JP6657563B2 - Power storage unit - Google Patents

Description

  The present invention relates to a power storage unit in which a plurality of power storage cells are incorporated in a unit case to configure a power storage system for storing power.

  Power storage systems have been developed to store power and supply the stored power to the outside. When the power storage system is used in a factory or an office building, the power can be backed up when the power consumption reaches a peak, and the power storage cell can be charged when the power consumption is low. In addition, a power storage system is used to stably use distributed renewable energy such as wind power and solar power while maintaining a power demand balance.

  A power storage system for storing power includes a number of power storage cells including a lithium ion secondary battery and a lithium ion capacitor. A plurality of power storage cells are incorporated in a unit case, and a set of power storage packs, that is, a power storage unit is assembled by the power storage cells and the unit case. The power storage unit is built in multiple stages in a housing in which a plurality of shelves are provided at an interval vertically, that is, a power storage rack. In the power supply room, a plurality of power storage racks each including a power storage unit are arranged to form a power storage system.

  Patent Literature 1 discloses a battery unit panel in which a plurality of battery units are arranged in multiple stages in a housing.

JP 2013-196908 A

  As described in Patent Document 1, in a mode in which battery units are arranged in multiple stages in a housing, an air supply port is provided in a front wall of the housing, and a cooling fan mounted on the housing is provided. As a result, cooling air is generated in the housing. The generated cooling air flows from the front side to the rear side in the unit case to cool the battery cells, that is, the power storage cells.

  Since a power storage unit for forming a power storage system is used continuously for a long period of time, high reliability as well as heat dissipation of a power storage cell is required.

  An object of the present invention is to improve the reliability of a power storage unit.

  The power storage unit of the present invention is a power storage unit having a plurality of cylindrical power storage cells, a power storage cell group including a plurality of the power storage cells arranged in parallel, and a unit incorporating the power storage cell group. A case; and a pressure breaking portion provided in the unit case and broken when an internal pressure of the unit case reaches a first predetermined pressure. A safety valve that operates when the internal pressure reaches a second predetermined pressure is provided on an end face of the power storage cell, and the pressure rupture portion is provided on a side surface of the unit case facing the end face of the power storage cell. I have.

  The power storage unit is provided in the power storage cell group configured by a plurality of power storage cells arranged in parallel, a unit case in which the power storage cell group is incorporated, and the unit case. And a pressure breaking portion that is broken when the pressure reaches a predetermined pressure. A safety valve that operates when the internal pressure reaches a second predetermined pressure is provided on an end face of the storage cell, and the pressure breaking portion is provided on a side surface of the unit case facing the end face of the storage cell. . Therefore, even if the safety valve of the power storage cell operates, the internal pressure of the unit case does not become excessively high, and the reliability of the power storage unit is improved.

FIG. 3 is a front perspective view illustrating the appearance of the power storage unit. It is a perspective view on the back side showing the appearance of a power storage unit. FIG. 3 is an exploded perspective view of a unit case constituting the power storage unit. It is a perspective view which shows the bottom cover of a unit case. It is a perspective view which shows the middle frame of a unit case. It is a perspective view which shows the upper cover of a unit case. (A) is a perspective view showing the inner surface of one side plate of the unit case, and (B) is a perspective view showing the outer surface of the other side plate of the unit case. It is a perspective view showing a control box provided in the front of a unit case. It is a front view which shows the cold air inlet formed in the front plate of a unit case. It is a front view which shows the cold air outlet formed in the back plate of a unit case. It is the perspective view which looked at the output terminal side from the output terminal side which has a some storage cell and is integrated in a unit case. FIG. 12 is a perspective view of the storage cell group viewed from the opposite side of FIG. 11. It is a longitudinal section of an electric storage unit which shows a flow of cooling air in a unit case. 13A is a plan view showing the upper storage cell group shown in FIG. 12, and FIG. 13B is a plan view showing the lower storage cell group. FIG. 3 is a wiring diagram illustrating a connection state of detection wiring provided in a storage cell group. FIG. 4 is a front view of the storage cell group showing the detection wiring routed to the output terminal side of the storage cell group. FIG. 17 is a front view of the power storage cell group, showing the detection wiring routed on the opposite side of FIG. 16 of the power storage cell group. It is a perspective view which shows the detection wiring of the temperature detection sensor crawled on the middle frame. It is a front view of the middle frame which shows the state where the detection wiring of the temperature detection sensor was attached to the middle frame. FIG. 3 is a block diagram illustrating a control circuit to which a voltage detection line and a temperature detection line are connected. (A) is a sectional view showing one end of the electric storage cell mounted on the unit case, and (B) is an enlarged sectional view of a part A in (A). (A) is an enlarged front view which shows the rear end part of the inner surface of a side plate, (B) is a BB sectional drawing in (A).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The power storage pack, that is, the power storage unit 10 has a unit case 11 having a substantially rectangular parallelepiped shape, and a power storage cell group 13 including 12 power storage cells 12a to 12l is incorporated in the unit case 11, as shown in FIG. . Each storage cell 12 is a lithium ion secondary battery, and is formed in a columnar shape. The power storage cell group 13 includes an upper power storage cell group 13a configured by six power storage cells 12a to 12f, and a lower power storage cell group 13b configured by six power storage cells 12g to 12l. The storage cells 12 are mounted in the case 11 in two upper and lower stages.

  As shown in FIGS. 11 and 12, the power storage cells 12 constituting the upper power storage cell group 13 a include a power storage cell 12 disposed on the front side of the unit case 11 and a power storage cell 12 disposed on the rear side. Symbols a to f are assigned to the direction. FIG. 1 shows a front side of the unit case 11, and FIG. 2 shows a rear side of the unit case 11. On the other hand, the storage cells 12 constituting the lower storage cell group 13b are denoted by reference signs g to l from the storage cells 12 arranged on the back side of the unit case 11 to the storage cells 12 arranged on the front side. Have been. Each of the storage cell groups 13a and 13b is configured such that the storage cells 12 are arranged in parallel with a gap therebetween. The power storage cells 12 in the upper power storage cell group 13a and the lower power storage cell group 13b are arranged in parallel so as to overlap vertically with a gap therebetween. In the specification, when the power storage cell 12 at a specific location is indicated, the description is given with reference numerals a to l.

  As shown in FIG. 3, the unit case 11 has a rectangular bottom cover 21, a middle frame 22 is attached to the bottom cover 21, and an upper cover 23 is attached to the middle frame 22. The bottom cover 21, the middle frame 22, and the upper cover 23 constitute a case main body 11a having a skeletal structure that accommodates all the power storage cells 12 with a gap therebetween. A side plate 24 is attached to one side of the case body 11a, and a side plate 25 is attached to the other side.

  As shown in FIG. 1, a front plate 26 is attached to the front side of the case body 11a, and the front plate 26 is formed by upper and lower ventilation frames 26a and 26b and a central ventilation frame 26c. A control box 27 is provided on the front side of the case body 11a so as to approach the side plate 25, and the control box 27 is covered by a cover 27a. As shown in FIG. 2, a back plate 28 is attached to the back of the case body 11a, and the back plate 28 is formed by upper and lower ventilation frames 28a and 28b and a central ventilation frame 28c.

  The power storage unit 10 has a unit case 11 assembled by the members shown in FIG. 3 and a plurality of power storage cells 12 incorporated therein. A power storage system is constructed by arranging a plurality of power storage units 10 in a power storage rack in multiple stages. Up, down, front and rear of the power storage unit 10 indicate the position and direction in a state where the power storage unit 10 is arranged in the power storage rack. The power storage unit 10 has the front side, that is, the front plate 26 facing the front side of the power storage rack. Placed on the shelf.

  The bottom cover 21 is integrally formed of resin, and has a bottom wall 31 and three lower cell holders 32 extending in the longitudinal direction on the inner surface thereof, as shown in FIG. The cell holders 32 are provided so as to protrude from the bottom wall 31 at the left and right sides of the bottom wall 31 and at the center in the width direction of the bottom wall 31. In each cell holder 32, six substantially semicircular concave surfaces 33 are formed corresponding to the six storage cells 12g to 12l constituting the lower storage cell group 13b. 12l is held by the lower cell holder 32 in a state where the lower semicircular portion at both ends and the central portion of each storage cell 12 enters the concave surface 33. An abutting surface 34 is provided between the concave surfaces 33 adjacent in the longitudinal direction.

  As shown in FIG. 6, the upper lid 23 has an upper wall 35 and an upper cell holder 36 extending in the longitudinal direction on the inner surface thereof. Three cell holders 36 are provided corresponding to the cell holders 32 of the bottom lid 21, and the upper lid 23 is also integrally formed of resin. Six substantially semicircular concave surfaces 37 are formed in each of the cell holders 36 so as to correspond to the six storage cells 12a to 12f constituting the upper storage cell group 13a. 12f are covered by the cell holder 36 with the upper semicircular portions at both ends and the central portion entering the concave surface 37. The abutment surface 34 is provided between the concave surfaces 37 adjacent in the longitudinal direction.

  As shown in FIG. 5, the middle frame 22 has three intermediate cell holders 41 extending in parallel, and each cell holder 41 includes a lower cell holder 32 provided on the bottom lid 21 and an upper lid It is sandwiched between the upper cell holder 36 provided on the base member 23. The cell holder 41 is integrally connected to a wiring guide tube (wiring guide portion) 42 extending in a lateral direction, that is, a direction traversing the case main body, and four air guides 43. It is provided close to.

  Here, the wiring guide tube 42 will be described. As shown in FIG. 5, the wiring guide tube 42 includes an intermediate cell holder 41a disposed at one end in the direction crossing the case main body (the longitudinal direction of the power storage cell 12) and the other cell holder 41a on the opposite side. It is joined to an intermediate cell holder 41b arranged at the end and an intermediate cell holder 41c arranged at a substantially central position. That is, the wiring guide tube 42 is joined to the three intermediate cell holders 41. The wire guide tube 42 has, for example, a cylindrical hollow structure, and can accommodate a plurality of wires such as a voltage detection line and a temperature detection line described later in the hollow portion. That is, a plurality of wires can be passed through the hollow portion of the wire guide tube 42. Specifically, in the structure shown in FIG. 5, the intermediate cell holder 41 has three parts that are in contact with the power storage cell 12, cell holders 41 a, 41 b, and 41 c, and extends in a direction crossing the case body (the power storage cell 12 A hollow structure is formed from one end portion (cell holder 41a) to the other end portion (cell holder 41b) on the opposite side (longitudinal direction). Is penetrated by the hollow structure of the wiring guide tube 42 up to the outer surface side of the other end. Although the outer shape of the wiring guide tube 42 is circular, the outer shape of the wiring guide tube 42 may be a shape that does not hinder the flow of cooling air, for example, a rhombus.

  Since the wiring guide tube 42 is formed integrally with the intermediate cell holder 41, the rigidity of the middle frame 22 shown in FIG. 5 can be increased.

  In addition, a region (corresponding to a space where an air guide 43 described later is provided) between four power storage cells 12 adjacent in the front-rear direction and the vertical direction in the two cell holders 41 (41a, 41b) arranged at both ends described above. Area), and a plurality of such areas are provided side by side in the two cell holders 41 (41a, 41b) arranged at both ends described above. 17, the wiring guide tube 42 is provided in a region closest to the controller (control unit) 74, as shown in FIG. In other words, the wiring guide tube 42 is provided close to the front side of the unit case 11 shown in FIG. 1 as described above.

  As a result, the distance from the wiring guide tube 42 to the controller 74 can be shortened, so that the distance of the place where the number of wires is the largest can be shortened, and a plurality of wires at the place where the number of wires is the largest can be collected. The degree can be improved. That is, the region from the wiring guide tube 42 to the controller 74 is a region where the plurality of wirings drawn out from the wiring guide tube 42 and other wirings are merged and routed, so that the number of wirings is inevitably increased. Therefore, by shortening the distance in this region where the number of wirings is inevitably increased, it is possible to reduce the dispersion of the wirings and improve the degree of grouping of a plurality of wirings.

  Further, as shown in FIGS. 16 and 17, the wiring guide tube 42 is provided at a position between the upper storage cell group 13a and the lower storage cell group 13b. Thus, both the wiring from the upper storage cell group 13a and the wiring from the lower storage cell group 13b can enter the wiring guide tube 42 with substantially the same length. After a plurality of wirings from the group are collected without waste, they can enter the wiring guide tube 42 or be taken out from the wiring guide tube 42. In other words, the degree of freedom of wiring can be improved.

  As shown in FIGS. 16 and 17, the wiring guide tube 42 is provided at a position that does not overlap with each of the plurality of busbars in a side view (view viewed from the side) where the side plates 24 and 25 of the power storage unit 10 are removed. Have been. Thereby, each of the plurality of wirings passed through the wiring guide tube 42 is routed without contacting each of the plurality of bus bars, so that damage to the plurality of wirings due to contact with the bus bar can be reduced.

  As shown in FIG. 5, on the lower surface of each cell holder 41, six substantially semicircular concave surfaces 44 corresponding to the six power storage cells 12g to 12l constituting the lower power storage cell group 13b are provided. Are formed, and each of the storage cells 12g to 12l is sandwiched between the cell holder 41 and the cell holder 32 in a state in which both ends and a central upper semicircle part enter the concave surface 44. An abutting surface 34a is provided between the concave surfaces 44 adjacent to each other in the longitudinal direction so as to correspond to the abutting surface 34 of the bottom cover 21, so that both abutting surfaces 34, 34a are abutted. Thus, each of the storage cells 12g to 12l is held between the bottom lid 21 and the middle frame 22, that is, in a state of being sandwiched.

  Six substantially semicircular concave surfaces 45 are formed on the upper surface of each cell holder 41 in correspondence with the six power storage cells 12a to 12f constituting the upper power storage cell group 13a. The cells 12 a to 12 f are sandwiched between the cell holder 41 and the cell holder 36 with both ends and a lower semicircular portion of the central part entering the concave surface 45. An abutting surface 34a is provided between the concave surfaces 45 adjacent to each other in the longitudinal direction so as to correspond to the abutting surface 34 of the upper lid 23, so that both abutting surfaces 34, 34a are abutted. The respective storage cells 12 a to 12 f are sandwiched between the upper lid 23 and the middle frame 22.

  As described above, the six cylindrical power storage cells 12 constituting the lower power storage cell group 13b shown in FIGS. 11 and 12 include the lower cell holder 32 provided on the bottom cover 21 and the middle frame 22. The two end portions and the central portion are sandwiched by the intermediate cell holder 41 provided in the case body 11 and incorporated into the case main body 11a. The six power storage cells 12 constituting the upper power storage cell group 13a have both ends and a central portion formed by an upper cell holder 36 provided on the upper lid 23 and an intermediate cell holder 41 provided on the middle frame 22. Are assembled in the case main body 11a in a state of being clamped. Both ends of each storage cell 12 constitute left and right side parts as a storage cell group 13 formed by all the storage cells 12. Under a state where all the power storage cells 12 are accommodated in the case main body 11a, the bottom cover 21 is fastened to the lower side of the middle frame 22 by a screw member (not shown), and the upper cover 23 is fastened to the upper side of the middle frame 22. . Side plates 24 and 25 are fastened to both sides of the case body 11a by screw members (not shown).

  FIG. 21A is a cross-sectional view showing one end of a power storage cell incorporated in a unit case, and FIG. 21B is an enlarged cross-sectional view of a portion A in FIG. 21A. FIG. 21 shows the power storage cell 12 sandwiched between the cell holder 32 of the bottom cover 21 and the cell holder 41 of the middle frame 22, and hatching is omitted. An accommodating groove 46 is formed at the bottom of each concave surface 33, 44 so as to be exposed to the concave surface 33, 44. An elastic member 47 made of a soft resin or rubber is inserted into the accommodation groove 46. The surface of the elastic member 47 projects radially inward from the concave surfaces 33 and 44. Therefore, when the power storage cell 12 is positioned between the concave surface 33 of the cell holder 32 and the concave surface 44 of the cell holder 41 and the cell holder 32 and the cell holder 41 are abutted, the elastic member 47 is contracted and deformed in the radial direction to store the electric power. The cell 12 is held in the unit case 11. Specifically, the power storage cell 12 is sandwiched and held from both sides in the radial direction by a pair of vertically opposed elastic members 47. At this time, the contracted and deformed elastic member 47 comes into close contact with the outer peripheral surface of the power storage cell 12 by the elastic restoring force. The one-to-one set of the elastic members 47 sandwiches the cells by at least two or more sets with respect to one cell.

  Assuming that the radius of the storage cell 12 is R1 and the radius of the concave surfaces 33 and 44 is R2, the radius R2 of the concave surfaces 33 and 44 is set to be larger than the radius R1 of the storage cell 12, and the concave surfaces 33 and 44 and the A gap 48 of ΔR is formed between the outer peripheral surface and the outer peripheral surface. If the radius of the accommodation groove 46 is R3, the depth d0 of the accommodation groove 46 is d0 = R3-R2. Assuming that the initial thickness of the elastic member 47 before the contraction deformation is d1, the amount of deformation of the elastic member 47, that is, the amount of crushing is approximately Δd. Similar elastic members 47 are provided on the other concave surfaces 37 and 45. For example, if the initial thickness d1 of the elastic member 47 is 2.6 mm and the depth d0 is 2.2 mm, the crush amount Δd is 0.2 mm. Assuming that the compression ratio k is a ratio obtained by dividing the crush amount Δd by the initial thickness d1, the compression ratio k = 100 × Δd / d1 = 100 × 0.2 / 2.6 = 7.7%. Preferably, the initial thickness d1 and the crush amount Δd of the elastic member 47 may be selected so that the compression ratio k is in the range of about 5 to 15%.

  As shown in FIG. 21, a vertical line orthogonal to the center line of the vertically adjacent storage cells 12 and vertically traversing the center line of the vertically adjacent storage cells 12 is defined as a reference line O. The elastic member 47 extends in the circumferential direction within a range of an angle θ in the left-right direction in FIG. In the present embodiment, the angle θ is set to about 30 degrees. That is, in the present embodiment, the elastic members 47 extend from the reference line O to the left and right within a range of 30 degrees or less. When the storage cell 12 is sandwiched between the concave surfaces 33 and 44 via the elastic member 47, not only the centering positioning of the storage cell 12 is achieved, but also the concave surface does not directly contact the outer peripheral surface of the storage cell 12. . As a result, even if there is a processing error in the bottom lid 21 and the middle frame 22 made of hard resin, these are prevented from digging into the power storage cell 12, and damage to the power storage cell 12 due to the bite is prevented, and the power storage The reliability of the unit 10 can be improved.

  Moreover, since the elastic member 47 is in close contact with the outer peripheral surface of the power storage cell 12, the heat dissipation of the power storage cell 12 can be improved. When an elastic member 47 is interposed between the storage cell 12 and the concave surface in a certain range in the circumferential direction, a gap 48 is formed between the concave surfaces 33 and 44 and the outer peripheral surface of the storage cell 12. The cooling air passing through 48 cools the power storage cell 12 and the elastic member 47, and also cools components disposed outside the cell holder 41 at both ends. Thereby, the heat dissipation of the power storage cell 12 can be improved, and the reliability of the power storage unit 10 can be improved.

  When the elastic member 47 is provided over the entire circumferential direction of the concave surface, the centering function of the power storage cell 12 can be enhanced. On the other hand, when the elastic member 47 is provided on a part of the concave surface in the circumferential direction, the gap 48 shown in FIG. 21 is formed, and the heat dissipation is enhanced. Also, when the elastic member 47 is provided on the entire circumferential surface of the concave surface or on a part of the circumferential direction, the surface of the elastic member 47 is in close contact with the outer peripheral surface of the power storage cell 12. Are firmly fixed with an appropriate force, and the displacement of the storage cell 12 is prevented. The angle θ shown in FIG. 21 is preferably in a range from 15 degrees to 45 degrees. If the angle θ is 15 degrees or more, the contact area of the elastic member 47 in contact with the storage cell 12 increases, so that there is less concern that the storage cell 12 moves from a predetermined position due to vibration during transportation or an earthquake. If it is necessary to increase the reliability against vibration, such as when installing near a moving body or a power source such as an electric motor that generates vibration, set the angle θ close to 45 degrees and make it larger. Is preferred. When the angle θ is 45 degrees or less, the opening of the gap 48 of ΔR between the concave surfaces 33 and 44 and the outer peripheral surface of the power storage cell 12 becomes larger, and the flow of exhaust gas when the power storage cell 12 is abnormal is increased. It is done more smoothly. The material of the elastic member 47 is preferably silicone rubber, but may be EPDM or fluorine rubber having excellent chemical resistance. The hardness of the elastic member 47 may be about 50, and is preferably 40 or more and 60 or less. If the hardness is less than 40, the cell is too soft, and even if the interface between the cell and the elastic member 47 is in close contact, when a force is applied in the circumferential direction of the cell, there is a concern that the cell will rotate in the circumferential direction due to the circumferential shear force. is there. On the other hand, if the hardness exceeds 60, it is too hard to be easily deformed, and there is a concern that the degree of adhesion in the cell circumferential direction is reduced.

  As shown in FIGS. 1 and 9, the ventilation frame 26a constituting the front plate 26 is provided with a cool air inlet 51a, the ventilation frame 26b is provided with a cold air inlet 51b, and the ventilation frame 26c is provided with a cold air flow. An inlet 51c is provided. On the other hand, as shown in FIGS. 2 and 10, the ventilation frame 28a constituting the back plate 28 is provided with a cool air outlet 52a, the ventilation frame 28b is provided with a cold air outlet 52b, and the ventilation frame 28c is provided. A cool air outlet 52c is provided.

  As shown in FIG. 13, an upper cold air passage 53a is formed between the upper lid 23 and the upper power storage cell group 13a, and the lower cold air passage 53a is provided between the bottom lid 21 and the lower power storage cell group 13b. A cool air passage 53b is formed. Further, an intermediate cold air passage 53c is formed between the upper storage cell group 13a and the lower storage cell group 13b. The cool air inlet 51a and the cool air outlet 52a face the cool air passage 53a, the cool air inlet 51b and the cool air outlet 52b face the cold air passage 53b, and the cool air inlet 51c and the cool air outlet 52c face the cold air passage 53c. . The opening areas of the upper and lower cold air inlets 51a, 51b and the cold air outlets 52a, 52b are set to be substantially the same. The vertical dimension of the central cold air inlet 51c is longer than the vertical dimension of the cold air inlets 51a and 51b, and the central cold air inlet 51c has an opening area larger than that of the upper and lower cold air inlets 51a and 51b. Is set large, and the opening area is about twice as large. Similarly, the central cold air outlet 52c has an opening area approximately twice as large as that of the cold air outlets 52a and 52b.

  A wiring guide tube 42 is arranged in a space formed between the four power storage cells 12a, 12b, 121, and 12k on the front side, and four wirings formed between the four power storage cells 12 on the downstream side. An air guide 43 is arranged in each of the spaces.

  When the power storage unit 10 is arranged on the power storage rack, the cooling air generated in the power storage rack flows into the unit case 11 from the cool air inlets 51a, 51b, 51c formed in the front plate 26. The cooling air that has flowed in from the central cold air inlet 51c passes through the cold air passage 53c between the upper and lower two power storage cells 12a and 121 on the most upstream side and collides with the wiring guide tube 42. Part of the cooling air that has collided branches up and down and flows into the gap between the two power storage cells 12a and 12b and into the gap between the two power storage cells 12l and 12k. The cooling air branched upwards flows from the cool air inlet 51a and collides with the cooling air flowing through the cool air passage 53a along the inner surface of the upper lid 23, and along the rear side of the power storage cell 12a and the front side of the power storage cell 12b. Flow to cool each storage cell. Similarly, the cooling air branched downward flows into the cooling air inlet 51b and collides with the cooling air flowing through the cold air passage 53b along the inner surface of the bottom cover 21, and the back side of the power storage cell 12l and the front surface of the power storage cell 12k. Flow along the sides to cool each storage cell. As described above, the wiring guide tube 42 has a function as an air guide that branches the cooling air up and down, and the wiring guide tube 42 is also cooled by the cooling air.

  The cooling air that has passed through the cold air passage 53c between the upper and lower power storage cells 12b and 12k collides with the air guide 43. The air guide 43 has a cross section in a cross shape, and includes an upper projection 43a projecting upward, a lower projection 43b projecting downward, and a horizontal projection 43c projecting horizontally toward the upstream side. Have. Therefore, a part of the cooling air that has collided with the air guide 43 on the most upstream side branches up and down and flows into the gap between the two power storage cells 12b and 12c and into the gap between the two power storage cells 12k and 12j. I do. The cooling wind branched upward collides with the cooling wind flowing along the inner surface of the upper lid 23, flows along the rear side of the power storage cell 12b and the front side of the power storage cell 12c, and cools each power storage cell. Similarly, the cooling air branched downward collides with the cooling air flowing along the inner surface of the bottom lid 21 and flows along the back side of the storage cell 12k and the front side of the storage cell 12j to cool each storage cell. I do. Similarly, cooling air is branched from the other three air guides 43 on the downstream side to reliably cool the power storage cell 12. In this manner, the cooling air is guided to the outer peripheral surface of the power storage cell 12 and can reliably cool the power storage cell 12, so that the durability and reliability of the power storage unit 10 can be improved.

  Since the opening area of the middle cold air inlet 51c is set larger than the upper and lower cold air inlets 51a and 51b, the opening area of the middle cold air inlet 51c is set to be equal to the opening area of the upper and lower cold air inlets 51a and 51b. The cooling air flowing between the upper power storage cell group 13a and the lower power storage cell group 13b is narrowed by the gap between the upper and lower power storage cells, and cool air flows along the upper lid 23 as compared with the same embodiment. The flow velocity is higher than the cooling air flowing through the passage 53a and the cooling air flowing through the cool air passage 53b along the bottom lid 21. Thus, the cooling air flowing in the unit case 11 includes cooling air having different flow velocities, and the cooling air is automatically stirred and mixed, so that the cooling effect of the power storage cell 12 is enhanced. The cooling air outlets 52a to 52c also have an opening area corresponding to the cool air inlets 51a to 51c, so that the cooling air can be agitated and the cooling effect of the power storage cell 12 can be enhanced.

  Terminal electrodes are provided on both end faces of the storage cells 12, and the storage cells 12 constituting the storage cell group 13 are connected in series. To connect in series, the terminal electrodes at both ends of the horizontally adjacent storage cells 12 have opposite polarities, and the terminal electrodes at both ends of the vertically adjacent storage cells 12 also have opposite polarities. ing. As shown in FIGS. 11 and 14, when the terminal electrode on the right end face of power storage cell 12 a disposed on the front side of upper power storage cell group 13 a is a positive electrode, the terminal electrode is a positive electrode terminal of power storage unit 10. The bus bar 61a of the negative terminal of the power storage unit 10 is mounted on the terminal electrode of the power storage cell 121 on the lower side. Another storage cell is connected in series between these storage cells 12a and 12l, and an intermediate bus bar 61 is attached to the terminal electrodes of the storage cells 12 adjacent to each other. In power storage unit 10 having a total of 12 power storage cells 12, a total of 13 bus bars including 11 intermediate bus bars 61 and positive and negative bus bars 61a and 61b are provided.

  As shown in FIG. 1, an opening 62a from which the bus bar 61a protrudes is provided on the front end surface of the side plate 24, and an opening 62b from which the bus bar 61b protrudes is provided. When a plurality of power storage units 10 are arranged in a power storage rack and the power storage units 10 are electrically connected, bus bars 61a and 61b protruding from openings 62a and 62b are connected to bus bars of other power storage units 10 by power supply members. You.

  FIG. 15 shows an electrical connection state of all the storage cells 12 by the bus bars 61, 61a, and 61b. One end of each of the voltage detection lines 63a to 63m is connected to each bus bar in order to detect whether or not the output voltage of the storage cell 12 has reached a set value. The other end of each of the voltage detection lines 63a to 63m is connected to a controller (control unit) 74 on a control board in the control box 27. In other words, one ends of a plurality of voltage detection lines (a plurality of wirings) 63a to 63m for detecting output voltages of the plurality of storage cells 12 are connected to bus bars corresponding to the plurality of storage cells 12, respectively. The other ends of the plurality of voltage detection lines 63a to 63m are connected to the controller 74.

  As shown in FIG. 5, a plurality of support protrusions (projections) 64 are provided on the outer surface of the two cell holders 41 corresponding to both ends of the storage cell 12 so as to protrude outward. 64 is provided with a horizontal slit 65 into which wiring is inserted. Each support projection 64 substantially corresponds to the position of the air guide 43. That is, in each of the two cell holders 41, the plurality of support protrusions 64 are regions between four power storage cells 12 adjacent in the front-rear direction and the vertical direction of the power storage unit 10, and a power storage cell group above this region. It is provided at a position between 13a and the lower storage cell group 13b. Of the two cell holders 41, the support projection 64 of the cell holder 41 on the left side when viewed from the front, that is, on the control box 27 side is provided with a vertical slit 66 as shown in FIG.

  FIG. 16 shows a voltage detection line connected to the right bus bar of the storage cell group 13. The two voltage detection lines 63a and 63m connected to the power storage cells 12a and 12l on the front side and the voltage detection line 63k connected to the power storage cell 12k adjacent to the power storage cell 12l on the rear side are inside the wiring guide tube 42. And is connected to the controller 74 in the control box 27. The other four voltage detection lines 63c, 63e, 63g, and 63i extend longer along the end surface of the storage cell group 13 than the other three voltage detection lines 63a, 63k, and 63m. And is held by the cell holder 41.

  Since the horizontal slits 65 are provided in the plurality of support protrusions 64, the voltage detection lines connected to the power storage cells 12 of the upper power storage cell group 13 a via the bus bar and the power storage of the lower power storage cell group 13 b are provided. A voltage detection line connected to the cell 12 via a bus bar is joined near the support protrusion 64, inserted into the slit 65 together, and held by the support protrusion 64. Furthermore, by providing the horizontal slit 65 and the vertical slit 66 on the support protrusion 64, the voltage detection lines drawn from a plurality of directions are joined at the support protrusion 64 having the vertical slit 66. While being able to hold | maintain, those voltage detection lines can be sent out directly under the same support protrusion 64. Further, in the support projection 64 having the vertical slit 66, the direction of the voltage detection line to be sent can be divided into a plurality of directions as necessary. As described above, it is possible to increase the degree of freedom in routing the voltage detection line.

  FIG. 17 shows a voltage detection line connected to the left bus bar of the storage cell group 13. The seven voltage detection lines connected to the right bus bar as shown in FIG. 16 are extended from the wiring guide tube 42 and held by the slits 65 and 66 as shown in FIG. Extends to The two voltage detection lines 63l and 63j connected to the left bus bar are directly connected to the controller 74 in the control box 27 without being held by the support protrusion 64. The other four voltage detection lines 63b, 63d, 63f, and 63h extend longer along the end surface of the storage cell group 13 than the two voltage detection lines 63l and 63j. It is inserted and held by the cell holder 41.

  As described above, the plurality of voltage detection lines (wirings) disposed outside the cell holder 41 (cell holder 41a) disposed farthest from the controller 74 pass through the wiring guide tube 42 (through the controller). The cell is fed out of the cell holder 41 (cell holder 41b) disposed closest to the cell 74, where it merges with the other plurality of voltage detection lines, and all of the plurality of voltage detection lines are gathered together without being separated. Connected to controller 74. Thereby, a plurality of voltage detection lines can be passed through the inside of the wiring guide tube 42 and extended to the outside of the cell holder 41 (cell holder 41b) on the opposite side, and can be extended to the opposite side without separating the wiring. Can be.

  As described above, the wiring as a voltage detection line that is crawled inside each of the side plates 24 and 25 and extends long along the end surface of the storage cell group 13 is held by the support protrusion 64, and the upper storage cell group Since it is fixed between the bus bars 13a and the lower storage cell group 13b, it does not shift due to cooling air, vibration, or the like flowing in the unit case 11, and the voltage detection line is prevented from contacting the storage cells 12. You. Also, even if the fastening bolt between the upper storage cell 12 and the bus bar is loosened and one of the fastening parts is disengaged, the support projection 64 can prevent the bus bar from hanging down, and the electrical connection with the lower storage cell 12 can be prevented. Short circuit can be prevented. The thickness of the support projection 64 is 3 mm. It is preferable that the thickness of the support projection 64 is 1 mm or more, since even if the support projection 64 hits the support projection 64 due to the sagging of the bus bar, cracking or chipping does not occur. Further, the gap between the tip of the support protrusion 64 and the inner surface of the side plate 24 is 5 mm or less, so that even if the gap is shifted due to vibration or the like, the voltage detection line does not come off from the slits 65 and 66. The cross-sectional shape of the support protrusion 64 is rectangular, but may be a shape formed by an arc, an L shape, or a cross shape. Thereby, durability and reliability of power storage unit 10 can be improved.

  Further, as shown in FIGS. 16 and 17, in a side view (field of view viewed from the side) in which the side plates 24 and 25 of the power storage unit 10 are removed, each of the plurality of support protrusions 64 corresponds to each of the plurality of bus bars. It is provided in a position that does not overlap with. Thereby, each of the plurality of voltage detection lines can be routed so as not to overlap with each of the plurality of bus bars, and damage due to contact of the voltage detection lines with the bus bar can be reduced.

  In order to detect the temperature of the storage cell 12, a thermistor is mounted on the storage cell 12 as a temperature detection sensor. A platinum resistance temperature detector or a linear resistance other than the thermistor may be used. FIG. 18 is a perspective view showing the temperature detection sensors 71a and 71b and the temperature detection lines 72a and 72b from the respective sensors. FIG. 19 is a front view of the middle frame showing a state where the temperature detection lines are attached to the middle frame. is there. In FIG. 19, the voltage detection lines are not shown.

  As shown in FIGS. 18 and 19, the temperature detection sensor 71a is attached to the front side of the second power storage cell 12k from the front side of the power storage unit 10, that is, the second power storage cell 12k from the upstream side of the cooling air. On the other hand, the temperature detection sensor 71b is attached to the back side of the second power storage cell 12h from the back side, that is, the second from the downstream side of the cooling air.

  The temperature detection sensors 71a and 71b are connected to the control box 27 via temperature detection lines 72a and 72b, respectively.

  The method of attaching the temperature detection sensors 71a and 71b is not limited. For example, as shown in FIG. 18, the temperature detection sensors 71a and 71b are attached to the curved side surfaces of the cylindrical storage cells 12k and 12h using an adhesive film or an adhesive. The mounting position of the temperature detection sensors 71a and 71b is between the center and the end of the curved side surface of the power storage cells 12k and 12h, and is on the side plate 25 side (end side). That is, it is arranged inside the cell holder 41 on the control box 27 side.

  As shown in FIG. 18, the respective temperature detection lines 72a and 72b are drawn out of the cell holder 41 through through holes 73a and 73b provided in the cell holder 41 and extend to the control box 27. The temperature detection lines 72a, 72b drawn out of the cell holder 41 through the through holes 73a, 73b are held by the support protrusions 64, similarly to the above-described voltage detection lines. That is, the temperature detection lines 72a and 72b are held by the support projections 64 on the outer surface of the cell holder 41 on the side plate 25 side of the two cell holders 41 corresponding to both ends of the storage cell 12. The support projection 64 is provided with a slit 65 in the horizontal direction, and the temperature detection lines 72a, 72b are inserted into the slit 65, whereby the temperature detection lines 72a, 72b are held by the cell holder 41.

  Thus, by providing the temperature detection sensors 71a and 71b on the control box 27 side, the length of the temperature detection lines 72a and 72b can be shortened as compared with the case where the temperature detection sensors 71a and 71b are provided on the opposite side to the control box 27. Further, by arranging the temperature detection sensors 71a and 71b on the curved side surfaces of the power storage cells 12k and 12h, it is possible to secure a large bonding area and to firmly fix the temperature detection sensors 71a and 71b. Further, by providing the temperature detection sensor 71b on the side plate 25 side (end side) of the curved side surface of the power storage cell 12h, it is possible to measure the temperature on the end side where the temperature is likely to be higher than the central part and to use for temperature management. it can. Further, the temperature detection lines 72a and 72b are drawn out of the cell holder 41 through the through holes 73a and 73b provided in the cell holder 41, and are held by the support projections 64 outside the cell holder 41, so that the cooling air and vibration The temperature detection line can be prevented from coming into contact with the power storage cell 12 without being shifted due to the above. Thereby, the reliability of the power storage unit 10 can be improved.

  Since the storage cells 12 are cooled by the cooling air flowing in the unit case 11, the temperature of the storage cells 12 does not rise excessively. The temperature of the storage cells 12 arranged in the unit case 11 tends to be lower in the storage cells 12 on the upstream side of the cooling air than in the storage cells 12 on the downstream side. Although temperature detection sensors may be attached to all the storage cells 12, instead of such a configuration, when the temperatures of the two storage cells 12 on the upstream side and the downstream side are detected, the temperature of the storage cell on the high-temperature side is detected. Based on the temperature of the storage cells on the low temperature side, the temperature of all the storage cells 12 constituting the storage cell group 13 can be managed. For example, the average temperature of all the power storage cells 12 can be calculated by calculating the temperatures of the two power storage cells 12 on the upstream side and the downstream side, and can be used for temperature management.

  As described above, by detecting the temperatures of at least two power storage cells 12 on the high temperature side and the low temperature side, temperature management such as detecting the average temperature of the power storage cells 12 in the power storage unit 10 can be performed. In addition, if the temperature at two points on the high temperature side and the low temperature side is known based on the amount of cooling air flowing in the unit case 11 and the environmental temperature, it is known in advance in the model case how much a temperature difference occurs between the cells. By comparing the distribution data with the distribution data, even if the temperature of the cell other than the cell whose temperature is detected becomes abnormally high, it can be used for detecting the abnormality.

  According to the study of the present inventors, when the temperatures of all the storage cells 12 were monitored, the temperature rise on the front side of the second storage cell 12 k from the upstream in the lower storage cell group 13 b was the lowest, It has been found that the temperature rise on the back side of the second storage cell 12h from the downstream side of the storage cell group 13b is highest. Therefore, as shown in FIG. 13, FIG. 18 and FIG. 19, a temperature detection sensor 71a is attached to the front side of the power storage cell 12k to detect the temperature of the power storage cell 12k which has the lowest temperature, and the rear side of the power storage cell 12h. And the temperature detection sensor 71b is attached to the power storage cell 12h to detect the temperature of the storage cell 12h having the highest temperature. Here, from the results of the monitoring, the temperature of the second storage cell 12k from the upstream side as the temperature of the low-temperature storage cell in the lower storage cell group 13b and the temperature of the high-temperature storage cell in the lower storage cell group 13b are used. Although the temperature of the second power storage cell 12h from the downstream side is used, the present invention is not limited to this. For example, the temperature of the low-temperature storage cell is any one of the four upstream storage cells 12a, 12b, 121, and 12k, and the high-temperature storage cell is the four downstream storage cells 12e. , 12f, 12g, and 12h. Alternatively, the power storage cell on the upstream side or the downstream side may be selected based on the center of the unit case 11 (case main body 11a). That is, as the temperature of the storage cell on the low temperature side, a storage cell group selected from the storage cell group arranged on the side of the front plate 26 from the center of the unit case 11 (case main body 11a) (12a, 12a in FIG. 12b, 12c, 12l, 12k, 12j), a temperature detection sensor is attached, and the temperature of the storage cell on the high-temperature side is arranged on the opposite side of the front plate 26 from the center of the unit case 11 (case main body 11a). The temperature detection sensor may be attached to any of the storage cell groups (12d, 12e, 12f, 12g, 12h, and 12i in FIG. 13). As described above, the combination of the power storage cells for detecting the temperature can be appropriately changed.

  FIG. 20 is a block diagram showing a control circuit to which the voltage detection line and the temperature detection line are connected. The voltage detection lines 63a to 63m are connected to the controller 74, respectively. The controller 74 is provided on a control board incorporated in the control box 27. The controller 74 calculates the potential difference between the positive terminal and the negative terminal of each storage cell 12 based on the detection signals from the voltage detection lines 63a to 63m. The temperature detection lines 72a and 72b are also connected to the controller 74, respectively. The controller 74 calculates the temperatures of the two storage cells 12 based on the detection signals from the temperature detection lines 72a and 72b.

  The signals of the respective calculation results are sent to an external display unit 75, and the display unit 75 displays the voltage value and the temperature value of the power storage cell 12. As the display form of the voltage value, the voltage values of all the storage cells 12 can be displayed, or the storage cells of the highest voltage and the lowest voltage can be displayed. In addition, as a display form of the temperature, the detected temperature of the two storage cells is displayed, the above-mentioned average temperature is displayed, an alarm or an alarm indicating an abnormality is displayed, blinking, an alarm sound is generated. can do. Further, when the average temperature of the storage cells 12 becomes higher than a predetermined temperature, the cooling air flow is increased to lower the temperature of the storage cells 12, and when the average temperature is lower than the predetermined temperature, the cooling air flow is reduced to reduce the consumption of the cooling fan. Power can be reduced. In addition, when the temperature of one of the two storage cells becomes higher than a predetermined temperature, the temperature is notified by a warning sound, blinking, or the like, or an abnormal signal is recognized and the abnormal signal is transmitted to the system control unit 77. By doing so, the main circuit can be cut off. Further, when the voltage value of the storage cell 12 exceeds or falls below a predetermined voltage value, the main circuit is notified by issuing a warning sound, blinking, or the like, or by communicating an abnormal signal to the system control unit 77. Can be shut off. In addition, the main circuit is shut off by estimating the life of the power storage cell from the change over time of the voltage value of the power storage cell 12 and notifying with a warning sound or blinking, or by communicating an abnormal signal to the system control unit 77. be able to. In addition, when the variation of the voltage value between the storage cells 12 is greater than the predetermined voltage variation, a predetermined signal is communicated to the system control unit 77 to perform the charging / discharging operation so as to be within the predetermined voltage value range. can do.

  The lithium ion secondary battery as the storage cell 12 has a liquid or gel electrolyte sealed inside. If the temperature of the storage cell 12 exceeds the steady temperature range and rises excessively, the internal pressure of the storage cell 12 may exceed a predetermined pressure (second predetermined pressure). Therefore, when the internal pressure exceeds the predetermined pressure, the gas in the power storage cell 12 is released to the outside in order to release the gas from the power storage cell 12 as shown in FIG. 16 and FIG. A safety valve 76 is provided. The predetermined pressure is a pressure at which the safety valve 76 of the storage cell 12 is operated. When the internal pressure of the power storage cell 12 increases with an increase in the internal temperature of the power storage cell 12, and the internal pressure reaches the second predetermined pressure, that is, the operating pressure, the safety valve 76 is opened. Each safety valve 76 is provided on both end faces of the storage cell 12. Therefore, even if the safety valve 76 is operated or opened, and the gasified contents are discharged to the outside, the discharged gas is blown to the inner surfaces of the side plates 24 and 25 to be applied to the other power storage cells 12 in the unit case 11. No damage.

  If the safety valve 76 operates, the released gas is ejected from the storage cell 12 into the unit case 11, and the internal pressure of the unit case 11 rises instantaneously. If the unit case 11 is destroyed by the suddenly rising internal pressure, there is a possibility that components such as a controller and wiring may be destroyed depending on the location of the failure. Therefore, when the safety valve 76 operates, a specific portion of the unit case 11 is positively destroyed. In the present embodiment, a specific portion between the longitudinal center of the unit case 11 and the back surface of the unit case 11 is positively destroyed.

  FIG. 22A is an enlarged front view showing the rear end of the side plate 25, and FIG. 22B is a sectional view taken along line BB in FIG. 22A.

  On the inner surface of the rear end of the side plate 25, two pressure breaking portions 81a and 81b are provided vertically. Each of the pressure rupture portions 81a and 81b is parallel to each other, and extends in the front-rear direction, that is, in the opposite direction of the front plate 26 and the back plate 28, and one of the two parallel grooves 82 and 83. The end portions (in the present embodiment, the end portions on the back plate side) are defined by a communication groove 84 for communicating with each other, and have a tongue shape. In the following description, the ends of the parallel grooves 82 and 83 on the back plate side may be referred to as rear ends, and the ends on the front plate side may be referred to as front ends. The pressure rupture portions 81a and 81b defined by the grooves on three sides are connected to the side plate 25 at the base having the same thickness as the side plate 25. FIG. 22 shows a pressure rupture portion provided on the side plate 25, but a pressure rupture portion is provided corresponding to the other side plate 24. The pressure rupture portions 81a and 81b and the safety valve 76 (not shown in FIG. 22) are installed facing each other in the longitudinal direction (axial direction) of the storage cell 12. Since the weak portion is installed in the immediate vicinity opposite to the safety valve 76, the pressure rupture portions 81a and 81b are quickly opened even when the internal pressure instantaneously rises due to the gas released from the safety valve 76, and the unit case 11 is opened. Total loss can be prevented. As shown in FIGS. 16 and 17, in the storage cell 12, since the safety valves 76 are provided on both end surfaces in the axial direction, the pressure rupture portions are also provided on both side plates 24 and 25 of the unit case 11 so as to face the pressure rupture portions. However, when the safety valve 76 of the storage cell 12 is provided at only one location on one end face, the pressure breaking portion may be provided only on the side plate facing the safety valve 76.

  The thickness between the parallel grooves 82 and 83 and the bottom surface of the communication groove 84 and the outer surface of the side plate 25 is smaller than other portions of the side plate 25. If the safety valve 76 is operated to release gas into the unit case 11 and the pressure in the unit case 11 becomes higher than a predetermined pressure (first predetermined pressure), the pressure destruction portions 81a and 81b will generate grooves by the gas pressure. Destroyed in the part of. The first predetermined pressure is a pressure for opening the pressure breaking portions 81a and 81b. When the internal pressure of the unit case 11 rises and reaches the first predetermined pressure, that is, the breaking pressure, the pressure breaking portions 81a and 81b are broken. In other words, the first predetermined pressure, that is, the breaking pressure acts on the pressure breaking portions 81a and 81b with the rise of the internal pressure of the unit case 11, and directs the pressure breaking portions 81a and 81b to the outside of the unit case 11. The bending force. Due to the breaking pressure, at least one of the tongue-shaped pressure breaking portions is broken at the groove portion, and a communication hole for gas release is formed in the side plate. Even if the pressure rupture portions 81a and 81b are broken, the bases of the pressure rupture portions 81a and 81b are not separated from the side plates 24 and 25, and the pressure rupture portions 81a and 81b are prevented from scattering outside. Further, when the grooves constituting the pressure rupture portions 81a and 81b are ruptured, the pressure rupture portions 81a and 81b have the base portions as fixed ends and the ends (free ends) opposite to the base portions are directed outward. Bend to rotate. For this reason, the gas released into the unit case 11 is guided by the pressure breaking portions 81a and 81b and is ejected toward the rear of the unit case 11. The depth of the parallel grooves 82 and 83 of the pressure rupture portions 81a and 81b increases from the front end to the rear end. In the pressure breaking portions 81a and 81b, the communication groove 84 has the largest groove depth. The thinnest wall thickness between the bottom surfaces of the parallel grooves 82 and 83 of the pressure breaking portions 81a and 81b, the bottom surface of the communication groove 84, and the outer surface of the side plate 25 was 25% of the thickness of the side plate 25. Although the grooves of the pressure rupture portions 81a and 81b are provided on the storage cell 12 side (inside the side plates 24 and 25), they may be provided outside the side plates 24 and 25.

  The location where the pressure breaking portions 81a and 81b are provided is not limited to the rear side of the unit case 11. However, if the pressure rupture portions 81a, 81b are provided at a position distant from the front of the unit case 11 in which the control box 27 is provided, even if the pressure rupture portions 81a, 81b are destroyed, the controller 74 in the control box 27 will not be damaged. Damage to the control circuit is prevented. As described above, even if the safety valve 76 of the power storage cell 12 is operated, unintended portions of the power storage unit 10 are prevented from being destroyed. Can be prevented. Thereby, the reliability of the power storage unit 10 can be improved.

  The form of the pressure rupture portions 81a and 81b is not limited to the illustrated one, and there is also an embodiment in which the tongue-shaped pressure rupture portions 81a and 81b are rotated by 90 degrees. In this embodiment, the parallel grooves 82 and 83 extend in the direction in which the bottom cover 21 and the top cover 23 face each other, and the communication groove 84 connects the bottom cover side ends of the parallel grooves 82 and 83 or the top cover side ends. Let it. Further, instead of the parallel grooves 82 and 83 and the communication groove 84, a slit having a small gap may be used. Further, in the present embodiment, since the storage cell groups 13 are vertically stacked in two stages, the two pressure breaking portions 81a and 81b are arranged vertically. Accordingly, the above-described effect can be obtained both when the safety valve 76 of the storage cell 12 included in the upper storage cell group 13a operates and when the safety valve 76 of the storage cell 12 included in the lower storage cell group 13b operates. Can be When the number of stacking layers of the storage cell group 13 increases or decreases, the number of pressure rupture portions can be increased or decreased accordingly.

  As shown in FIGS. 16 and 17, in a side view (field of view viewed from the side) in which side plates 24 and 25 of power storage unit 10 are removed, each of the plurality of voltage detection lines and temperature detection lines is Are arranged so as not to overlap with each of the safety valves 76. Thus, it is possible to reduce damage to each of the plurality of voltage detection lines and the temperature detection lines due to the influence of gas release in the operation of the safety valve 76.

  The shape of the wiring guide portion (the wiring guide tube 42) is not limited to the cylindrical shape, and the cross-sectional shape in a direction intersecting the longitudinal direction of the cylindrical shape may be, for example, an L-shape or a U-shape. Any shape can be used as long as the shape can hold the wiring.

  The present invention is not limited to the above embodiment, and can be variously modified without departing from the gist thereof. For example, the illustrated power storage unit 10 includes twelve power storage cells 12, but the number of power storage cells 12 is not limited to twelve and may be any number. The storage cell 12 is a lithium ion secondary battery, but may be a lithium ion capacitor.

DESCRIPTION OF SYMBOLS 10 ... Power storage unit, 11 ... Unit case, 11a ... Case main body, 12, 12a-12l ... Power storage cell, 13 ... Power storage cell group, 13a ... Upper power storage cell group, 13b ... Lower power storage cell group, 21 ... Bottom Lid, 22: Middle frame, 23: Upper lid, 24, 25: Side plate, 26: Front plate, 27: Control box, 28: Back plate, 31: Bottom wall, 32: Lower cell holder, 33: Concave surface, 34 , 34a butting surface, 36 ... upper cell holder, 37 ... concave surface, 41, 41a-41c ... middle cell holder, 42 ... wiring guide tube, 43 ... air guide, 44, 45 ... concave surface, 46 ... accommodation groove 47, elastic member, 48, gap, 51a to 51c, cool air inlet, 52a to 52c, cool air outlet, 61, 61a, 61b, bus bar, 63a to 63m, voltage detection line, 64, support protrusion , 65, 66 ... slit, 71a, 71b ... temperature sensor, 72a, 72b ... temperature detection line, 76 ... safety valve, 81a, 81b ... pressure lesion.

Claims (5)

A power storage unit having a plurality of cylindrical power storage cells,
A storage cell group configured by a plurality of the storage cells arranged in parallel;
A unit case incorporating the storage cell group,
A pressure breaking portion provided in the unit case and broken when an internal pressure of the unit case reaches a first predetermined pressure;
A safety valve is provided at an end face of the storage cell, the safety valve being operated when the internal pressure reaches a second predetermined pressure,
The pressure breaking portion is provided as a part of the side plate on a side plate of the unit case facing the end face of the power storage cell,
The pressure rupture portion is separated from other portions of the side plate by two parallel grooves parallel to each other and a communication groove communicating one end of each of the parallel grooves.
The thickness between the bottom surface of the two parallel grooves and the communication groove and the outer surface of the side plate is smaller than the thickness of the other part of the side plate,
Power storage unit. The power storage unit according to claim 1,
At the front of the unit case is provided a control box in which a controller connected to the power storage cell is accommodated,
The pressure breaking portion is provided between a longitudinal center of the unit case and a back surface of the unit case.
Power storage unit. The power storage unit according to claim 2,
The unit case has a bottom cover and a top cover facing each other, a front plate and a rear plate facing each other, and a pair of side plates facing each other,
The pressure breaking portion is provided on at least one of the pair of side plates,
Power storage unit. The power storage unit according to claim 3 ,
The two parallel grooves extend in a direction in which the front plate and the rear plate face each other,
The communication groove connects end portions of the two parallel grooves on the back plate side,
Power storage unit. The power storage unit according to claim 3 ,
The two parallel grooves extend in a direction in which the bottom lid and the top lid face each other,
The communication groove connects the ends of the two parallel grooves on the bottom lid side or the ends on the top lid side,
Power storage unit.

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