JP5605252B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device including a structure that applies a binding force to a plurality of power storage elements arranged side by side in a predetermined direction.

  A battery pack mounted on a vehicle or the like has a battery stack and a pack case that houses the battery stack. The battery stack has a plurality of single cells arranged in one direction, and a binding force is applied to the plurality of single cells. Here, by arranging a pair of end plates at positions sandwiching the plurality of unit cells and connecting the pair of end plates with a band, a binding force can be applied to the plurality of unit cells.

JP 2008-192551A JP 2001-236937 A JP 2010-092610 A JP 2007-184200 A JP 2003-051299 A

  If the configuration of the battery pack can be simplified, for example, the manufacturing process of the battery pack can be simplified.

A power storage device according to a first invention of the present application includes a plurality of power storage elements arranged side by side in a predetermined direction, and a case that houses the plurality of power storage elements. The case includes a plurality of power storage elements in a predetermined direction. Using a pair of first regions arranged in a sandwiched position and a second region extending in a predetermined direction and connected to the pair of first regions, a binding force in a predetermined direction is applied to the plurality of power storage elements, The case has a pair of covers each including a first region and a second region, and each cover has a rib formed in the first region and a hook formed in the second region. A binding force is applied to the plurality of power storage elements by engagement of the ribs and hooks in the cover .

A method for manufacturing a power storage device according to a second invention of the present application includes a plurality of power storage elements arranged in a predetermined direction, a first region having a rib, and a pair of covers each including a second region extending in a predetermined direction and having a hook. A method for manufacturing a power storage device comprising: a step of arranging a plurality of power storage elements in a predetermined direction; a step of arranging a first region of a pair of covers at a position sandwiching the plurality of power storage elements in a predetermined direction; by moving the first area of the cover towards each other, the steps of restraining the plurality of power storage devices in a predetermined direction, by releasing the force to move toward each other the first region of the pair of covers, each cover having engaging a rib on the other side of the cover hook, a.

According to a second aspect of the invention, the ribs of each cover only engaged with the other end of the cover hook, can provide restraining force to the plurality of power storage elements.

Here, by moving the first regions of the pair of covers in a direction approaching each other, the hook can be moved to a position where it can engage with the rib. If the first regions of the pair of covers are moved in a direction approaching each other, the plurality of power storage elements can be compressed. By compressing the plurality of power storage elements, the hook can get over the rib and engage the hook and the rib. On the other hand, if another cover different from the pair of covers is connected to the cover using a bolt, a case for housing a plurality of power storage elements can be configured.

  According to the present invention, the structure of the power storage device can be simplified by using the first region and the second region of the case in a structure that applies a binding force to the plurality of power storage elements.

1 is an exploded view of a battery pack that is Embodiment 1. FIG. It is a figure when the battery pack which is Example 1 is seen from one direction. 6 is a diagram illustrating a part of the manufacturing process of the battery pack that is Embodiment 1. FIG. 6 is a diagram illustrating a part of the manufacturing process of the battery pack that is Embodiment 1. FIG. 6 is a diagram illustrating a part of the manufacturing process of the battery pack that is Embodiment 1. FIG. 6 is a diagram illustrating a part of the manufacturing process of the battery pack that is Embodiment 1. FIG. 6 is a top view of a battery pack that is Embodiment 2. FIG. 6 is a diagram illustrating a part of a manufacturing process of a battery pack that is Embodiment 2. FIG.

  Examples of the present invention will be described below.

  A battery pack (power storage device) that is Embodiment 1 will be described with reference to FIGS. 1 and 2. FIG. 1 is an exploded view of the battery pack, and shows a part of the battery pack. FIG. 2 is a diagram when the battery pack is viewed from one direction (X direction). 1 and 2, the X axis, the Y axis, and the Z axis are axes orthogonal to each other. In this embodiment, the Z axis is an axis corresponding to the vertical direction. The relationship among the X axis, the Y axis, and the Z axis is the same in other drawings.

  The battery pack 1 can be mounted on a vehicle and can be used as a power source for running the vehicle. If the electric energy output from the battery pack 1 is converted into kinetic energy by the motor / generator, the vehicle can be driven using this kinetic energy. Further, if the kinetic energy generated during braking of the vehicle is converted into electric energy by the motor / generator, this electric energy can be stored in the battery pack 1 as regenerative power.

  The battery pack 1 includes a battery stack 100 and a pack case 200 that houses the battery stack 100. The battery stack 100 includes a plurality of single cells (storage elements) 10 arranged in the X direction, and the plurality of single cells 10 are electrically connected in series. As the unit cell 10, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor (capacitor) can be used instead of the secondary battery. The number of the single cells 10 can be appropriately set based on the required output of the battery pack 1 and the like.

  A positive electrode terminal 11 and a negative electrode terminal 12 are provided on the upper surface of the unit cell 10. A power generation element that charges and discharges is housed inside the unit cell 10. The power generation element includes a positive electrode plate, a negative electrode plate, and a separator (including an electrolytic solution) disposed between the positive electrode plate and the negative electrode plate. The positive electrode plate is one in which a positive electrode active material layer is formed on the surface of the current collector plate, and the negative electrode plate is one in which the negative electrode active material layer is formed on the surface of the current collector plate. The positive electrode terminal 11 is electrically connected to the positive electrode plate (current collector plate) of the power generation element, and the negative electrode terminal 12 is electrically connected to the negative electrode plate (current collector plate) of the power generation element.

  In two unit cells 10 adjacent in the X direction, the positive terminal 11 of one unit cell 10 is electrically connected to the negative terminal 12 of the other unit cell 10 via a bus bar (not shown). By using a plurality of bus bars, the plurality of single cells 10 arranged in the X direction can be electrically connected in series. The battery stack 100 may include a plurality of single cells 10 that are electrically connected in parallel.

  In the present embodiment, the plurality of single cells 10 are arranged in the X direction, but the present invention is not limited to this. Specifically, a plurality of unit cells 10 can be used to form one battery module, and the plurality of battery modules can be arranged in the X direction. The plurality of single cells 10 included in the battery module are electrically connected in series. If each battery module is provided with a positive electrode terminal and a negative electrode terminal, a plurality of battery modules can be electrically connected using a bus bar.

  A pair of end plates (first regions) 20 are disposed at both ends of the battery stack 100 in the X direction. In FIG. 1, only one end plate 20 is shown. The end plate 20 has ribs 21 on the surface opposite to the surface facing the unit cell 10. When the end plate 20 is viewed from the X direction, the rib 21 is formed at a position surrounding the outer edge of the end plate 20. That is, the rib 21 is formed in a ring shape. The end plate 20 can be formed of metal, for example.

  The pack case 200 includes an upper cover 31, a lower cover 32, and a pair of side covers (second regions) 33 and 34. The upper cover 31, the lower cover 32, and the pair of side covers 33 and 34 can be formed of, for example, metal.

  The upper cover 31 is disposed above the battery stack 100, and forms an air movement passage S <b> 1 above the battery stack 10. The passage S <b> 1 can be used as a passage for supplying air used for temperature adjustment of the unit cell 10 to the unit cell 10. By supplying the temperature adjusting air to the cell 10, the temperature of the cell 10 can be maintained within a desired temperature range, and deterioration of the cell 10 can be suppressed. If a duct is connected to the passage S1, air for temperature adjustment can be guided to the passage S1 through the duct.

  When the unit cell 10 generates heat due to charging / discharging or the like, the unit cell 10 can be cooled by heat exchange between the unit cell 10 and the air by supplying cooling air to the unit cell 10. When the unit cell 10 is excessively cooled by an external environment or the like, the unit cell 10 can be warmed by supplying heat to the unit cell 10 by heat exchange between the unit cell 10 and the air. it can.

  If a spacer is disposed between two unit cells 10 that are adjacent in the X direction, air for temperature adjustment can be made to enter between the two unit cells 10. Thereby, the air for temperature control can be made to contact the surface of the cell 10 efficiently. The spacer can be formed of a resin, for example.

  The upper cover 31 extends in the X direction, and has a pair of flanges 31a at both ends in the Y direction. Openings 31b are formed at both ends of each flange 31a in the X direction. In FIG. 1, only the opening part 31b formed in the end of each flange 31a is shown. Bolts are attached to the opening 31b when the upper cover 31 and the side covers 33, 34 are connected.

  The lower cover 32 is disposed below the battery stack 100, and forms an air movement passage S <b> 2 below the battery stack 100. The passage S <b> 2 can be used as a passage for discharging the air used for adjusting the temperature of the unit cell 10. By guiding the air after heat exchange to the passage S2, the air after heat exchange can be moved to the outside of the battery pack 1. If a duct is connected to the passage S2, air from the passage S2 (air after heat exchange) can be moved to the outside of the battery pack 1 through the duct.

  The lower cover 32 extends in the X direction, and has a pair of flanges 32a at both ends in the Y direction. Openings 32b are formed at both ends of each flange 32a in the X direction. In FIG. 1, only the opening part 32b formed in the end of each flange 32a is shown. Bolts are attached to the opening 32b when the lower cover 32 and the side covers 33, 34 are connected.

  The side cover 33 extends in the X direction and has a pair of flanges 33a at both ends in the Z direction. Openings 33b are formed at both ends of each flange 33a in the X direction. In FIG. 1, only the opening 33b formed at one end of each flange 33a is shown. Bolts are attached to the opening 33b when connecting the side cover 33 and the upper cover 31 (or the lower cover 32).

  The side cover 33 has a hook 33 c, and the hook 33 c engages with the rib 21 of the end plate 20. The size of the hook 33c can be set as appropriate. That is, it is only necessary to maintain the state in which the hook 33c and the rib 21 are engaged with each other.

  The side cover 34 has the same structure as the side cover 33, and has a pair of flanges 34a, an opening 34b, and a hook 34c. The pair of side covers 33 and 34 are disposed at positions that sandwich the battery stack 100 in the Y direction.

  In this embodiment, the upper cover 31, the lower cover 32, and the pair of side covers 33, 34 are connected using bolts, but the present invention is not limited to this. For example, the four covers 31 to 34 can be connected by welding.

  In this embodiment, the passage S1 is used as an air supply passage and the passage S2 is used as an air discharge passage. However, the passage S1 can be used as an air discharge passage and the passage S2 can be used as an air supply passage. . In this embodiment, the air moving passages S1 and S2 are formed using the upper cover 31 and the lower cover 32. However, the air moving passage is formed using the pair of side covers 33 and 34. You can also. In this case, the air travels in the Y direction and is guided from the supply path to the discharge path.

  Next, a method for manufacturing the battery pack 1 will be described. 3 to 6 are diagrams for explaining a part of the manufacturing process of the battery pack 1. 3 to 6 show the process of attaching the side cover 33 of the pair of side covers 33, 34, the process of attaching the side cover 34 is also the same.

  First, a plurality of unit cells 10 are arranged in the X direction, and a pair of end plates 20 are arranged so as to sandwich the plurality of unit cells 10 in the X direction. A pair of restraining devices 300 are disposed on the pair of end plates 20. The pair of restraining devices 300 can apply restraining force to the plurality of unit cells 10 sandwiched between the pair of end plates 20 by moving in a direction approaching each other.

  Next, as shown in FIG. 3, one hook 33 c of the side cover 33 is hooked on the rib 21 of one end plate 20 of the pair of end plates 20. In the state shown in FIG. 3, the restraining device 300 does not apply restraining force to the plurality of single cells 10, and the distance between the pair of end plates 20 is L <b> 1.

  When the distance between the pair of end plates 20 is L1, one of the two hooks 33c provided on the side cover 33 can be hooked on the corresponding rib 21, while the other hook 33c is It cannot be hooked on the corresponding rib 21. The other hook 33 c cannot be hooked on the corresponding rib 21 by colliding with the corresponding rib 21.

  Next, as shown in FIG. 4, a restraining force F is applied to the plurality of single cells 10 by moving the pair of restraining devices 300 in a direction approaching each other. By applying the binding force F to the plurality of unit cells 10, the plurality of unit cells 10 are compressed, and the distance between the pair of end plates 20 is L2 smaller than L1. By narrowing the distance between the pair of end plates 20, the pair of end plates 20 can be positioned between the two hooks 33c of the side cover 33 as shown in FIG. That is, the hook 33c that has collided with the rib 21 in the state shown in FIG.

  When the restraining force F by the restraining device 300 is released from the state shown in FIG. 5, the unit cell 10 tries to return to the original state, and the distance between the pair of end plates 20 increases. When the distance between the pair of end plates 20 increases, the ribs 21 of the pair of end plates 20 come into close contact with the two hooks 33c of the side cover 33, as shown in FIG. After the rib 21 comes into close contact with the hook 33c, the restraining device 300 is removed.

  In the state shown in FIG. 6, the distance between the pair of end plates 20 is L3. The interval L3 is narrower than the interval L1 and wider than the interval L2. By setting the distance L3 in this way, the side cover 33 can be attached to the pair of end plates 20, and in the state where the side cover 33 is attached to the pair of end plates 20, a binding force is applied to the plurality of single cells 10. Can continue to give. By continuing to apply the binding force to the unit cell 10, it is possible to suppress the expansion and contraction of the unit cell 10 due to charging and discharging.

  After the side covers 33 and 34 are fixed to the pair of end plates 20, a plurality of unit cells 10 can be electrically connected by connecting bus bars to the positive terminal 11 and the negative terminal 12 of the unit cell 10. . Further, the pack case 200 can be configured by connecting the upper cover 31 and the lower cover 32 to the side covers 33 and 34.

  According to the present embodiment, the side covers 33 and 34 constitute a part of the pack case 200 and are used to apply a binding force to the plurality of single cells 10. By providing the side covers 33 and 34 with two functions, the number of parts can be reduced as compared with the case where a dedicated member for each function is used.

  Further, since the rib 21 of the end plate 20 is formed in a ring shape when the end plate 20 is viewed from the X direction, even if the hooks 33c, 34c of the side plates 33, 34 are hooked on the rib 21, the rib 21 It is possible to prevent 21 from being deformed.

  In this embodiment, when the end plate 20 is viewed from the X direction, the ribs 21 are formed along the outer edge of the end plate 20, but the present invention is not limited to this. That is, the rib 21 may be formed in a region inside the outer edge of the end plate 20 when the end plate 20 is viewed from the X direction. Here, the rib 21 should just be formed in the ring shape. On the other hand, if the strength of the rib 21 can be ensured, it is not necessary to form the rib 21 in a ring shape, and the rib 21 can be provided only in the portion that engages with the hooks 33c and 34c.

  In the present embodiment, the pack case 200 is configured by the four covers 31 to 34, but is not limited thereto. That is, at least two of the four covers 31 to 34 can be integrally configured. For example, the pack case 200 can be configured by integrally forming the upper cover 31 and the pair of side covers 33 and 34 and connecting the integrally formed cover and the lower cover 32. In addition, the pack case 200 can be configured by integrally forming the lower cover 32 and the pair of side covers 33 and 34 and connecting the integrally formed cover and the upper cover 31.

  In this embodiment, two hooks 33c (34c) are provided at both ends of the side cover 33 (34), but the hooks 33c (34c) can be provided only at one end of the side cover 33 (34). In this case, the portion where the hook 33c (34c) is not provided can be fixed to the end plate 20 using a bolt or a rivet.

  The battery pack 1 which is Example 2 will be described. FIG. 7 is a top view showing a partial structure of the battery pack 1. In the present embodiment, the same reference numerals are used for the same members as those described in the first embodiment. Hereinafter, differences from the first embodiment will be mainly described.

  In the present embodiment, a binding force is applied to the plurality of single cells 10 using the two covers 40. The cover 40 includes an end cover portion (first region) 41 and a side cover portion (second region) 42. The end cover part 41 has the same function as the end plate 20 described in the first embodiment. The end cover part 41 has a rib 43, and the rib 43 corresponds to the rib 21 described in the first embodiment.

  The side cover part 42 has a hook 44, and the hook 44 corresponds to the hooks 33c and 34c described in the first embodiment. The hook 44 of one cover 40 is engaged with the rib 43 of the other cover 40. By using the two covers 40, the plurality of single cells 10 can be surrounded in the XY plane.

  The upper cover 31 and the lower cover 32 described in the first embodiment are connected to the two covers 40. The pack case 200 is constituted by the cover 40, the upper cover 31 and the lower cover 32.

  A method for manufacturing the battery pack 1 of this embodiment will be described. FIG. 8 is a diagram for explaining a part of the manufacturing process of the battery pack 1.

  First, similarly to Example 1, a plurality of single cells 10 are arranged in the X direction. And a pair of cover 40 is arrange | positioned so that the end cover part 41 may pinch | interpose the some cell 10. FIG. Each end cover portion 41 is provided with a restraining device 300, and the restraining device 300 applies a restraining force F to the plurality of single cells 10.

  When the restraining force F of the restraining device 300 acts on the end cover part 41, the two end cover parts 41 move in directions toward each other, and the plurality of single cells 10 are compressed. When the two end cover portions 41 approach each other, the hooks 44 of one cover 40 move along the ribs 43 of the other cover 40 due to the deformation of the side cover portion 42, as shown in FIG. When the hook 44 of one cover 40 gets over the rib 43 of the other cover 40, the hook 44 is hooked on the rib 43 by the side cover portion 42 returning to its original state.

  After the two hooks 44 are hooked on the corresponding ribs 43, the restraining force by the restraining device 300 is released. When the restraining force by the restraining device 300 is released, the compressed unit cell 10 tries to return to the original state, and the two end cover parts 41 move in directions away from each other. Accordingly, the ribs 43 are in close contact with the corresponding hooks 44, and the two covers 40 are fixed. When the ribs 43 and the hooks 44 are in close contact with each other, the two covers 40 keep the binding force applied to the plurality of single cells 10. By applying a binding force to the plurality of unit cells 10, expansion and contraction of the unit cells 10 can be suppressed.

  In the present embodiment, the cover 40 constitutes a part of the pack case 200 and is used to give a binding force to the plurality of single cells 10. Thereby, the same effect as Example 1 can be acquired. Further, the cover 40 of the present embodiment is formed by integrally forming the end plate 20 and the side cover 33 (34) described in the first embodiment, and the number of parts can be reduced as compared with the first embodiment. .

1: Battery pack (power storage device) 10: Single battery (power storage element)
11: Positive terminal 12: Negative terminal 20: End plate (first region) 21: Rib 31: Upper cover 31a: Flange 31b: Opening 32: Lower cover 32a: Flange 32b: Opening 33, 34: Side cover (second) Area) 33a, 34a: Flange 33b, 34b: Opening 33c, 34c: Hook 40: Cover 41: End cover (first area)
42: Side cover part (second region) 43: Rib 44: Hook 100: Battery stack 200: Pack case 300: Restraining devices S1, S2: Air movement path

Claims (4)

A plurality of power storage elements arranged side by side in a predetermined direction;
A case for accommodating the plurality of power storage elements,
The case includes a pair of first regions arranged at positions sandwiching the plurality of power storage elements in the predetermined direction, and a second region extending in the predetermined direction and connected to the pair of first regions. , Applying a restraining force in the predetermined direction to the plurality of power storage elements ,
The case has a pair of covers each including the first region and the second region,
Each of the covers has a rib formed in the first region and a hook formed in the second region, and the plurality of power storage elements are engaged by engagement of the rib and the hook in the pair of covers. The power storage device is characterized in that the binding force is applied to the power storage device. A method of manufacturing a power storage device, comprising: a plurality of power storage elements arranged in a predetermined direction; a pair of covers each including a first region having a rib and a second region extending in the predetermined direction and having a hook;
A step of arranging said plurality of power storage devices in the predetermined direction,
Disposing the first region of the pair of covers at a position sandwiching the plurality of power storage elements in the predetermined direction;
Moving the first regions of the pair of covers in a direction approaching each other to restrain the plurality of power storage elements in the predetermined direction;
By releasing the force to move toward each other said first region of said pair of cover, the steps of engaging the said ribs of each cover before Symbol hook of the cover of the mating,
A method for manufacturing a power storage device, comprising: The method for manufacturing a power storage device according to claim 2 , wherein the hook is moved to a position engageable with the rib by moving the first regions of the pair of covers in a direction approaching each other. . 4. The case for housing the plurality of power storage elements is configured by connecting another cover different from the pair of covers to the cover using a bolt. 5. Manufacturing method of power storage device.

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