JP6991748B2 - Battery module - Google Patents

Description

The present invention relates to a battery module including a battery cell provided with a discharge valve for suppressing an increase in the internal pressure of the outer case, and more particularly to a battery module for normally exhausting high-temperature gas and foreign matter discharged from the outer case from a discharge duct. ..

The internal pressure of a secondary battery may become abnormally high depending on the charging / discharging current value and external conditions during use. An abnormal rise in internal pressure causes the battery case to be destroyed. To prevent this adverse effect, a secondary battery equipped with a discharge valve that opens at a set pressure has been developed. The secondary battery provided with this discharge valve is configured to open when the internal pressure becomes higher than the set value, suppress the increase in the internal pressure of the outer case, and prevent the outer case from being destroyed by the abnormal internal pressure. There is. The battery module provided with this type of secondary battery is provided with an exhaust duct for exhausting the high-temperature and high-pressure exhaust gas discharged from the opened exhaust valve to the outside. The exhaust duct is connected to the opening of the discharge valve and guides the high-temperature and high-pressure exhaust gas discharged from the opening to the outside to exhaust the gas. (See Patent Document 1)

Further, in recent years, a secondary battery has been developed in which a ring-shaped thin-walled portion is locally provided on the bottom surface of an outer can to serve as a discharge valve (see Patent Document 2). The secondary battery having the above configuration has a feature that the opening area of the exhaust valve can be relatively widened. A battery module equipped with this type of secondary battery connects a discharge duct to the opening of a discharge valve provided on the bottom of the outer can to exhaust high-temperature and high-pressure exhaust gas discharged from the bottom side of the outer can to the outside. Assembled as a structure.

Japanese Unexamined Patent Publication No. 2014-170613 Japanese Unexamined Patent Publication No. 2017-69184

As described above, in a secondary battery in which a thin-walled portion is provided on the bottom surface of the outer can to serve as an exhaust valve, the surface on which the exhaust valve is located is the "exhaust side end surface" and the surface on the opposite side where the sealing plate is located is "non-exhaust". It becomes "side end face". A battery module including such a secondary battery can be configured such that the secondary batteries are arranged in the same posture and the discharge valves are lined up on one surface of the battery module. With this configuration, by arranging the exhaust duct on one side of the battery module in which the exhaust valves are lined up, it is possible to connect the exhaust valve and the exhaust duct of each secondary battery.
On the other hand, when the internal pressure of the secondary battery becomes abnormally high, the sealing plate side located on the non-exhaust side end face is destroyed before the discharge valve provided on the bottom side opens, and the non-exhaust side end face side. High temperature and high pressure exhaust gas may be ejected from. Since the secondary battery has a caulking structure or a structure in which the sealing plate is fixed to the opening of the outer can by laser welding, it is difficult to achieve strength comparable to the bottom surface of the outer can manufactured by drawing a metal plate. When the internal pressure becomes abnormally high, the end face on the non-exhaust side, which is the sealing plate side, cannot be completely damaged. In particular, a secondary battery having a large charge / discharge capacity has an extremely high internal electrode density, which may cause an imbalance in internal pressure. The imbalance of the internal pressure generated inside the secondary battery causes damage to parts other than the exhaust valve before the exhaust valve is opened by the internal pressure.

Since the battery module having the above configuration does not have an exhaust duct on the non-exhaust side end face, if the non-exhaust side end face is destroyed, high temperature and high pressure exhaust gas is injected into the battery module, and the safety is remarkably improved. It causes a decrease.

The present invention has been developed for the purpose of solving the above drawbacks. An important object of the present invention is a simple structure capable of exhausting high-temperature and high-pressure exhaust gas discharged from the non-exhaust side end face of the secondary battery to the outside without changing the structure of the secondary battery. The purpose is to provide a battery module.

Means for Solving Problems and Effects of Invention

A battery module according to an aspect of the present invention has a plurality of end faces having an exhaust port for a discharge valve that opens at a set pressure as an exhaust side end face and an end face opposite to the exhaust side end face as a non-exhaust side end face. The battery cell, the battery holder in which each battery cell is arranged in a fixed position, the discharge duct connected to the discharge port of the battery cell arranged in the fixed position in the battery holder, and the battery cell are arranged inside. The pressure-resistant case is equipped with a pressure-resistant case that has the strength to withstand the temperature and pressure of the leaked gas discharged from the non-exhaust side end face, and closes the non-exhaust side end face side of the built-in battery cell to exhaust. A leakage gas discharge opening is provided on the side end face side, and the structure is such that the leakage gas discharged from the non-exhaust side end face is discharged from the discharge opening of the pressure resistant case.

Since the above battery module has a simple structure, high-temperature and high-pressure exhaust gas discharged from the non-exhaust side end face of the battery cell can be guided to the exhaust duct without changing the structure of the battery cell. High temperature and high pressure exhaust gas can be exhausted to the outside. That is, since the battery module is provided with a pressure-resistant case for arranging the battery cell inside, the pressure-resistant case closes the non-exhaust side end face side of the battery cell and provides an exhaust opening on the exhaust side end face side. This is because even if the non-exhaust side end face is destroyed and the leaked gas is discharged, the pressure resistant case guides the leaked gas to the exhaust side end face and discharges it from the discharge opening without discharging the leaked gas from the non-exhaust side end face. In particular, the above battery module is easy to insert the battery cell into the pressure resistant case and guide the leaked gas discharged from the non-exhaust side end face to the exhaust side end face without changing the structure of the battery cell itself. With this structure, the leaked gas discharged due to the destruction of the non-exhaust side end face is guided to the exhaust side end face with a pressure resistant case to prevent the harmful effect of the leaked gas being discharged inside.

In a battery module according to an aspect of the present invention, a battery case of a battery cell is airtightly connected to an outer can having one end opened to close the bottom surface and an opening edge of the outer can to seal the opening. It is composed of a sealing plate provided with electrode terminals, and a discharge valve that destroys the thin part at a set pressure is provided on the bottom surface of the outer can, with the bottom surface of the outer can as the exhaust side end face and the sealing plate side not. It can be the end face on the exhaust side.

In the above battery module, the sealing plate side where the electrode terminals are provided is the non-exhaust side end face, and a thin wall portion is provided on the bottom surface of the outer can to serve as an exhaust valve. Therefore, the opening area of the exhaust valve is increased to open the valve. High-temperature and high-pressure exhaust gas can be quickly exhausted from the exhaust valve. Further, since the leaked gas discharged here is guided to the discharge duct with the sealing plate side as the non-exhaust side end surface and discharged, there is a connecting portion between the outer can and the sealing plate, and the exhaust is on the bottom side of the outer can. Even if the strength is lower than that of the side end face and this part is destroyed, high safety is realized by discharging the leaked gas to the exhaust side end face with the pressure resistant case.

In the battery module according to an aspect of the present invention, the battery cell can be a cylindrical battery. By using a cylindrical battery as the battery cell, this battery module realizes the feature that the charge / discharge capacity can be increased with respect to the volume of the battery cell, and it is difficult to realize high strength compared to the bottom surface of the outer can. It has the feature that high safety can be realized by surely preventing the breakage on the side with a stopper. The reason why a cylindrical battery can have a larger charge / discharge capacity than a square battery because of its shape is that positive and negative electrode plates laminated via an insulating separator are spirally wound to form a cylindrical electrode, which is cylindrical. This is because it can be assembled by inserting it into an outer can. The cylindrical electrode manufactured by winding the laminated electrode plates in a spiral shape can increase the electrode density in the winding process, and since the cylindrical electrode is inserted into the cylindrical outer can, the electrode density is high. It can be inserted and assembled in a state to increase the charge / discharge capacity. However, since the cylindrical battery connects the opening edge of the outer can and the sealing plate by caulking, it is difficult to make the strength of the sealing plate side comparable to the bottom surface of the outer can, and the sealing plate side is destroyed by abnormal internal pressure. However, the above battery modules are difficult to increase in strength compared to the bottom side, and the stopper reliably prevents destruction due to internal pressure on the sealing plate side, so a cylindrical battery is used to achieve high capacity. On the other hand, it has the feature of preventing the destruction of the sealing plate side and realizing high safety.

In the battery module according to an aspect of the present invention, the discharge opening of the pressure resistant case can be connected to the discharge duct, and by this structure, the leaked gas discharged to the non-exhaust side end face is discharged to the outside by using the discharge duct. There is a feature that can be done.

In the battery module according to an aspect of the present invention, the shape of the pressure resistant case can be a metal cylinder that closes the end face on the non-exhaust side. Further, in the battery module according to an aspect of the present invention, the pressure resistant case can be connected to the electrode terminal of the battery cell provided on the non-exhaust side end face and used together with the lead plate.

Furthermore, in the battery module according to an aspect of the present invention, the pressure resistant case can be made of plastic, and the pressure resistant case is integrally molded and fixed to the plastic main body portion and the main body portion. It is composed of a metal lead terminal connected to the electrode terminal of the battery cell, and the main body is connected to a tubular cover portion that covers the outer peripheral surface of the battery cell and one end of the tubular cover portion. The lead terminal has a tubular portion, a welded plate portion connected to one end of the tubular portion and welded to the electrode terminal of the battery cell, and a welded plate portion so as to have an end surface cover portion that covers the non-exhaust side end surface. The lead terminal has a shape consisting of a bus bar connection portion connected to the cylinder portion on the opposite side, and the cylinder portion penetrates the plastic main body portion inward and outward, and the bus bar connection portion is outside the end face cover portion. The welded plate part is located inside the end face cover part, integrally molded and fixed to the main body part, and leads to the electrode terminal of the battery cell arranged inside the main body part of the pressure resistant case. The structure may be such that the welded plate portion of the terminal is welded.

It is the schematic sectional drawing of the battery module which concerns on embodiment of this invention. It is the schematic sectional drawing of the battery module which concerns on other embodiment of this invention. It is the schematic sectional drawing of the battery module which concerns on other embodiment of this invention. It is a partial cross-sectional view of the battery module shown in FIG. FIG. 4 is a cross-sectional view taken along the line AA of the battery module shown in FIG. It is a partial sectional view of the battery module which concerns on other embodiment of this invention. It is a partial cross-sectional view of the battery module shown in FIG. It is a partial cross-sectional view of the pressure-resistant case according to another embodiment of this invention. It is a partial sectional view of the battery module which concerns on other embodiment of this invention. FIG. 9 is a cross-sectional view of the pressure resistant case shown in FIG. It is a partial sectional view of the battery module which concerns on other embodiment of this invention. It is a perspective view which shows the metal terminal of the battery module shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below exemplify a configuration for embodying the technical idea of the present invention, and the present invention is not specified as the following. Further, the member shown in the claims is by no means specified as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention to the present invention unless otherwise specified. It is just an example of explanation. The size and positional relationship of the members shown in each drawing may be exaggerated for the sake of clarity. Further, in the following description, members of the same or the same quality are shown with the same name and reference numeral, and detailed description thereof will be omitted as appropriate. Further, each element constituting the present invention may be configured such that a plurality of elements are composed of the same member and the plurality of elements are combined with one member, or conversely, the function of one member is performed by the plurality of members. It can also be shared and realized. In addition, the contents described in some examples and embodiments can be used in other embodiments and embodiments.

An example in which the battery module shown below is mainly applied to a power source for driving an electric vehicle such as a hybrid vehicle that runs on both an engine and a motor and an electric vehicle that runs only on a motor will be described. The battery module of the present invention may be used for vehicles other than hybrid vehicles and electric vehicles, and may be used for applications other than electric vehicles that require high output, such as power storage devices for homes and factories.

In the battery module shown in FIGS. 1 to 3, a plurality of battery cells 1, a pressure-resistant case 2 in which the battery cells 1 are arranged inside, and each battery cell 1 covered by the pressure-resistant case 2 are placed in a fixed position. The battery holder 3 to be arranged, the bus bar 6 of a thick metal plate connected to the electrode terminal 5 of the battery cell 1 arranged at a fixed position by the battery holder 3 via a lead plate, and the battery cell 1 are provided. The discharge duct 9 connected to the discharge port 8 of the discharge valve 7 and the housing 4 containing the above parts are provided.

The battery cell 1 is a cylindrical battery of a lithium ion secondary battery. However, the present invention does not specify the battery cell as a lithium ion secondary battery, and all other rechargeable secondary batteries, such as non-aqueous electrolyte secondary batteries other than lithium ion secondary batteries and other secondary batteries. Can be. In the cylindrical battery which is the battery cell 1, the opening of the cylindrical outer can 10 that closes the bottom is hermetically sealed with a sealing plate 11 to form a battery case 12. The outer can 10 is manufactured by deep drawing a metal plate. The sealing plate 11 has a disk shape, and a convex electrode terminal 5 is provided at the center thereof. The sealing plate 11 is insulated from the outer peripheral edge of the outer can 10 by a caulking structure via an insulating material and fixed to an airtight structure.

The battery cell 1 is provided with a discharge valve 7 on the bottom surface of the outer can 10. The discharge valve 7 opens when the internal pressure of the battery cell 1 becomes higher than the set pressure, and exhausts the internal gas to the outside to prevent the battery case 12 from being destroyed. The internal pressure of the battery cell 1 is generated under severe conditions such as overcharging, overdischarging, excessive current, physical impact, internal short circuit, external short circuit, and abnormally high temperature of the battery. The battery cell 1 prevents the battery case 12 from exploding by opening the discharge valve 7 in a state where the internal pressure becomes abnormally high.

The discharge valve 7 is provided on one end surface of the battery cell 1. The battery cell 1 shown in the figure is provided with a discharge valve 7 on the bottom surface and is not provided with a discharge valve 7 on the upper end. The bottom surface provided with the exhaust valve 7 is the exhaust side end surface T1 for exhausting the exhaust gas, and the upper end surface without the exhaust valve 7 is the non-exhaust side end surface T2 for not discharging the exhaust gas.

The battery cell 1 in the figure is provided with a ring-shaped thin-walled portion on the bottom surface of the outer can 10 to serve as a discharge valve 7. The discharge valve 7 having this structure can control the set pressure for opening the valve by adjusting the thickness of the thin portion. The set pressure for opening the valve can be increased by making the thin part thinner and the set pressure for opening the valve can be increased by making the thin part thicker. When the internal pressure of the battery cell 1 becomes higher than the set pressure, the thin portion of the discharge valve 7 breaks and opens. In the discharge valve 7 composed of the ring-shaped thin-walled portion 13, since the thin-walled portion 13 is broken in the valve open state, the discharge port 8 is opened inside the thin-walled portion 13.

The battery cell 1 is provided with an exhaust valve 7 only on the exhaust side end surface T1, and when the internal pressure rises, the exhaust valve 7 is opened to discharge high-temperature and high-pressure exhaust gas from the exhaust side end surface T1 to the outside of the battery case 12. The battery cell 1 is provided with the exhaust valve 7 only on the exhaust side end surface T1 and does not provide the exhaust valve 7 with the opposite end surface as the non-exhaust side end surface T2. Using this battery cell 1, a huge number of battery modules are mass-produced, and all battery cells are used under conditions in which charging / discharging conditions and external environment are significantly different. It is extremely difficult for 1 to eliminate leakage gas from the non-exhaust side end surface T2. In particular, since the battery cell 1 is required to be lightweight and have a large capacity, it is necessary to reduce the weight of the battery case as a thin metal plate, and it is not possible to eliminate gas leakage from the non-exhaust side end surface T2. Extremely difficult.

In the battery modules of FIGS. 1 to 3, the battery cell 1 is arranged inside the pressure resistant case 2 and is arranged in a fixed position by the battery holder 3. The pressure-resistant case 2 guides the leaked gas discharged from the non-exhaust side end surface T2 of the battery cell 1 to the exhaust side end surface T1 and discharges the gas. The battery cell 1 arranged inside the pressure-resistant case 2 exhausts the leaked gas ejected to the non-exhaust side end surface T2 by the pressure-resistant case 2 even if the non-exhaust side end surface T2 is damaged and the leaked gas is ejected. It is guided to the side end surface T1 and discharged.

The pressure resistant case 2 withstands the temperature and pressure of the leaked gas discharged from the non-exhaust side end face T2, and discharges the leaked gas ejected from the non-exhaust side end face T2 from the exhaust side end face T1. The pressure resistant case 2 closes the non-exhaust side end surface T2 of the battery cell 1. In order to discharge the leaked gas discharged from the battery cell 1 to the non-exhaust side end surface T2, the pressure resistant case 2 is provided with an exhaust opening 14 on the exhaust side end surface T1. The pressure-resistant case 2 guides the leaked gas discharged from the non-exhaust side end surface T2 to the exhaust side end surface T1 and discharges the gas. The pressure resistant case 2 is manufactured by pressing a metal plate or molding a plastic insulating material. The metal pressure resistant case 2 can be used together with a lead plate connected to the electrode terminal 5 of the battery cell 1 arranged inside. The metal pressure resistant case 2 is arranged so as to be insulated from the outer can 10 by arranging an insulating material on the inner surface. This is because there is a voltage difference between the pressure-resistant case 2 and the outer can 10 of the internal battery cell 1.

In the pressure resistant case 2 made of plastic, the leader wire 15 having one end connected to the electrode terminal 5 is arranged so as to be insulated from the outer can 10, or the metal terminal 23 is airtightly fixed at a position facing the electrode terminal 5. Then, the metal terminal 23 is electrically connected to the bus bar 6 via the electrode terminal 5.

In the battery module shown in the cross-sectional view of FIG. 1, the pressure resistant case 2 is a metal case. The pressure resistant case 2 is used in combination with a lead plate that connects the convex electrode, which is the electrode terminal 5 of the battery cell 1, to the bus bar 6. The pressure-resistant case 2 is manufactured by deep-drawing a metal plate and pressing the non-exhaust side end surface T2 into a cylindrical shape that is closed by the closing plate portion 2A. The closing plate portion 2A is welded to the electrode terminal 5 of the battery cell 1 arranged inside the cylinder and fixed to the battery cell 1. The closing plate portion 2A is fixed to the electrode terminal 5 by laser welding, resistance welding, and ultrasonic welding. In the pressure resistant case 2 of FIG. 1, which is also used for the lead plate, the inner surface of the closing plate portion 2A is connected to the electrode terminal 5, and the outer surface is connected to the bus bar 6.

In the metal pressure resistant case 2, the insulating material 17 is arranged between the battery cell 1 and the outer can 10. In the pressure-resistant case 2 of FIG. 4, a cylindrical insulating material 17 is arranged in order to insulate the outer can 10 of the battery cell 1. The insulating material 17 is manufactured by molding plastic. The insulating material 17 is manufactured by molding plastic into a cylindrical shape whose inner diameter is substantially equal to the outer diameter of the battery cell 1 and whose outer diameter is substantially equal to the inner shape of the pressure resistant case 2. The pressure resistant case 2 is arranged. The insulating material 17 is provided with a gas groove 17A on the inner surface in order to allow the leaked gas discharged to the non-exhaust side end surface T2 to flow to the exhaust side end surface T1. FIG. 5 shows a partial cross-sectional view of the insulating material 17 provided with the gas groove 17A on the inner surface. The insulating material 17 shown in this figure is provided with a plurality of rows of gas grooves 17A on the inner surface so as to extend in the axial direction of the cylinder. The insulating material 17 in FIG. 4 covers the outer peripheral portion of the bottom surface of the outer can 10. The insulating material 17 covers up to the bottom surface of the outer can 10, but the insulating material does not necessarily cover the bottom surface of the outer can, and does not cover the entire outer can, and the end face on the non-exhaust side of the outer can is not covered. It is also possible to cover a part of the side (the upper part of the outer can 10 in FIG. 4). The insulating material 17 that covers a part of the outer can 10 guides the leaked gas discharged from the end of the gas groove 17A to the discharge duct 9 by the gas groove 17A provided on the inner surface of the battery holder 3.

In the battery modules of FIGS. 1 and 4, even if the non-exhaust side end surface T2 of the battery cell 1 is destroyed and the leaked gas is ejected from the inside, the leaked gas is inside the pressure resistant case 2, to be exact, the insulating material 17. It passes through the gas groove 17A, is guided to the discharge opening 14, and is discharged to the outside from the discharge duct 9. Therefore, even if the non-exhaust side end surface T2 is destroyed by the internal pressure, the leaked gas is not ejected into the battery module, and the harmful effects of the leaked gas can be prevented.

In the metal pressure resistant case 2, the insulating material 17 provided on the inner surface can be used as a heat shrink tube. The pressure-resistant case 2 in which the heat-shrinkable tube is arranged inside can be insulated from the battery cell 1 without using an insulating material formed of plastic. This is because the heat-shrinkable tube serves as an insulating material to insulate the pressure-resistant case 2 and the outer can 10. The battery module having this structure is provided with a gas groove 17A in the pressure resistant case 2 as shown in a partial cross-sectional view of FIG. This is to guide the leaked gas ejected to the non-exhaust side end surface T2 to the exhaust side end surface T1. The pressure-resistant case 2 having this structure is provided with a gas groove 17A having a shape having a gas groove 17A extending in the axial direction, that is, a tubular portion formed into a corrugated shape in a step of pressing a metal plate.

In the battery modules of FIGS. 1 and 4, the battery cell 1 is inserted inside the metal pressure resistant case 2 via the insulating material 17, and the closed plate portion 2A of the pressure resistant case 2 is welded to the electrode terminal 5 to form a battery. Assembled as a unit U, the battery unit U is arranged in the battery storage portion of the battery holder 3, and each battery cell 1 is arranged in a fixed position.

In the battery module of FIG. 2, the pressure resistant case 2 is made of plastic as an insulating material. In the pressure-resistant case 2 made of plastic, the leader wire 15 connected to the electrode terminal 5 is arranged between the outer can 10 and the leader wire 15. FIG. 7 shows a detailed cross-sectional view of FIG. In the battery module shown in this figure, the leader wire 15 is arranged inside the pressure-resistant case 2 so as to be insulated from the outer can 10. In the pressure-resistant case 2 of FIGS. 2 and 7, plastic is molded into a shape in which one end of the tubular body is closed by the closing plate portion 2A. One end of the leader wire 15 is connected to the electrode terminal 5, and the other end is connected to a bus bar 6 arranged on the exhaust side end surface T1. In order to insulate the leader wire 15 from the outer can 10 of the battery cell 1, a plastic insulating material 17 is arranged between the leader wire 15 and the outer can 10. The insulating material 17 is made of plastic in a cylindrical shape. Similar to the insulating material 17 in FIG. 1, the insulating material 17 has an inner shape substantially equal to the outer shape of the battery cell 1 and an outer shape substantially equal to the inner shape of the pressure resistant case 2 so that the battery cell 1 is placed inside and outside. The pressure resistant case 2 is arranged. Further, since the lead plate is arranged between the insulating material 17 and the pressure resistant case 2, a wiring groove for arranging the leader wire 15 is provided on the outer surface. The leader wire 15 is arranged in the wiring groove and is arranged between the leader wire 15 and the pressure resistant case 2. Further, the insulating material 17 is provided with a gas groove 17A on the inner surface in the same manner as the insulating material 17 in FIG.

In the battery module shown in the cross-sectional view of the pressure resistant case 2 of FIG. 8, the leader wire 15 is inserted between the battery cell 1 and the leader wire 15 in place of the tubular insulating material 17 shown in FIG. The insulation guide 21 is arranged only in the portion insulated from the outer can 10. The insulation guide 21 is made of plastic in a groove shape in which a wiring groove 21A for guiding the leader wire 15 is provided on the pressure resistant case side. The insulation guide 21 extends in the lead-out direction of the leader wire 15 and is arranged between the outer can 10 of the battery cell 1 and the pressure-resistant case 2. The pressure-resistant case 2 made of plastic is provided with both a fitting recess 22 for arranging the insulating guide 21 at a fixed position and a gas groove 17A on the inner surface.

The battery module of FIG. 9 is arranged on the inner surface of the pressure resistant case 2 with the leader wire 15 as a covered wire. The leader wire 15 having an insulating coating on the surface does not need to be provided with an insulating material or an insulating guide between the leader wire 15 and the outer can 10 of the battery cell 1. This is because the insulating coating insulates the outer can 10 of the battery cell 1. In this battery module, as shown in a partial cross-sectional view of FIG. 10, a wiring groove 20 for arranging a covered wire is provided on the inner surface of a cylinder on the inner surface of the pressure resistant case 2, and a leader wire 15 is arranged here. ..

In the battery module of FIGS. 7 to 10, the leader wire 15 is connected to the electrode terminal 5 of the battery cell 1, the leader wire 15 is arranged on the inner surface of the pressure resistant case 2 and pulled out to the discharge opening 14, and the inside of the pressure resistant case 2 is drawn. The battery cell 1 is inserted into the battery unit U to form a battery unit U. The battery unit U is arranged at a fixed position of the battery holder 3 and assembled as a battery module.

In the battery module shown in FIG. 3, the metal terminal 23 is fixed to the pressure resistant case 2 made of plastic. In this battery module, as shown in the detailed view of FIG. 11, the electrode terminal 5 is connected to the bus bar 6 via the metal terminal 23. The metal terminal 23 is manufactured by pressing a metal plate. FIG. 12 shows a perspective view of the metal terminal 23. The metal terminal 23 in this figure is formed by processing a metal plate into a shape in which one end (lower end in the figure) of the cylinder is closed by the connection plate 23A. A connection piece 23B is provided at the open end of the cylinder so as to project. A protruding portion 23C is provided on the outside of the cylinder in order to improve the connection strength with the plastic case. The protrusion 23C strengthens the connection strength with the plastic case to be fixed, and fixes the metal terminal 23 to the plastic pressure resistant case 2 so as not to be displaced. Therefore, the leaked gas to be ejected is surely discharged to the exhaust side end surface T1. The metal terminal 23 is integrally molded and fixed to the plastic in the process of molding the plastic case. The metal terminal 23 is fixed to the plastic case so that the connection plate 23A is arranged inside the plastic case and the connection piece 23B is arranged outside, and airtightly closes the non-exhaust side end surface T2 of the plastic case. The metal terminal 23 integrally molded and fixed to the pressure-resistant case 2 seals the non-exhaust side end surface T2 of the plastic pressure-resistant case 2 in an ideal state to reliably prevent gas leakage. The pressure resistant case 2 made of plastic is provided with a plurality of rows of gas grooves 17A on the inner surface. The gas groove 17A flows the leaked gas discharged to the non-exhaust side end surface T2 side to the exhaust side end surface T1 and guides it to the exhaust duct 9.

In the above battery module, the battery cell 1 is inserted into the withstand voltage case 2, the metal terminal 23 of the withstand voltage case 2 is connected to the electrode terminal 5 of the battery cell 1, and the battery unit U is used as the battery unit U. It is placed in place and assembled.

The battery holder 3 is manufactured by molding a resin such as a thermoplastic resin which is an insulating material. The battery holder 3 is preferably made of a resin having excellent flame retardancy and heat resistance. As such a resin, for example, PC (polycarbonate), PP (polypropylene), nylon and the like can be used.

In the battery holder 2 shown in FIGS. 1 to 3, the battery unit U is arranged in the battery accommodating portion 3A and arranged in a fixed position. In the battery holder 3 of FIGS. 1 to 3, the battery unit U is arranged in a parallel posture, the opening end side of the pressure resistant case 2 is arranged on substantially the same plane, and the battery unit U is arranged at the discharge port 8 of the discharge valve 7 of the battery cell 1. It is arranged at a position where the discharge duct 9 is connected. The battery holder 2 has a plurality of battery storage units 3A, and the battery unit U is arranged in the battery storage unit 3A. The battery storage unit 3A has an internal shape in which the battery unit U can be arranged, and the battery unit U is inserted inside and arranged at a fixed position. The battery holder 3 has a partition wall between the battery storage portions 3A, and the battery units U are arranged on both sides of the partition wall in an insulated state.

The battery holder 3 of FIGS. 1 to 3 has a welded opening 3B at the upper end for connecting the electrode terminal 5 to the bus bar 6. The battery holder 3 in the figure is a central portion in the longitudinal direction of the battery unit U, and is divided into upper and lower holder units in the figure. The holder unit is divided into upper and lower parts, and the battery is inserted into the battery storage unit 3A, and then connected to each other to arrange the battery unit U in a fixed position. In the battery holder 3 which can be divided into upper and lower parts and the battery unit U can be arranged in the battery storage part, the openings provided at the upper and lower ends of the battery storage part 3A are made smaller than the outer shape of the battery unit U, and the battery unit U is made into a battery. The battery unit U can be held so as not to move to the outside from the storage portion 3A, that is, the battery unit U is not displaced in the vertical direction. However, although not shown, the battery holder may be provided with an opening at the end into which the battery unit can be inserted, and the battery unit can be inserted through the opening and placed in a fixed position.

The battery holder 3 has a metal plate bus bar 6 arranged at a fixed position. In the battery modules of FIGS. 1 and 3, positive and negative bus bars 6 are arranged at both ends of the battery storage portion 3A provided in the battery holder 3. The positive and negative bus bars 6 are connected to the electrode terminals 5 via the lead plates indicated by the arrows. In the battery modules of FIGS. 1 and 3, one bus bar 6 is connected to the convex electrode, and the other bus bar 6 is connected to the bottom surface side of the outer can. In the battery module of FIG. 2, since the leader wire 15 connected to the electrode terminal 5 is pulled out to the discharge opening 14 side of the pressure resistant case 2, the positive and negative bus bars 6 are insulated and arranged on the discharge opening side of the pressure resistant case 2. Then, the leader line 15 is connected to one bus bar 6, and the bottom surface of the outer can 10 is connected to the other bus bar. In the battery modules of FIGS. 1 to 3, adjacent battery cells 1 are connected in parallel by a bus bar 6, but the battery module of the present invention can also connect adjacent battery cells in series via a bus bar. ..

The exhaust duct 9 discharges the high-temperature and high-pressure exhaust gas discharged from the discharge valve 7 of each battery cell 1 to the outside of the housing 4. The exhaust duct 9 is arranged so as to be connected to the opening of the exhaust valve 7 provided on the exhaust side end surface T1 of the battery cell 1. The discharge duct 9 has a plurality of opening windows 24 connected to the discharge port 8 of the discharge valve 7 of each battery cell 1, and the opening at the tip thereof is arranged outside the housing 4 of the battery module.

The housing 4 is a metal case, and the battery holder 3, the bus bar 6, and the discharge duct 9 are fixedly arranged in a fixed position. The battery holder 3 and the discharge duct 9 are connected to the integrated structure and fixed at a fixed position of the housing 4. The bus bar 6 is fixed in place on the battery holder 3. Although not shown, the discharge duct 9 is fixed to the battery holder or sandwiched between the battery holder and the housing and arranged in a fixed position. The housing 4 is screwed, fitted, or the like to fix the battery holder 3 and the discharge duct 9 to a fixed position inside. The housing 4 fixes the battery holder 3 in place, and the battery holder 3 fixed in place fixes the pressure-resistant case 2 and the battery cell 1 in place. In the battery module in which the battery cell 1 and the pressure-resistant case 2 are fixed in place, the pressure-resistant case 2 and the battery cell 1 do not move relative to each other due to the leaked gas ejected from the non-exhaust side end surface T2. The pressure-resistant case 2 that does not move relative to the battery cell 1 causes the leaked gas ejected to the non-exhaust side end face T2 to flow to the exhaust side end face T1. In the relative movement between the pressure-resistant case 2 and the battery cell 1, the housing 4 fixes the battery holder 3 in a fixed position, the battery holder 3 is arranged in a fixed position, and the battery holder 3 is the pressure-resistant case 2 and the battery cell 1. This can be realized not only by a structure in which and is fixed in a fixed position, but also by a structure in which the battery holder 3 fixes the pressure resistant case 2 and the battery cell 1 in a fixed position. As shown in FIG. 4, the structure in which the battery holder 3 fixes the pressure-resistant case 2 and the battery cell 1 in place is such that the battery unit U is displaced in the axial direction in the battery holder 3 divided into a pair of holder units. It can also be realized by arranging the holder units in a non-separable state and connecting the pair of holder units to a structure that does not separate them. The state in which the battery unit U does not shift in the axial direction is realized by making the openings at both ends of the battery housing portion 3A smaller than the outer diameter of the battery cell 1. A structure for connecting a pair of holder units in a non-separable state is not shown, but one holder unit is provided with a locking arm, and the locking arm is connected to the other holder unit with a locking structure, or a pair of holders. This can be realized by a structure in which the unit is pressed by the housing 4 from both ends.

The metal bus bar 6 arranged inside the housing 4 is arranged so as to be insulated from the metal housing 4. Insulation between the bus bar 6 and the housing 4 is realized by providing a gap, arranging an insulating separator 25, or arranging parts made of an insulating material such as a discharge duct. In the battery modules of FIGS. 1 to 3, since the bus bar 6 arranged on the non-exhaust side end surface T2 and the housing 4 are arranged so as to face each other, the separator 25 is integrally molded and provided in the battery holder 3. The separator 25 is partially provided on the surface facing the housing 4, and the tip surface is projected to the inner surface of the housing 4 to provide a gap between the housing 4 and the bus bar 6. The bus bar 6 is arranged in this gap, and the bus bar 6 is arranged so as to be insulated from the housing 4. Further, the separator 25 comes into contact with the inner surface of the housing 4 to arrange the battery holder 3 in a fixed position to prevent the battery holder 3 from being displaced. The separator 25 is fixed to the housing 4 with a set screw 26 penetrating the housing 4, so that the housing 4 and the battery holder 3 can be reliably fixed in place.

In the above battery module, even if the internal pressure of the non-exhaust side end face rises and is destroyed, the pressure resistant case guides the leaking gas to the exhaust side end face and discharges it. The battery cell can make the battery case as thin as possible to increase the charge / discharge capacity with respect to the unit weight and unit volume, but this reduces the strength of the thin battery case and thus the fracture strength of the non-exhaust side end face. It causes. In the above battery module, even if the non-exhaust side end face of the battery cell is destroyed, the leaked gas can be guided to the exhaust side end face and discharged without being discharged from the non-exhaust side end face, so this type of battery cell is used. In the battery module, high safety can be realized while increasing the capacity.

The battery module of the present invention can be effectively used for a power supply module having a structure in which high-temperature and high-pressure exhaust gas is discharged from the exhaust side end face in a state where the internal pressure of the battery cell rises.

1 ... Battery cell 2 ... Pressure-resistant case 2A ... Blocking plate part 3 ... Battery holder 3A ... Battery storage part 3B ... Welding opening 4 ... Housing 5 ... Electrode terminal 6 ... Bus bar 7 ... Discharge valve 8 ... Discharge port 9 ... Discharge duct 10 ... Exterior can 11 ... Seal plate 12 ... Battery case 13 ... Thin-walled part 14 ... Discharge opening 15 ... Leader wire 17 ... Insulation material 17A ... Gas groove 20 ... Wiring groove 21 ... Insulation guide 21A ... Wiring groove 22 ... Fitting recess 23 ... Metal terminal 23A ... Connection plate 23B ... Connection piece 23C ... Projection 24 ... Opening window 25 ... Separator 26 ... Set screw T1 ... Exhaust side end face T2 ... Non-exhaust side end face U ... Battery unit

Claims (6)

A plurality of battery cells having an exhaust valve end face provided with an exhaust valve opening at a set pressure as an exhaust side end face and an end face opposite to the exhaust side end face as a non-exhaust side end face.
A battery holder in which the battery cells are arranged in a fixed position,
A battery module including a discharge duct connected to the discharge port of the battery cell arranged at a fixed position in the battery holder.
It is equipped with a pressure resistant case in which the battery cell is arranged inside.
The pressure-resistant case has the strength to withstand the temperature and pressure of the leaked gas discharged from the non-exhaust side end face, and also
By closing the non-exhaust side end face side of the built-in battery cell,
An exhaust gas discharge opening is provided on the exhaust side end face side.
The structure is such that the leaked gas discharged from the non-exhaust side end face is discharged from the discharge opening of the pressure resistant case.
The battery cell
An exterior can that opens one end and closes the bottom,
The battery case is provided with a sealing plate that is airtightly connected to the opening edge of the outer can, seals the opening, and is provided with an electrode terminal.
The battery cell is provided with the discharge valve on the bottom surface of the outer can, which destroys a thin portion at a set pressure.
A battery module characterized in that the bottom surface of the outer can is an exhaust side end face and the sealing plate side is a non-exhaust side end face. The battery module according to claim 1 .
A battery module characterized in that the battery cell is a cylindrical battery. The battery module according to claim 1 or 2 .
A battery module characterized in that the discharge opening of the pressure resistant case is connected to the discharge duct. The battery module according to any one of claims 1 to 3 .
A battery module characterized in that the pressure-resistant case is a metal cylinder having a non-exhaust side end face closed. The battery module according to claim 4 .
A battery module characterized in that the pressure resistant case is connected to an electrode terminal of the battery cell provided on a non-exhaust side end surface and used in combination with a lead plate. A plurality of battery cells having an exhaust valve end face provided with an exhaust valve opening at a set pressure as an exhaust side end face and an end face opposite to the exhaust side end face as a non-exhaust side end face.
A battery holder in which the battery cells are arranged in a fixed position,
A battery module including a discharge duct connected to the discharge port of the battery cell arranged at a fixed position in the battery holder.
It is equipped with a pressure resistant case in which the battery cell is arranged inside.
The pressure-resistant case has the strength to withstand the temperature and pressure of the leaked gas discharged from the non-exhaust side end face, and also
By closing the non-exhaust side end face side of the built-in battery cell,
An exhaust gas discharge opening is provided on the exhaust side end face side.
The structure is such that the leaked gas discharged from the non-exhaust side end face is discharged from the discharge opening of the pressure resistant case.
The pressure resistant case is made of plastic
The pressure-resistant case includes a plastic main body and a metal lead terminal connected to an electrode terminal of the battery cell integrally molded and fixed to the main body.
The main body portion has a tubular cover portion that covers the outer peripheral surface of the battery cell, and an end face cover portion that is connected to one end of the tubular cover portion and covers the non-exhaust side end surface.
The lead terminal has a cylinder portion, a welded plate portion connected to one end of the cylinder portion and welded to the electrode terminal of the battery cell, and a bus bar connection portion connected to the cylinder portion on the opposite side of the welded plate portion. It consists of
In the lead terminal, the tubular portion penetrates the main body portion made of plastic inward and outward, the bus bar connection portion is arranged outside the end face cover portion, and the weld plate portion is the end face cover portion. It is located inside the main body and is integrally molded and fixed to the main body.
A battery module in which the welded plate portion of the lead terminal is welded to the electrode terminal of the battery cell arranged inside the main body portion of the pressure resistant case.

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