner diameter of the temperature-sensitive resistance element 10 is c. a
> C, that is, by partially overlapping the temperature-sensitive resistance element 10 and the reinforcing ring 5, the reinforcing ring 7 is formed by the flat portion of the positive electrode terminal 3 via the temperature-sensitive resistance element 10. It will be pressed down. Thereby, the reliability of the thermal welding of the reinforcing ring 7 and the cleavage film 6 is improved, and the sealing performance of the battery is improved.

When the temperature-sensitive resistor 10 is used, the contact area A between the outermost step portion 5c of the cover plate 5 and the temperature-sensitive resistor 10 is defined as the area on one main surface of the temperature-sensitive resistor.
It is desirable to satisfy the relationship of A ≧ 0.25B. If the contact area A is smaller than this range, the electric resistance increases, and the load characteristics of the battery are impaired.

[0049]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments to which the present invention is applied will be described based on experimental results.

Example 1 A Li foil (length: 240 mm, width: 23 m) was used as a belt-shaped negative electrode.
m) was prepared.

Further, a belt-shaped positive electrode was produced as follows.

First, 90 parts by mass of heat-treated MnO ₂ as a positive electrode active material, 6 parts by mass of graphite as a conductive agent, and polytetrafluoroethylene (PT) as a binder
FE) was mixed with 4 parts by mass to prepare a positive electrode mixture. Then, this positive electrode mixture was disposed on both sides of a stainless steel expanded metal serving as a positive electrode current collector, and was molded into a belt shape to produce a positive electrode (length: 245 mm, width: 24.5 mm).

The dimensions of the positive electrode, the negative electrode, and the microporous polyethylene film serving as the separator were adjusted so as to be appropriately accommodated in a battery can having an outer diameter of 17 mm and a height of 34 mm. Then, the positive electrode and the negative electrode were stacked with a separator interposed therebetween, and spirally wound many times to produce a spiral electrode element.

The spirally wound electrode element thus manufactured was housed in a battery can, and a nickel negative electrode lead was led out from the negative electrode and welded to the battery can.

Subsequently, a safety valve was manufactured as follows.

First, a lid plate was prepared. This lid plate is a dish-shaped disk made of stainless steel. The cover plate has a through hole for venting gas at a substantially central portion, and two step portions are formed around the through hole.

Then, on the first step from the through hole side of the lid plate, a laminated film (cleavage film) in which a 20 μm thick Al foil is laminated with a 40 μm thick polyethylene-based resin.
Then, a safety valve was manufactured by housing the reinforcing ring and heat welding. The reinforcing ring is formed with a through-hole having a shape in which two circles are partially overlapped.

Next, a cylindrical battery can having one end closed and the other end opened is prepared. In this battery can, a constriction was formed in the vicinity of the end on the opening side, and an insulating gasket coated with asphalt was attached to a projection formed in the battery can by the constriction.

Then, a stainless steel positive electrode lead was led out from the positive electrode current collector of the spiral electrode element and was welded to the cover plate.

Subsequently, 0.7 mol / l of LiCF ₃ SO ₃ was placed in a mixed solvent consisting of 60 parts by volume of propylene carbonate and 40 parts by volume of dimethoxyethane in the battery can.
The dissolved electrolyte was injected.

Next, the safety valve prepared above is placed on an insulating gasket attached to a battery can, and a ring-shaped temperature-sensitive resistance element is further placed on a cover plate constituting the safety valve.
A positive electrode terminal having a convex portion and having a flat portion around the convex portion was provided, and the battery can 2 was caulked to produce a unit cell (primary battery).

Then, a washer 7 made of polypropylene was arranged on the positive electrode terminal of this unit cell. Next, an outer label using a heat-shrinkable plastic film as a base material was coated with an adhesive on the back surface, and then wound around the outer peripheral surface of the unit cell and bonded. Thereafter, the washer was pressed by thermally shrinking the outer labels protruding above and below the unit cell, thereby producing a cylindrical nonaqueous electrolyte battery having a diameter of 17 mm and a height of 34 mm.

In this non-aqueous electrolyte battery, the dimensions of the cover plate and the reinforcing ring of the safety valve, the temperature-sensitive resistance element, and the positive electrode terminal are as follows.

Safety valve: height difference h between the height position of the outermost step portion of the cover plate and the height position of the upper surface of the reinforcing ring; 0.18
mm, outer diameter a of reinforcing ring; 11.1 mm inner diameter b of outer peripheral flat portion of positive electrode terminal: 9.6 mm inner diameter c of temperature-sensitive resistance element: 5 mm Comparative Example 1 Except that safety valve was manufactured as follows. A non-aqueous electrolyte battery was fabricated in the same manner as in Example 1.

As shown in FIGS. 6 (a) and 6 (b), a lid plate was prepared in which the outer peripheral portion was vertically raised, and a cleavage membrane and a reinforcing plate were disposed inside the lid plate. Then, the cleaved membrane and the reinforcing plate were fixed to the cover plate by heat welding at a temperature of 160 ° C. for 1 minute, and the outer periphery of the cover plate was caulked to produce a safety valve.

However, here, the volume of the safety valve is equal to that of the first embodiment.
The width of the positive electrode was set to 24 mm because it was larger than the volume of the safety valve manufactured in the above.

The non-aqueous electrolyte battery prepared as described above was discharged at 1.2 A for 3 seconds, and then discharged.
A pulse discharge such as interruption for 2 seconds is performed at a final voltage of 1.3 V.
I went up. Table 1 shows the discharge capacity at that time.

[0068]

[Table 1]

As can be seen from Table 1, the battery of Example 1 has a larger positive electrode width, so that a larger discharge capacity can be obtained than the battery of Comparative Example 1.

From this, a safety valve is formed by storing the cleavage membrane and the reinforcing ring on the first step of the cover plate having at least two steps, and the outermost step of the cover plate and the positive electrode terminal It has been found that, when the flat portions are brought into contact, the volume occupied by the safety valve is reduced, and the discharge capacity is improved.

Next, 50 of the batteries produced in Example 1 and Comparative Example 1 were stored at a temperature of 80 ° C. for 20 days. Another 50 pieces were stored at a temperature of 100 ° C. for 24 hours. Then, the presence or absence of leakage of the electrolyte after storage was examined. Table 2 shows the number of batteries in which liquid leakage occurred.

[0072]

[Table 2]

As shown in Table 2, in the battery of Example 1,
The generation of liquid leakage is suppressed in both storage at a temperature of 80 ° C and storage at a temperature of 100 ° C. On the other hand, in the battery of Comparative Example 1, storage at a temperature of 80 ° C.
Liquid leakage was observed in four batteries, and leakage was observed in four batteries during storage at a temperature of 100 ° C.

From this, a safety valve is formed by storing the cleavage film and the reinforcing ring on the first step of the cover plate having at least two steps, and the outermost step of the cover plate and the positive electrode terminal are formed. It was found that when the flat portion of the battery was brought into contact, the lid plate was folded and the folded portion was brought into contact with the flat portion of the positive electrode terminal, whereas the sealing performance of the battery was improved.

[0075]

As is clear from the above description, in the non-aqueous electrolyte battery of the present invention, the safety valve comprises a cover plate having a through-hole formed therein, and a cleaving membrane for closing the through-hole of the cover plate. The cover plate has at least two steps around the through hole, and the cleavage membrane and the reinforcing ring are housed on the first step from the through hole side of the cover plate. As a result, the volume occupied by the safety valve is small, and accordingly, the volume for accommodating the electrodes can be secured. In addition, since this safety valve does not require a complicated folding step, the manufacturing process can be simplified. Furthermore, in this safety valve, since conduction with the positive electrode terminal is made by contact between the outermost step portion of the lid plate and the flat outer peripheral portion of the positive electrode terminal, a good contact state is obtained, and the load characteristics of the battery are improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a main part showing an example of a non-aqueous electrolyte primary battery to which the present invention is applied.

FIG. 2 is an exploded sectional view showing a safety valve incorporated in the non-aqueous electrolyte primary battery.

FIG. 3 is a perspective view showing a step of a cover plate constituting the safety valve.

FIG. 4 is a cross-sectional view illustrating a height relationship between a step portion on an outermost periphery of a cover plate and an upper surface of a reinforcing ring.

FIG. 5 is a plan view showing an example of a reinforcing ring constituting the safety valve.

FIG. 6 is a schematic cross-sectional view of a main part showing another example of a nonaqueous electrolyte primary battery to which the present invention is applied.

7A and 7B show a safety valve of a conventional non-aqueous electrolyte primary battery, in which FIG. 7A is a cross-sectional view showing a state before the cover plate is swaged, and FIG. 7B is a cross-sectional view showing a state where the cover plate is swaged. FIG.

[Explanation of symbols]

1 Battery case, 2 Safety valve, 3 Positive electrode terminal, 4 Spiral electrode element, 5 Cover plate, 6 Cleavable membrane, 7 Reinforcing ring,
10 Temperature-sensitive resistance element

Claims (4)

[Claims] A negative electrode and a positive electrode are housed in a battery can having an opening, and the opening of the battery can is sealed at an end on the opening side of the battery can, and the battery can exceeds a predetermined internal pressure. A non-aqueous electrolyte battery in which a safety valve that releases internal pressure when the internal pressure is released and a positive electrode terminal that has an exhaust hole are attached via an insulating gasket, wherein the safety valve includes a lid plate having a through-hole formed therein, A cleaving membrane for closing the through hole of the plate, and a reinforcing ring, wherein the lid plate has at least two steps around the through hole, and the cleaving membrane and the reinforcing ring are on the through hole side of the lid plate. A non-aqueous electrolyte battery, which is housed on a first-stage stepped portion. 2. The positive electrode terminal has a convex portion protruding outside the battery can at a substantially central portion, and a flat portion is formed around the convex portion, and the flat portion is a cover plate constituting a safety valve. When the outer diameter of the reinforcing ring is a and the inner diameter of the flat part of the positive electrode terminal is b, the relationship a> b is satisfied, and the reinforcing ring is 2. The non-aqueous electrolyte battery according to claim 1, wherein the height of the lid is higher than the height of the outermost step by less than 0.2 mm. 3. The positive electrode terminal has a convex portion at a substantially central portion protruding outside the battery can, a flat portion is formed around the convex portion, and the positive electrode terminal is provided on a step portion on the outermost periphery of the cover plate. The nonaqueous electrolyte battery according to claim 1, wherein a ring-shaped temperature-sensitive resistance element is provided, and a flat portion of the positive electrode terminal is joined to the temperature-sensitive resistance element. 4. When the outer diameter of the reinforcing ring is a, the inner diameter of the flat portion of the positive electrode terminal is b, and the inner diameter of the temperature-sensitive resistance element is c,
a> b and a> c are satisfied, and the height position of the upper surface of the reinforcing ring is set to be higher than the height position of the outermost step portion of the cover plate by less than 0.2 mm. 4. The non-aqueous electrolyte battery according to claim 3, wherein a non-aqueous electrolyte battery is used.