JP6746962B2 - Battery module - Google Patents

Description

The present invention relates to a battery module including at least one battery, and more particularly to a structure related to releasing internal pressure of the battery.

Battery modules containing at least one battery are known. Patent Document 1 below discloses a battery module (100) in which an assembled battery (120) including a plurality of lithium ion battery cells (140) is housed in a casing (110) (see paragraph 0056). A structure for opening the inside of the battery such as a safety valve (145) is provided on the end surface of the lithium ion battery cell (140) (see paragraph 0072). The reference numerals in parentheses are the reference numerals used in Patent Document 1 below, and are not related to the reference numerals used in the description of the embodiments of the present application.

JP, 2010-113999, A

When the safety valve of the battery is opened, the hot electrode body inside the battery may be discharged together with the gas through the opening.

An object of the present invention is to suppress discharge of the electrode body when the safety valve is opened.

The battery module of the present invention includes at least one battery, is further disposed on one electrode end surface side of the battery, and defines an exhaust chamber sealed at the periphery between the battery and the exhaust chamber cover, A safety valve is provided on the electrode end surface on the exhaust chamber side of the battery, and is placed on the exhaust chamber cover to release the pressure inside the battery, and the tip faces a part of the safety valve. A blocking protrusion that blocks discharge of the electrode body. It is possible to prevent the blocking protrusion from coming into contact with the electrode body via the safety valve or directly and preventing the electrode body from being discharged to the outside of the battery.

Further, it is possible to arrange a laminated body in which metal plates are laminated in a state in which there is a gap, each metallic plate having a hole provided at a position facing the electrode end surface of the battery, in the exhaust chamber. it can. Since the laminated body captures the high temperature fine particles discharged from the inside of the battery, the discharge of the fine particles to the outside of the exhaust chamber can be suppressed.

When the safety valve is opened, the blocking protrusion can prevent the electrode body from being discharged from the battery.

It is an exploded perspective view of the battery module of this embodiment. FIG. 3 is a cross-sectional view showing a configuration of a negative electrode end surface of a battery and an exhaust chamber around it. It is a figure which shows the negative electrode end surface of a battery. It is a figure which shows the state which the safety valve opened.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a schematic configuration of the battery module 10. In the following description, the terms representing directions and directions such as up/down/left/right, side, front, and back indicate the directions in the drawings used in the description unless otherwise specified, and the battery module 10 is actually installed. It is not related to the direction of

The battery module 10 houses a plurality of batteries 12. The plurality of batteries 12 are electrically connected in a predetermined manner to form an assembled battery. The battery 12 has a substantially columnar shape, and one end of the cylinder is provided with a positive electrode and the other end is provided with a negative electrode. The end faces provided with the positive electrode and the negative electrode are referred to as a positive electrode end face 13A and a negative electrode end face 13B (see FIGS. 2 and 4), respectively, and are collectively referred to as an electrode end face. In this battery module 10, the battery 12 is arranged with the end having the positive electrode facing upward. The lower end of each battery 12 is housed in a housing hole 16 provided in the battery holder 14, and is held in the battery holder 14. The battery holder 14 has a substantially plate shape, and the accommodating holes 16 are two-dimensionally arranged on the plate plane. In this embodiment, the accommodation holes 16 are arranged in four rows extending from the front right side toward the left rear side in FIG. 1, and the accommodation holes 16 in the adjacent rows are arranged with a shift of a half pitch. Each accommodation hole 16 has a cylindrical shape that fits into the cylindrical shape of the battery 12, and the battery 12 is inserted into this cylinder and held by the battery holder 14. Therefore, in this battery module 10, the plurality of batteries 12 are arranged in four rows. The plurality of batteries 12 are arranged in a rectangular range that is long in the direction in which the rows extend. The length of the accommodating hole 16 in the direction of the central axis of the cylinder is sufficient to prevent the held battery 12 from wobbling. The accommodation hole 16 penetrates the battery holder 14 in the plate thickness direction, and the lower end of the battery 12 is exposed downward.

A holding case 18 is provided so as to surround the sides and the upper side of the entire batteries 12 held by the battery holder 14 and arranged two-dimensionally. The holding case 18 is fixed to the battery holder 14 with its lower end in contact with the upper surface of the battery holder 14. The holding case 18 has a ceiling plate 20 near its upper end. The ceiling plate 20 is provided with holding openings 22 respectively corresponding to the batteries 12 arranged. The holding opening 22 has a step formed on the peripheral edge, and the step portion engages with the peripheral edge of the upper end of each battery 12 to hold each battery 12 at its upper end.

A positive electrode bus bar 24 is arranged further above the ceiling plate 20. The positive electrode bus bar 24 is electrically connected to the positive electrode of each battery 12 via a positive electrode connecting wire 26. Four positive electrode bus bars 24 are provided.

On the other hand, below the battery holder 14, a negative electrode bus bar module 28 is arranged. The negative electrode bus bar module 28 is formed by integrating four negative electrode bus bars 30 by resin molding. The negative electrode bus bar 30 is electrically connected to the negative electrode of each battery 12 via a negative electrode connecting wire 32. Further, an inter-group bus bar 34 that electrically connects the three positive electrode bus bars 24 and the three negative electrode bus bars 30 extends obliquely downward from the positive electrode bus bar 24 along the side surface of the holding case 18. The entire upper part of the ceiling plate 20 and the positive electrode bus bar 24 is covered with an upper cover (not shown), and the side surface of the holding case 18 where the inter-group bus bar 34 is provided and the inter-group bus bar 34 are covered with a side cover (not shown). It is being appreciated.

The plurality of batteries 12 are divided into four groups in the longitudinal direction of the battery module 10, and four positive electrode bus bars 24 and four negative electrode bus bars 30 correspond to these groups. The batteries 12 belonging to each group are connected in parallel by each positive electrode bus bar 24 and the negative electrode bus bar 30, and each group is connected in series by the inter-group bus bar 34.

An exhaust chamber cover 36 is arranged below the battery holder 14. An exhaust chamber 38 is formed between the battery holder 14 and the exhaust chamber cover 36. The negative electrode bus bar module 28 is provided with a hole 40 at a position facing the battery 12 and the housing hole 16. Due to this hole 40, the negative electrode end surface 13B of the battery 12 faces the exhaust chamber 38. Blocking projections 42 are arranged on the bottom surface of the exhaust chamber cover 36 so as to correspond to the negative electrode end surfaces 13B of the batteries 12. Further, in the exhaust chamber 38, a laminated body 46 in which metal plates 44 are laminated with a gap is arranged. A hole 48 is provided in each of the metal plates 44 at a position facing the negative electrode end surface 13B of the battery 12. The holes 48 provided in each metal plate 44 overlap each other when the metal plates 44 are stacked, and become the holes 50 of the stacked body 46.

In addition to the hole 40 facing the battery 12, the negative electrode bus bar module 28 has a communication hole 51 that communicates the front and back. Further, the battery holder 14 has an exhaust hole 53 which is opened on the lower surface so as to face the communication hole 51 and which is further opened on the side surface to the outside. The exhaust chamber 38 is in communication with the outside of the battery module 10 via the communication hole 51 and the exhaust hole 53, and the gas discharged from the battery 12 into the exhaust chamber 38 is the communication hole 51 and the exhaust hole 53, depending on the case. Are guided to a predetermined area around the battery module 10 by a flow path to which an exhaust duct (not shown) subsequent thereto is added.

FIG. 2 is a cross-sectional view showing the peripheral structure of the negative electrode end surface 13B. The battery 12 houses the electrode body 52. A space between the battery holder 14 and the exhaust chamber cover 36 is sealed by a negative electrode bus bar module 28. The negative electrode end surface 13B is provided with a safety valve 54 that opens and releases the internal pressure when the internal pressure of the battery 12 increases. The safety valve 54 is formed by engraving a cut groove 56 on a member on the end face of the battery 12, and when the member on the end face receives a pressure of a predetermined value or more, the end face is split by the cut groove 56 and the inside of the battery 12 is opened. To be done. The cut groove 56 is formed, for example, in a circular shape on the negative electrode end surface 13B as shown in FIG. The negative electrode connecting wire 32 extends from the edge of the hole 40 of the negative electrode bus bar module toward the center and is welded to the safety valve 54.

On the bottom surface of the exhaust chamber cover 36, a blocking protrusion 42 that blocks the electrode body 52 from being discharged from the battery 12 when the safety valve 54 is opened is arranged. The blocking protrusion 42 blocks the discharge of the electrode body 52 by contacting the electrode body 52 to be discharged via the safety valve 54 or directly. The shape of the blocking protrusion 42 may be a cone, a truncated cone or other conical shape, a frustum shape, or a columnar shape. The tip of the blocking projection 42 opposes, preferably abuts, a part of the safety valve 54, supports the safety valve 54 when the safety valve 54 opens at this part, and prevents discharge of the electrode body 52 via the safety valve 54. The position and range where the blocking protrusion 42 faces or abuts the safety valve 54 are determined so as to obtain a sufficient opening area when the safety valve 54 is opened.

A laminated body 46 is arranged in the exhaust chamber 38. The laminated body 46 is formed by laminating a plurality of metal plates 44 with a gap therebetween. The metal plate 44 can be made of stainless steel. The gap between the metal plates 44 may be 0.4 mm, for example. In the laminated body 46, a hole 50 is formed at a position facing the negative electrode end surface 13B provided with the safety valve 54.

FIG. 4 is a diagram showing a state in which the safety valve 54 is open. In FIG. 4, the safety valve 54 of the right battery 12 is open. Due to the rise in the internal pressure of the battery 12, the cut groove 56 is ruptured and the safety valve is opened. Even if the cut groove 56 is torn, the safety valve 54 is not completely removed because the blocking protrusion 42 supports the safety valve 54, and the blocking protrusion 42 contacts the electrode body 52 via the safety valve 54. If the safety valve 54 is completely detached, the blocking protrusion 42 directly contacts the electrode body 52. The blocking projection 42 abuts the electrode body 52, which is about to be discharged from the battery 12, through the safety valve 54 or directly to prevent the discharge of the electrode body 52. The blocking protrusion 42 faces the end surface of the electrode body 52 with the negative electrode end surface 13B of the battery 12 interposed therebetween. Preferably, the blocking protrusion 42 is arranged so that its center coincides with the centers of the battery 12 and the electrode body 52. The safety valve 54 opens along the side surface of the blocking protrusion 42. By making the blocking protrusion 42 a cone or a truncated cone, the safety valve 54 can be opened along the slope where the circular cut groove 56 is torn anywhere on the circumference.

When the safety valve 54 is opened, the particles inside the battery 12 are discharged into the exhaust chamber 38 together with the high temperature gas. The discharged fine particles enter the gaps of the surrounding laminated body 46 and are captured there. Therefore, it is possible to prevent the particulates from being discharged from the exhaust chamber 38 through the communication hole 51 and the exhaust hole 53. Further, since the gas and the fine particles remove heat from the laminated body 46, even if some gas passes through the laminated body 46 and is discharged from the exhaust chamber 38, the temperature thereof is lowered. The laminated body 46 is provided for the purpose of trapping the particles discharged from the battery 12 in the exhaust chamber 38 and/or reducing the temperature of the particles discharged into the exhaust chamber 38 and the temperature of the gas.

As described above, when the safety valve 54 is opened, the blocking protrusion 42 suppresses the discharge of the electrode body 52 from the battery 12, and the stacked body 46 captures the fine particles from the battery 12. The safety valve may be provided on the positive electrode end surface 13A.

<Other aspects of battery module>
A battery module including at least one battery,
An exhaust chamber cover that is disposed on one electrode end surface side of the battery and that defines an exhaust chamber sealed at a peripheral edge between the battery and the battery,
A safety valve provided on the end surface of the electrode on the exhaust chamber side of the battery to release the pressure inside the battery,
A laminated body, which is arranged in an exhaust chamber and is formed by laminating metal plates in a state where there is a gap, in which each metal plate has a hole provided at a position facing the electrode end surface of the battery,
A battery module.

10 battery module, 12 battery, 13A positive electrode end surface, 13B negative electrode end surface, 14 battery holder, 16 housing hole, 18 holding case, 20 ceiling plate, 22 holding opening, 24 positive electrode bus bar, 26 positive electrode connecting wire, 28 negative electrode bus bar module, 30 negative electrode bus bar, 32 negative electrode connecting wire, 34 inter-group bus bar, 36 exhaust chamber cover, 38 exhaust chamber, 40 hole (for negative electrode bus bar module), 42 blocking protrusion, 44 metal plate, 46 laminated body, 48 metal plate hole, 50 hole of laminated body, 51 communicating hole, 52 electrode body, 53 exhaust hole, 54 safety valve, 56 cut groove.

Claims (2)

A battery module including at least one battery,
An exhaust chamber cover that is disposed on one electrode end surface side of the battery and that defines an exhaust chamber sealed at a peripheral edge between the battery and the battery,
A safety valve provided on the end surface of the electrode on the exhaust chamber side of the battery to release the pressure inside the battery,
The surface of the exhaust chamber side of the exhaust chamber cover, the tip is arranged to coincide with the center of the battery inside the electrode body, and the tip is contacting the center of the safety valve, when the safety valve is open, via the safety valve Alternatively, a blocking protrusion that directly contacts the electrode body inside the battery and blocks discharge of the electrode body from the inside of the battery ,
A battery module. The battery module according to claim 1, wherein
A laminated body, which is arranged in an exhaust chamber and is formed by laminating metal plates in a state where there is a gap, each metal plate being provided with a hole at a position facing an electrode end face of a battery,
A battery module having.

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