JP2009230896A - Safety device for battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety device for battery, in which electric current flows stably even when vibration and shock are added on a battery, and a risk can be avoided appropriately when an abnormality occurs to the battery, and which has excellent productivity. <P>SOLUTION: The safety device S for battery comprises a battery lid 1, a ring member 2, a safety valve 10 having a current breaking mechanism and a gas release mechanism, an insulator 20, a disk 30, and a sub disk 40. The battery lid 1, the ring member 2, and the safety valve 10 each have all conductivity and the battery lid 1 and the safety valve 10 are jointed by welding through the ring member 2, and the insulator 20 has a cylindrical shape. A shelf 24 which intersects perpendicularly with the axial direction of the cylinder is installed inside the cylinder, and the safety valve 10 is insertion engaged on the battery lid 1 side of the shelf 24, and the disk 30 is insertion-engaged on the power source element side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a battery safety device and a secondary battery using the same. In particular, the present invention relates to a battery safety device having a current interruption mechanism and a gas release mechanism used for a battery in which a sealed container such as a nonaqueous electrolyte secondary battery is used, and a secondary battery to which the battery safety device is attached.

  In recent years, electronic devices have been improved in performance due to advances in electronic technology, and sealed container type batteries having a high energy density typified by lithium ion secondary batteries have been used as power sources for these electronic devices. In an airtight container type battery, when an abnormality such as overcharge or short circuit occurs, the temperature in the battery container rises, whereby the electrolyte is decomposed to generate gas and the pressure in the battery container rises. If the pressure in the battery container rises excessively, the battery may ignite, break down, leak electrolyte, etc., and there is a risk of harming the human body or damaging electronic devices in use.

  Conventionally, in order to avoid these dangers, the pressure inside the battery container rises due to abnormalities such as overcharge and short circuit, and when a specific pressure is reached, a mechanism that shuts off the current and releases the generated gas to the outside of the battery system Thus, a safety device having a safety valve having a gas release mechanism for reducing the pressure in the battery container as a component is used. The safety device is connected to the lead from the power generation element of the secondary battery, and is disposed on the lower surface of the battery lid. The outer periphery of the battery lid is aligned with the outer periphery of the safety device, and the outside is covered with an insulating gasket. It is wrapped and attached to the open end of the outer can containing the power generation element via a gasket.

  When the secondary battery is energized, the current from the power generation element flows through the lead to the safety valve and from the safety valve to the battery lid. Conventionally, as described above, the battery lid and the safety valve are assembled by aligning the outer peripheral surfaces of the battery lid and wrapping the outer peripheral portion with an insulating gasket and caulking the open end of the battery outer can. In this method, the battery lid and the safety valve are only physically aligned, and the interval between the mating surfaces of the two differs depending on the assembly conditions when caulking to the battery outer can, and also changes due to vibration and impact. Sometimes. When the distance between the mating surfaces of the battery lid and the safety valve changes, there is a problem that the resistance during energization changes, the amount of current becomes unstable, and the battery life is shortened. The change in resistance during energization becomes more prominent when batteries are used connected in parallel or in series.

  Proposals have been made to make the interval between the mating surfaces of the battery lid and the safety valve constant. For example, in Patent Documents 1 and 2, when assembling the battery lid and the safety valve to the open end of the battery outer can, as shown in FIG. 11, the outer periphery of the battery lid is wrapped by folding the outer periphery of the safety valve, A method is described in which the outer periphery is covered with an insulating gasket and assembled to the open end of the battery outer can via the gasket. This method is improved compared to a method in which the outer periphery of the battery lid and the outer periphery of the safety valve are simply combined. However, the battery lid and the safety valve are only physically combined and are the same as in the past, and are not sufficient to solve the above problems. Moreover, the assembly of the battery lid and the safety device is a separate process, and there is a problem in production.

Japanese Patent No. 3351392 Japanese Patent No. 3387118

  The present invention provides a battery safety device capable of avoiding danger appropriately and having good productivity even when a battery is subjected to vibrations or shocks, in which current flows stably and abnormality occurs in the battery. Objective.

  The invention of claim 1 is a battery safety device comprising a battery lid, a ring material, a current shut-off mechanism and a gas release mechanism, an insulator, a disk, and a sub-disk, wherein the battery lid, the ring material, and the safety valve are Both have conductivity, the battery lid and the safety valve are connected by welding via the ring material, the insulator is cylindrical, and is orthogonal to the axial direction of the cylinder inside the cylinder A safety device for a battery in which a safety valve is fitted to the battery lid side of the shelf and a disk is fitted to the power supply element side.

  According to a second aspect of the present invention, in the battery safety device according to the first aspect of the invention, the battery cover is formed of nickel-based metal or iron-based metal, and the ring material is formed of two layers of nickel-based metal and aluminum-based metal. And a safety device for a battery in which the safety valve is formed of an aluminum-based metal.

  The invention according to claim 3 is a secondary battery in which the battery safety device according to any one of claims 1 or 2 is installed on the top of a power generation element, and the battery safety device and the positive electrode lead are connected. is there.

  In the battery safety device according to the first aspect of the present invention, the battery lid and the safety valve are connected to each other in a conductive state by welding through a ring material, and the safety valve has a current interruption mechanism and a gas discharge mechanism for avoiding danger. Is held. In addition, the battery lid, ring material, and safety valve are integrated by welding in the same process, and the safety valve, insulator, and disc are assembled in a simple process such as fitting and insertion, and the productivity of manufacturing battery safety devices is excellent. . Since the battery lid and the safety valve are integrated, the performance of the safety device can be easily inspected in practical use. The secondary battery using the battery safety device of the present invention has a small change in the amount of current even when subjected to vibration or impact during use, and is likely to be subjected to vibration or impact during use, such as an automobile or construction equipment. This contributes to improved battery reliability.

  The battery safety device according to a second aspect of the present invention has the same effect as that of the first aspect, wherein the battery cover is formed of nickel-based metal or iron-based metal, and the safety valve is formed of aluminum-based metal. It is difficult to directly weld nickel-based metal or iron-based metal to aluminum-based metal. By disposing a ring material made of nickel-based metal and aluminum-based metal between the battery lid and the safety valve, the battery lid and the safety valve can be easily welded via the ring material. Since the battery lid and the safety valve are connected in a state of good conductivity, it is possible to suppress the influence of the resistance change during electrical distribution.

  The invention of claim 3 relates to a secondary battery in which the battery safety device of claim 1 or claim 2 is incorporated. Even if the obtained secondary battery is subjected to vibration or shock, the current flows stably, and when a battery abnormality occurs, the current can be appropriately interrupted and gas can be released appropriately, and danger avoidance is facilitated.

  Hereinafter, an embodiment of a battery safety device S according to the present invention will be described with reference to the drawings. FIG. 1 is a structural cross-sectional view of a battery safety device according to an embodiment of the present invention. 1 are denoted by the same reference numerals in the drawings described in FIG. 2 and subsequent drawings. The battery safety device S includes a battery lid 1, a ring material 2, a safety valve 10, an insulator 20, a disk 30 and a sub disk 40.

  The joint surface 3 between the battery lid 1 and the ring material 2 and the joint surface 4 between the ring material and the safety valve 10 are connected by welding. The battery safety device of the present invention has less resistance change during electrical distribution than the conventional case where the surfaces of the battery lid 1 and the safety valve 10 are physically aligned, and the distance between the battery lid 1 and the safety valve 10 is small. Since it does not change due to vibration or impact, the current flows stably. Welding is performed by spot welding, partial welding, full surface welding, or the like by any one of known welding methods such as ultrasonic welding, laser welding, and resistance welding. After the battery lid 1, the ring material 2 and the safety valve 10 are integrated by welding, as shown in FIG. 1, the outer peripheral edge 17 of the safety valve 10 may be bent to wrap around the outer peripheral edge of the battery lid 1. It is good and it does not have to be wrapped. The battery lid 1, the ring member 2, and the safety valve 10 connected together by welding are covered with an insulating gasket 5, and a battery in which a power generation element (not shown) is accommodated via the gasket 5. It is attached by caulking to the opening of the outer can 6. Thereby, the battery outer can becomes a sealed container.

  The safety valve 10 has a dish shape convex to the power generation element side, a flat flange 11 is formed on the outer periphery of the dish-shaped bottom surface, and a convex surface 12 is formed on the power generation element side at the center of the dish-shaped bottom surface. A projection 13 is formed at the center of the projection to project toward the power generation element side. The lower outer peripheral portion 18 of the safety valve 10 is fitted and crimped to the battery lid side of the shelf 24 provided inside the insulator 20. A flat disk 30 made of an aluminum-based metal is inserted and held on the power source element side of the shelf 24 of the insulator 20.

  A central hole 21 through which the protrusion 13 of the safety valve 10 passes is provided at the center of the shelf 24 inside the insulator 20, and a plurality of gas vent holes 22 are provided at the periphery. The disk 30 has a flat plate shape, and a through hole 31 through which the protrusion 13 of the safety valve 10 passes is provided at the center, and a plurality of gas passage holes 32 are provided at the periphery. The sub disk 40 formed of an aluminum-based metal is attached to the disk 30 by a method such as welding without closing the gas passage hole 32 and closing the through hole 31. The surface of the sub disk 40 on the battery lid side is connected to the protrusion 13 of the safety valve 10 by a method such as welding. The lead 50 from the power generation element is connected to the side of the power generation element of the sub disk 40. Thereby, the lead 50 is electrically connected to the battery lid 1. The lead 50 may be connected to the disk 30.

  2A is a plan view seen from the power generation element side of the battery lid 1, and FIG. 2B is a side sectional view. The planar shape of the battery lid 1 may be a shape corresponding to the shape of the battery outer can 6, and may be any shape such as a circle or a polygon. In the present invention, for the sake of convenience, the planar shape of the battery lid 1, the ring material 2, the safety valve 10, the insulator 20, and the disk 30 as viewed from the top is described as a circle. The peripheral part of the battery lid 1 is formed with a flange 1A, and the central part is formed with a concave surface 1B when viewed from the power supply element side. The concave surface 1B is provided with an exhaust hole 7 for exhausting gas generated due to abnormality of the secondary battery to the outside of the battery. Although the number of the exhaust holes 7 should just be 1 or more, it is preferable to provide in 2-5 places at equal intervals on the inclined surface of the concave surface 1B. There are no particular restrictions on the size and shape of the exhaust hole 7 as long as the pressure of the gas released when the battery is abnormal is designed to be as low as possible.

  The battery lid 1 is made of a conductive material. Among the conductive materials, it is preferable that the conductive material is formed of a nickel-based metal or an iron-based metal. The battery lid 1 is manufactured by a known press working or casting method using the metal material. When the battery lid 1 is formed of an iron-based metal, it is preferable to perform nickel plating for the purpose of improving the corrosion resistance, surface hardness, etc. of the battery lid 1. When the battery lid 1 is formed of a nickel-plated iron-based metal, the nickel-plated iron-based metal may be pressed in advance, or after the battery lid 1 is formed of the iron-based metal, the nickel plating is performed. May be performed.

  Nickel plating of the battery lid 1 is performed by a known nickel method. A method of performing nickel plating after copper plating in advance is preferable. As the type of nickel plating, semi-glossy or matte nickel plating is preferable. The thickness of the nickel plating is 0.5 μm or more, more preferably 1.0 to 100.0 μm. The nickel-based metal refers to pure nickel or an alloy of nickel and one or more metals selected from copper, iron, molybdenum, and other metals, the main component of which is nickel. The iron-based metal refers to a known cold-rolled steel plate, hot-rolled steel plate, and an alloy containing 80% or more of iron-based components.

  3A is a plan view of the ring member 2 viewed from the power supply element side, and FIG. 3B is a side sectional view. The ring material 2 is manufactured by a known punching method or pressing method, and has a hollow disk shape. The ring material 2 is formed of a conductive material that can be welded to the battery lid 1 and the safety valve 10. The ring material 2 is preferably formed of two metal layers, one surface of which is a nickel-based metal 2A and the other surface is an aluminum-based metal 2B. As a specific example, a clad material made of a nickel-based metal and an aluminum-based metal manufactured by a known cold welding method or the like can be given. The clad material may be either an overlay clad material or an inlay clad material. The outer diameter of the ring material 2 may be substantially the same as the outer diameter of the battery lid 1, but is preferably 95 to 100% of the outer diameter of the battery lid 1. The inner diameter of the ring material 2 is preferably in the range of 55 to 90% of the outer diameter of the ring material 2. The aluminum metal refers to pure aluminum or an alloy of aluminum and one or more metals selected from magnesium, manganese, silicone, copper, and other metals, and aluminum is a main component.

  The thickness of the ring material 2 is 0.05 to 1.5 mm, preferably 0.1 to 1.0 mm. When the thickness of the ring material 2 is thinner than the above lower limit, it is difficult to weld the battery lid 1 and the safety valve 10. If it is thicker than the above upper limit, the battery safety device becomes larger or heavier. When the ring material 2 is composed of two layers of a nickel-based metal 2A and an aluminum-based metal 2B, the thickness of the aluminum-based metal 2B is preferably greater than the thickness of the nickel-based metal 2A. By increasing the thickness of the aluminum-based metal 2B, the conductivity of the ring material 2 becomes better. The battery lid 1, the ring material 2 and the safety valve 10 are arranged with the nickel metal surface of the ring material 2 facing the battery lid 1 and the aluminum meter metal surface facing the safety valve 10 side. 10 can be welded simultaneously. Further, after welding the aluminum metal surface of the ring material 2 and the safety valve 10, the nickel metal surface of the ring material 2 and the battery lid 1 may be welded, and the nickel metal of the battery lid 1 and the ring material 2 may be welded. After welding the surfaces, the aluminum metal surface of the ring material 2 and the safety valve 10 may be welded.

  The safety valve 10 is formed of a conductive metal, but is preferably formed of an aluminum-based metal. The safety valve 10 is manufactured by a known press working method. 4A is a plan view seen from the battery lid side of the safety valve 10, and FIG. 4B is a side sectional view. The safety valve 10 has a dish shape that protrudes toward the power supply element. The dish-shaped outer peripheral end 17 serves as a guide when the battery lid 1 and the ring material 2 are installed. The height of the outer peripheral end portion 17 is usually designed to be slightly higher than the sum of the thickness of the battery lid 1 and the thickness of the ring material 2. The outer peripheral end 17 may be bent to enclose the battery lid 1 after the battery lid 1, the ring material 2 and the safety valve 10 are connected by welding. It is also possible to use the safety valve 10 having a shape without an outer peripheral end shown in FIG.

  A flat flange 11 is formed on the outer periphery of the dish-shaped outer peripheral end 17 of the safety valve 10, a convex surface 12 is formed on the power generation element side inside the flange 11, and a power generation element is formed at the center of the convex surface 12. A protruding portion 13 that protrudes toward the side is formed. The shape of the protruding portion 13 is not particularly limited, but is preferably a substantially conical shape or a substantially trapezoidal shape in which the power generation element side is narrowed for ease of processing. The tip of the protrusion 13 may be flat or may swell toward the power supply element. The size 13a of the protrusion 13 on the convex surface 12 is preferably 3 to 25% of the diameter 12a of the concave surface 12, and more preferably 5 to 20%. Further, the depth 13b of the protrusion 13 is a depth at which the thickness of the battery safety device S can be suppressed as much as possible by connecting to the sub disk 40. Preferably, (thickness of shelf 24 of insulator 20 + thickness of disk 30) ≦ 13b <(thickness of shelf 24 of insulator 20 + thickness of disk 30 + 0.2 mm).

  A groove 15 surrounding the protrusion 13 is formed on the flat surface of the convex surface 12. Further, a plurality of linear groove portions 16 are formed from the groove portion 15 toward the outer peripheral portion of the convex surface 12. In the groove 15 and the linear groove 16, the pressure inside the battery container further increases after the protrusion 13 and the sub disk 40 are separated by the pressure of gas generated due to the abnormality of the battery and the current is interrupted. And when it reaches a predetermined pressure, it is a part that cleaves and releases the gas in the battery container. The shape of the groove 15 is not particularly limited as long as the shape surrounds the protrusion 13. Considering the workability of the groove 15, it is preferably circular. Further, the inner diameter of the groove portion 15 is not particularly limited, but is preferably large so that the pressure at the time of gas discharge can be made as low as possible because it is related to the pressure of gas discharge when it is cleaved. For example, the diameter 15a of the groove 15 is larger than the diameter 13a of the protrusion 13, and is preferably 10 to 35% of the diameter 12a of the convex surface 12, more preferably 15 to 30%.

  As shown in FIG. 6, the groove portion 15 is preferably provided with a discontinuous portion 14. Due to the abnormality of the battery, the pressure in the battery rises, and the protrusion 13 and the sub disk 30 are disconnected by the set pressure for current interruption, and the current is interrupted. Furthermore, since the pressure rises, the groove 15 and the linear groove 16 are cleaved at the set pressure. Since the discontinuous portion 14 is provided inside the groove portion 15, it is not separated from the safety valve 10. When the discontinuous portion 14 is not provided, the inside of the groove portion 15 is separated from the safety valve 10 by cleavage, and the inside of the separated groove portion 15 may short-circuit the safety valve 10 and the disk 30 or the sub disk 40 or the lead 50. . When a short circuit occurs, a current flows again through the battery safety device S, and the secondary battery may return to an abnormal state.

  The size 14a of the discontinuous portion 14 only needs to be a size that is not separated by the pressure at the time of cleavage of the groove portion 15, and is, for example, 1/50 to 1/2 of the circumferential length of the groove portion 15; Preferably, the size may be 1/20 to 1/3. The depth of the groove 15 and the linear groove 16 corresponds to the pressure at the time of cleavage, and is determined by the cleavage design pressure of the battery used. Although it is preferable that the depth of the groove part 15 and the linear groove part 16 is the same, it does not necessarily need to be the same. Moreover, it is preferable that the line width of the groove part 15 and the linear groove part 16 is formed in the range of 0.05-0.5 mm.

  In FIG. 4A, the linear groove portion 16 is indicated by a straight line in the radial direction passing through the center of the protruding portion 13, but the linear groove portion 16 is not limited to this. For example, the linear groove 16 may be a straight line that does not pass through the center of the protrusion 13 or may be a radial curve. Although the number of the linear groove portions 16 is not particularly limited, it is preferably in the range of 2 to 10 in general. The length of the linear groove portion 16 is preferably as long as possible because the linear groove portion 16 is a portion where the linear groove portion 16 is cleaved with a predetermined pressure and releases gas when an abnormality occurs, as in the case of the groove portion 15.

  The insulator 20 is made of an insulating material. A resin molded product produced by a known resin molding method such as an injection molding method, a compression molding method, a cast molding method, or a press molding method is preferred. As the resin, a resin having low hygroscopicity and excellent heat resistance is preferably used. Specific examples of suitable resin materials include polypropylene, polybutylene terephthalate, polyacetal, polycarbonate, polyphenylene ether, and phenol resin. These resin materials may be mixed with glass fibers, inorganic additives, and the like.

  The external appearance of the insulator 20 has a cylindrical shape, and has various shapes such as a cylinder and a polygonal column. Hereinafter, a cylindrical shape will be described as an example. 7A is a plan view seen from the battery lid side of the insulator 20, and FIG. 7B is a side sectional view. The insulator 20 has a cylindrical shape, and a shelf 24 orthogonal to the axial center of the cylinder is provided inside the cylinder. A central hole 21 through which the protrusion 13 of the safety valve 10 can pass is provided in the central part of the shelf 24, and a plurality of gas passage holes 22 are provided in the peripheral part. The center hole 21 may have any shape and size that does not come into contact with the protrusion 13 of the safety valve 10 when the battery safety device S is assembled. The gas passage hole 22 has a shape that allows the generated gas to pass through when an abnormality occurs in the battery. The gas passage hole 22 closes the gas vent hole 32 provided in the periphery of the disk 30 as much as possible. Any shape and size are acceptable. A plurality of gas vent holes 32 are preferably provided symmetrically with respect to the center of the insulator 20.

  The safety valve 10 is fitted and held on the battery lid side of the shelf 24 of the insulator 20 so as to abut, and the disk 30 is fitted and held on the power supply element side of the shelf 24 so as to abut. Thereby, the safety valve 10 and the disk 30 are insulated. The shelf 24 of the insulator 20 may have a structure in which 55 to 95% of the inner diameter of the insulator 20 is provided and the hole serves as the central hole 21 and the gas passage hole 22. The insulator 20 is preferably provided with a rotation prevention 23 in order to prevent the held safety valve 10 from rotating and rattling.

  The disk 30 is preferably formed of a conductive material having a tensile strength greater than that of the safety valve 10. A preferred material for the disk 30 is an aluminum-based metal. By making the tensile strength of the material used for the disk 30 higher than that of the safety valve 10, the deformation of the safety valve 10 becomes larger than the deformation of the disk 30 when the pressure in the battery container rises due to the occurrence of a battery abnormality. The load on the connection portion between the protrusion 13 of the safety valve 10 and the sub-disk 40 is increased, and the connection portion is easily peeled off with a predetermined pressure. When the safety valve 10 and the disk 30 are formed of the same conductive material, the thickness of the disk 30 is designed to be thicker than that of the safety valve 10.

  The disk 30 has a flat plate shape. Hereinafter, a disk shape will be described as an example. 8A is a plan view of the disk 30 as viewed from the battery lid side, and FIG. 8B is a side sectional view. The disk 30 has a disk shape, and is manufactured by a known pressing method or cutting method. A through hole 31 through which the protrusion 13 of the safety valve 10 can pass is provided at the center of the disk 30, and a plurality of gas vent holes 32 are provided at the periphery. The through-hole 31 may be of a size that does not come into contact with the protrusion 13 of the safety valve 10 when the battery safety device S is assembled, and there is no particular restriction on the shape. A preferable shape of the through hole 31 is a circle. The vent hole 32 may have any shape and size that allows gas generated when the battery is abnormal to pass. A plurality of gas vent holes 32 are preferably provided symmetrically with respect to the center of the disk 30. The disk 30 is fitted and held on the power source element side of the shelf 24 of the insulator 20 so as to abut. The disk 30 is preferably provided with an anti-rotation 33 for preventing rotation and rattling after being fitted to the insulator 20.

  The sub disk 40 is made of a conductive material. The sub disk 40 is preferably formed of an aluminum-based metal having a thickness of 0.03 to 0.5 mm. As shown in FIG. 9, the sub-disk 40 is brought into contact with the surface of the disk 30 on the power generation element side, closes the through hole 31 of the disk 30, and is connected to the disk 30 by a known welding method. The sub disk 40 is opposed to the entire area of the through hole 31, has a shape and a size that completely closes the through hole 31 and does not block the gas vent hole 32.

  The substantially central portion of the surface of the sub disk 40 on the battery lid side is connected to the tip of the protrusion 13 of the safety valve 10 that has passed through the through hole 31 of the disk 30 by a known welding method. The connection strength between the sub-disk 30 and the protrusion 13 and the connection strength between the disk 30 and the sub-disk 40 are not particularly limited as long as they are not separated by an impact such as vibration or dropping. Both connection strengths may be equal, and either connection strength may be large.

  The lead 50 from the power generation element is connected to either the disk 30 or the sub disk 40 by a known welding method.

  In the battery safety device S of the present invention, the insulator 20, the disk 30, and the sub disk 40 may be assembled to the safety valve 10 after the battery lid 1, the ring material 2, and the safety valve 10 are connected by welding. After the insulator 20, the disk 30, and the sub disk 40 are assembled to the battery 10, the battery lid 1, the ring material 2, and the safety valve 10 may be welded.

  The battery safety device S of the present invention can be assembled by a known and simple method of fitting and welding, and does not require special equipment or manufacturing technology, so that workability is good. Further, since the battery lid 1 and the safety valve 10 are integrated in advance, the productivity is also good. An example of a method for incorporating the battery safety device S of the present invention into the battery is as follows. After the lead 50 is connected to the surface of the disk 30 or the sub-disk 40 on the power generation element side, the battery of the battery safety device S of the present invention is connected. The outer periphery of the lid 1, the ring material 2 and the safety valve 10 is sandwiched between gaskets 5 and caulked on the upper opening end of the battery outer can 6.

  Next, the operation of the battery safety device S of the present invention incorporated in the battery will be described. FIG. 10 is a view showing only the safety valve 10 taken out and its operating condition. The description will be made with the safety valve 10 having a shape in which the groove 15 surrounding the protrusion 13 of the safety valve 10 has a discontinuous portion 14.

  FIG. 10A shows the state of the safety valve 10 when the battery is normal. In this state, current flows from the sub disk 40 to the safety valve 10, the ring material 2, and the battery lid 1 through the lead 50 from the power generation element. When an abnormality such as overcharge or short circuit occurs in the battery, the temperature in the battery container rises, gas is generated due to the temperature rise, and the pressure in the battery container rises. The generated gas passes through the gas vent hole 32 of the disk 30 and the gas passage hole 22 of the insulator 20 and applies pressure to the power generation element side surface of the convex portion 12 of the safety valve 10. As a result, as shown in FIG. 10B, the convex portion 12 of the safety valve 10 is pushed up to the lid side of the battery, and a separation force is applied to the connecting portion between the projection 13 of the safety valve 10 and the sub disk 40. . When the pressure in the battery container further rises and the pressure applied to the convex portion 12 of the safety valve 10 reaches the design pressure value for disconnecting the connecting portion between the protruding portion 13 of the safety valve 10 and the sub disk 40, the protruding portion 13 of the safety valve 10. And the sub-disk 40 are disconnected, and the current is cut off. It should be noted that the connection part may be disconnected only at the connection point, and a part of the sub disk 40 at the connection point may be torn off.

  Since the gas generation continues for a while even when the current is cut off, the pressure in the battery container further rises, and when the pressure reaches the design value for the cleavage of the groove 15 and the linear groove 16, as shown in FIG. Thus, the groove part 15 and the linear groove part 16 of the safety valve 10 are cleaved. By this cleavage, the gas in the battery container is released out of the battery system from the exhaust hole 7 formed in the battery lid 1. Thereby, the abnormal state of the battery is eliminated. Since there is a discontinuous portion 14 inside the groove portion 15 surrounding the protrusion 13 of the safety valve 10, the state is directed toward the lid side of the battery and is not separated from the safety valve 10. Therefore, after the abnormal state of the battery is resolved, the safety device of the present invention continues the current interruption state, and the battery is maintained in a safe state.

  As described above, the battery safety device according to the present invention has a stable current even if it receives vibration or shock during normal operation, and when an abnormality occurs in the battery, the pressure in the battery container increases and reaches a predetermined pressure. Then, the current is cut off, and subsequently, the groove 15 and the linear groove 16 of the safety valve 10 are cleaved to release gas, thereby eliminating the abnormal state of the battery. In the safety device S of the present invention, after the abnormal state is resolved, the current interruption state is reliably maintained, and the battery does not return to the abnormal state again.

  The battery safety device of the present invention can be applied to many types of batteries having a pressure release mechanism. The battery in which the safety device of the present invention is incorporated can be used for various electronic devices, and the safety of these electronic devices can be improved.

1 is a cross-sectional view of a configuration of a battery safety device according to an embodiment of the present invention. Plan view and side cross-sectional view of battery cover Top view and side cross-sectional view of ring material Top view and side sectional view of the safety valve Side sectional view of a safety valve with a flat outer peripheral edge Top view of a safety valve with discontinuities in the groove Plan view and side cross-sectional view of insulator Top view and side sectional view of the disc Cross section of the connection between the protrusion and the sub disk Operation diagram of safety valve of the present invention Cross-sectional view of a conventional battery safety device

Explanation of symbols

S Battery safety device 1 Battery cover 1A Battery cover flange 1B Concave surface of battery cover 2 Ring material 2A Nickel metal of ring material 2B Aluminum metal of ring material 3 Welded surface of battery cover and ring material 4 Ring material and safety valve Welding surface 5 Gasket 6 Battery outer can 7 Battery cover exhaust hole
DESCRIPTION OF SYMBOLS 10 Safety valve 11 Flange part of safety valve 12 Concave surface of safety valve 12a Inner diameter of concave surface 13 Projection part 13a Diameter of projection part 13b Depth of projection part 14 Groove part discontinuous part 14a Size of discontinuous part 15 Groove part 16 Linear groove part 17 Dish Shaped outer peripheral edge 18 Lower outer peripheral part of safety valve 20 Insulator 21 Insulator central hole 22 Insulator gas passage hole 23 Insulator rotation / movement prevention 24 Shelf inside insulator cylinder 30 Disc 31 Disc through-hole 32 Disc vent hole 33 Prevention of disc rotation / movement 40 Sub disc 50 Lead

Claims (3)

  In a battery safety device comprising a battery lid, a ring material, a current cutoff mechanism and a gas release mechanism, an insulator, a disk and a sub disk, the battery lid, the ring material and the safety valve are all conductive. The battery lid and the safety valve are connected by welding via the ring material, the insulator is cylindrical, and a shelf perpendicular to the axial direction of the cylinder is provided inside the cylinder, A safety device for a battery, wherein a safety valve is fitted to the battery lid side of the shelf, and a disk is fitted to the power supply element side.   2. The battery safety device according to claim 1, wherein the battery cover is formed of nickel-based metal or iron-based metal, the ring material is formed of two layers of nickel-based metal and aluminum-based metal, and the safety valve is formed of aluminum-based metal. A safety device for a battery, characterized in that it is formed of.   A secondary battery comprising the battery safety device according to claim 1 installed on an upper part of a power generation element, and connected to the battery safety device and a lead from the power generation element.

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