JP6421829B2 - Power storage unit - Google Patents

Description

  The present invention relates to a power storage unit that constitutes a power storage system for storing power by incorporating a plurality of power storage cells in a unit case.

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

  A power storage system for storing electric power includes a large number of power storage cells including lithium ion secondary batteries and lithium ion capacitors. A plurality of power storage cells are assembled in the unit case, and one set of power storage pack, that is, a power storage unit is assembled by the power storage cells and the unit case. The power storage unit is incorporated in multiple stages in a housing, that is, a power storage rack, in which a plurality of shelf plates are provided at intervals in the vertical direction. A plurality of power storage racks in which power storage units are incorporated are arranged in the power supply chamber to form a power storage system.

  Patent Document 1 describes a battery unit panel in which a plurality of battery units are arranged in multiple stages in a casing.

JP 2013-196908 A

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

  Since the power storage unit for forming the power storage system is continuously used for a long period of time, not only heat dissipation of the power storage cell but also high reliability 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, the power storage cell group including a plurality of the power storage cells arranged in parallel, and the power storage included in the power storage cell group A pair of cell holders for holding the cell from both sides in the radial direction of the electricity storage cell; a concave surface formed in one of the pair of cell holders into which a part of the electricity storage cell enters in the radial direction; and the other of the pair of cell holder And a concave surface into which the other part of the storage cell in the radial direction enters, and an elastic member provided on the concave surface and in close contact with the outer peripheral surface of the storage cell by elastic restoring force.

  The power storage unit has a power storage cell group including a plurality of power storage cells arranged in parallel. The storage cells included in the storage cell group are held from both radial sides by a pair of cell holders. One of the pair of cell holders is formed with a concave surface into which a part of the storage cell in the radial direction enters, and the other of the pair of cell holders is formed with a concave surface into which another part of the storage cell in the radial direction enters. . Furthermore, each concave surface is provided with an elastic member that is in close contact with the outer peripheral surface of the storage cell by elastic restoring force. Thereby, each electrical storage cell is firmly hold | maintained with moderate force, and the reliability of an electrical storage unit is improved.

It is a perspective view of the front side which shows the external appearance of an electrical storage unit. It is a perspective view of the back side which shows the appearance of an electrical storage unit. It is a disassembled perspective view of the unit case which comprises an electrical storage unit. It is a perspective view which shows the bottom cover of a unit case. It is a perspective view which shows the inner frame of a unit case. It is a perspective view which shows the upper cover of a unit case. (A) is a perspective view which shows the inner surface of one side plate of a unit case, (B) is a perspective view which shows the outer surface of the other side plate of a unit case. It is a perspective view which shows the control box provided in the front of a unit case. It is a front view which shows the cold wind inflow port formed in the front plate of a unit case. It is a front view which shows the cold wind outflow port formed in the back plate of a unit case. It is the perspective view which looked at the electrical storage cell group which has several electrical storage cells and is integrated in a unit case from the output terminal side. It is the perspective view which looked at the electrical storage cell group from the opposite side of FIG. It is a longitudinal cross-sectional view of the electrical storage unit which shows the flow of the cooling air in a unit case. (A) is a top view which shows the upper electrical storage cell group shown by FIG. 12, (B) is a top view which shows the lower electrical storage cell group. It is a wiring diagram which shows the connection state of the detection wiring provided in an electrical storage cell group. It is a front view of the electrical storage cell group which shows the detection wiring wound around the output terminal side of the electrical storage cell group. It is a front view of the electrical storage cell group which shows the detection wiring wound around the other side of FIG. 16 of an electrical storage cell group. It is a perspective view which shows the detection wiring of the temperature detection sensor wound around the middle frame. It is a front view of a middle frame which shows the state where the detection wiring of the temperature detection sensor was attached to the middle frame. It is a block diagram which shows the control circuit to which a voltage detection line and a temperature detection line are connected. (A) is sectional drawing which shows one edge part of the electrical storage cell with which the unit case was mounted | worn, (B) is an expanded sectional view of the A section 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 substantially rectangular parallelepiped unit case 11, and a power storage cell group 13 including twelve power storage cells 12a to 12l is incorporated in the unit case 11 as shown in FIG. . Each power storage cell 12 is a lithium ion secondary battery, and is formed in a cylindrical shape. The storage cell group 13 includes an upper storage cell group 13a configured by six storage cells 12a to 12f and a lower storage cell group 13b configured by six storage cells 12g to 12l. In the case 11, the storage cells 12 are mounted in two upper and lower stages.

  As shown in FIG. 11 and FIG. 12, the storage cell 12 constituting the upper storage cell group 13 a is changed from the storage cell 12 arranged on the front side of the unit case 11 to the storage cell 12 arranged on the back side. Reference signs a to f are attached. FIG. 1 shows the front side of the unit case 11, and FIG. 2 shows the back 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 symbols g to l from the storage cells 12 arranged on the back side of the unit case 11 toward the storage cells 12 arranged on the front side. Has been. Each of the storage cell groups 13a and 13b is configured by storing the storage cells 12 in parallel with a gap therebetween. The storage cells 12 in the upper storage cell group 13a and the lower storage cell group 13b are arranged in parallel so as to overlap each other with a gap therebetween. In the specification, in the case of indicating the storage cell 12 at a specific location, the description will be given with reference numerals a to l.

  As shown in FIG. 3, the unit case 11 has a rectangular bottom lid 21, and a middle frame 22 is attached to the bottom lid 21, and a top lid 23 is attached to the middle frame 22. The bottom lid 21, the middle frame 22 and the top lid 23 constitute a case body 11 a having a skeleton structure that accommodates all the 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 near the side plate 25 on the front side of the case body 11a, and the control box 27 is covered with a cover 27a. As shown in FIG. 2, a back plate 28 is attached to the back side 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 includes 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 multiple stages in a power storage rack. The top, bottom, front and back of the power storage unit 10 indicate the position and direction when the power storage unit 10 is disposed in the power storage rack. The power storage unit 10 has the front side, that is, the front plate 26 facing the front of the power storage rack. Placed on the shelf board.

  The bottom lid 21 is integrally formed of resin, and as shown in FIG. 4, has a bottom wall 31 and three lower cell holders 32 extending in the longitudinal direction on the inner surface thereof. The cell holder 32 protrudes from the bottom wall 31 on the left and right sides of the bottom wall 31 and the widthwise center of the bottom wall 31. In each cell holder 32, six substantially semicircular concave surfaces 33 are formed corresponding to the six power storage cells 12g to 12l constituting the lower power storage cell group 13b. 12l is held by the lower cell holder 32 in such a state that both end portions and the lower semicircular portion of the central portion of each storage cell 12 enter 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 includes 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 so as to correspond to the cell holder 32 of the bottom lid 21, and the upper lid 23 is also integrally formed of resin. In each cell holder 36, six substantially semicircular concave surfaces 37 are formed corresponding to the six power storage cells 12a to 12f constituting the upper power storage cell group 13a. ˜12f is covered with the cell holder 36 in such a state that the upper end semicircular portions at both ends and the central portion enter the concave surface 37. An abutting surface 34 is provided between the concave surfaces 37 adjacent in the longitudinal direction.

  As shown in FIG. 5, the middle frame 22 includes three intermediate cell holders 41 extending in parallel. Each cell holder 41 includes a lower cell holder 32 provided on the bottom lid 21, and an upper lid. 23, and is sandwiched between the upper cell holder 36 provided at 23. The cell holder 41 is integrally connected by a wiring guide tube (wiring guide portion) 42 extending in the horizontal direction, that is, in a direction crossing the case main body, and four air guides 43, and the wiring guide tube 42 is connected to the front side of the unit case 11. 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 41 a disposed at one end in the direction crossing the case body (longitudinal direction of the storage cell 12) and the other of the other side. It is joined to an intermediate cell holder 41b disposed at the end and an intermediate cell holder 41c disposed at a substantially central position. That is, the wiring guide tube 42 is joined to the three intermediate cell holders 41. The wiring guide tube 42 has, for example, a cylindrical hollow structure, and a plurality of wires such as a voltage detection line and a temperature detection line described later can be accommodated 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 portions that are in contact with the storage cell 12, cell holders 41 a, 41 b, 41 c, and the direction across the case body (the storage cell 12 A hollow structure is formed from one end portion (cell holder 41a) in the longitudinal direction to the other end portion (cell holder 41b) on the opposite side, and therefore, from the outer surface side of one end to the opposite side The outer end side of the other end of the wiring guide tube 42 penetrates through the hollow structure. The outer shape of the wiring guide tube 42 is circular, but 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.

  Further, in the two cell holders 41 (41a, 41b) arranged at both ends described above, it corresponds to a region between four power storage cells 12 adjacent in the front-rear direction and the vertical direction (corresponding to a space in which an air guide 43 described later is provided). Area), and a plurality of these areas are provided side by side in the two cell holders 41 (41a, 41b) arranged at both ends. Among these regions, as shown in FIG. 17, the wiring guide tube 42 is provided in a region closest to the controller (control unit) 74. 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.

  Thereby, since the distance from the wiring guide tube 42 to the controller 74 can be shortened, the distance of the part with the largest number of wirings can be shortened, and a plurality of wirings are gathered at the part with the large number of wirings. The degree can be improved. That is, the area from the wiring guide tube 42 to the controller 74 is an area where a plurality of wirings fed out from the wiring guide tube 42 and other wirings are joined and drawn, so the number of wirings inevitably increases. Therefore, by shortening the distance in this region where the number of wirings inevitably increases, it is possible to reduce the distribution of the respective wirings and improve the degree of grouping of the plurality of wirings.

  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. Thereby, both the wiring from the upper storage cell group 13a and the wiring from the lower storage cell group 13b can be made to enter the wiring guide tube 42 with substantially the same length. It is possible to enter the wiring guide tube 42 or take it out from the wiring guide tube 42 after gathering a plurality of wires from each other without waste. In other words, the degree of freedom of wiring routing 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 bus bars in a side view (view from the side direction) with the side plates 24 and 25 of the power storage unit 10 removed. It has been. Thereby, since each of the plurality of wirings passed through the wiring guide tube 42 is routed without contacting each of the plurality of bus bars, it is possible to reduce damage of the plurality of wirings due to contact with the bus bars.

  As shown in FIG. 5, on the lower surface of each cell holder 41, there are six substantially semicircular concave surfaces 44 corresponding to the six energy storage cells 12g to 12l constituting the lower energy storage cell group 13b. Each of the storage cells 12g to 12l is sandwiched between the cell holder 41 and the cell holder 32 in such a state that both upper ends and the upper half circle at the center enter the concave surface 44. Between the concave surfaces 44 adjacent to each other in the longitudinal direction, an abutting surface 34a is provided in correspondence with the abutting surface 34 of the bottom lid 21, and both abutting surfaces 34, 34a are in a state of being abutted. Thus, each of the storage cells 12g to 12l is held between the bottom lid 21 and the middle frame 22 in a state of being sandwiched.

  Six substantially semicircular concave surfaces 45 are formed on the upper surface of each cell holder 41 so as to correspond to 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 end portions and the lower semicircular portion of the central portion entering the concave surface 45. Between the concave surfaces 45 adjacent to each other in the longitudinal direction, an abutting surface 34a is provided corresponding to the abutting surface 34 of the upper lid 23, and both abutting surfaces 34, 34a are abutted. Each of the storage cells 12 a to 12 f is sandwiched between the upper lid 23 and the middle frame 22.

  As described above, the six cylindrical energy storage cells 12 constituting the lower energy storage cell group 13b shown in FIGS. 11 and 12 include the lower cell holder 32 provided on the bottom lid 21 and the middle frame 22. Both end portions and the central portion are sandwiched by the intermediate cell holder 41 provided in the case, and are assembled into the case main body 11a. The six energy storage cells 12 constituting the upper energy storage cell group 13a are configured such that the upper cell holder 36 provided on the upper lid 23 and the intermediate cell holder 41 provided on the middle frame 22 Is inserted into the case main body 11a. In addition, the both ends of each power storage cell 12 constitute left and right side portions as the power storage cell group 13 formed by all the power storage cells 12. Under the state where all the storage cells 12 are accommodated in the case main body 11a, the bottom lid 21 is fastened to the lower side of the middle frame 22 by a screw member (not shown), and the upper lid 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 portion of a power storage cell incorporated in the unit case, and FIG. 21B is an enlarged cross-sectional view of a portion A in FIG. FIG. 21 shows the storage cell 12 sandwiched between the cell holder 32 of the bottom lid 21 and the cell holder 41 of the middle frame 22, and hatching is not shown. An accommodation groove 46 is formed in the bottom of each concave surface 33, 44 so as to be exposed to the concave surfaces 33, 44. An elastic member 47 made of soft resin or rubber is inserted into the housing groove 46. The surface of the elastic member 47 protrudes radially inward from the concave surfaces 33 and 44. Therefore, when the 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 brought into contact with each other, the elastic member 47 is contracted and deformed in the radial direction. The cell 12 is held in the unit case 11. Specifically, the storage cell 12 is sandwiched and held from both sides in the radial direction by a pair of upper and lower elastic members 47. At this time, the elastic member 47 contracted and deformed is brought into close contact with the outer peripheral surface of the storage cell 12 by an elastic restoring force. The one-to-one set of elastic members 47 sandwiches the cells in at least two sets with respect to one cell.

  When 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 larger than the radius R1 of the storage cell 12, and the concave surfaces 33 and 44 and the storage cell 12 A clearance 48 of ΔR is formed between the outer peripheral surface. When 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 shrinkage deformation is d1, the deformation amount, that is, the crushing amount of the elastic member 47 is substantially 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 crushing amount Δd is 0.2 mm. When the compression rate k is a ratio obtained by dividing the crushing amount Δd by the initial thickness d1, the compression rate k = 100 × Δd / d1 = 100 × 0.2 / 2.6 = 7.7%. Preferably, the initial thickness d1 and crushing amount Δd of the elastic member 47 may be selected so that the compression rate k is in the range of about 5 to 15%.

  As shown in FIG. 21, a vertical line that is orthogonal to the center line of the vertically adjacent storage cells 12 and that crosses the center line of the vertically adjacent storage cells 12 up and down is defined as a reference line O. The elastic member 47 extends in the circumferential direction in the range of the 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 member 47 extends 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. . Thereby, even if there is a processing error in the bottom lid 21 made of hard resin, the middle frame 22 and the like, they are prevented from biting 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, when the elastic member 47 is in close contact with the outer peripheral surface of the storage cell 12, the heat dissipation of the storage cell 12 can be enhanced. If the elastic member 47 is interposed in a certain range in the circumferential direction between the storage cell 12 and the concave surface, a gap 48 is formed between the concave surfaces 33 and 44 and the outer peripheral surface of the storage cell 12. Cooling of the storage cell 12 and the elastic member 47 is achieved by the cold air passing through 48, and cooling of the components disposed outside the cell holder 41 at both ends is also achieved. Thereby, the heat dissipation of the electrical storage cell 12 can be improved, and the reliability of the electrical storage unit 10 can be improved.

  If the elastic member 47 is provided in the entire circumferential direction of the concave surface, the alignment function of the storage cell 12 can be enhanced. On the other hand, when the elastic member 47 is provided in a part of the concave surface in the circumferential direction, a gap 48 shown in FIG. 21 is formed, and heat dissipation is improved. Even when the elastic member 47 is provided in the entire circumferential direction of the concave surface or in a part of the circumferential direction, the surface of the elastic member 47 is in close contact with the outer peripheral surface of the electricity storage cell 12. Is firmly fixed with an appropriate force, and displacement of the storage cell 12 is prevented. The angle θ shown in FIG. 21 is preferably in the range of 15 degrees to 45 degrees. When the angle θ is 15 degrees or more, the contact area of the elastic member 47 in contact with the storage cell 12 is increased, so that there is less concern that the storage cell 12 moves from a predetermined position due to vibration during transportation or an earthquake. When it is necessary to increase the reliability against vibration, such as when installing near a power source such as a moving body or an electric motor that generates vibration, the angle θ should be set close to 45 degrees. Is preferred. Further, 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 storage cell 12 becomes larger, and the flow of exhaust gas when the storage cell 12 is abnormal is increased. Performed more smoothly. The material of the elastic member 47 is preferably silicone rubber, but EPDM or fluorine rubber having excellent chemical resistance may be used.

  If the elastic member 47 is too soft, even if the interface between the storage cell 12 and the elastic member 47 is in close contact, if a force is applied in the cell circumferential direction, the elastic member 47 is elastically deformed in the same direction, and the storage cell 12 May rotate in the same direction. On the other hand, if the elastic member 47 is too hard, it is difficult to be deformed, and there is a concern that the degree of adhesion between the storage cell 12 and the elastic member 47 in the cell circumferential direction is lowered.

  Therefore, the results of experiments conducted by the present inventors to obtain a suitable hardness of the elastic member 47 will be described. Table 1 below shows the relationship among the hardness of the elastic member 47, the tightening torque (T1) of the screw member, and the shear displacement amount of the elastic member 47, which has been clarified from this experiment. The screw member tightening torque (T1) is a tightening torque of the screw member for fastening the middle frame 22 and the upper lid 23 together. When the screw member is tightened, the elastic member 47 is compressed in the thickness direction and elastically deformed. At this time, if the compression amount (deformation amount) of the elastic member 47 is appropriate, the storage cell 12 and the elastic member 47 are in close and necessary contact. In this experiment, a plurality of elastic members 47 having the same dimensions (thickness: 2.75 mm, width: 6.2, length: 30.0 mm) and different hardnesses were prepared. The tightening torque (T1) required for compressing to 2.4 mm was measured. When the elastic member 47 is inserted into the receiving groove 46, the width of the elastic member 47 is compressed to 6.0 mm.

  The shear displacement amount of the elastic member 47 is the amount of elastic deformation in the same direction that occurs in the elastic member 47 that is in close contact with the storage cell 12 when a circumferential force is applied to the storage cell 12. As will be described later, the bus bar is fixed to the terminal electrode of the storage cell 12 with a bolt. At this time, a circumferential force is applied to the storage cell 12 as the bolts for fixing the terminal electrode and the bus bar are tightened. In this experiment, a shear displacement amount (elastic deformation amount) of the elastic member 47 was measured when a tightening torque (T2) of 6 N · m was applied to a bolt for fixing the terminal electrode and the bus bar.

表１より、弾性部材４７の硬度が４０以上６５以下の範囲内である場合、５Ｎ・ｍ以下の締め付けトルク（Ｔ１）によって弾性部材４７の厚みが２．４ｍｍに圧縮され、かつ、６Ｎ・ｍの締め付けトルク（Ｔ２）が掛かっても弾性部材４７のせん断変位量が１．０ｍｍ以下に抑えられることがわかる。

From Table 1, when the hardness of the elastic member 47 is in the range of 40 to 65, the thickness of the elastic member 47 is compressed to 2.4 mm by a tightening torque (T1) of 5 N · m or less, and 6 N · m. It can be seen that the shear displacement amount of the elastic member 47 can be suppressed to 1.0 mm or less even when the tightening torque (T2) is applied.

  The optimum tightening torque (T1) varies depending on the type of screw member. For example, when a screw member having an optimum tightening torque (T1) of 6 N · m is used, an elastic member 47 having a hardness of 50 to 55 is used. Is preferred. This is because the elastic member 47 having a hardness of 50 to 55 is reduced to 2.4 mm by a tightening torque (T1) of 3.0 to 3.3 N · m which has a sufficient margin for an optimum tightening torque (6 N · m). This is because even when compressed and a tightening torque (T2) of 6 N · m is applied, there is almost no shear displacement.

  As shown in FIGS. 1 and 9, the ventilation frame 26a constituting the front plate 26 is provided with a cold 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 cold air outlet 52a, the ventilation frame 28b is provided with a cold air outlet 52b, and the ventilation frame 28c is provided with A cold 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 storage cell group 13a, and a lower side passage is formed between the bottom lid 21 and the lower storage cell group 13b. A cold air passage 53b is formed. Further, an intermediate cool air passage 53c is formed between the upper storage cell group 13a and the lower storage cell group 13b. The cold air inlet 51a and the cold air outlet 52a face the cold air passage 53a, the cold air inlet 51b and the cold air outlet 52b face the cold air passage 53b, and the cold air inlet 51c and the cold air outlet 52c face the cold air passage 53c. . The opening areas of the upper and lower cold air inlets 51a and 51b and the cold air outlets 52a and 52b are set to be substantially the same. The vertical dimension of the central cold wind inlet 51c is longer than the vertical dimension of the cold wind inlets 51a and 51b, and the central cold wind inlet 51c has a larger opening area than the upper and lower cold wind inlets 51a and 51b. Is set large, and the opening area is about double. Similarly, the central cold air outlet 52c has an opening area approximately twice 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 the four power storage cells 12 formed between the four power storage cells 12 on the downstream side thereof. An air guide 43 is disposed in each space.

  When the power storage unit 10 is arranged in the power storage rack, the cooling air generated in the power storage rack flows into the unit case 11 from the cold air inlets 51a, 51b, 51c formed in the front plate 26. The cooling air flowing in from the central cold air inlet 51c passes through the cold air passage 53c between the two upper and lower storage cells 12a, 12l on the uppermost stream side and collides with the wiring guide tube. A part of the collided cooling air branches up and down and flows into the gap between the two energy storage cells 12a and 12b and the gap between the two energy storage cells 12l and 12k. The cooling air branched upwards collides with the cooling air flowing in the cold air passage 53a along the inner surface of the upper lid 23 from the cold air inlet 51a, and along the back side of the storage cell 12a and the front side of the storage cell 12b. It flows and cools each electrical storage cell. Similarly, the cooling air branched downward collides with the cooling air flowing in the cold air passage 53b along the inner surface of the bottom lid 21 through the cold air inlet 51b, and the rear surface side of the storage cell 12l and the front surface of the storage cell 12k. It flows along the side and cools each power storage cell. Thus, 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 storage cells 12b and 12k collides with the air guide 43. The air guide 43 has a cross-shaped cross section, and includes an upper protrusion 43a that protrudes upward, a lower protrusion 43b that protrudes downward, and a horizontal protrusion 43c that protrudes horizontally toward the upstream side. Have. Accordingly, a part of the cooling air that collides with the air guide 43 on the most upstream side branches up and down and flows into the gap between the two storage cells 12b and 12c and the clearance between the two storage cells 12k and 12j. To do. The cooling air branched upward collides with the cooling air flowing along the inner surface of the upper lid 23, and flows along the back side of the storage cell 12b and the front side of the storage cell 12c to cool each 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. To do. Similarly, the other three air guides 43 on the downstream side branch the cooling air to reliably cool the storage cell 12. Thus, since the cooling air is guided to the outer peripheral surface of the storage cell 12 and the storage cell 12 can be reliably cooled, the durability and reliability of the storage unit 10 can be improved.

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

  Terminal electrodes are provided on both end faces of the storage cell 12, and the storage cells 12 constituting the storage cell group 13 are connected in series. In order to connect in series, the terminal electrodes at both ends of the storage cells 12 adjacent in the horizontal direction have opposite polarities, and the terminal electrodes at both ends of the storage cells 12 adjacent in the vertical direction also have opposite polarities. ing. As shown in FIG. 11 and FIG. 14, when the terminal electrode on the right end surface of the storage cell 12a arranged on the front side of the upper storage cell group 13a is a positive electrode, the terminal electrode includes the positive terminal of the storage unit 10 The bus bar 61a is attached, and the negative electrode terminal bus bar 61b of the electricity storage unit 10 is attached to the terminal electrode of the electricity storage cell 12l on the lower side. Other energy storage cells are connected in series between these energy storage cells 12a and 12l, and an intermediate bus bar 61 is attached to the terminal electrodes of the energy storage cells 12 adjacent to each other. In the 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, the front end surface of the side plate 24 is provided with an opening 62a from which the bus bar 61a protrudes, and an opening 62b from which the bus bar 61b protrudes. When a plurality of power storage units 10 are arranged in a power storage rack and the power storage units 10 are electrically connected, the bus bars 61a and 61b protruding from the openings 62a and 62b are connected to the bus bars of the other power storage units 10 by power feeding members. The

  FIG. 15 shows an electrical connection state of all the storage cells 12 by the bus bars 61, 61a, 61b. One end of 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 is a set value. The other end of each voltage detection line 63 a to 63 m is connected to a controller (control unit) 74 on the control board in the control box 27. That is, one end portions of the plurality of voltage detection lines (a plurality of wirings) 63a to 63m that detect the output voltages of the plurality of storage cells 12 are connected to the bus bars corresponding to the plurality of storage cells 12, respectively, The other end portions of the plurality of voltage detection lines 63 a to 63 m are connected to the controller 74.

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

  FIG. 16 shows a voltage detection line connected to the right bus bar of the storage cell group 13. Two voltage detection lines 63a and 63m connected to the storage cells 12a and 12l on the front side, and a voltage detection line 63k connected to the storage cell 12k adjacent to the storage cell 12l on the back side are provided in 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 line connected to the storage cell 12 of the upper storage cell group 13a via the bus bar and the storage of the lower storage cell group 13b. The voltage detection line connected to the cell 12 via the bus bar can be merged in the vicinity of the support protrusion 64 and can be inserted into the slit 65 and held by the support protrusion 64. Further, by providing the support protrusion 64 with the horizontal slit 65 and the vertical slit 66, the voltage detection lines drawn from a plurality of directions are joined at the support protrusion 64 having the vertical slit 66. The voltage detection lines can be held and sent out directly below the same support protrusion 64. Further, in the support protrusion 64 having the vertical slit 66, the direction of the voltage detection line to be sent out can be divided into a plurality of directions as required. As described above, the degree of freedom in routing the voltage detection line can be increased.

  FIG. 17 shows a voltage detection line connected to the left bus bar of the storage cell group 13. As shown in FIG. 17, the seven voltage detection lines connected to the right bus bar are drawn out from the wiring guide tube 42 and held in the slits 65 and 66 as shown in FIG. It 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, and are respectively formed in the slits 65 of the support protrusion 64. Inserted and held by the cell holder 41.

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

  In this way, the wiring as the voltage detection line that is wound around the inner side of each of the side plates 24 and 25 and extends along the end face of the storage cell group 13 is held by the support protrusion 64, and the upper storage cell group 13a and the lower storage cell group 13b are fixed between the bus bars, so that they are not displaced by cooling air or vibration flowing in the unit case 11, and the voltage detection line is prevented from contacting the storage cell 12. The In addition, even if the fastening bolt between the upper storage cell 12 and the bus bar is loosened and one of the fastening parts is removed, the support protrusion 64 can prevent the bus bar from hanging downward, and the electrical connection with the lower storage cell 12 can be prevented. Can prevent electrical short circuit. The thickness of the support protrusion 64 is 3 mm. It is preferable that the thickness of the support protrusion 64 is 1 mm or more because cracks and chips do not occur even if the support protrusion 64 hits the support protrusion 64 due to the bus bar hanging down. 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, and the voltage detection line does not come off from the slits 65 and 66 even if it is displaced by vibration or the like. Although the cross-sectional shape of the support protrusion 64 is rectangular, it may be a circular arc shape, an L shape, or a cross shape. Thereby, durability and reliability of the electrical storage unit 10 can be improved.

  Further, as shown in FIGS. 16 and 17, each of the plurality of support protrusions 64 is a plurality of bus bars in a side view (viewed from the side direction) with the side plates 24 and 25 of the power storage unit 10 removed. It is provided at a position where it does not overlap. Thus, each of the plurality of voltage detection lines can be routed so as not to overlap 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 attached to the storage cell 12 as a temperature detection sensor. A platinum resistance temperature detector or a linear resistor other than the thermistor may be used. 18 is a perspective view showing temperature detection sensors 71a and 71b and temperature detection lines 72a and 72b from the respective sensors, and FIG. 19 is a front view of the middle frame showing a state in which 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 storage cell 12k from the front side of the power storage unit 10, that is, the second 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 storage cell 12h from the back side, that is, 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.

  Although there is no restriction | limiting in the attachment method of the temperature detection sensors 71a and 71b, for example, as shown in FIG. 18, it attaches to the curved side surface of column-shaped electrical storage cells 12k and 12h using an adhesive film, an adhesive agent, etc. Further, the temperature detection sensors 71a and 71b are attached to the side plate 25 side (end portion side) between the central portion and the end portion of the curved side surface of the storage cells 12k and 12h. That is, it is arranged inside the cell holder 41 on the control box 27 side.

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

  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 of the control box 27. Further, by arranging the temperature detection sensors 71a and 71b on the curved side surfaces of the storage cells 12k and 12h, a wide bonding area can be secured, and the temperature detection sensors 71a and 71b can be firmly fixed. In addition, by providing the temperature detection sensor 71b on the side plate 25 side (end side) of the curved side surface of the storage cell 12h, the temperature on the end side, which tends to be higher than the central portion, can be measured and used for temperature management. it can. Further, the temperature detection lines 72 a and 72 b are pulled out to the outside of the cell holder 41 through the through holes 73 a and 73 b provided in the cell holder 41 and are held by the support protrusions 64 outside the cell holder 41, thereby cooling air and vibration Therefore, it is possible to prevent the temperature detection line from coming into contact with the storage cell 12 without being deviated due to the like. Thereby, the reliability of the electrical storage unit 10 can be improved.

  Since the energy storage cell 12 is cooled by the cooling air flowing in the unit case 11, the temperature of the energy storage cell 12 does not increase excessively. The temperature of the storage cell 12 arranged in the unit case 11 tends to be lower in the storage cell 12 on the upstream side of the cooling air than in the storage cell 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 cell on the low temperature side and 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, which can be used for temperature management.

  As described above, temperature management such as detecting the average temperature of the storage cells 12 in the storage unit 10 can be performed by detecting the temperatures of at least two storage cells 12 on the high temperature side and the low temperature side. In addition, if the temperature at two locations on the high temperature side and the low temperature side is known depending on the amount of cooling air flowing in the unit case 11 and the environmental temperature, the model case knows in advance how much the temperature difference between the cells will occur. By comparing with the distribution data, even when the temperature is abnormally high except in the cell where the temperature is detected, it can be used for detecting the abnormality.

  According to the study by the present inventors, when the temperatures of all the storage cells 12 were monitored, the temperature increase on the front side of the second storage cell 12k from the upstream side in the lower storage cell group 13b 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 the highest. Therefore, as shown in FIGS. 13, 18 and 19, a temperature detection sensor 71a is attached to the front side of the storage cell 12k to detect the temperature of the storage cell 12k having the lowest temperature, and the back side of the storage cell 12h. The temperature detection sensor 71b is attached to the battery cell 12h to detect the temperature of the storage cell 12h having the highest temperature. Here, from the result of monitoring, the temperature of the second storage cell 12k from the upstream side is set as the temperature of the high-temperature storage cell as the temperature of the low-temperature storage cell in the lower storage cell group 13b. Although the temperature of the second storage cell 12h from the downstream side is used, it is not limited to this. For example, as the temperature of the low temperature side storage cell, the temperature of any of the four upstream storage cells 12a, 12b, 121, or 12k, and as the temperature of the high temperature side storage cell, the four downstream storage cells 12e. , 12f, 12g, 12h may be used. Further, the storage cell on the upstream side or the downstream side may be selected on the basis of the central portion of the unit case 11 (case body 11a). That is, as the temperature of the low-temperature side storage cell, a storage cell group selected from the storage cell group arranged on the front plate 26 side from the center of the unit case 11 (case body 11a) (in FIG. 13, 12a, 12b, 12c, 12l, 12k, 12j) is attached to any one of the temperature detection sensors, and the temperature of the storage cell on the high temperature side is arranged on the side opposite to the front plate 26 from the center of the unit case 11 (case body 11a). A temperature detection sensor may be attached to any of the storage cell groups (12d, 12e, 12f, 12g, 12h, 12i in FIG. 13). Thus, the combination of the storage cells for detecting the temperature can be changed as appropriate.

  FIG. 20 is a block diagram illustrating 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 a potential difference between the positive terminal and the negative terminal of each storage cell 12 based on 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 signal of each calculation result is sent to the external display part 75, and the voltage value and temperature value of the electrical storage cell 12 are displayed on the display part 75. As the voltage value display mode, the voltage values of all the storage cells 12 can be displayed, or the storage cells having the highest voltage and the lowest voltage can be displayed. In addition, as the temperature display mode, the detected temperature of the two storage cells is displayed, the above-mentioned average temperature is displayed, the alarm or alarm for notifying abnormality is displayed, flashing, or the alarm sound is sounded. can do. Further, when the average temperature of the storage cell 12 is higher than a predetermined temperature, the cooling air volume is increased to decrease the temperature of the storage cell 12, or when the average temperature is lower than the predetermined temperature, the cooling air volume is decreased to reduce the consumption of the cooling fan. Electric power can be reduced. In addition, when either one of the two power storage cells has a temperature higher than a predetermined temperature, a warning sound or flashing is notified, or a temperature abnormality is recognized and an abnormal signal is communicated to the system control unit 77. By doing so, the main circuit can be shut 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 a warning sound, blinking, or the like, or an abnormal signal is communicated to the system control unit 77. Can be cut off. In addition, the life of the storage cell is estimated from the change over time of the voltage value of the storage cell 12, and the main circuit is shut off by notifying with a warning sound, blinking, etc., or communicating an abnormal signal to the system control unit 77. be able to. Further, when the variation in the voltage value between the cells of the storage cell 12 is larger than the predetermined voltage variation, the charge / discharge operation is performed so as to be within the predetermined voltage value range by communicating a predetermined signal to the system control unit 77. can do.

  The lithium ion secondary battery as the storage cell 12 has a liquid or gel electrolyte sealed therein. In the unlikely event that the temperature of the storage cell 12 exceeds the steady temperature range and the temperature rises excessively, it is assumed that the internal pressure of the storage cell 12 exceeds a predetermined pressure (second predetermined pressure). Therefore, in the unlikely event that the internal pressure exceeds this predetermined pressure, in order to release the gas of the electricity storage cell 12 to the outside, on both end faces of the electricity storage cell 12, as shown in FIG. 16 and FIG. A safety valve 76 is provided. The predetermined pressure is a pressure for operating the safety valve 76 of the storage cell 12. As the internal temperature of the storage cell 12 increases, the internal pressure of the storage cell 12 increases, and when 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 activated, that is, opened, and the gasified contents are released to the outside, the released gas is blown to the inner surfaces of the side plates 24 and 25 and is applied to the other storage cells 12 in the unit case 11. There is no damage.

  If the safety valve 76 is activated, the released gas is ejected from the storage cell 12 into the unit case 11, and the internal pressure of the unit case 11 increases rapidly. When the unit case 11 is destroyed due to the rapidly increasing internal pressure, there is a possibility that parts such as a controller and wiring may be destroyed depending on the part to be destroyed. Therefore, in the unlikely event that the safety valve 76 is activated, a specific part of the unit case 11 is actively destroyed. In the present embodiment, a specific portion between the center in the longitudinal direction of the unit case 11 and the back surface of the unit case 11 is positively destroyed.

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

  On the inner surface of the rear end portion of the side plate 25, two pressure breaking portions 81a and 81b are provided vertically. Each of the pressure breaking portions 81a and 81b is parallel to each other and extends in the front-rear direction, that is, in the opposing direction of the front plate 26 and the back plate 28, and one of the parallel grooves 82 and 83. It is demarcated by the communication groove | channel 84 which connects end parts (end parts by the side of a backplate in this embodiment), and becomes a tongue piece shape. In the following description, the end portion on the back plate side of the parallel grooves 82 and 83 may be referred to as a rear end portion, and the end portion on the front plate side may be referred to as a front end portion. The pressure breaking portions 81 a and 81 b defined by the grooves on the three sides are connected to the side plate 25 at the base portion having the same thickness as the side plate 25. Although FIG. 22 shows the pressure destruction part provided in the side plate 25, the pressure destruction part is provided corresponding to the other side plate 24 as well. The pressure breakers 81a and 81b and the safety valve 76 (not shown in FIG. 22) are installed facing the longitudinal direction (axial direction) of the storage cell 12. Since the portion weak in strength is disposed in the immediate vicinity of the safety valve 76 as described above, the pressure destruction portions 81a and 81b are quickly opened even when the internal pressure rises due to the gas released from the safety valve 76, and the unit case 11 Can prevent total loss. As shown in FIGS. 16 and 17, in the electricity storage cell 12, the safety valve 76 is provided on both end surfaces in the axial direction, so that the pressure breaking portion is also provided on both side plates 24 and 25 of the unit case 11 so as to face each other. However, if only one safety valve 76 of the storage cell 12 is installed on one end face, the pressure breaking part may be provided only on the side plate facing it.

  The thickness between the bottom surfaces of the parallel grooves 82 and 83 and the communication groove 84 and the outer surface of the side plate 25 is thinner than other portions of the side plate 25. If the safety valve 76 is actuated 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 breakers 81a and 81b are grooved by the gas pressure. It will be destroyed in the part. The first predetermined pressure is a pressure that opens the pressure breakers 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 as the internal pressure of the unit case 11 increases, and the pressure breaking portions 81a and 81b are directed to the outside of the unit case 11. This is 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 discharge is formed in the side plate. Even if the pressure breaking portions 81a and 81b are broken, the base portions of the pressure breaking portions 81a and 81b are not separated from the side plates 24 and 25, and the pressure breaking portions 81a and 81b are prevented from being scattered outside. Further, when the groove portions constituting the pressure breaking portions 81a and 81b are broken, the pressure breaking portions 81a and 81b have the base portion as a fixed end portion and the end portion (free end) opposite to the base portion faces outward. And bend to turn. For this reason, the gas released into the unit case 11 is guided by the pressure breakers 81 a and 81 b and is ejected toward the rear of the unit case 11. The parallel grooves 82 and 83 of the pressure breaking parts 81a and 81b are deeper from the front end toward the rear end. In the pressure breaking parts 81a and 81b, the groove depth of the communication groove 84 is the deepest. The thinnest wall thickness between the bottom surfaces of the parallel grooves 82 and 83 of the pressure breaking portions 81 a and 81 b, the bottom surface of the communication groove 84, and the outer surface of the side plate 25 is 25% of the thickness of the side plate 25. The grooves of the pressure breaking portions 81a and 81b are provided on the storage cell 12 side (inside the side plates 24 and 25), but may be on the outside of the side plates 24 and 25.

  The location where the pressure breaking portions 81 a and 81 b are provided is not limited to the back side of the unit case 11. However, if the pressure breaking portions 81a and 81b are provided at positions away from the front surface of the unit case 11 where the control box 27 is provided, even if the pressure breaking portions 81a and 81b are broken, the controller 74 in the control box 27 is provided. This prevents the control circuit from being damaged. In this way, even if the safety valve 76 of the power storage cell 12 is operated, an unintended location of the power storage unit 10 is prevented from being destroyed, so that a chain abnormality occurs due to the operation of the safety valve 76. Can be prevented. Thereby, the reliability of the electrical storage unit 10 can be improved.

  The form of the pressure breaking portions 81a and 81b is not limited to that shown in the figure, and there is an embodiment in which the tongue-shaped pressure breaking portions 81a and 81b are rotated by 90 degrees. In this embodiment, the parallel grooves 82 and 83 extend in the opposing direction of the bottom lid 21 and the top lid 23, and the communication groove 84 communicates the ends on the bottom lid side or the end portions on the top lid side of the parallel grooves 82 and 83. Let Further, instead of the parallel grooves 82 and 83 and the communication groove 84, a slit having a thin gap may be used. Furthermore, in this embodiment, since the electrical storage cell group 13 is laminated | stacked two steps up and down, the two pressure destruction parts 81a and 81b are arranged side by side up and down. As a result, the above effect can be obtained both when the safety valve 76 of the storage cell 12 included in the upper storage cell group 13a is operated and when the safety valve 76 of the storage cell 12 included in the lower storage cell group 13b is operated. It is done. When the number of stacked layers of the storage cell group 13 increases or decreases, the number of pressure breaking parts can be increased or decreased accordingly.

  Further, as shown in FIGS. 16 and 17, when the side plates 24 and 25 of the power storage unit 10 are removed, a plurality of voltage detection lines and temperature detection lines are provided in a side view (view from the side direction). The safety valves 76 are routed so as not to overlap each other. Thereby, each damage of the several voltage detection line and temperature detection line by the influence of the gas discharge | release by the action | operation of the safety valve 76 can be reduced.

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

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although the illustrated power storage unit 10 includes twelve power storage cells 12, the number of power storage cells 12 is not limited to twelve, and may be any number. Moreover, although the electrical storage cell 12 is a lithium ion secondary battery, it is good also as a lithium ion capacitor.

  The power storage unit is applied to a power storage system for storing power and supplying the stored power to the outside.

Claims (6)

A power storage unit having a plurality of cylindrical storage cells,
A storage cell group composed of a plurality of the storage cells arranged in parallel;
A pair of cell holders for holding the storage cells included in the storage cell group from both radial sides of the storage cells;
A concave surface that is formed on one of the pair of cell holders and into which a part of the storage cell in the radial direction enters,
A concave surface formed on the other of the pair of cell holders, into which another part of the storage cell in the radial direction enters,
Wherein provided on the concave surface, in close contact with the outer peripheral surface of the storage cells by the elastic restoring force caused by the shrinkage deformation, it has a, an elastic member separate from said cell holder,
The elastic member provided on one of the pair of concave surfaces facing each other across the storage cell is provided on a part of the circumferential direction of the concave surface,
The elastic member provided on the other of the pair of concave surfaces facing each other across the storage cell is provided on a part of the circumferential direction of the concave surface,
Each of the elastic members is contracted and deformed so that the thickness thereof decreases by 5% to 15%, and is in close contact with the outer peripheral surface of the storage cell.
Power storage unit. The power storage unit according to claim 1,
An upper storage cell group composed of a plurality of the storage cells arranged in parallel;
A lower storage cell group constituted by a plurality of the storage cells arranged in parallel;
An upper cell holder for holding the power storage cells included in the upper power storage cell group;
A lower cell holder for holding the power storage cells included in the lower power storage cell group;
The storage cell included in the upper storage cell group is sandwiched between the upper cell holder and the storage cell included in the lower storage cell group is sandwiched between the lower cell holder. An intermediate cell holder sandwiched between
The concave surface provided with the elastic member is formed on each of the upper cell holder, the lower cell holder and the intermediate cell holder,
Power storage unit. The power storage unit according to claim 2,
A case body formed by an upper lid provided with the upper cell holder, a bottom lid provided with the lower cell holder, and an intermediate frame provided with the intermediate cell holder;
A front plate provided in front of the case body;
A back plate provided on the back of the case body;
A side plate provided on each side of the case body,
Power storage unit. In the electrical storage unit of any one of Claims 1-3,
The surface of the elastic member that is in close contact with the outer peripheral surface of the storage cell protrudes radially inward from the concave surface, and a gap is formed between the outer peripheral surface of the storage cell and the concave surface. ,
Power storage unit. In the electrical storage unit of any one of Claims 1-4,
The elastic member is inserted into an accommodation groove formed on the concave surface.
Power storage unit. The power storage unit according to claim 5 ,
Each of the elastic members is orthogonal to the center line of the storage cell and extends within a range of 30 degrees to the left and right from a reference line that crosses the center line up and down.
Power storage unit.

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