JP2005340053A - Sealed storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed storage battery provided with a low-cost pressure switch function having an inner space for storing an electrode group restrained from becoming small by reducing a volume occupied by a lid body including the pressure switch and simplifying a structure. <P>SOLUTION: A pressure switch mechanism is constructed by a sealing plate 1 made of metal, an electrically insulated valve body 4 arranged on the sealing plate airtightly sealing a through-hole 1A, and a connection member 5. The valve body is capable of slide movement along a wall face of the through-hole, or capable of expansion and contraction. The connection member changes its position according to the slide movement or expansion/contraction of the valve body. When an internal pressure of the storage battery exceeds a prescribed value, an electric contact point of the connection member and the sealing plate is separated from the sealing plate accompanying the slide movement or expansion of the valve body, whereby, the mechanism of breaking a circuit connecting an electrode plate and an external terminal is constructed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealed storage battery, and more particularly to a sealed storage battery capable of rapid charging within 30 minutes.

  Examples of the sealed storage battery include alkaline storage batteries such as a nickel hydride storage battery and a nickel cadmium storage battery. The storage battery is suitable for cycle use because of its excellent overcharge resistance, overdischarge resistance, and charge / discharge cycle characteristics, and as a power source for portable small electronic devices such as mobile phones, small electric tools and small personal computers. Widely used. In addition, due to the strong desire of users to end charging in a short time, development of an alkaline storage battery capable of rapid charging that can be completed in a short time such as 15 to 30 minutes is desired.

  For example, when trying to quickly charge a nickel metal hydride storage battery, heat generated due to ohmic loss, heat generated due to the hydrogen storage reaction of the hydrogen storage alloy, heat generated due to the reaction that absorbs oxygen generated from the positive electrode at the end of charging at the negative electrode, Since the temperature of the storage battery becomes high and the constituent materials of the storage battery change in quality, the characteristics may deteriorate. In addition, since the amount of gas generated inside the storage battery increases, the pressure inside the storage battery rises, and as a result, the exhaust valve operates and leaks, or the electrolyte solution dissipates to the outside as gas and droplets. There is a risk that the characteristics of the storage battery will deteriorate, such as an increase in internal impedance.

  In order to solve the above-mentioned problems that occur when performing quick charging, charging is stopped when the pressure inside the storage battery rises above a predetermined value during charging, and charging is performed when the pressure inside the storage battery drops below a predetermined value. In order to resume, a sealed storage battery has been proposed in which a circuit connecting an electrode plate and an external terminal is provided with a switch function for controlling on / off of the circuit. (For example, see Patent Document 1)

WO2002 / 0119364 A1 (FIG. 2A, FIG. 2B) The sealed storage battery described in the patent document has a lid as shown in FIG. A member for sealing is referred to as a lid). In FIG. 6, the open end of the battery case of the sealed storage battery 21 is hermetically sealed by a grommet 26 made of a synthetic resin molded body and a connection terminal 23 fitted in a through hole provided in the central portion thereof. . A metal sealing plate 25 is disposed outside the grommet 26, and a cap-like positive external terminal 27 is in contact with the outside thereof. The positive electrode plate 30 and the connection terminal 23 are connected via a positive electrode lead plate 29. Normally, the metal ring 24 joined to the connection terminal 23 is in contact with the sealing plate, and the circuit connecting the positive electrode plate 30 and the positive electrode external terminal (cap) 27 is on. When the internal pressure of the storage battery rises above a predetermined value during charging, the central portion of the grommet 26 bends upward, the metal ring 24 moves upward, and the contact point between the metal ring 24 and the sealing plate 25 becomes the sealing plate. 25, the circuit is switched from on to off and charging is stopped. When the pressure inside the storage battery drops and drops below a predetermined value while charging is stopped, the metal ring moves downward by the pressing force of the elastic body 28, contacts the sealing plate, the circuit switches from OFF to ON, and charging resumes Is done.

  However, the sealed battery with a built-in pressure switch shown in FIG. 6 is charged when the abnormal internal pressure rises during normal charging / discharging and the packing member bends and the circuit connecting the positive electrode plate and the positive external terminal is disconnected. Therefore, the pressure inside the storage battery does not greatly exceed the predetermined value during charging, but the structure of the pressure switch function is complicated, and the occupied volume of the lid is larger than that of the storage battery without a pressure switch. There is a problem that the capacity of the battery is reduced because the internal space that can accommodate the electrode plate group is small. Furthermore, since the number of parts used is large and the structure is complicated, the cost is high, and there is a disadvantage that the production efficiency is inferior when the lid is assembled and assembled.

  The present invention has been made in view of the problems of the prior art, and by reducing the volume occupied by the pressure switch and simplifying the structure, the internal space for accommodating the electrode plate group is reduced. Therefore, it is intended to provide a sealed storage battery with a pressure switch function that is inexpensive.

This invention achieves the said objective by making the structure of a sealed storage battery into the following structures.
The sealed storage battery according to the present invention is connected to a circuit that connects at least one of the positive electrode plate and the negative electrode plate to an external terminal, and when the internal pressure of the storage battery is equal to or lower than a predetermined value, In a sealed storage battery having a pressure switch function that disconnects the circuit when the pressure exceeds a predetermined value, a metal sealing plate is disposed at the open end of the battery case, and one side is disposed outside the sealing plate. The external plate is disposed, and the sealing plate and the one electrode plate are electrically connected via a lead member, and an electrical insulating layer is disposed between the sealing plate and the external terminal. The external terminal and the sealing plate are electrically connected via a metal spring and a connection member, and the through hole provided in the sealing plate is hermetically sealed with an electrically insulating valve body, The valve body is slidable along the wall surface of the through hole, and the connecting member is the valve body. The position is changed by sliding, and the valve body slides when the pressure inside the storage battery exceeds a predetermined value, and the electrical contact with the sealing plate of the connecting member is caused by the sliding from the sealing plate. It is a sealed storage battery having a function of disconnecting a circuit connecting an electrode plate and an external terminal by being separated. (Claim 1)

  The sealed storage battery according to the present invention is the sealed storage battery according to claim 1, wherein the valve body is a sheet that can be stretched and deformed with a peripheral edge portion fixed to a sealing plate, and the connecting member is positioned by the stretching deformation of the valve body. In general, the external terminal and the sealing plate are electrically connected via a metal spring and a connecting member, and the valve body extends when the pressure inside the storage battery exceeds a predetermined value, A sealed storage battery having a function of cutting a circuit connecting an external terminal and an electrode plate when an electrical contact with the sealing plate of the connecting member is separated from the sealing plate with the elongation. (Claim 2)

  According to claim 1 and claim 2 of the present invention, there is provided a sealed storage battery capable of rapid charging without reducing an effective internal volume as compared with a conventional sealed storage battery having no pressure switch function. Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view of an essential part of a sealed storage battery showing a first embodiment of the present invention.
In FIG. 1A, the internal pressure of the storage battery is equal to or lower than a predetermined value, and the connecting member 5 and the sealing plate 1 are electrically connected via the contact 5A with the sealing plate 1 of the connecting member 5, Indicates that the switch is on. The positive electrode current collector terminal 7 and the sealing plate 1 joined to the end of the positive electrode plate constituting the electrode plate group 8 are connected via the positive electrode lead plate 10. An electrical insulating sheet 2 is disposed between the sealing plate 1 and the cap-like positive external terminal 3 (hereinafter referred to as a cap). Normally, as shown in FIG. 1A, the connecting member 5 and the sealing plate 1 are in contact with each other, and the sealing plate 1 and the cap 3 are connected via the connecting member 5 and the metal spring 6. The circuit connecting the positive electrode plate and the cap 3 is in an on state.

  When the pressure inside the storage battery rises above a predetermined value during charging, the valve body 4 slides upward along the wall surface of the through hole 1A provided in the sealing plate 1 as shown in FIG. Then, the connecting member 5 fixed to the valve body 4 moves upward, the contact 5A is separated from the sealing plate 1, the switch is switched from on to off, and charging is stopped. When the internal pressure of the storage battery drops below a predetermined value while charging is stopped, the valve body 4 slides downward by the pressing force of the spring 6, the connecting member 5 contacts the sealing plate 1 through the contact 5A, and the switch is turned off. The charging is resumed by switching from to ON.

  In addition, although the predetermined value of the pressure inside a storage battery here is not specifically limited, 1.7-3.0 megapascals (MPa) are preferable in a cylindrical nickel metal hydride storage battery or a nickel cadmium storage battery. 2.0 to 2.6 MPa is more preferable. If the predetermined value is less than 1.7 MPa, it takes a long time for the circuit connecting one electrode plate and the external terminal to be off during charging. There is a risk of insufficient charging. When the predetermined value of the internal pressure of the storage battery exceeds 3.0 MPa, the storage battery temperature during charging exceeds the upper limit (about 60 ° C.) of the preferable temperature of the storage battery, and the storage battery constituent material such as the active material is altered and the discharge capacity decreases. There is a fear. Moreover, there is a possibility that the seal between the battery case can and the sealing plate (crimp seal in FIG. 1) may be broken due to an increase in the pressure inside the storage battery. The size of the predetermined value is the size of the compression stress (determined by the elastic modulus of the spring) of the spring 6, the thickness of the valve body 4 {the size of the cross-sectional area of the valve body 4 (the size of the cross-sectional area of the through hole 1A). Can be set to a desired size.

  In this embodiment, the connecting member 5 is fixed to the valve body 4, and the valve body 4 slides up and down along the through-hole 1 </ b> A provided in the sealing plate 1, so that the connecting member 5 is constantly sealed during the movement. There is no possibility of being inclined with respect to the sealing plate parallel to the plate. Therefore, when the pressure inside the storage battery rises and the connecting member 5 rises, the contact point 5A with the sealing plate is surely separated from the sealing plate 1, so that the reliability when the switch is switched from on to off is high.

  FIG. 1 (c) is a diagram showing a state when the pressure inside the storage battery is further increased as compared with FIG. 1 (b), and the valve body 4 is further increased compared with FIG. 1 (b). The space inside the battery (the space below the sealing plate 1 in the figure) and the space inside the cup (the space partitioned by the sealing plate 1 and the cap 3) by the cutout 4A provided on the side surface of the valve body 4 The gas accumulated in the storage battery is moved to the space inside the cap through the notch 4A, and further released to the outside through the exhaust hole 3A provided in the external terminal 3. The

  In this embodiment, the contact point 5A may be a flat surface as shown in FIG. 2 without forming the contact point of the connection member 5 with the sealing member 1 in a protruding shape.

  In the first embodiment, the valve body 4 is made of electrical insulation and is not particularly limited as long as it is a material excellent in resistance to electrolytic solution. However, since it is inexpensive, it is made of polypropylene, polyethylene or the like. A synthetic resin molding such as a polyolefin-based synthetic resin or polytetrafluoroethylene is preferred. Among these, a molded article of polytetrafluoroethylene is a particularly preferable material because it is excellent in dimensional stability at high temperatures and has excellent airtightness and slidability of the contact surface with the through hole 1A of the sealing plate 1.

The material of the sealing plate is not particularly limited, and nickel or nickel-plated steel plate can be applied. The thickness of the sealing plate is preferably 0.4 mm or more, and more preferably 0.6 mm or more so that the valve body 4 slides perpendicularly to the sealing plate without being inclined. In order to keep the thickness of the lid as small as possible, the thickness of the sealing plate is preferably 1 mm or less. In addition, it is preferable that the contact surface between the valve body 4 and the through hole 1A has a high airtightness, and the through hole 1A has a smooth surface without unevenness so that the valve body 4 slides smoothly. The diameter of the through-hole 1A provided in the sealing plate 1 varies depending on the size of the storage battery and is not particularly limited. For example, in the case of AA, the diameter of the through-hole 1A is preferably 1 to 3 mm. If the diameter is less than 1 mm, the pressure applied to the valve body is small when the pressure inside the storage battery rises, and the sensitivity to pressure change may be poor. If the diameter exceeds 3 mm, the valve body 4 tends to be inclined when the pressing force of the spring 6 is applied to the valve body 4.
Moreover, the electrical insulation layer arrange | positioned between the cap 3 and the sealing board 1 is not specifically limited, The coating film or sheet | seat of a synthetic resin is applicable.

(Second Embodiment)
FIG. 3 is a diagram showing a state when the pressure inside the storage battery rises above a predetermined value in the second embodiment of the present invention. In the second embodiment, one end of the connecting member 5 is fixed to the sealing plate 1 via an electrically insulating hinge (hinge) 12, and the other end has a contact 5 </ b> A with the sealing plate 1. The valve body slides upward because the pressure inside the storage battery increases during charging, as in the first embodiment. However, the connecting member 5 is paralleled upward by sliding of the valve body. Instead of moving, the hinge 12 is opened as a fulcrum, and the contact 5A with the sealing plate 1 provided at a position opposite to the hinge 12 of the connecting member 5 is separated from the sealing plate 1 and the switch is switched from on to off. According to this embodiment, one end of the connection member is fixed, and the entire connection member 5 does not move, but only the contact 5A changes its position up and down, so there is an advantage that the operation reliability of the switch is high. . The hinge 12 may be made of an electrically insulating material, and the material is not particularly limited, but a synthetic resin such as a polyamide resin, a polyester resin, or a polycarbonate resin can be used.

(Third embodiment)
FIG. 4 is a diagram illustrating a state when the pressure inside the storage battery rises above a predetermined value in the third embodiment of the present invention. In the present embodiment, the valve body 5 is an expandable / contractable sheet, the peripheral portion of the valve body 5 is fixed to the sealing plate 1, and the through hole 1A provided in the sealing plate 1 is hermetically sealed. . When the pressure inside the storage battery rises and exceeds a predetermined value, the valve body 5 extends and bends upward as shown in the figure. When the bending occurs, the connecting body moves upward, the contact 5A of the connecting member 5 with the sealing plate 1 is separated from the sealing plate 1, and the switch is switched from on to off.

  In the embodiment, the material of the stretchable sheet constituting the valve body 4 is not particularly limited, and various synthetic rubbers such as chloroprene rubber and acrylic rubber, and natural rubber sheets can be applied. The thickness of the sheet is not particularly limited, but is preferably 0.3 to 1.5 mm. If the thickness is less than 0.3 mm, the mechanical strength of the sheet may be insufficient, and the sheet may be damaged, resulting in loss of airtightness. If the thickness exceeds 1.5 mm, the stretchability of the sheet is inferior and the switch function is impaired. There is a fear. In the embodiment, the diameter of the through hole 1A is not particularly limited. In addition, the size and shape of the seat that is the valve body 4 are not particularly limited, but in order to uniformly expand and contract the valve body 4, it is preferably a circular shape, and the diameter thereof is 3 mm or more. If the diameter is less than 3 mm, the extension of the seat, which is the valve body 4, is small, and the pressure switch may not function.

  In this embodiment, since it is not guaranteed that the connecting member 5 moves in parallel when moving upward, the connecting member 5 is turned off when the pressure switch is switched from on to off (the connecting member moves upward). There is a possibility that the contact plate 5A is inclined with respect to the sealing plate 1 and the contact point 5A is not separated from the sealing plate 1. In order to eliminate the fear, in order to move the connecting member 5 in parallel, the outer peripheral end surface of the connecting member 5 is not brought into contact with the inner surface of the cylindrical member, and the connecting member 5 is brought into contact with the inner wall of the cylindrical member. It is effective to make it slide along. Although details are omitted, in FIG. 3, the side wall of the cap 3 is perpendicular to the sealing plate 1, the outer diameter of the connecting member 5 is made equal to the inner diameter of the cap 3, and the outer peripheral end surface of the prescriptive member 5 is brought into contact with the inner wall of the cap 3. By making contact, the connecting member 5 can be slid along the inner wall of the cap 3.

(Fourth embodiment)
FIG. 5 is a diagram showing a state when the pressure inside the storage battery rises above a predetermined value in the fourth embodiment of the present invention. In the present embodiment, the valve body 5 is a sheet that can be expanded and contracted as in the third embodiment, and the peripheral portion of the valve body 5 is fixed to the sealing plate 1, and the through hole 1 </ b> A provided in the sealing plate 1. Is hermetically sealed. When the pressure inside the storage battery rises and exceeds a predetermined value, the valve body 5 extends and bends upward as shown in the figure. When the bending occurs, the connection member 5 opens with the electrically insulating hinge 12 attached to one end thereof as a fulcrum, the contact with the sealing plate provided at the other end is released from the sealing plate, and the switch is turned off.

Hereinafter, the present invention will be described in detail with reference to one example, but the present invention is not limited to the example described below.
(Example 1)
To 94 parts by weight of nickel nitrate, 1 part by weight of cobalt nitrate and 5 parts by weight of zinc nitrate are added. Ammonium sulfate and aqueous sodium hydroxide solution are added dropwise to an aqueous solution in which this is dissolved, and the pH is kept in the range of 11-12. Then, nickel hydroxide particles in which Co and Zn were dissolved were precipitated. This was washed with water and dried to obtain nickel hydroxide powder. Next, nickel hydroxide powder was put into an aqueous solution composed of ammonium sulfate and sodium hydroxide, and cobalt sulfate and sodium hydroxide aqueous solution were added dropwise thereto while stirring and controlling to pH 10-12. After maintaining at a predetermined pH for 1 hour, this was washed with water and dried to obtain nickel hydroxide powder coated with cobalt hydroxide. The content of cobalt hydroxide in the nickel hydroxide powder thus obtained was 6%. Further, after the nickel hydroxide particles coated with cobalt hydroxide were put into NaOH having a temperature of 50 ° C. adjusted to 14 N with the nickel hydroxide powder and stirred, the oxidation value of nickel hydroxide was 2.10. The amount of K ₂ S ₂ O ₈ was changed so that Two hours after the addition of K ₂ S ₂ O ₈ , this was washed with water and dried, and then 98 parts by weight of the powder was mixed with 2 parts by weight of ytterbium oxide. Further, an aqueous solution in which a thickener was dissolved was added to form a paste. This was filled into a nickel porous substrate and then pressed to a predetermined thickness to obtain a positive electrode plate.

MmNi _3.8 Al _0.3 Co _0.7 Mn _0.2 (Mm is misch metal, a mixture of La30%, Ce50%, Pr5%, Nd15%) Weigh each metal so that it has an inert atmosphere. Then, an alloy ingot was prepared in a high frequency induction melting furnace and heat-treated at 1000 ° C. This was pulverized to a size of 75 μm or less to obtain a hydrogen storage alloy powder. Next, 99.5 parts by weight of this hydrogen storage alloy powder was mixed with 0.5 part by weight of ytterbium oxide, an aqueous solution in which a thickener was dissolved was further added, and what was made into a paste using polytetrafluoroethylene as a binder was obtained. After applying to both sides of the punching metal and drying, it was pressed to a predetermined thickness to obtain a negative electrode plate.

The weight ratio of polypropylene to ethylene-vinyl alcohol copolymer is 50:50, and 60 wt. Of splittable composite fiber having a fineness of 3 deniers and a polypropylene, each of which is alternately adjacent to each other in the fiber cross section, and polypropylene as a core component. And wet papermaking to a weight per unit area of 45 g / m ² using 40 parts by weight of a core-sheath composite fiber having a denier of 2 denier having polyethylene as a sheath component, and simultaneously entangling the fibers by jetting a high-pressure water flow onto the paper. The splittable conjugate fiber was split to obtain a nonwoven fabric having a fineness of 0.2 denier after splitting. The thickness was adjusted to 0.12 mm to obtain a separator.

  A positive electrode plate and the negative electrode plate having a capacity 1.2 times larger than the positive electrode capacity were prepared, and a wound electrode plate group was produced by winding the positive electrode plate in a spiral shape with the separator interposed therebetween. The width of the electrode plate group was 42 mm. This electrode plate group is housed in a cylindrical metal can, and after an electrolyte of 7N KOH and 1N LiOH is injected in an amount of 1.16 ml per positive electrode capacity 1 Ah, it has the structure shown in FIG. When the internal pressure of the storage battery rose above 2.4 megapascals (MPa), an AA-sized cylindrical nickel-metal hydride storage battery was fabricated by sealing with a cover body that shuts off the energized state. . The valve body 4 was a molded body made of polytetrafluoroethylene, and its diameter (same as the diameter of the through hole 1A provided in the sealing plate 1) was 3 mm. The thickness of the nickel sealing plate 1 was 2 mm. This example is referred to as Example 1.

(Comparative Example 1)
The conventional pressure switch mechanism having the structure shown in FIG. 6 is provided, and when the internal pressure of the storage battery rises above 2.4 MPa, it is sealed with a lid body that shuts off the energized state. A cylindrical nickel-metal hydride storage battery having the same AA size as in Example 1 except that the width of the electrode plate group was 40 mm was produced. This example is referred to as Comparative Example 1.

(Comparative Example 2)
A conventional AA size cylindrical nickel-metal hydride storage battery was prepared which was not equipped with a pressure switch and was equipped with an exhaust valve in which a through hole provided in a sealing plate was sealed with a rubber valve. Note that a wound electrode plate group having a width of 42 mm was applied. This example is referred to as Comparative Example 2.

(Initialization)
The sealed nickel-metal hydride storage battery according to Example 1, Comparative Example 1, and Comparative Example 2 was measured at an ambient temperature of 20 ° C.
Formed in First time (1st cycle), it was charged at 40 mA for 50 hours, then charged at 100 mA for 12 hours, left for 1 hour, and then discharged at 200 mA with a discharge cut voltage of 1.0 V. From the 2nd cycle to the 10th cycle, the battery was charged at 400 mA for 6 hours, allowed to stand for 1 hour, and then discharged at 400 mA at a discharge cut voltage of 1.0 V.
(Discharge capacity evaluation 1)
Ten batteries after completion of the initialization according to Example 1, Comparative Example 1, and Comparative Example 2 were prepared. The batteries were charged at 400 mA for 6 hours at an ambient temperature of 20 ° C., and left at 400 mA after being left for 1 hour. The battery was discharged at a cut voltage of 1.0 V, and the discharge capacity was determined.
(Discharge capacity evaluation 2)
Ten batteries after completion of the initialization according to Example 1, Comparative Example 1, and Comparative Example 2 were prepared, respectively, and a constant voltage of 1.62 V was applied to the batteries at an ambient temperature of 20 ° C. and charged for 15 minutes. After leaving it for 1 hour, it was discharged at a constant current of 2000 mA with a discharge cut voltage of 0.9 V, and the discharge capacity was determined.
(Evaluation of charge / discharge cycle test)
Ten batteries after completion of the initialization according to Example 1, Comparative Example 1, and Comparative Example 2 were prepared, and the battery was charged with a constant voltage of 1.62 V at an ambient temperature of 20 ° C. for 15 minutes. . After standing for 1 hour, the battery was discharged at a constant current of 2000 mA with a discharge cut voltage of 0.9V. This charging / discharging was made into 1 cycle, and charging / discharging was implemented repeatedly. The cycle number of the battery was defined as the cycle number at which the discharge capacity decreased to 80% of the discharge capacity at the first cycle in the charge / discharge cycle.

表１に示したように、放電容量評価１によれば本発明に係る実施例１および従来の圧力スイッチを備えない比較例２が２０００ｍＡｈであったのに対して、比較例が１９００ｍＡｈと、実施例１、比較例２に比べ放電容量が低かった。比較例１の場合は、実施例１および比較例２に比べて蓋体の厚さが大きく、電槽缶内に収納できる極板群の幅が小さくなったために放電容量が低くなった。
放電容量評価２によれば、実施例１に比べて比較例１および比較例２の放電容量が低い。比較例１は、前記のように極板群の幅が実施例１に比べて放電容量が低くなったものであり、比較例２の場合は、充電中に蓄電池の温度が好ましい温度の上限（６０℃）を超えて上昇したために充電効率が低くなったことと、充電中に蓄電池内部の圧力が上昇して排気弁が開いている間に電解液が外部に逸散して蓄電池の内部インピーダンスが上昇したために放電容量が低くなったものである。 Table 1 shows the results of discharge capacity evaluation 1 and discharge capacity evaluation 2 of Example 1, Comparative Example 1 and Comparative Example 2 (average value of 10 samples).

As shown in Table 1, according to discharge capacity evaluation 1, Example 1 according to the present invention and Comparative Example 2 without a conventional pressure switch were 2000 mAh, while Comparative Example was 1900 mAh. The discharge capacity was lower than in Example 1 and Comparative Example 2. In the case of the comparative example 1, the discharge capacity was lowered because the thickness of the lid was larger than that of the first example and the comparative example 2, and the width of the electrode plate group that could be accommodated in the battery case was reduced.
According to the discharge capacity evaluation 2, the discharge capacity of Comparative Example 1 and Comparative Example 2 is lower than that of Example 1. In Comparative Example 1, as described above, the width of the electrode plate group is such that the discharge capacity is lower than that in Example 1. In Comparative Example 2, the temperature of the storage battery during charging is the upper limit of the preferable temperature ( 60 ° C), the charging efficiency was low, and the internal battery impedance was increased while the exhaust valve was open and the electrolyte was dissipated outside while the exhaust valve was open. As a result, the discharge capacity is lowered.

表２に示すように、実施例１および比較例１は、５００サイクル以上のサイクル寿命を有するのに対して、比較例２はサイクル寿命が１９０サイクルと極端に短い。実施例１および比較例１においては、充電中に圧力スイッチ機能が動作し、蓄電池の温度が好ましい温度の上限（６０℃）を超えて上昇することと排気弁が動作するのを抑制することによって、活物質等の構成材料が変質したり、電解液が外部に逸散するのを抑制したのに対して、比較例２においては充電中に蓄電池の温度が好ましい温度の上限（６０℃）を超えて上昇したために活物質等の構成材料が変質したり、電解液が外部に逸散したために早期に放電容量が低下したと考えられる。 Table 2 shows the charge / discharge cycle test results (10 average values) of Example 1, Comparative Example 1, and Comparative Example 2.

As shown in Table 2, Example 1 and Comparative Example 1 have a cycle life of 500 cycles or more, while Comparative Example 2 has an extremely short cycle life of 190 cycles. In Example 1 and Comparative Example 1, the pressure switch function operates during charging, by suppressing the temperature of the storage battery from exceeding the upper limit (60 ° C.) of the preferred temperature and operating the exhaust valve. In contrast, in Comparative Example 2, the upper limit (60 ° C.) of the preferable temperature of the storage battery during charging was suppressed while the constituent materials such as the active material were altered and the electrolyte was prevented from escaping to the outside. It is considered that the discharge capacity was reduced early because the constituent material such as the active material was altered due to the increase in excess, or the electrolyte was dissipated outside.

  The present invention relates to a sealed storage battery having a built-in pressure switch mechanism that switches on and off a circuit connecting an electrode plate and a terminal in accordance with the pressure inside the storage battery, by reducing the occupied volume of the lid. The present invention provides an inexpensive sealed storage battery that maintains a high capacity and has high industrial utility value.

It is principal part sectional drawing of the sealed storage battery which shows the 1st Embodiment of this invention. It is principal part sectional drawing of the sealed storage battery which shows the 1st Embodiment of this invention. It is principal part sectional drawing of the sealed storage battery which shows the 2nd Embodiment of this invention. It is principal part sectional drawing of the sealed storage battery which shows the 3rd Embodiment of this invention. It is principal part sectional drawing of the sealed storage battery which shows the 4th Embodiment of this invention. It is principal part sectional drawing of the sealed storage battery of the pressure switch built-in type which concerns on the former proposal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing plate 1A Through-hole 2 Electrical insulation layer 3 Cap 3A Exhaust hole 4 Valve body 5 Connection member 6 Spring 9 Battery case can

Claims (2)

  The circuit is connected to a circuit connecting at least one of the positive electrode plate and the negative electrode plate and the external terminal when the pressure inside the storage battery is equal to or lower than a predetermined value, and the pressure exceeds a predetermined value. In a sealed storage battery having a pressure switch function that sometimes disconnects the circuit, a metal sealing plate is disposed at the open end of the battery case, and one external terminal is disposed outside the sealing plate, The plate and the one electrode plate are electrically connected via a lead member, and an electrical insulating layer is disposed between the sealing plate and the external terminal. Normally, the external terminal and the sealing plate are made of metal. The through hole provided in the sealing plate is hermetically sealed with an electrically insulating valve body, and the valve body is attached to the wall surface of the through hole. The connecting member is positioned by sliding the valve body. When the internal pressure of the storage battery exceeds a predetermined value, the valve body slides, and the electrical contact with the sealing plate of the connecting member is separated from the sealing plate along with the sliding, so that the electrode plate and the external A sealed storage battery having a function of cutting a circuit connecting terminals. The valve body according to claim 1, wherein the valve body is a sheet that can be stretched and deformed with a peripheral edge portion fixed to a sealing plate, and the connection member changes its position by the stretching deformation of the valve body, The terminal and the sealing plate are electrically connected via a metal spring and a connection member, and the valve body extends when the pressure inside the storage battery exceeds a predetermined value. A sealed storage battery comprising a function of cutting a circuit connecting an external terminal and an electrode plate when an electrical contact with a sealing plate is separated.

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