JP2008084845A - Cylindrical primary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable cylindrical primary battery which keeps low a surface temperature of a body portion of a battery at a short circuit. <P>SOLUTION: A thermal conductivity λ(W/mK) of a resin sealing body 5 of a sealing assembly 11 provided with a PTC element 9 and a generated heat amount Q(W) at the time of tripping of the PTC element 9 are set up to satisfy a relational expression (1): 0.12≤λ≤0.27, a relational expression (2): 1.0≤Q≤1.5, and a relational expression (3): Q≤-3.33λ+1.9. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cylindrical primary battery provided with a PTC element.

Conventionally, for the purpose of improving the safety of a battery, various studies have been made on a cylindrical primary battery including a PTC element that prevents heat generation of the battery due to an overcurrent during a short circuit.
For example, Patent Document 1 proposes that the surface of the negative electrode current collector is covered with an electronic conductor mainly composed of polyethylene and having a PTC function. However, the electron conductor coated on the surface of the negative electrode current collector is easily decomposed by the alkaline electrolyte, and the PTC function may not be sufficiently exhibited.

  Further, in Patent Document 2, in a lithium secondary battery having a structure in which an opening end portion of an outer can caulks a flange portion of a sealing plate peripheral portion via a gasket, a PTC element is provided between the flange portion of the sealing plate and the gasket. Has been proposed. However, the lithium secondary battery is different from the alkaline battery in the structure of a sealing portion such as a current collector or an explosion-proof mechanism. Therefore, it is necessary to newly examine how to incorporate a PTC element suitable for the structure of an alkaline battery.

Furthermore, for example, Patent Document 3 proposes that a sealing body including a PTC element is used for an alkaline battery or a lithium battery. When an overcurrent flows, the PTC element generates a heat (self trip) and when the temperature reaches a predetermined temperature, the PTC element has a function of rapidly increasing the resistance (trip). It is said that when a battery is accidentally short-circuited, the PTC element trips and an overcurrent is cut off, thereby suppressing abnormal heat generation of the battery.
JP 2003-217596 A JP-A-9-199106 No. 97/006538

  However, the configuration proposed in Patent Document 3 has the following problems. That is, when a large current is consumed almost continuously in a normal use state such as continuous light emission of a strobe or continuous shooting of a digital still camera, the PTC element as a resistor gradually generates heat, and the PTC is not intended. The element may be activated.

  Although it is desirable to operate the PTC element at the lowest possible temperature during a short circuit, it is difficult to balance the heat generation temperature and the operating temperature of the PTC element in terms of battery design. Therefore, the heat generation of the battery due to the overcurrent at the time of short circuit cannot be sufficiently suppressed, and the user often feels that the battery body is hot.

  Moreover, the heat generation of the PTC element itself when tripped by an overcurrent at the time of a short circuit causes thermal damage to the resin sealing body covering the PTC element due to the structure of the battery. As a result, the resin sealing body may be thermally deformed or carbonized at a high temperature, which may deteriorate the sealing performance of the battery and cause liquid leakage.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a highly reliable cylindrical primary battery in which the surface temperature of the battery body during a short circuit is kept low. .

In order to achieve the above object, the present invention provides:
A bottomed cylindrical battery case including a power generation element therein; an external terminal plate; a connection plate electrically connected to the power generation element; a PTC element disposed between the external terminal plate and the connection plate; A cylindrical primary battery comprising: a negative electrode current collector electrically connected to an external terminal plate; and a sealing assembly including a resin sealing body and closing an opening of the battery case;
The following relational expressions (1) to (3) are satisfied, where λ (W / m · K) is the thermal conductivity of the resin sealing body and Q (W) is the amount of heat generated when the PTC element is tripped. A cylindrical primary battery is provided.
(1) 0.12 ≦ λ ≦ 0.27
(2) 1.0 ≦ Q ≦ 1.5
(3) Q ≦ −3.33λ + 1.9

  Here, the “thermal conductivity λ” of the resin sealant can be measured as follows. That is, the resin constituting the resin sealing body is molded into a disk shape to produce a test piece, irradiated with laser light from one of the obtained test pieces, and a laser flash method for measuring the temperature response of the other surface, “Thermal conductivity λ” can be measured. For example, a test piece having a diameter of 10 mm and a thickness of 1 mm can be produced using LFA427 manufactured by NETZSCH, and the thermal conductivity λ can be measured.

  Further, the “heat generation amount Q” at the time of trip of the PTC element can be measured as follows. In other words, a PTC element and an ammeter are connected in series with a nickel lead wire having a width of 5.0 mm and a thickness of 0.1 mm to a cylindrical primary battery in which no PTC element is incorporated (for example, an AA alkaline battery). Form a circuit. The voltage of the PTC element and the current of the circuit are measured 3 minutes and 5 minutes after the obtained circuit is closed, and the power of the PTC element is obtained by the product of the obtained voltage value and current value. The calorific value Q can be calculated from the average value of the power after 3 minutes and after 5 minutes.

  The power generating element in the present invention means a positive electrode mixture, a gelled negative electrode, and an alkaline electrolyte. Therefore, the connecting plate only needs to be electrically connected to any one of the positive electrode mixture, the gelled negative electrode, and the alkaline electrolyte.

  According to the above configuration, the PTC element is attached to the battery case so as to be covered with the resin sealing body having low thermal conductivity. Therefore, when the battery is short-circuited, the heat generated by the PTC element can be made difficult to be transmitted to the battery case, and an increase in the surface temperature of the body part of the battery can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the highly reliable cylindrical primary battery which suppressed the surface temperature of the trunk | drum of the battery at the time of a short circuit can be implement | achieved.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a front view of a cross section of a part of an embodiment (AA alkaline battery (LR6)) of a cylindrical primary battery according to the present invention.

  As shown in FIG. 1, a plurality of hollow cylindrical positive electrode mixtures (pellets) 2 are accommodated inside a bottomed cylindrical battery case 1 that also serves as an external terminal. A gelled negative electrode 3 is disposed in the hollow portion of the positive electrode mixture 2 via a bottomed cylindrical separator 4. The positive electrode mixture 2, the separator 4 and the gelled negative electrode 3 contain an alkaline electrolyte.

The battery case 1 is obtained, for example, by press-molding a nickel-plated steel sheet into a predetermined size and shape.
The separator 4 is made of, for example, a nonwoven fabric mainly composed of polyvinyl alcohol fiber and rayon fiber.

For the positive electrode mixture 2, for example, a mixture of a positive electrode active material containing manganese dioxide powder, a conductive agent such as graphite powder, and an alkaline electrolyte such as an aqueous potassium hydroxide solution is used.
For the gelled negative electrode 3, for example, a mixture of a negative electrode active material such as zinc powder or zinc alloy powder, a gelling agent such as sodium polyacrylate, and an alkaline electrolyte such as an aqueous potassium hydroxide solution is used. .

  In addition, it is preferable to use the zinc alloy powder excellent in corrosion resistance as the negative electrode active material, and more preferable that mercury, cadmium, lead, or all of them are not added in consideration of the environment. Examples of the zinc alloy include zinc alloys containing indium, aluminum, and bismuth.

  The opening of the battery case 1 is closed by a sealing assembly 11 after storing power generation elements such as the positive electrode mixture 2 and the gelled negative electrode 3. The sealing assembly 11 includes an external terminal plate 7, a connecting plate 8 electrically connected to the negative electrode current collector 6, a PTC element 9, and a resin sealing body 5. The outer surface of the battery case 1 is covered with an exterior label 10.

  FIG. 2 is an enlarged cross-sectional view of the main part of the sealing portion of the cylindrical primary battery shown in FIG. As shown in FIG. 2, the resin sealing body 5 has a through-hole into which the negative electrode current collector 6 is press-fitted in the center, and has an annular thin portion 5b that works as a safety valve around it. In the outer peripheral part of the annular thin part 5b, a cylindrical outer peripheral part 5a is formed continuously with the annular thin part 5b.

  For example, the resin sealing body 5 is obtained by injection molding polypropylene, nylon or the like into a predetermined size and shape.

  The external terminal plate 7 has a flange portion 7a at the peripheral portion, and the connecting plate 8 has a flange portion 8a at the peripheral portion. For the external terminal board 7, for example, a nickel-plated steel sheet is used. Moreover, it is preferable to use a tin-plated steel plate or a nickel-plated steel plate for the connecting plate 8 in terms of low contact resistance.

  A ring-shaped PTC element 9 is disposed between the flange portion 7 a of the external terminal plate 7 and the flange portion 8 a of the connecting plate 8. The opening end of the battery case 1 is bent so as to wrap the upper end of the outer peripheral edge 5a of the resin sealing body 5 on the step portion 1a provided in the vicinity of the opening of the battery case 1. The bent portion is caulked inward, and the flange portion 7a of the external terminal plate 7, the disk-shaped (ring-shaped) PTC element 9 having an opening portion, and the flange portion 8a of the connecting plate 8 are formed into a resin sealing body. It is tightened so as to be covered with the outer peripheral edge 5a.

  For the PTC element 9, for example, a material sold under the name of a polyswitch manufactured by Tyco Electronics Raychem Co., Ltd. is used. The PTC element 9 has a function of rapidly increasing the resistance (trip) when a predetermined temperature (for example, 90 to 110 ° C.) is reached. Further, even if the PTC element 9 has the same resistance value per unit area, when the sealing assembly 11 is formed, if the outer diameter or inner diameter when processed into a ring shape, for example, by press punching, is different, Will also be different. That is, the larger the ring area, the greater the amount of heat generated.

Here, the greatest feature of the present invention is that when the thermal conductivity of the resin sealing body 5 is λ (W / m · K), and the amount of heat generated when the PTC element 9 is tripped is Q (W), The following relational expressions (1) to (3) are satisfied.
(1) 0.12 ≦ λ ≦ 0.27
(2) 1.0 ≦ Q ≦ 1.5
(3) Q ≦ −3.33λ + 1.9

By satisfying the relational expressions (1) to (3), an increase in the surface temperature of the cylindrical primary battery (particularly the side surface portion) can be more reliably suppressed.
Further, if the thermal conductivity λ of the resin sealing body 5 is set to 0.19 W / m · K or less and the heat generation amount Q at the time of trip of the PTC element 9 is set to 1.25 W or less, the cylindrical primary battery can be more effectively used. The surface temperature can be kept low, which is preferable.

  Further, the resin sealing body 5 may be formed of polypropylene. If it does in this way, the heat resistance with respect to the heat_generation | fever of the PTC element 9 will improve. In addition, the resin sealing body 5 may be formed of 6,6 nylon or 6,12 nylon having a thermal conductivity λ of 0.23 W / m · K or more. In this case, the alkali resistance can be improved. it can.

  As mentioned above, although typical embodiment of this invention was described, this invention is not limited only to these. For example, the PTC element can take various shapes, and is not limited to a continuous ring shape. For example, the PTC element may be a discontinuous ring shape having a gap in part. Further, for example, discontinuous island portions may be included.

  Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to the examples shown below. In the following examples, cylindrical primary batteries having the structures shown in FIGS. 1 and 2 were produced.

Example 1
(1) Preparation of positive electrode mixture Manganese dioxide and graphite were mixed at a weight ratio of 90:10. Then, the obtained mixture and a 35% by weight aqueous solution of potassium hydroxide as an alkaline electrolyte were mixed at a weight ratio of 100: 3, sufficiently stirred, and then compression molded into flakes to form a flake-shaped positive electrode. A mixture was obtained. Next, the flaky positive electrode mixture is pulverized into granules, and the obtained powder is classified with a sieve, and a 10-100 mesh powder is pressure-formed into a hollow cylinder to obtain a pellet-shaped positive electrode mixture 2. Obtained.

(2) Preparation of gelled negative electrode Sodium polyacrylate as a gelling agent, 35 wt% aqueous solution of potassium hydroxide as an alkaline electrolyte, and negative electrode active material were mixed at a weight ratio of 1:33:66, A gelled negative electrode 3 was obtained. As the negative electrode active material, a zinc alloy powder containing 0.025 wt% indium, 0.015 wt% bismuth, and 0.004 wt% aluminum was used.

(3) Production of Sealing Assembly Mixture of polypropylene (BC4ASW manufactured by Nippon Polypro Co., Ltd., hereinafter the same) and talc (P3 manufactured by Nihon Talc Co., Ltd., hereinafter the same) (with talc of 0.2 The resin sealing body 5 having a predetermined dimension and a ring shape was produced by injection molding. Further, a mixture of the above polypropylene and talc was formed into a disk shape to prepare a test piece having a diameter of 10 mm and a thickness of 1 mm for measuring the thermal conductivity λ, and the thermal conductivity was measured using LFA427 manufactured by NETZSCH. λ was measured. As a result, the thermal conductivity λ of the resin sealing body 5 was 0.12 W / m · K.

  The PTC element 9 is made of a ring-shaped material (outer diameter 12) having a thickness of 0.3 mm, a specific resistance value of 0.03Ω at 20 ° C., and a specific resistance value of 10,000Ω at a high temperature of 120 ° C. 3 mm and an inner diameter of 9.7 mm). The heat generation amount Q at the time of trip of the PTC element 9 was 1.00 W.

  The external terminal plate 7 and the connecting plate 8 were obtained by processing a nickel-plated steel plate having a thickness of 0.3 mm so as to have a predetermined size and shape with a press.

  Next, the negative electrode current collector 6 obtained by pressing a brass wire strip into a nail shape and plating the surface with tin was electrically welded to the connecting plate 8. Thereafter, the negative electrode current collector 6 was inserted into the through hole at the center of the resin sealing body 5 (so that the negative electrode current collector 6 was fixed by the resin sealing body 5). A PTC element 9 was placed on the flange 8 a of the connecting plate 8, and the external terminal plate 7 was placed so as to sandwich the PTC element 9 to obtain a sealing assembly 11.

(4) Assembly of Cylindrical Primary Battery An AA alkaline battery (LR6) having the structure shown in FIG. 1 was produced by the following procedure.
Two positive electrode mixtures 2 obtained as described above were inserted into the battery case 1, and the positive electrode mixture 2 was pressurized with a pressurizing jig and adhered to the inner wall of the battery case 1. A bottomed cylindrical separator 4 was disposed in the center of the positive electrode mixture 2 in close contact with the inner wall of the battery case 1. A predetermined amount of a 36 wt% aqueous solution of potassium hydroxide was injected into the separator 4 as an alkaline electrolyte. After a predetermined time had elapsed, the gelled negative electrode 3 obtained above was filled in the separator 4.

  The separator 4 was a non-woven fabric mainly containing polyvinyl alcohol fibers and rayon fibers. The opening end portion of the battery case 1 is bent so as to wrap the upper end of the outer peripheral edge portion 5a of the resin sealing body 5, and the bent portion is crimped to the flange portion 7a of the external terminal plate 7 to seal the opening portion of the battery case 1. . The outer surface of the battery case 1 was covered with the exterior label 10 to produce a cylindrical primary battery.

Example 2
In this example, the PTC element 9 was obtained by stamping into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 8.7 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 1.26 W. A cylindrical primary battery was produced in the same manner as in Example 1 except for the PTC element 9.

Example 3
In this example, the PTC element 9 was obtained by stamping into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 7.8 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 1.50 W. A cylindrical primary battery was produced in the same manner as in Example 1 except for the PTC element 9.

Example 4
In this embodiment, 5% by weight of talc is added to polypropylene, kneaded sufficiently, and then a resin sealing body 5 having a predetermined size and shape by injection molding and a test piece for measuring thermal conductivity are provided. Produced. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.19 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

Example 5
In this example, the PTC element 9 was obtained by stamping into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 8.7 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 1.26 W. A cylindrical primary battery was produced in the same manner as in Example 4 except for the PTC element 9.

Example 6
In this example, after adding 10% by weight of talc to polypropylene and kneading sufficiently, a resin sealing body 5 having a predetermined size and shape by injection molding and a test piece for measuring thermal conductivity are provided. Produced. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.27 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

Example 7
In this example, 0.5% by weight of talc was added to nylon 6,6 (Leona 1300S manufactured by Asahi Kasei Co., Ltd., the same shall apply hereinafter), kneaded sufficiently, and then injection molding was carried out to predetermined dimensions and A resin sealing body 5 having a shape and a test piece for measuring thermal conductivity were prepared. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.25 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

Example 8
In this embodiment, 1% by weight of talc is added to nylon 6 and 6, and after kneading sufficiently, the resin sealing body 5 having a predetermined size and shape by injection molding, and for measuring the thermal conductivity A test piece was prepared. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.27 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

Example 9
In this example, 0.5% by weight of talc was added to nylon 6,12 (Zytel (trade name) manufactured by DuPont, USA) and kneaded sufficiently, and then a predetermined size and shape were obtained by injection molding. The resin sealing body 5 which has, and the test piece for thermal conductivity measurement were produced. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.23 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

<< Comparative Example 1 >>
In this comparative example, the PTC element 9 was obtained by stamping into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 9.9 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 0.89 W. A cylindrical primary battery was produced in the same manner as in Example 1 except for the PTC element 9.

<< Comparative Example 2 >>
In this comparative example, polypropylene was used to produce a resin sealing body 5 having a predetermined size and shape and a test piece for measuring thermal conductivity by injection molding. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.11 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

<< Comparative Example 3 >>
In this comparative example, the PTC element 9 was obtained by stamping into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 7.4 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 1.59 W. A cylindrical primary battery was produced in the same manner as in Example 1 except for the PTC element 9.

<< Comparative Example 4 >>
In this comparative example, the PTC element 9 was obtained by stamping into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 7.8 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 1.50 W. A cylindrical primary battery was produced in the same manner as in Example 4 except for the PTC element 9.

<< Comparative Example 5 >>
In this comparative example, the PTC element 9 was obtained by punching into a ring shape having an outer diameter of 12.3 mm and an inner diameter of 8.7 mm. The heat generation amount Q at the time of trip of the PTC element 9 was 1.26 W. A cylindrical primary battery was produced in the same manner as in Example 9 except for the PTC element 9.

<< Comparative Example 6 >>
In this comparative example, 5% by weight of talc is added to nylon 6 and 6, after kneading sufficiently, the resin sealing body 5 having a predetermined size and shape by injection molding, and for measuring the thermal conductivity A test piece was prepared. From the measurement result of the thermal conductivity of this test piece, the thermal conductivity λ of the resin sealing body 5 was 0.29 W / m · K. A cylindrical primary battery was produced in the same manner as in Example 1 except for the resin sealant 5.

[Evaluation test]
(1) For each of the batteries obtained above, five batteries were connected to the battery case 1 and the external terminal plate 7 via a nickel lead wire having a thickness of 0.1 mm to externally short-circuit the batteries. . The surface temperature of the battery body at this time was measured with a thermocouple, and the maximum temperature was examined. The surface temperature of the body part of the battery is preferably 70 ° C. or lower, and more preferably 65 ° C. or lower.

(2) Further, two hours after the battery was externally short-circuited, it was visually examined whether or not liquid leakage occurred between the battery case 1 and the sealing assembly 11.

(3) In addition, each of the four batteries was continuously fired at a rate of once per 10 seconds using a Canon strobe / speed lighter 580EX, and the PTC element 9 was activated by 20 times. I checked if the flash could not fire.
The evaluation results are shown in Table 1.

  In Examples 1 to 9 of the present invention, the thermal conductivity λ of the resin sealing body 5 and the calorific value Q of the PTC element 9 are well balanced, and the surface temperature of the body part of the battery at the time of short circuit is all 70 ° C. or less. It was suppressed. Further, the PTC element 9 did not operate unintentionally during the strobe light emission test, and there was nothing that caused liquid leakage when the battery was short-circuited.

  In Comparative Example 2, during the stroboscopic light emission test, the stroboscope stopped emitting light at the 14th time, and liquid leakage occurred after the battery was short-circuited. That is, when the thermal conductivity λ of the resin sealing body 5 is less than 0.12 W / m · K, heat is not easily transmitted, and the PTC element 9 is unintentionally activated by the heat generated by the PTC element 9 itself, or the outside of the resin sealing body 5 The peripheral edge portion 5a is damaged by heat accumulation, causes deformation and carbonization, and liquid leakage occurs. Moreover, in the comparative example 6, the surface temperature of the battery trunk | drum part at the time of a short circuit was as high as 93 degreeC. That is, when the thermal conductivity λ of the resin sealing body 5 exceeds 0.27 W / m · K, heat generated by the PTC element 9 is easily transmitted to the battery case 1, and the surface temperature of the body portion of the battery can be kept low. Can not.

  In Comparative Example 1, the strobe could not emit light at the 17th time during the strobe light emission test. That is, when the heat generation amount Q at the time of trip of the PTC element 9 is less than 1.0 W, the PTC element 9 is likely to operate unintentionally with a small heat generation amount. In Comparative Example 3, liquid leakage occurred after the battery was short-circuited. That is, when the heat generation amount Q at the time of trip of the PTC element 9 exceeds 1.5 W, the outer peripheral edge portion 5a of the resin sealing body 5 is damaged by heat and is deformed or carbonized to cause liquid leakage.

  In Comparative Examples 3 to 5, the heat generation amount Q of the PTC element 9 is large with respect to the thermal conductivity λ of the resin sealing body 5, and the surface temperature of the body portion of the battery at the time of short circuit cannot be sufficiently suppressed, and the heat generation As a result, the outer peripheral edge 5a of the resin sealing body 5 was deformed and carbonized, leading to liquid leakage.

  Here, FIG. 3 shows Examples 1 to 9 and Comparative Examples 1 to 6 of the present invention, the thermal conductivity λ of the resin sealing body 5 on the horizontal axis, and the heat generated when the PTC element 9 is tripped on the vertical axis. It is explanatory drawing shown on the coordinate made into quantity Q. FIG. As shown in FIG. 3, as a result of experiments conducted by the present inventors, it is preferable to use the resin sealing body 5 having a lower thermal conductivity as the PTC element 9 having a higher calorific value is used, and the thermal conductivity of the resin sealing body 5. There is a negative correlation between λ and the heat generation amount Q when the PTC element 9 is tripped. That is, it has been found that a critical line that can suppress the surface temperature of the body of the battery sufficiently low during a short circuit is a straight line represented by Q = −3.33λ + 1.9. That is, it is preferable that Q ≦ −3.33λ + 1.9 is satisfied within the range of the thermal conductivity λ of the resin sealing body 5 and the calorific value Q when the PTC element 9 is tripped.

  Further, the thermal conductivity λ of the resin sealing body 5 is 0.12 W / m · K ≦ λ ≦ 0.19 W / m · K, and the heat generation amount Q of the PTC element 9 is 1.0 W ≦ Q ≦ 1.25 W. In Examples 1, 2, 4 and 5 of the present invention, the surface temperature of the body part of the battery at the time of short circuit was suppressed to 65 ° C. or less.

  In the above-described embodiment, the case of using the resin sealing body 5 of polypropylene, nylon 6,6 and nylon 6,12 has been described. However, polyolefin resins other than polypropylene (for example, polyethylene, polystyrene, etc.), nylon, Of course, the present invention can be applied to the case where the resin sealing body 5 made of a polyamide resin other than 6, 6 and nylon 6, 12 is used.

  In addition, the effect of the present invention is not affected by the difference in power generation elements, and is not limited to the zinc-manganese dioxide system of the above-described embodiment, but is also zinc-nickel system, lithium-iron disulfide system, lithium-manganese system. It can be applied to various types of cylindrical primary batteries such as lithium-fluorinated graphite, and the same effect can be obtained.

  The cylindrical primary battery of the present invention has high reliability and can be suitably used with peace of mind for power supplies of electronic devices and portable devices.

It is the front view which made a part of one embodiment (AA alkaline battery) of the cylindrical primary battery of the present invention a section. It is the longitudinal cross-sectional view which expanded the principal part of the sealing part of the cylindrical primary battery shown in FIG. It is explanatory drawing (graph) which showed the Example and comparative example of this invention on the coordinate of (The calorific value Q at the time of the trip of the thermal conductivity (lambda) -PTC element of a resin sealing body).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery case 2 Positive electrode mixture 3 Gel-like negative electrode 4 Separator 5 Resin sealing body 5a Outer peripheral edge part 5b Annular thin part 6 Negative electrode collector 7 External terminal board 8 Connection board 7a, 8a Eave part 9 PTC element 10 Exterior label 11 Sealing Assembly

Claims (4)

A cylindrical battery case with a bottom that contains a power generation element inside;
An external terminal plate, a connecting plate electrically connected to the power generation element, a PTC element disposed between the external terminal plate and the connecting plate, a negative electrode current collector electrically connected to the external terminal plate, And a sealing assembly that closes an opening of the battery case;
A cylindrical primary battery comprising:
The following relational expressions (1) to (3) are satisfied, where λ (W / m · K) is the thermal conductivity of the resin sealing body and Q (W) is the amount of heat generated when the PTC element is tripped. A cylindrical primary battery characterized by that.
(1) 0.12 ≦ λ ≦ 0.27
(2) 1.0 ≦ Q ≦ 1.5
(3) Q ≦ −3.33λ + 1.9   2. The cylindrical primary battery according to claim 1, wherein λ satisfies 0.12 ≦ λ ≦ 0.19, and Q satisfies 1.0 ≦ Q ≦ 1.25.   The cylindrical primary battery according to claim 1 or 2, wherein the resin sealing body is made of polypropylene.   2. The cylindrical primary battery according to claim 1, wherein the resin sealing body is made of 6,6 nylon or 6,12 nylon, and the λ satisfies 0.23 ≦ λ ≦ 0.27.

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