JPH10321213A - Safety device for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device which can surely interrupt a current in the outside of a chamber for housing an electrode when the internal pressure of a vessel is abnormally raised, and prevent the firing even when a spark is generated at that time by providing a blade part supported by a bulkhead and moved together with the bulkhead to cut a conductor. SOLUTION: When a gas is generated in a battery reaction part 20 to cause an abnormal internal pressure rise of a vessel 10, the body part of a bulkhead 110 is pressed upward. When the energizing force reaches a certain fixed magnitude, the body part of the bulkhead 110 moves a recessed part 112 together with a blade part 130. The blade part 130 moved to the position of a conductor 120 cuts the conductor 120. Even if a spark is generated in the cut part at this time, an electrolyte and vapor or decomposed gas thereof are never fired since they are present in a position separated by the bulkhead 110. The current path of the current carried from the battery reaction part 20 to an outer lid 32 is interrupted by the cutting of the conductor 120, and the abnormal gas generating reaction in the battery reaction part 20 is consequently stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a battery safety device.

[0002]

2. Description of the Related Art In recent years, as the functionality of portable electric devices such as cellular phones, portable video cameras, and notebook computers has been improved,
The need for higher capacity and higher energy density in batteries serving as the power source is rapidly increasing. Under such circumstances, a battery having a high energy density such as a lithium secondary battery has been developed, and such a battery has been widely used.

[0003] In a battery having such a high energy density, an unexpected abnormal battery reaction does not necessarily occur because a highly active battery reaction occurs. For example, when a short circuit, overcharging, overheating, or the like occurs, it is assumed that an abnormal chemical reaction occurs in the battery reaction section and a large amount of gas is generated. At this time, the internal pressure of the battery container is abnormally increased, and the container may be ruptured. Of course, not all batteries are at risk of such a rupture, but it is extremely important to equip battery containers with safety devices that can prevent the rupture of the container in order to cope with any contingencies. It is.

Conventionally, as such a battery safety device, a device that detects an abnormal increase in internal pressure and shuts off a current path, as disclosed in Japanese Patent Application Laid-Open No. 2-28863, for example, is known. I have. The safety mechanism is to interrupt the current path to stop abnormal chemical reaction and prevent gas generation. However, this battery safety device has a problem in that a current path cutoff unit is provided in a room in which the electrolyte is stored. For example, in a lithium secondary battery, a flammable electrolyte such as an organic solvent is generally used. In such a battery, when the current path is interrupted and a spark is generated, it is conceivable that the gas or the electrolytic solution in the container jumps and ignites the gas or the electrolytic solution. Further, it is conceivable that the battery may explode due to such ignition.

Therefore, a battery safety device as shown in FIG. 9 has been proposed, for example, as shown in FIG.
No. 01). This battery safety device is provided with a current path cut-off device outside a room in which an electrolyte is stored. The current path cut-off device includes a current cutoff valve 1 having a contact projection 1a,
And a blocking terminal 2 attached in contact with the contact projection. When an abnormal increase in the internal pressure of the container occurs in the battery safety device, the contact protrusion 1a is detached from the cutoff terminal 2 to cut off the current. However, depending on the state of contact between the contact protrusion 1a and the cutoff terminal 2, an electrically large contact resistance may be generated, and good conductivity may not be obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and provides good conductivity at a cut-off portion during normal use, and accommodates electrolyte when abnormal internal pressure rise of a container. The current path can be reliably shut off outdoors
It is an object of the present invention to provide a battery safety device that does not ignite an electrolytic solution, its vapor, a decomposition gas, or the like even if a spark occurs at that time.

[0007]

SUMMARY OF THE INVENTION One of the battery safety devices according to the present invention is to shield an opening of a container for accommodating a battery electrode and an electrolyte and to move outwardly of the container in response to a rise in the internal pressure of the container. A moving partition, a conductor disposed outside the partition to conduct the battery reaction part and the terminal, and a blade supported by the partition and moving with the partition to cut the conductor. It is characterized by the following.

[0008] One of the battery safety devices of the present invention comprises a partition which covers an opening of a container for accommodating a battery electrode and an electrolytic solution and moves outwardly of the container in response to a rise in the internal pressure of the container; An electrical conductor arranged outside the battery for electrically connecting the battery reaction part and the terminal, a first shear blade member supported by the partition wall and moving together with the partition wall, and a second shear blade member fixed to the outside of the conductor; And a shear blade section configured to shear and cut the conductor with the first shear blade member and the second shear blade member.

[0009] One of the battery safety devices of the present invention is a partition that shields an opening of a container for accommodating a battery electrode and an electrolytic solution and moves outwardly of the container in response to an increase in the internal pressure of the container.
A first conductive member disposed outside the partition and electrically connected to the battery reaction unit; and a second conductive member electrically connected to the terminal and abutted on the first conductive member.
A conductor comprising a conductive member, and the first conductive member
A spring for urging in a direction separating from the conductive member, a high-pressure chamber filled with high-pressure gas and pressing the first conductive member against the second conductive member against the urging force of the spring, and a partition supported by the partition and the partition And a pin member that moves together with the high-pressure chamber to break the high-pressure chamber and lose its pressing force.

[0010] One of the battery safety devices of the present invention is a partition for shielding an opening of a container for accommodating a battery electrode and an electrolytic solution, and a first conductive member formed integrally with the partition and electrically connected to a battery reaction section. A member, a second conductive member that is in contact with the first conductive member by the pressing force of the partition and is in conduction with the terminal, and a negative pressure is applied to a chamber disposed outside the partition and located inside the partition. An outer lid forming a negative pressure chamber for attracting the partition and pressing the first conductive member against the second conductive member, and surrounding an abutting portion between the first conductive member and the second conductive member in the negative pressure chamber. And a shielding member for shielding from the first conductive member when the internal pressure of the container rises abnormally, sending gas in the container into the negative pressure chamber to remove the negative pressure, and removing the pressing force of the partition. The member is separated from the second conductive member.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A battery to which the battery safety device of the present invention can be applied is only required to have a container for accommodating a battery reaction part involved in a battery reaction, and a primary battery is a secondary battery. And any type of battery. The shape of the battery is not limited. The possible forms of the battery safety device are described below. (About the battery safety device according to claim 1) The battery safety device of the present invention includes the three members of the partition wall, the conductor, and the blade portion as described above. The form of each of these members will be described below.

The partition is not particularly limited in its form. For example, the partition is a thin plate having the same shape as the opening of the container, and its main body is separated from the conductor by a predetermined distance. Can be directly or indirectly fixed to a container. In this example, since the central portion of the main body is movable outward in response to the increase in the internal pressure of the container, the central portion of the partition moves outward in the container in response to the increase in the internal pressure of the container. .

As the conductor, a conductive material that directly or indirectly conducts between the battery reaction portion and the terminal can be used. That is, it may be electrically connected to the battery reaction unit with the partition wall interposed therebetween, or may be electrically connected without the partition wall interposed therebetween. In the former case, at least a portion of the partition wall to be energized needs to be made of a conductive material, and may be entirely formed of a conductive material. In the latter, the partition does not necessarily need to be made of a conductive material.For example, a part of the conductive body is extended inside the partition, or the conductive body is connected to another conductive member that is electrically connected to the battery reaction part, so that the conductive body can be connected to the battery. It can be made to conduct to the part.

The above conductor is not particularly limited in its form, and may be, for example, linear or plate-shaped. However, it is preferable that the plate-like member is used when a large current flows. The shape of the blade is not particularly limited. For example, a sharp knife having a one-character horizontal cross section like a kitchen knife can be used. When electrical insulation is required, the whole may be formed from an insulating material, or the base may be formed from a metal and the surface thereof may be provided with an insulating coating.

In the battery safety device of the present invention, a cutout groove may be provided at a portion where the conductor is cut by the blade. For example, if a blade having a one-character horizontal cross section as described above is used as the blade, it is preferable to provide a linear cutout groove so that the blade edge just hits the groove. In the battery having the above configuration, when the internal pressure of the container is within a safe range, the current flows in the order of the battery reaction section, the partition, the conductor, and the terminal. When an abnormal internal pressure rise of the container occurs due to an abnormal chemical reaction in the battery reaction section due to a short circuit, overcharge, or the like in the battery, the partition wall is pushed upward by the urging force of the internal pressure. When the urging force reaches a certain size, the partition wall moves upward together with the blade, and presses the blade against the conductor to cut the conductor into two.

By cutting the conductor in this way,
In the current flowing from the battery reaction section to the outer lid, the current path is interrupted halfway, and the current flow is stopped. as a result,
The abnormal gas generation reaction in the battery reaction section is cut off and eventually stopped, so that the cause of the abnormal increase in the internal pressure is removed, and the abnormal increase in the internal pressure is stopped. Further, when an abnormal increase in the internal pressure is very rapid, it may be difficult to immediately stop the increase in the internal pressure even if the current is interrupted by the conductor. In the safety device of the present battery, even if the current is interrupted in this way, in case a larger internal pressure is generated in the container,
It is preferable to provide a safety valve in the partition wall or the container which can be broken by the large internal pressure to release the pressure to the outside. This safety valve further increases the certainty of preventing battery rupture,
Further security can be ensured.

Specifically, such a safety valve can be formed by providing a thin-walled portion, a notch, or the like which breaks when a large pressure acts on a part of the partition wall. Alternatively, such a thin portion or notch may be provided on a part of the wall (side surface) of the container inside the partition. When using the latter, make sure that the electrolyte does not leak
Preferably, a space is provided between the battery reaction section and the partition wall, and a safety valve is provided on a container wall in contact with the space.

In addition to the above-described structure, the safety device of the present battery has a configuration in which the partition wall has conductivity and the blade portion has a cylindrical blade, and the partition wall and the conductor are provided in a cylindrical hole of the blade portion. And a conductive lead for conducting between the two. At this time, for example, a cylindrical shape can be used for the blade portion, and the shape of the blade can be any one of three types as shown in FIG. When the notch groove is provided in the conductor, it is desirable that the shape of the notch groove be selected in accordance with the shape of the blade portion. For example, if a cylindrical blade is used, various circular notches as shown in FIG. 12 can be used. In addition, if a blade having a tubular shape with a rectangular cross section is used, various square notches as shown in FIG. 13 can be used.

In this battery safety device, the conductor is cut off so as to be cut out by the cylindrical blade. That is, the cut portion is a closed curve, and an insulating blade portion is interposed between the two cut portions. Therefore, the current transmitted from the conductive lead cannot flow to the terminal through the conductor. Also in this battery safety device, it is preferable to provide a rupture valve in the partition wall or the container which can be broken by an internal pressure larger than the internal pressure at which current is interrupted and release the pressure to the outside similarly to the above battery safety device. (About the battery safety device according to claim 3) The battery safety device of the present invention includes the three members of the partition wall, the conductor, and the shearing blade as described above. The form of each of these members will be described below.

The partition is not particularly limited in its form. For example, as in the above-mentioned example of the battery safety device according to the first aspect, the partition has a thin plate shape having the same shape as the opening of the container. While keeping the main body at a predetermined distance from the conductor,
A container whose peripheral edge is directly or indirectly fixed to a container can be used. The shape of the conductor is not particularly limited, and may be, for example, linear or plate-like as in the above-described example.

The shear blade portion is further divided into two members, a first shear blade member and a second shear blade member. The first shear blade member and the second shear blade member each have an edge at the tip portion, and the first shear blade member is directly or indirectly connected to the partition, and the second shear blade member is directly or indirectly connected to the container. By attaching, a shearing blade part can be configured. The positional relationship is set such that the edges face each other along the broken surface of the conductor to be cut and are along the broken surface.

When the internal pressure rises abnormally, the first shear blade member and the second shear blade member are applied to both sides of the portion of the conductor to be cut, and a shear force acts on the cut fracture surface. Let it. The shearing force allows the conductor to be cut into two as if it were cut with scissors. In the battery safety device of the present invention, similarly to the battery safety device of the first aspect, a rupture valve that is ruptured by an internal pressure larger than the internal pressure at which current is interrupted and that can release the pressure to the outside is provided on the partition wall or the container. Is preferred. (About the battery safety device according to claim 4) As described above, the battery safety device of the present invention is provided with five kinds of members of the partition, the conductor, the spring, the high pressure chamber, and the pin member. The form of each of these members will be described below.

The partition is not particularly limited in its form. For example, as in the above-described example of the battery safety device according to claim 1, the partition has a thin plate shape having the same shape as the opening of the container. It is possible to use one in which the main body is separated from the conductor by a predetermined distance and the peripheral edge is directly or indirectly fixed to the container. The conductor is further divided into two types of members, a first conductive member and a second conductive member.
The first conductive member is a member that is located outside the partition wall and is electrically connected to the battery reaction unit. Further, the second conductive member is a member located outside the first conductive member and electrically connected to the terminal. These members are in contact with each other by pressing the second conductive member against the first conductive member by the high-pressure chamber. It is preferable to use a material having good conductivity as a material constituting these members, and an aluminum alloy or the like can be used in consideration of mechanical strength and the like.

The type of the spring is not particularly limited by the type of the spring. For example, a coiled spring can be used. In this coil-shaped spring, the first conductive member can be urged in a direction separating from the second conductive member by using the expansion and contraction force. The high-pressure chamber can be configured by enclosing a high-pressure gas in a hollow sealed bag-like member. The pressure of the high-pressure gas is not particularly limited, and may be a size such that the second conductive member pressed against the first conductive member is fixed.

The type of the pin member is not particularly limited by the type of the pin. For example, a nail-shaped pin member can be used. When this nail-shaped pin member is used, the first conductive member and the second conductive member each having a through-hole extending outwardly of the container can be used. At this time, the first conductive member and the second conductive member are arranged side by side so that the respective through holes are continuous in the outer direction of the container, and the high-pressure chamber is installed immediately outside the through hole of the second conductive member. The pin member can be positioned in the through hole such that the pin tip faces outward, and attached to the partition.

In this battery safety device, when the internal pressure of the container is normal, the current flows through the battery reaction section, the partition, and the first
It flows in the order of the conductive member, the second conductive member, and the terminal. When an abnormal chemical reaction occurs in the battery reaction part due to a short circuit, overcharge, or the like in the battery and an abnormal increase in the internal pressure of the container occurs, the partition wall is pushed upward by the urging force of the internal pressure. When the urging force reaches a certain level, the partition wall and the pin member move upward, and the pin end of the pin member is pressed against the high-pressure chamber.

Thus, the bag-like member of the high-pressure chamber is broken by the pin member, and the sealed high-pressure gas is released. As a result, the high-pressure chamber loses the pressing force of the first conductive member against the second conductive member, and cannot press the first conductive member against the second conductive member against the urging force of the spring.
At this time, the first conductive member is separated from the second conductive member by the action of the spring, and the current is interrupted.

In the battery safety device of the present invention as well, similar to the battery safety device of the first aspect, a rupture valve which can be broken by an internal pressure larger than the internal pressure at which current is interrupted and which can release the pressure to the outside is provided with a partition or a rupture valve. Preferably, it is provided in a container. (About the battery safety device according to claim 5) As described above, the battery safety device of the present invention includes the five types of members of the partition, the first conductive member, the second conductive member, the outer lid, and the shielding member. The form of each of these members will be described below.

The partition is not particularly limited in its form. For example, as in the above-mentioned example of the battery safety device according to claim 1, the partition has a thin plate shape having the same shape as the opening of the container. It is possible to use one in which the main body is separated from the conductor by a predetermined distance and the peripheral edge is directly or indirectly fixed to the container. The first conductive member is a member that is located outside the partition wall and is electrically connected to the battery reaction unit. Also, the second
The conductive member is a member located outside the first conductive member and electrically connected to the terminal. It is preferable to use a material having good conductivity as a material constituting these members, and an aluminum alloy or the like can be used in consideration of mechanical strength and the like.

The outer lid is a member that seals a space located outside the partition and forms a negative pressure chamber in which a negative pressure is applied to the chamber located inside the partition. The negative pressure chamber can draw the partition wall in its own direction, that is, outwardly with respect to the container, by its own negative pressure. The second conductive member can be pressed against the first conductive member and brought into contact with each other by the pressing force of the partition wall by the negative pressure chamber.

The shielding member is provided in the negative pressure chamber, and shields a contact portion between the first conductive member and the second conductive member from the surroundings, so that gas in the container flowing into the negative pressure chamber when current is interrupted can be prevented. It is a member that does not touch the contact portion. That is, this member isolates the contact portion between the first conductive member and the second conductive member from the negative pressure chamber into which the gas in the container flows. The member desirably has a structure that seals the contact portion between the first conductive member and the second conductive member and its atmosphere.
For example, if the first conductive member has a cylindrical shape, a bellofram-shaped one can be used.

In this battery safety device, when the internal pressure of the container is normal, the current flows in the order of the battery reaction section, the first conductive member, and the second conductive member. If an abnormal internal pressure rise occurs in the container due to an abnormal chemical reaction in the battery reaction section due to a short circuit or overcharge in this battery, the gas in the abnormally increased container is sent to the negative pressure chamber, and the negative pressure rises. The negative pressure in the pressure chamber is removed.

Here, in the present invention, the method of sending the abnormally increased internal pressure of the container into the negative pressure chamber is not particularly limited, but the partition is broken by a predetermined pressure and the container is moved into the negative pressure chamber. It is preferable to have a rupture valve to feed the gas inside. The rupture valve can be formed by providing a thin portion or a notch in a part of the partition wall that is in contact with the negative pressure chamber. Alternatively, a through hole may be provided in a part of the partition wall in contact with the negative pressure chamber, and a thin plate capable of closing the through hole may be attached. When the internal pressure of the container rises abnormally, such a rupture valve is ruptured by the urging force of the internal pressure, and the internal pressure of the container can be sent into the negative pressure chamber through the through hole.

When the negative pressure in the negative pressure chamber is removed in this way, the negative pressure chamber can no longer attract the partition, and the pressing force between the first conductive member and the second conductive member of the partition is removed. Thus, the first conductive member is separated from the second conductive member, and current is interrupted. In the battery safety device, it is preferable to provide a safety valve on the outer lid that can be broken by an internal pressure higher than the internal pressure at which current is interrupted and release the pressure to the outside.

[0035]

[Operation and Effect] In the battery safety device of the present invention, a thick conductive material capable of conducting a large current can be used for the conductor (conductive member). As a result, when the internal pressure of the container rises abnormally, the current path can be reliably shut off. therefore,
It can be used for large-capacity batteries in which large current flows.

Further, the current path can be cut off at a place where the current path is not exposed to the electrolytic solution composed of the organic solvent and its vapor or decomposition gas. Therefore, even if a spark is generated at the time of current interruption, the electrolyte and the like do not ignite. Accordingly, it is possible to prevent the battery from being ignited or ruptured due to such a spark. Further, the pressing force of the internal pressure at which the conductor is cut can be easily grasped in advance at the stage of designing the apparatus.
Therefore, the operating pressure at which the current interruption occurs can be easily set.

[0037]

The present invention will be described below in detail with reference to examples. In the following description, the vertical direction is defined by the vertical direction in the reference diagram. (Embodiment 1) In this embodiment, the safety device according to claim 1 is incorporated in a lithium secondary battery having a substantially cylindrical, rotationally symmetric outer shape. FIG. 1 schematically shows a battery part in which the battery safety device is incorporated.

In this battery, a battery reaction part 20 in which a battery reaction takes place is accommodated in a bottomed cylindrical container 10 having good conductivity and constituting a negative electrode terminal. It is sealed. The battery reaction section 20 is composed of an electrode assembly (not shown) and an electrolyte (not shown), and the electrode assembly is immersed in this electrolyte. The electrode assembly is a spiral electrode formed by spirally winding a current collector on the positive electrode side in a round bar standing along the axis and a separator made of a porous film between the sheet-like positive electrode and the negative electrode. Department. Further, the electrolytic solution is composed of various known organic solvents.

The cover 30 includes a battery safety device 100 and an outer cover 32 that protects the battery safety device 100 from the outside and also serves as an external positive terminal. The safety device 100 shields an opening of the container 10 containing the battery electrode and the electrolyte, and moves in the outward direction of the container 10 according to an increase in the internal pressure of the container 10,
The battery reaction unit 20 and the outer lid 3 are arranged outside the partition 510.
2 (terminal) and a conductor 120 for conducting, and a partition 110
And a blade 130 that is supported by the partition wall 110 and moves together with the partition 110 to cut the conductor 120. These members are integrated with the outer lid 32 by the outer peripheral frame 34 and attached to the container 10, and are electrically insulated from each other in the essential parts using various insulating members. Hereinafter, each of these members will be described.

The partition 110 is made of a substantially dish-shaped plate made of an aluminum alloy. The peripheral portion 110b is fixed to the container 10 by the outer peripheral frame 34 so that the main body 110a is positioned at a predetermined distance from the conductor 120. The main body 110a of the partition 110 has a concave portion 110c at the center thereof capable of holding the blade portion 130, and bent portions 110d and 110e are provided at two places around the concave portion 110c.
With. These bent portions 110d and 110e can be plastically deformed by the action of internal pressure from below. Also,
One end (left end) of the main body 110a is connected to the battery reaction section 20.
A conductive lead 112 that is electrically connected to the conductive lead 112 is attached.

Further, although not shown here, the partition 110 has a safety valve which can be broken by an internal pressure higher than an internal pressure at which a current is interrupted as described later and released to the outside. The conductor 120 is made of an aluminum alloy, and is made of a rectangular thin plate. At both ends, an arc-shaped protrusion is provided along the peripheral edge of the partition 110, and the protrusion is pressed between the partition 110 and the outer lid 32 to form a conductor 120.
Was fixed. One end (left end) is insulated from the partition wall with an insulating plate 122 interposed, and the other end (right end) is insulated from the outer lid 32 with an insulating plate 124 interposed.

The conductor 120 has a notch groove 120a, which is located at the center thereof and cut by the blade portion 130, and extends linearly and has an inverted V-shaped cross section. Here, in the cross section through which the current of the thin portion passes (in FIG. 1, the plane perpendicular to the paper surface of the thin portion corresponds), the entire cross section has a sufficient cross-sectional area to allow a large current to flow. The depth of the notch groove is set as described above.

The blade portion 130 has a one-character horizontal cross section as schematically shown in FIG. 10, and has a blade whose central portion of the blade edge protrudes in a triangular shape. Is coated with an insulating material. This member is fixed to the concave portion 110c of the partition 110 and the partition 1
10 supported. This blade portion 130 is a conductor 120
, The sharpest pointed tip of the cutting edge is pressed. Therefore, the position of the cut portion of the conductor 120 can be easily determined, and
The pressing force against can be concentrated locally,
The conductor 120 can be cut very easily.

When the blade 130 is pressed against the conductor 120, the conductor fixing member 140 for fixing the conductor 120 so that the conductor 120 does not move upward is moved. And provided between them. This member is made of an insulator, has a rectangular parallelepiped shape, and is fixed by being sandwiched between the conductor 120 and the outer lid 32. Outer lid 3
Numeral 2 is made of a disc-shaped thick material made of an aluminum alloy and protects the battery safety device 100 from the outside and also has a role of an external positive terminal. This member has a step 32a on the outer periphery thereof, and is fixed to the container 10 by being pressed by the outer peripheral frame 34 at the step 32a.
The central portion 32b protrudes upward from the outer peripheral portion, and the central portion 32b has one or more internal pressure release ports 32c. The internal pressure release port 32c opens the space surrounded by the partition 110 and the outer lid 32, and allows the main body of the partition 110 to easily move.

The outer peripheral frame 34 has an upper wheel plate 34a, a cylindrical portion 34b extending axially downward from the outer periphery of the upper wheel plate 34a, and a radially inner portion extending from the lower end of the cylindrical portion 34b. And a lower wheel plate portion 34c. This outer frame 34
Presses the peripheral portion of the partition wall 110 and the peripheral portion of the outer lid 32 with an insulating member described later interposed therebetween.
At b, the container 10 is welded and fixed in contact with the inner peripheral surface near the upper end opening. The outer peripheral frame 34 allows the partition 110
The outer lid 32 is fixed to the container 10, and the inside of the container 10 is sealed.

The cylindrical insulating member 36a with the hollow bottom and the wheel-plate-shaped insulating member 36b are
2 is provided for the purpose of insulating each outer peripheral portion from the container 10. In addition, the circular plate-shaped insulating material 36c
Is sandwiched between the outer peripheral portion of the partition 110 and the outer peripheral portion of the outer lid 32 to electrically separate and insulate both outer peripheral portions. further,
The circular plate-shaped insulating material 36d is joined to the lower surface of the lower circular plate portion 34c of the outer peripheral frame 34 to achieve electrical insulation of the lower surface of the lower circular plate portion 34c. These insulating materials can be formed from, for example, a resin-based material.

Further, between the conductor 120 and the outer lid 32,
One support member 140, 140 was provided. These support members 140, 140 have insulating properties and function to press down so that the conductor 120 does not move upward when pressed against the blade portion 130. In the battery having the above configuration, when the internal pressure of the container 10 is within a safe range,
The current flows in the order of the battery reaction part 20, the partition 110, the partition 110, the conductor 120, and the outer lid 32. At this time, in the partition 110, a current flows from the lead connection portion to the right end via the lead 112. In addition, the conductor 120 of the partition wall
In, current flows from the left end to the right end. The direction of the current flow is indicated by an arrow in the figure.

When gas is generated in the battery reaction section 20 due to short-circuiting, overcharging, or the like in the battery, and an abnormal increase in the internal pressure of the container 10 occurs, the partition 110 is pressed by the internal pressure.
Is pressed upward. When the urging force reaches a certain magnitude, the main body of the partition wall 110 is deformed and the concave portion 112 is moved upward together with the blade portion 130.
The blade 130 that has moved to the position of the conductor presses the cutting edge against the notch groove 120 a of the conductor 120.

At this time, since the conductor 120 is pressed down by the two support members 140 and 140 so as not to move upward, the pressing force of the blade portion 130 is effectively concentrated and the conductor 120 is Acts on the site to be cut. Therefore, the conductor 120 is reliably and easily cut into two by the blade portion 130. Also, the notch groove 12
According to 2, the conductor 120 can be cut without requiring a large pressing force of the blade portion 130.

Also, at this time, even if a spark is generated at the cut portion of the conductor 120, since the electrolytic solution composed of the organic solvent and its vapor or decomposition gas are present at the place separated by the partition 110, the spark is generated. There is no ignition of the electrolyte. By cutting the conductor 120 as described above, the current path of the current flowing from the battery reaction section 20 to the outer lid 32 is interrupted on the way, and the current flow is stopped. As a result, the power of the abnormal gas generation reaction of the battery reaction section 20 is cut off and eventually stopped. In this way, an abnormal increase in the internal pressure is stopped, and the rupture of the battery is prevented. (Embodiment 2) The battery safety device of the present embodiment is almost the same as the embodiment 1 except that the conductor has a bent portion at the center thereof. It was built into a lithium secondary battery having a rotationally symmetric outer shape. FIG. 2 schematically shows a battery portion in which the battery safety device is incorporated.

As shown in FIG. 2, in the battery safety device of the present embodiment, the partition wall 210 has a recess 210a at the center thereof which is slightly shallower than that of the first embodiment. The conductor 220 has an inverted V-shaped bent portion 220a, and the blade portion 230 has its cutting edge applied to the bent portion 220a to form the concave portion 210 of the partition wall 210.
a. With this bent portion 220a, the position of the cut portion of the conductor 220 is extremely reliably and easily determined. Further, the partition 210 has a safety valve (not shown) that can be broken by an internal pressure higher than an internal pressure at which a current is interrupted and released to the outside.

When an abnormal gas generation reaction occurs in the battery reaction section 20 due to a short circuit or overcharge in the battery and the internal pressure of the container 10 rises abnormally, the main body of the partition wall 210 is pushed upward by the pressure of the internal pressure. Pressed. When the urging force reaches a certain magnitude, the concave portion 210a moves upward together with the blade portion 230 while the main body portion of the partition wall 230 is deformed, and the cutting edge of the blade portion 230 is bent by the bent portion 220a of the conductor 220.
Is pressed against. In this way, the conductor 220 is
As a result, it is reliably and easily cut into two at the bent portion 220a. (Embodiment 3) In this embodiment, the safety device according to claim 2 is incorporated in a lithium secondary battery having the same cylindrical and rotationally symmetric outer shape as in the first embodiment. FIG. 3 schematically shows a battery part in which the battery safety device is incorporated.

As shown in FIG. 3, the battery safety device of this embodiment comprises a partition 310, a conductor 320 and a blade 330.
And incorporated in the battery in the same manner as in Example 1. The partition 310 has a concave portion 310 for supporting the blade portion 330.
a, except that the diameter of a is slightly increased.
10 is the same member. Further, the partition wall 310 has a safety valve (not shown) that can be broken by an internal pressure higher than an internal pressure at which a current is interrupted and released to the outside.

The conductor 320 has a disk-like shape and a notch groove 320 a having a shape corresponding to the blade portion 330.
The other members are the same as those of the conductor 120 of the first embodiment. This member has a partition wall 310 and an outer lid 3 all over its peripheral portion.
2 and is fixed to the container 10. At the peripheral portion, the partition wall 310 was attached insulated from the partition wall 310 by an insulating member, and a conductive lead 332 having elasticity was provided in the cylindrical hole of the blade section 330 to conduct the partition wall 310 and the conductor 320.

The shape of the notch groove 320a of the conductor 320 employed was (a) of the shape shown in FIG. The conductor 320 can be cut by the notch groove 320a without requiring a large pressing force with the blade portion 330. Here, in a cross section through which the current of the thin portion passes (in FIG. 3, two surfaces perpendicular to the paper surface of the thin portion correspond to each other), the cross section is sufficient in all cross sections to allow a large current to flow. The depth of the cutout groove 320a is set so as to have On the other hand, (b) of the blades shown in FIG. With this member, the cutting portion of the conductor 320 can be easily positioned, and the pressing force against the conductor 320 can be locally concentrated.

When the internal pressure of the container 10 is normal,
The current flows through the battery reaction section 20, the lead 312, the partition 310,
It flows in the order of the conductive lead 332, the conductor 320, and the outer lid 32. Here, in the conductor 320, current flows from the center to the periphery. When an abnormal chemical reaction occurs in the battery reaction section 20 due to a short circuit, overcharge, or the like in the battery, and an abnormal increase in the internal pressure of the container 10 occurs, the pressing force of the internal pressure pushes the main body 310a of the partition wall 310 upward. . When the bias reaches a certain size,
The two bent portions 310d and 310e of the partition wall 310 are deformed and the concave portion 310c moves upward together with the blade portion 330,
The edge of the blade 330 is pressed against the conductor 320. In this manner, as shown in FIG. 4, the portion of the conductor 320 that is electrically connected to the lead 340 is cut so as to be cut out. (Embodiment 4) In this embodiment, the safety device according to the third aspect is built in a lithium secondary battery having the same cylindrical and rotationally symmetric outer shape as in the first embodiment. FIG. 5 schematically shows a battery part in which the battery safety device is incorporated.

The battery safety device of the present embodiment shields the opening of the container 10 for accommodating the battery electrode and the electrolytic solution,
A partition wall 410 that moves outwardly of the container 10 in response to a rise in the internal pressure of 0, and a conductor 420 that is disposed outside the partition wall 410 and electrically connects the battery reaction section 20 and the outer lid 32 (terminal).
A first shear blade member 432 supported by the partition wall 410 and moving together with the partition wall 410, and a second shear blade member 434 fixed to the outside of the conductor 420. The first shear blade member 432 and the second shear blade Conductor 420 with member 434
And a shear blade section 430 that cuts by shearing.

The partition 410 is a member that shields the opening of the container 10 that contains the battery electrode and the electrolyte, and moves a part of the container 10 toward the outside of the container 10 in accordance with an increase in the internal pressure of the container 10. This member is made of a plate made of a substantially dish-shaped aluminum alloy. The main body 410a is made of the conductor 4
20 at a predetermined distance from its peripheral portion 410
It is fixed to the container 10 by the outer peripheral frame 34 at b.
The main body 410a includes two first shear blade members 432
a, 432a are supported at the same distance from the central axis of the battery. The main body 410a of the partition 410
Two bent portions 410c and 4 that can be plastically deformed
It has 10d. Further, the partition wall 410 has a safety valve (not shown) that can be broken by an internal pressure larger than an internal pressure at which a current is interrupted and released to the outside.

The conductor 420 is a member that is disposed above the partition wall 410 and energizes the battery reaction section 20 and the outer lid (terminal) 32. The conductor 420 is made of an elastic conductive material and has the same shape as the conductor 120 used in the first embodiment. The first shearing blade member 432 has an edge 4 having a rectangular parallelepiped main body and an edge angle of 90 ° at its tip.
32a. Also, the second shear blade member 43
Reference numeral 4 denotes a member having a body portion having a right-angled triangular cross section and a tip portion having an acute edge 434a having an edge angle of 90 ° or less. The attachment positions of these members are such that the respective edges 432a and 434a are extended surfaces of the fractured surface of the cut portion of the conductor 420 (in FIG. 5, a plane perpendicular to the paper surface of the cut portion corresponds). They are set so as to be substantially along and face each other.

When a gas is generated in the battery reaction section 20 due to a short circuit or overcharge in the battery and the internal pressure of the container 10 rises abnormally, the main body 410a of the partition wall 410 is pushed upward by the urging of the internal pressure. The bent portions 410c, 4
The center portion of the first shear blade member 4 is deformed while deforming 10d.
30a is moved upward. At this time, the first shear blade member 430a bends the main body of the conductor 420 and pushes it upward.

When the internal pressure further increases and reaches a predetermined pressure, the main body of the conductor 420 presses the edge 434 a of the second shear blade member 434. At this time, the edge 432a of the first shearing blade member 432 and the edge 434a of the second shearing blade member 434 cooperate to apply a vertical shearing force to the cut surface of the conductor 420 on the broken surface. .
The conductor 420 is cut into two at the cutting site by the shearing force. (Embodiment 5) In this embodiment, the safety device according to claim 4 is incorporated in a lithium secondary battery having the same substantially cylindrical, rotationally symmetric outer shape as in Embodiment 1. FIG. 6 schematically shows a battery part in which the battery safety device is incorporated.

The battery safety device according to the present embodiment shields the opening of the container 10 containing the battery electrode and the electrolyte,
A partition wall 510 that moves in the outer direction of the container 10 in response to a rise in the internal pressure of 0;
0, the first conductive member 522 that is electrically connected to the outer cover 32 (terminal)
A second conductive member 524 that is electrically connected to the first conductive member 522 and contacts the first conductive member 522 to the second conductive member 524.
A spring 530 for urging in a direction in which the first conductive member 52 is filled with high-pressure gas and against the urging force of the spring 530;
A high-pressure chamber 540 that presses the second member against the second conductive member 524;
A pin member 55 that is supported by the partition 510 and moves with the partition 510 to break the high-pressure chamber 540 and lose its pressing force.
0.

The partition wall 510 is made of a plate made of a substantially dish-shaped aluminum alloy. The peripheral edge portion 510b is fixed to the container 10 by the outer peripheral frame 34 so that the main body 510a is located at a predetermined distance from the conductor 520. A concave portion 510c is provided at the center of the main body 510a, and a plastically deformable bent portion 5 is formed around the concave portion 510c.
It has 10d. Further, a conductive lead 512 that is electrically connected to the battery reaction section 20 is attached to a lower portion of the concave portion 510c. Further, the partition wall 510 has a safety valve (not shown) that can be broken by an internal pressure greater than an internal pressure at which a current is interrupted and released to the outside.

The first conductive member 522 is made of a disc-shaped plate made of an aluminum alloy, and has a through hole 522a at the center thereof for passing a pin member. This member is fixed to the container 10 by pressing the peripheral portion 522b directly with the peripheral portion of the partition wall 510 and the peripheral portion of the outer lid 32 by the outer peripheral frame 34 with an insulating material interposed therebetween.

The second conductive member 524 is connected to the first conductive member 52.
2 is arranged on the upper side and extends downward in the axial direction.
a, a wheel plate member 524b extending radially outward from the lower end of the tubular portion 524a, and an outer wheel plate extending radially outward from the tip end of the wheel member 524b and further projecting radially outward from the upper portion. 524c. The tubular portion 524a and the wheel plate member 524b are integrally formed using an aluminum alloy as a material, and an outer wheel plate member 524c made of an insulator is integrally attached to the cylindrical portion 524a and the wheel plate member 524b. The second conductive member 524 includes the cylindrical portion 524a and the wheel plate member 52.
The lower end of 4b is in contact with the first conductive member 522, and the contact portion 526 conducts each other. The second conductive member 524 is provided with a conductive lead 526 for conducting with the outer lid 32.

The spring 530 is a suspension spring in which a linear member made of an insulator is wound in a coil shape and the upper end thereof is fixed to a spring fixing member 38 formed integrally with the outer lid 32. The spring fixing member 38 has a shaft portion 38 extending downward in the axial direction.
a and a protruding portion 38b extending radially outward from the lower end of the shaft portion 38a. The upper end portion of the spring 530 is hooked on the protruding portion 38b. The spring 530 has its lower end hooked on the protruding portion of the outer wheel plate member 524c, and urges the first conductive member 522 in a direction to separate it from the second conductive member 524.

The high-pressure chamber 540 has a bag-shaped hollow member 540a.
Is filled with a high-pressure gas 540b. This member is the second
It is arranged between the conductive member 524 and the outer lid 32, and is fixed so as to be pressed by each member. The high-pressure chamber 540 presses the first conductive member 522
Is pressed against the second conductive member 524. Pin member 55
0 has a nail-like shape whose tip 550a is sharp and sharp. This member is fixed to the concave portion 510 c of the partition 510 and is supported by the partition 510. In addition, this pin member 5
The base 50 is made of metal to prevent short-circuiting between the partition wall 510 and the second conductive member 524 in order to prevent the leading end 550a from touching the inner wall of the through hole of the conductor 524 due to an external impact or the like, thereby causing a short circuit. What was coated and molded was used.

When the internal pressure of the container 10 is normal,
The electric current is supplied to the battery reaction part 20, the conductive leads 512, the partition walls 5,
10, the first conductive member 522, the second conductive member 524, the conductive lead 526, and the outer lid 32 flow in this order. At this time, a current flows from the center to the periphery of the partition 510. In the first conductive member 522, the partition 5
An electric current flows from the peripheral portion in contact with 10 to the central portion. Second
In the conductive member 524, a current flows from the lower end portion to the connection portion of the lead 526 through the contact portion 526.

When a gas is generated in the battery reaction section 20 due to a short circuit, overcharge, or the like in the battery, and the internal pressure of the container 10 rises abnormally, the main body of the partition wall 510 is pushed upward by the urging force of the internal pressure. When the urging force reaches a certain level, the main body of the partition 510 is deformed and the recess 510c is moved upward together with the pin member 550, and the tip 550a of the pin member 550 is moved to the lower wall of the high-pressure chamber 540. Part.

Thus, the hollow member 540a of the high-pressure chamber 540
Is broken by the pin member 550, and the sealed high-pressure gas is released. As a result, the high-pressure chamber 540 loses the pressing force of the first conductive member 522 against the second conductive member 524, and resists the urging force of the spring 530.
22 cannot be pressed against the second conductive member 524. At this time, the first conductive member 522 is separated from the second conductive member 524 by the action of the spring 530. FIG. 7 shows a state in which the first conductive member 522 is separated from the second conductive member 524.

As described above, the first conductive member 522 is separated from the second conductive member 524, so that the current path of the current flowing from the battery reaction section 20 to the outer lid 32 is interrupted on the way, and the current flows. Can be stopped. As a result, the cause of the abnormal increase of the internal pressure is eliminated, the increase of the internal pressure is stopped, and the battery is prevented from exploding. (Embodiment 6) In this embodiment, the safety device according to claim 5 is incorporated in a lithium secondary battery having the same substantially cylindrical, rotationally symmetric outer shape as in Embodiment 1. FIG. 8 schematically shows a battery part in which the battery safety device is incorporated.

The battery safety device according to the present embodiment includes a partition wall 6 that shields the opening of the container 10 that contains the battery electrode and the electrolyte.
10, a first conductive member 622 formed integrally with the partition wall 610 and conducting with a battery reaction portion (not shown);
A second conductive member 624 which is brought into contact with the first conductive member 622 by the pressing force of
An outer lid 640 that forms a negative pressure chamber 630 that is disposed outside the chamber and is negatively pressured against a chamber located inside the partition 610 to attract the partition 610 and press the first conductive member 622 against the second conductive member 624; The first conductive member 622 in the pressure chamber 630
And a shielding member 650 that shields the contact portion 626 between the first conductive member 624 and the second conductive member 624 from the surroundings.

The partition 610 has a substantially dish shape, has a shape having a through hole for fitting the first conductive member at the center, and is a member made of insulating rubber or resin. This member has a peripheral portion 610c, a peripheral portion 640d of the outer lid 640, and an upper end 64 extending above a fixing member 642 fixed to the outer lid 640 by press-fitting or screwing.
2a, and is fixed with good sealing properties. This member also has a plastically deformable bent portion 610d.

The partition 610 is provided with a rupture valve 614 that is ruptured by a predetermined pressure in the container 10 and sends the gas in the container 10 to the negative pressure chamber 630. This burst valve 614
Is formed by providing a through hole 610d in a part of the partition 610 in contact with the negative pressure chamber 630, and closing the through hole 610d with a thin plate. The first conductive member 622 is made of a substantially cylindrical tube made of an aluminum alloy. This member has a substantially ring-shaped attachment member 622a that can be attached to the partition 610. Note that this mounting member 622a
May be made of an insulating material or a conductive material. In addition, a conductive member 612 that conducts with a battery reaction section (not shown) is attached to a lower end of the member.

The second conductive member 624 is made of a substantially coin-shaped thick plate made of an aluminum alloy. This member is integrally attached to the center of the outer lid 640. The negative pressure chamber 630 is a chamber surrounded by the partition 610, the outer lid 640, and the shielding member 650. This chamber has a pressure lower than the pressure of the space located inside the partition 610.

The outer lid 640 is hermetically fixed to the container 10 by welding or the like. Further, the internal pressure release port 64 of the outer lid 640 is provided.
0c was provided with a safety valve 644 that could be broken by an internal pressure greater than the internal pressure at which current interruption is described later and released to the outside. The shielding member 650 is a member made of belofram formed of an insulating material. This member has its lower end attached to the attachment member 622a of the first conductive member 622, and its upper end attached and fixed to the outer lid 640, and the first conductive member 622 and the second conductive member 62 are fixed.
4 is isolated from the negative pressure chamber 630.

In the battery of this configuration, when the internal pressure of the container 10 is normal, the current flows through the battery reaction section and the conductive lead 6.
12, the first conductive member 622, and the second conductive member 624 flow in that order. When a gas is generated in the battery reaction section due to a short circuit or overcharge in the battery and the internal pressure of the container 10 rises abnormally, the gas in the container 10 is sent to the negative pressure chamber 630 to remove the negative pressure, and the partition 610 is removed. The first conductive member 622 is separated from the second conductive member 624 against the pressing force of the first conductive member 622. That is, the rupture valve 614 provided on the partition 610 is ruptured by the urging force of the internal pressure of the container 10 that has abnormally risen,
The gas in the container 10 flows into the negative pressure chamber 630 through the rupture hole and the through hole 610d. As a result, the negative pressure chamber 6
30 rises to the same pressure as the inside of the container 10, the pressing force of the partition 610 is removed, and the first conductive member 6
22 is separated from the second conductive member 624.

At this time, even if the contact portion 626 between the first conductive member 622 and the second conductive member 624 is separated and a spark is generated, the electrolytic solution made of the organic solvent and the organic solvent are placed at a place separated by the shielding member 650. The spark does not ignite such an electrolyte or the like due to the presence of the vapor or cracked gas. As described above, the first conductive member 622 is
By being separated from the conductive member 624, the current path of the current flowing from the battery reaction section to the terminal (second conductive member 624) is interrupted on the way, and the flow of the current is stopped. As a result, the cause of the abnormal increase of the internal pressure is eliminated, the increase of the internal pressure is stopped, and the battery is prevented from exploding.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a first embodiment.

FIG. 2 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a second embodiment.

FIG. 3 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a third embodiment.

FIG. 4 is a longitudinal sectional view of a main part of a battery schematically showing a state when a battery safety device according to a third embodiment operates.

FIG. 5 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a fourth embodiment.

FIG. 6 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a fifth embodiment.

FIG. 7 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a fifth embodiment.

FIG. 8 is a longitudinal sectional view of a main part of a battery schematically showing a battery safety device according to a sixth embodiment.

FIG. 9 is a longitudinal sectional view of a main part of a battery schematically showing a conventional battery safety device.

FIG. 10 is a perspective view schematically showing the shape of a blade used in the battery safety device according to the first embodiment.

FIG. 11 is a perspective view schematically showing various shapes of a blade portion that can be used in the battery safety device according to the second embodiment.

FIG. 12 is a top view and a vertical sectional view schematically showing various shapes of a cutout groove which can be used in the battery safety device according to the second embodiment.

FIG. 13 is a top view and a vertical sectional view schematically showing various shapes of a cutout groove which can be used in the battery safety device according to the second embodiment.

[Explanation of symbols]

10: Container 20: Battery reaction part 30: Lid part 110:
Partition 120: Conductor 130: Blade

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Matsuzaka 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Tetsuya Nagata 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation (72) Inventor Tadayoshi Amano 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.

Claims (7)

[Claims] 1. A partition which covers an opening of a container for accommodating an electrode of a battery and an electrolytic solution and moves outwardly of the container in accordance with an increase in internal pressure of the container; A battery safety device comprising: a conductor for conducting a portion and a terminal; and a blade supported by the partition and moving with the partition to cut the conductor. 2. The battery according to claim 1, wherein the partition has conductivity, and the blade has a cylindrical blade and has a lead in the cylindrical hole for conducting the partition and the conductor. Safety equipment. 3. A partition for shielding an opening of a container for accommodating an electrode of a battery and an electrolytic solution and moving outwardly of the container in response to an increase in the internal pressure of the container; A first shear blade member supported by the partition and moving with the partition, and a second shear blade member fixed to the outside of the conductor. And a shear blade section that shears and cuts the conductor with the second shear blade member. 4. A partition for shielding an opening of a container for accommodating an electrode of a battery and an electrolytic solution and moving outwardly of the container in response to an increase in the internal pressure of the container; A conductor comprising: a first conductive member that is in electrical communication with the portion; and a second conductive member that is in electrical contact with the terminal and is in contact with the first conductive member; and separating the first conductive member from the second conductive member. A high-pressure chamber filled with high-pressure gas and pressing the first conductive member against the second conductive member against the biasing force of the spring; and a high-pressure chamber supported by the partition and moving with the partition. A pin member for breaking the high-pressure chamber and eliminating the pressing force thereof. 5. A partition for shielding an opening of a container for accommodating an electrode and an electrolyte of a battery, a first conductive member formed integrally with the partition and electrically connected to a battery reaction part, and A second conductive member that is in contact with the first conductive member and conducts with the terminal; and a negative pressure is applied to a chamber disposed outside the partition and located inside the partition to attract the partition and attract the first conductive member. The second
An outer lid for forming a negative pressure chamber pressed against the conductive member; and a shielding member for shielding a contact portion between the first conductive member and the second conductive member from surroundings in the negative pressure chamber. When the pressure rises abnormally, the gas in the container is sent to the negative pressure chamber to remove the negative pressure, and the first conductive member is separated from the second conductive member by removing the pressing force of the partition. Battery safety device to do. 6. The battery safety device according to claim 5, wherein the partition has a rupture valve that is ruptured by a predetermined pressure and sends gas in the container to the negative pressure chamber. 7. The battery safety device according to claim 1, wherein a safety valve is provided in the partition wall or the container, the safety valve being ruptured by an internal pressure greater than an internal pressure at which current is interrupted and releasing the pressure to the outside.