JP2019040812A - Assembled battery - Google Patents

Abstract

To provide an assembled battery which can easily protect a system by utilizing the bulge of a battery cell.SOLUTION: A battery assembly 100 according to the present invention includes a battery cell 150, a case 110 accommodating the battery cell 150 therein, and a fuse portion 240 held by the case 110. The fuse portion 240 is broken by expansion of the case 110 accompanying with expansion of the battery cell 150.SELECTED DRAWING: Figure 13

Description

  The present invention relates to an assembled battery.

  Conventionally, a battery pack in which a plurality of battery cells are housed in a member such as a housing is known. For example, Patent Document 1 discloses an assembled battery including a circuit breaker connected in series on an electrical connection circuit so that a power disconnection unit is disconnected when energized due to expansion of a battery cell.

Special table 2014-533424 gazette

  In general, the built-in battery cell swells during use of the battery pack, during charge / discharge or after aging, and the battery pack may be destroyed. For example, there is a possibility that a part of the bus bar that is welded to connect the battery cells comes off and a problem such as an external short circuit occurs. Before reaching such a situation, it is necessary to safely converge the system including the assembled battery. In the assembled battery described in Patent Document 1, the circuit breaker detects the swelling of the battery cell and disconnects the power disconnection unit, thereby achieving system safety. However, the bulge of the battery cell is not directly used, and the mechanism for disconnecting electricity is complicated.

  An object of the present invention made in view of such problems is to provide an assembled battery that can easily protect the system by utilizing the swelling of battery cells.

In order to solve the above problems, an assembled battery according to an embodiment of the present invention is provided.
A battery cell;
A case for accommodating the battery cell therein;
A fuse portion held in the case;
With
The fuse portion is disconnected due to expansion of the case accompanying expansion of the battery cell.

  According to the assembled battery according to the embodiment of the present invention, the system can be easily protected by utilizing the swelling of the battery cell.

It is an external appearance perspective view of the assembled battery which concerns on one Embodiment of this invention. It is an external appearance perspective view which shows the state which removed the upper case and gas exhaust pipe of the assembled battery. It is a figure which shows a fusible link single-piece | unit. It is a perspective view which shows arrangement | positioning of the battery cell accommodated in the assembled battery of FIG. It is a disassembled perspective view of the assembled battery of FIG. It is a figure which shows the state in which the battery cell was accommodated in the lower case and the cell holder. It is a perspective view of the assembled battery with which the sensor board | substrate was attached. It is a front view of the assembled battery with which the sensor board | substrate was attached. It is a top view of the assembled battery with the BAT case attached. It is a front view of the assembled battery of the state which connected the gas exhaust pipe to the gas duct. FIG. 10 is a top view corresponding to FIG. 9 and showing a first example in which only one relay is arranged. FIG. 10 is a top view corresponding to FIG. 9 and showing a second example in which only one relay is arranged. FIG. 13 is a first diagram schematically showing a cross-section along the XIII-XIII arrow line of FIG. 12. FIG. 13 is a second view schematically showing a cross section along the XIII-XIII arrow line of FIG. 12. FIG. 8 is a perspective view corresponding to FIG. 7 when only one relay is arranged.

  Hereinafter, an assembled battery 100 according to an embodiment of the present invention will be described with reference to the drawings. First, the configuration of the assembled battery 100 when two relays 220 are arranged will be described with reference to FIGS. 1 to 10. The drawings are schematic. The dimensions or ratios on the drawings do not necessarily match the actual ones. The depiction of each component in each drawing may be partially simplified.

  FIG. 1 is an external perspective view of an assembled battery 100 according to an embodiment of the present invention. FIG. 2 is an external perspective view showing a state where the upper case 300 and the gas exhaust pipe 600 of the assembled battery 100 are removed. FIG. 3 is a diagram showing the fusible link 240 alone. The assembled battery 100 includes an upper case 300, a lower case 110, a cell holder 120, a BAT case 500, and a gas exhaust pipe 600. The assembled battery 100 has a substantially rectangular parallelepiped shape. The surface facing the positive direction of the Y axis is also referred to as the first side surface of the battery pack 100. The surface facing the negative direction of the Y axis is also referred to as the second side surface of the battery pack 100. The surface facing the positive direction of the Z axis is also referred to as the upper surface of the assembled battery 100. The surface facing the negative direction of the Z axis corresponding to the opposite side of the upper surface is also referred to as the bottom surface of the battery pack 100. The surface facing the positive direction of the X axis is also referred to as the front surface of the battery pack 100. The surface facing the negative direction of the X axis corresponding to the opposite side of the front surface is also referred to as the back surface of the battery pack 100. The names of the surfaces of the assembled battery 100 can be applied as names indicating the surfaces of the lower case 110, the cell holder 120, and the BAT case 500. The descriptions of “lower” and “upper” are identifiers for distinguishing configurations. In the present embodiment, the configuration shown as the lower case 110 is located at the lower portion of the configuration shown as the upper case 300, but is not limited to the lower portion, and may be located at the upper portion or the side portion.

  The lower case 110, the cell holder 120, and the BAT case 500 are engaged with each other on the first side surface side by the engaging member 180. The lower case 110, the cell holder 120, and the BAT case 500 are engaged with each other also on the second side surface by the engaging member 180. A member in which the lower case 110, the cell holder 120, and the BAT case 500 are engaged is also referred to as a battery case. The lower case 110, the cell holder 120, the BAT case 500, and the battery case are also simply referred to as cases. Battery cells 150 (see FIG. 4) are accommodated in the battery case. The battery cell 150 may be a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

  The lower case 110, the cell holder 120, and the BAT case 500 may be made of a resin such as PBT (Poly-Butylene Terephthalate).

  The upper case 300 has a recess 301 in a part of the side where the upper surface and the front surface are connected. The upper case 300 has a recess 302 in a part of the side connecting the upper surface and the first side surface. The assembled battery 100 includes a first terminal 250 and a second terminal 260 at positions where the concave portion 301 and the concave portion 302 are provided, respectively. A packing 270 is disposed so as to surround the first terminal 250. Similarly, the packing 270 is disposed so as to surround the second terminal 260. The packing 270 is preferably formed of an arbitrary member having elasticity. However, the present invention is not limited to this, and the packing 270 may not have elasticity.

  The upper case 300 has an opening 303 on the first side surface. The assembled battery 100 includes a connector 310 at a position where the opening 303 is provided.

  The assembled battery 100 may include a first relay 221 and a second relay 222 on the upper surface of the battery case. The first relay 221 and the second relay 222 are collectively referred to as a relay 220 when they do not need to be distinguished from each other. The relay 220 may be positioned on the lower case 110 or may be positioned over the lower case 110 and the cell holder 120. The number of relays 220 is not limited to two and may be one or three or more.

  The assembled battery 100 may include a bus bar 160 that is electrically connected to a terminal of the battery cell 150. The bus bar 160 may be connected to the positive terminal and the negative terminal of the battery cell 150, respectively. The assembled battery 100 may include a copper bus bar 280 on the upper surface of the battery case. The number of copper bus bars 280 included in the assembled battery 100 is not limited to four, and may be three or less, or may be five or more. Hereinafter, the four copper bus bars 280 are distinguished as copper bus bars 280a to 280d, respectively. When not distinguishing each copper bus bar, the copper bus bar 280 is collectively referred to.

  The first relay 221 may be electrically connected to the second terminal 260 at one end via the fusible link 240 and the copper bus bar 280a. The first relay 221 may be electrically connected to the bus bar 160 at the other end via the copper bus bar 280b. The second relay 222 may be electrically connected to the first terminal 250 at one end via the copper bus bar 280c. The second relay 222 may be electrically connected to the bus bar 160 at the other end via the copper bus bar 280d. The first relay 221 and the second relay 222 function as a switching element that connects or disconnects the battery cell 150 in parallel with each component outside the assembled battery 100 in the power supply system.

  The upper case 300 may be made of a resin such as PBT, for example. The upper case 300 covers the battery cell 150, the copper bus bar 280, the relay 220, the sensor substrate 230, and the fusible link 240, thereby preventing corrosion and short circuit of electronic components and metal parts inside the assembled battery 100.

  The sensor substrate 230 is electrically connected to the battery cell 150 and measures a current flowing through a circuit including the first secondary battery or a voltage applied to the circuit including the battery cell 150 by an appropriate method. The sensor substrate 230 includes a BMS (Battery Management System). The BMS is communicably connected to the control unit of the power supply system, and controls the relay 220 and the sensor board 230.

  As shown in FIG. 3, the fusible link 240 (fuse portion) includes a fuse body 241a (see FIG. 13), a fuse body 241a, a housing made of an insulating resin that houses and holds the fuse body 241a, and an insulating resin that covers the housing. A main body portion 241 including a cover. The fusible link 240 further includes a pair of terminal portions 242 that are connected to the main body portion 241 and project in opposite directions at both ends thereof. A substantially circular through hole 243 is formed in a substantially central portion of the terminal portion 242. The fuse body 241a of the fusible link 240 is blown when an overcurrent occurs. Further, the fuse main body 241 a of the fusible link 240 is disconnected due to expansion of the case accompanying expansion of the battery cell 150. That is, the fusible link 240 is configured such that the fuse body 241a is disconnected when the expansion amount of the battery cell 150 exceeds a predetermined threshold. The predetermined threshold may be an appropriate amount of swelling of the battery cell 150 at a stage where the system can be safely converged before the above-described problem occurs due to the swelling of the battery cell 150.

  Here, in the battery cell 150 laminated | stacked along the Z-axis direction, a pair of side surface 150a (refer FIG. 4) substantially orthogonal to a lamination direction swells outside along a lamination direction, respectively. As the battery cells 150 swell in the stacking direction, the upper surface and the bottom surface of the case housing the stacked battery cells 150 also expand outward.

  As shown in FIG. 2, for example, the fusible link 240 may be held on the upper surface of the lower case 110 in the positive Y-axis direction in which the battery cells 150 are stacked in two stages. As an example, the main body 241 of the fusible link 240 is separated from the upper surface of the lower case 110. However, the main body 241 of the fusible link 240 may be in contact with the upper surface of the lower case 110. In addition, the tip of the terminal portion 242 is fixed to a substantially central portion on the upper surface of the lower case 110 on the second stage side, for example. Without being limited thereto, the ends of the pair of terminal portions 242 may be fixed to both end portions of the upper surface of the lower case 110, respectively.

  As described above, the tip of the terminal portion 242 may be fixed on the expansion surface S <b> 1 configured by the upper surface of the lower case 110. In particular, the main body 241 of the fusible link 240 may be disposed at a site where the displacement of the expansion surface S1 of the lower case 110 is maximum. That is, the main body portion 241 may be disposed on the upper surface side of the lower case 110 so as to be located immediately above the portion where the amount of swelling of the battery cell 150 is maximum.

  Assume that the assembled battery 100 according to the present embodiment is mounted and used in a vehicle such as a vehicle including an internal combustion engine, a hybrid vehicle capable of traveling with the power of both the internal combustion engine and the electric motor. The assembled battery 100 may be mounted under a vehicle seat, for example. The assembled battery 100 may be mounted on a center console of a vehicle, for example. The assembled battery 100 is not limited to a vehicle, and may be used for other purposes.

  FIG. 4 is a perspective view showing the arrangement of the battery cells 150 accommodated in the assembled battery 100. The assembled battery 100 according to the present embodiment accommodates five battery cells 150-1 to 150-5. The number of battery cells 150 accommodated in the assembled battery 100 is not limited to five. The number of battery cells 150 accommodated in the assembled battery 100 can be appropriately determined according to the maximum output of the battery cells 150, the power consumed by a driven device such as a vehicle, and the like.

  The battery cell 150 has a substantially rectangular parallelepiped shape having six surfaces. Two of the six surfaces of the battery cell 150 have a larger area than the other four surfaces. Two surfaces having a relatively large area among the surfaces of the battery cell 150 are also referred to as flat surfaces. The battery cell 150 is disposed such that the flat surface is directed in the positive direction and the negative direction of the Z axis. In other words, the battery cell 150 is disposed such that the flat surface is substantially parallel to the upper surface and the bottom surface of the assembled battery 100. It can be said that the flat surface of the battery cell 150 is arranged along the upper surface of the case.

  In the assembled battery 100 according to this embodiment, the battery cells 150 are stacked in the Z-axis direction in two stages and three stages. The battery cells 150 stacked in two stages are arranged on the positive side of the Y axis. The battery cells 150 stacked in three stages are arranged on the negative direction side of the Y axis. The number of battery cells 150 stacked may be appropriately changed according to the number of battery cells 150 accommodated in the assembled battery 100.

  The surface on the positive side of the X axis of the battery cell 150 is also referred to as a cap surface 151. The battery cell 150 is disposed so that the cap surface 151 faces the front side of the battery pack 100. The battery cell 150 includes a positive electrode terminal 152, a negative electrode terminal 153, and a safety valve 154 on the cap surface 151. The cap surface 151 has a substantially rectangular shape having a long side and a short side. The positive terminal 152 and the negative terminal 153 are provided near both ends of the cap surface 151 in the long side direction. The positive terminal 152 and the negative terminal 153 are electrodes that output power from the battery cell 150. The positive electrode terminal 152 and the negative electrode terminal 153 are collectively referred to as an electrode terminal.

  The safety valve 154 is provided between the positive terminal 152 and the negative terminal 153. The safety valve 154 is opened to discharge the gas to the outside when the pressure generated in the battery cell 150 causes the pressure inside the battery cell 150 to exceed a predetermined pressure. The internal pressure of the battery cell 150 may be equal to or higher than a predetermined pressure when the battery cell 150 is deteriorated with age or when a thermal runaway occurs. The predetermined pressure can be appropriately determined according to the specifications of the battery cell 150.

  FIG. 5 is an exploded perspective view of the battery pack 100 shown in FIG. The battery module may be assembled as follows. The battery cells 150 are stacked in three and two stages with the insulating sheet 155 interposed therebetween, and are accommodated between the lower case 110 and the cell holder 120. Lower case 110 and cell holder 120 are engaged by engagement member 180. Copper bus bar 280, relay 220, and fusible link 240 are attached to the upper surface of lower case 110 and cell holder 120. A bus bar 160 is attached to the electrode terminal of the battery cell 150. FIG. 6 shows a state in which the battery cell 150 is accommodated in the lower case 110 and the cell holder 120. A gas cover 610 is attached to the cap surface 151 side of the battery cell 150 with a seal 630 interposed therebetween. The sensor substrate 230 is attached to the sensor attachment terminal of the bus bar 160. 7 and 8 are a perspective view and a front view of the assembled battery 100 to which the sensor substrate 230 is attached. After the sensor substrate 230 is attached, the BAT case 500 is engaged with the cell holder 120 by the engaging member 180 so as to cover the cap surface 151 side of the battery cell 150. FIG. 9 shows a top view of the assembled battery 100 to which the BAT case 500 is attached. After the BAT case 500 is attached, the gas discharge pipe 600 is attached to the gas duct 611 of the gas cover 610.

  The upper case 300 is attached so as to cover the entire battery module. The upper case 300 and the battery case are engaged with each other on the front side and the back side by the engaging member 190. The upper case 300 and the battery case may be engaged with each other, for example, by fitting a claw and a hole. The assembled battery 100 can be assembled according to the procedure example described above.

  In the assembly of the battery module, the battery cell 150 may be bonded to the cell holder 120 with an adhesive. The adhesive may be any adhesive that can bond the battery cell 150 and the cell holder 120. The adhesive may be, for example, an acrylic adhesive or an epoxy adhesive. The adhesive may be applied to the cell holder 120. The adhesive may be applied to a portion of the cell holder 120 that faces the cap surface 151 of the battery cell 150. The battery cell 150 may be inserted into the cell holder 120 after an adhesive is applied to the cell holder 120.

  After the battery cell 150 and the cell holder 120 are bonded, the bus bar 160 may be welded to the electrode terminal of the battery cell 150. When the electrode terminal and the bus bar 160 are welded, a high accuracy may be required for the positional relationship between the electrode terminal and the bus bar 160. In this case, the electrode terminal and the bus bar 160 can be easily welded by increasing the accuracy of the application position of the adhesive that bonds the battery cell 150 and the cell holder 120. Further, the battery cell 150 and the cell holder 120 are bonded to each other before the bus bar 160 is welded to the battery cell 150, so that the productivity of the battery module can be improved.

  The assembled battery 100 according to the present embodiment includes a first terminal 250 on the front side and a second terminal 260 on the first side surface (see FIG. 9). As described above, the first terminal 250 and the second terminal 260 are arranged on different surfaces, so that they can be easily identified. By doing in this way, it becomes easy to prevent the incorrect wiring at the time of mounting the assembled battery 100 in a vehicle.

  The length of the cable electrically connected to the first terminal 250 may be configured to be different from the length of the cable electrically connected to the second terminal 260. By doing in this way, it becomes easy to prevent the incorrect wiring at the time of mounting the assembled battery 100 in a vehicle.

  As shown in FIG. 5, the assembled battery 100 includes a gas cover 610 on the front side. The gas cover 610 may be made of a resin such as PBT, for example. FIG. 10 shows a front view of the assembled battery 100 in a state where the gas discharge pipe 600 is connected to the gas duct 611 of the gas cover 610. As shown in FIG. 10, the gas duct 611 protrudes from the opening 510 of the BAT case 500 to the front side of the BAT case 500. The front end 612 (see FIG. 5) of the gas duct 611 is inserted from the end of the gas exhaust pipe 600, and the gas duct 611 and the gas exhaust pipe 600 communicate with each other in a sealed state. The gas exhaust pipe 600 has a bifurcated structure in which a second pipe 603 is joined to an intermediate portion 602 of the first pipe 601 so as to be attached to each of the two gas ducts 611. One end of the first tube 601 is connected to the gas duct 611 on the battery cell 150-4 to 5 side, and the other end extends to the external space. One end of the second pipe 603 is connected to the gas duct 611 on the battery cell 150-1-3 side, and the other end is joined to the intermediate portion 602 of the first pipe 601.

  Hereinafter, the configuration of the assembled battery 100 when only one relay 220 is arranged will be described with reference to FIGS. 11 to 15.

  FIG. 11 is a top view corresponding to FIG. 9 and showing a first example in which only one relay 220 is arranged. FIG. 12 is a top view corresponding to FIG. 9 and showing a second example in which only one relay 220 is arranged. FIG. 13 is a first diagram schematically showing a cross section taken along the arrow XIII-XIII in FIG. FIG. 14 is a second diagram schematically showing a cross section along the XIII-XIII arrow line of FIG. FIG. 15 is a perspective view corresponding to FIG. 7 when only one relay 220 is arranged.

  For example, as illustrated in FIG. 11, the number of relays 220 may be one and only the first relay 221 may be disposed on the upper surface of the lower case 110. At this time, the first relay 221 is electrically connected to the second terminal 260 at one end via the copper bus bar 280a. The first relay 221 is electrically connected to the bus bar 160 at the other end via the copper bus bar 280b.

  A fusible link 240 is disposed on the upper surface of the lower case 110 in which the second relay 222 is disposed in the negative Y-axis direction, instead of the second relay 222. The fusible link 240 is electrically connected to the first terminal 250 at one end via the copper bus bar 280c. The fusible link 240 is electrically connected to the bus bar 160 at the other end via the copper bus bar 280d. At this time, the terminal portion 242 of the fusible link 240 is disposed on the lower case 110 side of the copper bus bar 280, that is, on the lower side. In particular, the terminal portion 242 is disposed immediately below the terminal so as to contact the copper bus bar 280. The terminal portion 242 and the copper bus bar 280 are fixed together to the lower case 110 by a fastening member such as a bolt 112a.

  As described above, the fusible link 240 is held on the expansion surface S2 of the portion that accommodates the pair having the largest number of layers in the lower case 110 that accommodates the two stacked battery cells 150 in an arrayed state. Good. More specifically, the fusible link 240 may be fixed to the upper surface of the lower case 110 on the battery cell 150 side that is stacked in three stages.

  As described above, the fusible link 240 is arranged so that the fuse body 241a is disconnected by the expansion of the lower case 110 accompanying the expansion of the battery cell 150.

  In particular, the tip of the terminal portion 242 may be fixed on the expansion surface S2 of the lower case 110. In FIG. 11, the pair of terminal portions 242 are fixed to the lower case 110 by the bolts 112 a in the substantially central portion of the expansion surface S <b> 2 in a state adjacent to the main body portion 241, but are not limited thereto. As shown in FIG. 12, the tips of the pair of terminal portions 242 may be fixed to both end portions of the expansion surface S2. That is, the pair of terminal portions 242 extending from the main body portion 241 along a predetermined direction, for example, the Y-axis direction, may be respectively fixed to both end portions of the expansion surface S2 in the Y-axis direction.

  The main body 241 of the fusible link 240 may be disposed so as to contact the expansion surface S <b> 2 of the lower case 110. That is, as schematically shown in FIG. 13, the bottom surface of the main body portion 241 may abut on the expansion surface S2.

  The fusible link 240, in particular, the main body 241 may be disposed at a portion where the displacement of the expansion surface S2 of the lower case 110 is maximum. That is, the main body portion 241 may be disposed on the upper surface side of the lower case 110 so as to be located immediately above the portion where the amount of swelling of the battery cell 150 is maximum. As an example, the main body 241 may be disposed on the expansion surface S2 so as to correspond to the substantially central portion of the side surface 150a where the expansion amount of the battery cell 150 is maximum.

  Here, a state in which the fuse body 241a is disconnected due to the swelling of the battery cell 150 will be described with reference to FIG.

  In a state before the battery cell 150 is expanded, the expansion surface S2 is substantially planar. The fuse main body 241a located in the main body 241 is held substantially linearly with the pair of terminal portions 242 protruding from the main body 241. The pair of terminal portions 242 are respectively fixed to the lower case 110 by bolts 112a. As described above, when the battery cell 150 expands, the expansion surface S2 is displaced outward. More specifically, the expansion surface S2 bulges outward, centering on the portion where the outward displacement is maximum. The main body portion 241 disposed at the portion where the outward displacement is maximized is largely pushed outward along with the bulge. The main body portion 241 is pushed outward from the fixing portions of the pair of terminal portions 242. Therefore, the fuse body 241a and the pair of terminal portions 242 transition from a substantially linear shape to a curved shape, and a large mechanical load is applied to the fuse body 241a. When the mechanical load exceeds a predetermined threshold, the fuse body 241a is disconnected.

  Although it has been described that the fuse body 241a is held substantially linearly with the terminal portion 242 in a state before the lower case 110 is expanded, the present invention is not limited to this. For example, as shown in FIG. 14, the terminal portion 242 of the fusible link 240 is fixed in a state where it is bent in a direction opposite to the expansion direction toward the tip (fixing point with the bolt 112 a) before the lower case 110 is expanded. May be. At this time, the fuse body 241a is held in a curved shape in advance. As a result, a certain amount of mechanical load is applied to the fuse body 241a from the beginning. Such a bending arrangement is realized by an appropriate configuration such as providing a fastening point of the terminal portion 242 by the bolt 112a on the opposite side, and providing a convex portion at a place where the fuse body 241a on the lower case 110 is placed. .

  When the assembled battery 100 detects a disconnection of the fuse body 241 a as the battery cell 150 swells, the battery cell 150 may be discharged by the inter-cell capacity balancer 320. The inter-cell capacity balancer 320 is disposed between the stacked battery cells 150 and is fixed on the sensor substrate 230 as shown in FIG. 15, for example. The inter-cell capacity balancer 320 is configured by an electric circuit element such as a resistor. The inter-cell capacity balancer 320 discharges the energy stored in the battery cell 150 by discharging the battery cell 150.

  According to the assembled battery 100 according to the embodiment of the present invention, the system can be easily protected by utilizing the swelling of the battery cell 150. That is, the assembled battery 100 can directly disconnect the fuse body 241a only by a dynamic action by the expansion of the lower case 110 accompanying the expansion of the battery cell 150. As described above, the assembled battery 100 does not require a separate detection unit for detecting the swelling of the battery cell 150 as in the prior art in order to disconnect the fuse body 241a, and has a mechanism for protecting the system. It can be simplified. Thus, the assembled battery 100 can reliably converge the system before the battery pack is destroyed due to the swelling of the battery cells 150.

  The assembled battery 100 can easily transmit the expansion force of the lower case 110 to the fuse body 241a by fixing the tip of the terminal portion 242 of the fusible link 240 on the expansion surface S1 or S2 of the lower case 110. That is, the assembled battery 100 can easily bend the fuse main body 241a with the fixed point of the fusible link 240 and the arrangement surface of the main body portion 241 as the fulcrum, and mechanically due to expansion. The load can be applied directly.

  In the assembled battery 100, the tip end of the terminal portion 242 is fixed to the end portion of the expansion surface S1 or S2, so that the region where the terminal portion 242 bends can be widened and a larger mechanical load can be applied to the fuse body 241a. it can. That is, since the difference between the amount of displacement of the lower case 110 in the main body 241 and the amount of displacement of the lower case 110 at the fixing point of the terminal portion 242 increases, the fuse main body 241a bends more greatly. As a result, the assembled battery 100 can reliably disconnect the fuse body 241a even when the battery cell 150 swells smaller.

  In the assembled battery 100, the terminal portion 242 is fixed in a bent state before the lower case 110 is expanded, so that the fuse body 241 a can be reliably disconnected even when the smaller battery cell 150 is expanded. it can. That is, the assembled battery 100 makes it easy to disconnect the fuse body 241a when the battery cell 150 swells by applying a certain mechanical load to the fuse body 241a from the beginning.

  The assembled battery 100 can transmit the expansion force of the lower case 110 to the fuse main body 241a more directly because the main body 241 contacts the expansion surface S1 or S2 of the lower case 110. Thereby, the assembled battery 100 can disconnect the fuse main body 241a more reliably when the battery cell 150 swells.

  The assembled battery 100 can increase the change in the deflection of the fuse body 241a before and after the battery cell 150 swells by disposing the body part 241 at the maximum displacement site of the expansion surface S1 or S2. Thereby, the assembled battery 100 can disconnect the fuse main body 241a more reliably when the battery cell 150 swells.

  In the battery pack 100, the fusible link 240 is held on the side where the number of stacked battery cells 150 is large, so that the change in the deflection of the fuse body 241a before and after the battery cell 150 bulges can be increased. That is, as the number of battery cells 150 stacked increases, the expansion of the lower case 110 accompanying the expansion of the battery cells 150 also increases. Thereby, the assembled battery 100 can disconnect the fuse main body 241a more reliably. Further, when the battery cells 150 are arranged in different numbers, the larger the number of the layers, the more easily heat is accumulated due to the heat generated during charging / discharging, and the deterioration of the battery cells 150 is quicker. It is possible to reliably detect deterioration of the battery cell 150 by providing the link 240.

  Since the assembled battery 100 includes the inter-cell capacity balancer 320, the energy of the battery cell 150 can be released when the disconnection of the fuse body 241a is detected, and the system can be converged safely. Thereby, the assembled battery 100 can prevent the destruction of the battery pack due to the swelling of the battery cells 150 in advance.

  It will be apparent to those skilled in the art that the present invention can be realized in other predetermined forms other than the above-described embodiments without departing from the spirit or essential characteristics thereof. Accordingly, the foregoing description is illustrative and not restrictive. The scope of the invention is defined by the appended claims rather than by the foregoing description. Some of all changes that fall within the equivalent scope shall be included therein.

  For example, the assembled battery 100 is not limited to a configuration in which the tip of the terminal portion 242 of the fusible link 240 is fixed on the expansion surface S1 or S2. If the fuse main body 241 a can be disconnected by the swelling of the battery cell 150, the tip of the terminal portion 242 may be fixed to the first side surface or the second side surface of the lower case 110.

  The assembled battery 100 is not limited to a configuration in which the main body 241 of the fusible link 240 is in contact with the expansion surface S2 of the lower case 110. If the fuse main body 241a can be disconnected due to the swelling of the battery cell 150, the main body 241 may be separated from the expansion surface S2.

  The assembled battery 100 is not limited to a configuration in which the main body 241 is disposed at a portion where the displacement of the expansion surface S1 or S2 is maximum. If the fuse main body 241a can be disconnected due to the swelling of the battery cell 150, the main body 241 may be disposed at any position on the expansion surface S1 or S2.

100 assembled battery 110 lower case (case)
112a bolt 120 cell holder (case)
DESCRIPTION OF SYMBOLS 150 Battery cell 150a Side surface 151 Cap surface 152 Positive electrode terminal 153 Negative electrode terminal 154 Safety valve 155 Insulation sheet 160 Bus bar 180, 190 Engagement member 220 Relay 221 First relay 222 Second relay 230 Sensor board 240 Fusible link (fuse part)
241 body portion 241a fuse body 242 terminal portion 243 through hole 250 first terminal 260 second terminal 270 packing 280 (280a, 280b, 280c, 280d) copper bus bar 300 upper case 301, 302 recess 303 opening 310 connector 320 inter-cell capacity balancer 500 BAT case (case)
510 opening 600 gas discharge pipe 601 first pipe 602 middle part 603 second pipe 610 gas cover 611 gas duct 612 tip 630 seal S1, S2 expansion surface

Claims (8)

A battery cell;
A case for accommodating the battery cell therein;
A fuse portion held in the case;
With
The fuse part is disconnected by expansion of the case accompanying expansion of the battery cell,
Assembled battery. The fuse part includes a main body part and a terminal part connected to the main body part, and a tip of the terminal part is fixed on an expansion surface of the case.
The assembled battery according to claim 1. The tip of the terminal portion is fixed to the end of the expansion surface.
The assembled battery according to claim 2. The terminal portion is fixed in a state where the terminal portion is bent in a direction opposite to the expansion direction toward the tip in a state before expansion of the case.
The assembled battery according to claim 2 or 3. The body portion contacts the expansion surface of the case;
The assembled battery according to any one of claims 1 to 4. The main body is disposed at a site where the displacement of the expansion surface of the case is maximum.
The assembled battery according to any one of claims 1 to 5. A plurality of the battery cells,
The case is accommodated in a state in which a plurality of stacked battery cells are arranged,
The fuse part is held on an expansion surface of a place that accommodates a set having the largest number of stacked battery cells in the case.
The assembled battery according to any one of claims 1 to 6. An inter-cell capacity balancer that is disposed between the stacked battery cells and discharges the battery cells after detecting disconnection of the fuse portion;
The assembled battery according to any one of claims 1 to 7.