Storage battery pack and storage battery cooling system

Abstract

Provided is a storage battery pack capable of cooling a battery cell main body of a storage battery module and also capable of appropriately cooling a battery cell terminal. A battery pack (1) is provided with: a plurality of battery modules (10); a battery case (31); a water jacket (40) that is disposed in the battery case (31) or inside the battery case (31) and that exchanges heat with the plurality of battery modules (10) by circulating a first cooling medium; a second evaporator (17) which is disposed in the battery case (31) or in the battery case (31), and through which a second cooling medium circulates and exchanges heat with air in the battery case (31); and a fan (13) that is disposed in the battery case (31) or in the battery case (31) and that circulates air therein.

Description

Technical Field

[0001] The present invention relates to a battery pack and a battery cooling system that can be mounted on a mobile object such as a vehicle. Background Art

[0002] In recent years, efforts to realize a low-carbon society or a decarbonized society have been actively carried out, and research related to electrification technology has been conducted in order to reduce CO2 emissions and improve energy efficiency in vehicles.

[0003] In electrification technology, batteries play an important role. Since batteries are heat-generating components, current is limited when the battery temperature reaches a predetermined temperature or above from the perspective of safety and prevention of battery degradation. Therefore, for example, a water jacket is provided in the battery pack to control the cooling of the battery so that the battery temperature is maintained within a desired temperature range.

[0004] Patent Document 1 describes that a water jacket is provided between batteries arranged in a plurality of rows, and a cooling fan is provided to send air from the rear to the front of the battery case.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2003-297439 Summary of the invention

[0008] Problems to be solved by the invention

[0009] However, in recent years, the heat resistance temperature of the cells constituting the battery module has become higher. Therefore, in the past, it was sufficient to cool the cells constituting the battery module. However, in recent years, although the temperature of the cells has not reached the critical temperature for current limitation, the terminal temperature of the cells may reach the critical temperature for current limitation.

[0010] The battery cooling method described in Patent Document 1 can cool the outer surface of the front battery module in the vehicle width direction by air supply from a cooling fan, but does not involve cooling of the cell terminals.

[0011] The present invention provides a battery pack and a battery cooling system capable of cooling a battery cell body of a battery module and also appropriately cooling a battery cell terminal.

[0012] Solutions to Solve Problems

[0013] The present invention provides a battery pack, wherein:

[0014] The battery pack has:

[0015] A plurality of battery cells having a positive terminal and a negative terminal;

[0016] a plurality of battery modules on which the plurality of single cells are stacked;

[0017] A battery housing, which accommodates the plurality of battery modules;

[0018] a water jacket disposed in the battery housing or inside thereof and allowing a first cooling medium to flow through to perform heat exchange with the plurality of battery modules;

[0019] a heat exchanger disposed in the battery housing or inside thereof and allowing the second cooling medium to flow through and perform heat exchange with the air inside; and

[0020] A fan is disposed in the battery case or inside thereof and circulates the air inside.

[0021] In addition, the present invention provides a battery cooling system, wherein:

[0022] The battery cooling system comprises:

[0023] The above-mentioned battery pack;

[0024] a cooling medium circuit for circulating the first cooling medium flowing through the water jacket;

[0025] a heat pump circuit for circulating the second cooling medium flowing through the heat exchanger;

[0026] a second heat exchanger capable of performing heat exchange between the first cooling medium and the second cooling medium; and

[0027] A control unit controls the heat exchanger, the second heat exchanger, and the fan.

[0028] Effects of the Invention

[0029] According to the present invention, it is possible to cool the cell main body of the battery module and also to appropriately cool the cell terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is an exploded perspective view of the battery pack 1 according to the first embodiment.

[0031] Figure 2 It is an exploded perspective view of the battery module 10 .

[0032] Figure 3 It is a perspective view of a laminated cell 21 .

[0033] Figure 4It is a perspective view showing the bus bar 22 for connecting the electrode tabs 212 of the laminated cells 21 .

[0034] Figure 5 It is a plan view showing the internal structure of the battery pack 1 .

[0035] Figure 6 yes Figure 5 AA line section view.

[0036] Figure 7 yes Figure 5 BB line cross-sectional view.

[0037] Figure 8 yes Figure 5 CC line section view.

[0038] Fig. 9 yes Figure 5 DD line cross-sectional view.

[0039] Fig.10 1 is a plan view schematically showing the flow of air generated by the fan 13 and showing the internal structure of the battery pack 1 .

[0040] Fig.11 is a diagram showing a battery cooling system 100 .

[0041] Fig.12 This is a timing chart of battery cooling control when rapid charging is started in a state where the cell temperature is lower than the cell cooling start temperature by a predetermined amount or more.

[0042] Fig.13 This is a timing chart of the battery cooling control when the rapid charging is started in a state where the cell temperature is close to the cell cooling start temperature.

[0043] Fig.14 It is a plan view showing the internal structure of the battery pack 1A according to the second embodiment and is a diagram schematically showing the flow of air generated by the fan 13 .

[0044] Fig.15 yes Fig.14 EE line cross-sectional view.

[0045] Description of reference numerals:

[0046] 1. 1A battery pack

[0047] 10, 10A battery module

[0048] 11 Junction Box

[0049] 13 Fan

[0050] 14 Control Unit

[0051] 15 Upper clearance (clearance)

[0052] 17 Second evaporator (heat exchanger)

[0053] 18 Battery cooling circuit (cooling medium circuit)

[0054] 19 Heat pump circuit

[0055] 21 Laminated single cell (single cell)

[0056] 21A square single battery (single battery)

[0057] 21a Positive electrode tab (positive terminal)

[0058] 21a1 Positive terminal (positive terminal)

[0059] 21b Negative electrode tab (negative terminal)

[0060] 21b1 Negative terminal (negative terminal)

[0061] 23, 23A busbar cover (terminal insulation cover)

[0062] 25 Space

[0063] 31 Battery housing

[0064] 33 Upper cover (cover)

[0065] 40 Water Jacket

[0066] 42 Cooler (second heat exchanger)

[0067] 51 First Division

[0068] 52 Second Division

[0069] 60 Cover plate (terminal insulation cover)

[0070] 83 Second Branch (Branch)

[0071] 100 Battery cooling system

[0072] 212 Electrode tab (single cell terminal)

[0073] 523 Front clearance (air passage)

[0074] 524 Center front clearance (air channel)

[0075] 526 Center rear clearance (air channel)

[0076] 527 Rear clearance (air channel). DETAILED DESCRIPTION

[0077] Hereinafter, a battery pack according to each embodiment of the present invention will be described with reference to the drawings.

[0078] [First embodiment]

[0079] The battery pack 1 according to the first embodiment of the present invention is configured to be mounted on an electric vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle. Figure 1 As shown, the battery pack 1 includes four battery modules 10, a junction box 11, an auxiliary machine 12, and a battery case 31 for accommodating them. The four battery modules 10 are arranged in two rows in the front-to-back direction and in two rows in the left-to-right direction. In addition, as long as there are two or more battery modules 10, the number can be set arbitrarily, and the arrangement is not particularly limited.

[0080] The battery modules 10 are electrically connected to each other via an electrical connection member (not shown). The electric power stored in the battery modules 10 is supplied to a motor or the like as a driving source of the vehicle. In the following description, the four battery modules 10 may be collectively referred to as batteries.

[0081] like Figure 2 As shown, the battery module 10 includes a cell stack 20 in which a plurality of laminated cells 21 are stacked, an intermediate plate 30 , a pair of end plates 37 , a pair of restraint members 38 , and a pair of cover plates 60 .

[0082] The laminated cell 21 is, for example, a solid-state battery. Figure 3 As shown, the laminated cell 21 composed of a solid-state battery has a positive electrode connected to a positive electrode tab 21a, a negative electrode connected to a negative electrode tab 21b, a solid electrolyte disposed between the positive electrode and the negative electrode, and a laminate film 21c for accommodating them, and is charged and discharged by the transfer of lithium ions between the positive electrode and the negative electrode through the solid electrolyte. In addition, a sealing portion 211 is provided on the periphery of the laminated cell 21. The positive electrode tab 21a extends from the sealing portion 211 located at one end side in the length direction of the laminated cell 21, and the negative electrode tab 21b extends from the sealing portion 211 located at the other end side in the length direction of the laminated cell 21. It should be noted that the positive electrode tab 21a and the negative electrode tab 21b can also extend from the sealing portion 211 located at one end side in the length direction of the laminated cell 21. Hereinafter, the positive electrode tab 21a and the negative electrode tab 21b are also collectively referred to as electrode tabs 212. Furthermore, the laminated cell 21 is not limited to a solid electrolyte, and may be a semi-solid electrolyte or a liquid electrolyte.

[0083] like Figure 4As shown, the cell stack 20 is formed by stacking a plurality of laminated cells 21 in the left-right direction. In this embodiment, each laminated cell 21 is arranged so that the electrode tab 212 extends in the front-back direction. Each laminated cell 21 is electrically connected via a bus bar 22 .

[0084] return Figure 2 The intermediate sheet 30 is provided in the middle portion in the stacking direction (here, the left-right direction) of the plurality of laminated cells 21. Two or more intermediate sheets 30 may be provided.

[0085] The pair of end plates 37 are provided at both ends of the plurality of laminated cells 21 in the stacking direction.

[0086] The pair of restraining members 38 are opposed to each other in the vertical direction and connected to the pair of end plates 37 to restrain the plurality of laminated cells 21. Here, the pair of restraining members 38 has a plate shape and covers the plurality of laminated cells 21, the intermediate plate 30, and the pair of end plates 37 from the vertical direction. In this example, the restraining members 38 are plate-shaped, but as long as the end plates 37 can be restrained in the stacking direction, the shape may be a ladder shape, a shape that does not cover the cells, or the like.

[0087] The pair of cover plates 60 are disposed outside the plurality of laminated cells 21 in the front-to-back direction and extend in the stacking direction. When viewed from the front-to-back direction, the cover plates 60 cover the bus bar 22 and the electrode tabs 212 of each laminated cell 21 via the bus bar cover 23 having electrical insulation, thereby protecting the bus bar 22 and the electrode tabs 212.

[0088] return Figure 1 The battery housing 31 includes a battery tray 32 for mounting a plurality of battery modules 10 and an upper cover 33 for covering the upper part of the battery modules 10. Figure 6 , Figure 7 , Fig. 9 As shown, an upper gap 15 is provided between the battery module 10 and the upper cover 33 .

[0089] like Figure 5 As shown, the battery tray 32 includes a bottom plate 321 on which the battery modules 10 are placed, a pair of side frames 322 provided on both left and right sides of the bottom plate 321 , and a front cross beam 333 , a center cross beam 334 , and a rear cross beam 335 connecting the pair of side frames 322 .

[0090] The front crossbeam 333 forms the front wall of the battery case 31, and the rear crossbeam 335 forms the rear wall of the battery case 31. The central crossbeam 334 divides the interior of the battery case 31 into two spaces, front and back. Two battery modules 10 are arranged on the left and right in the front space, and two battery modules 10 are arranged on the left and right in the rear space.

[0091] An upper frame 34 extending in the front-rear direction is mounted above two battery modules 10 located on the left and two battery modules 10 located on the right in the left and right central parts of the battery case 31. A junction box 11 is arranged in front of the upper frame 34, and an auxiliary machine 12 is arranged in the rear of the upper frame 34. The junction box 11 is provided with electronic components such as conductive components, fuses, and contactors that connect the power system inside the battery case 31 to the DC line outside the battery case 31. The auxiliary machine 12 is, for example, a battery ECU.

[0092] In addition, if Figures 6 to 9 As shown, a cover plate 36 is installed below the bottom plate 321 , and a water jacket 40 is formed between the bottom plate 321 and the cover plate 36 .

[0093] The water jacket 40 is provided over substantially the entire surface of the bottom plate 321. When the area in the internal space of the battery case 31 where the battery module 10 is arranged is set as the first partition 51, and the area where the battery module 10 is not arranged is set as the second partition 52, the water jacket 40 is provided over the first partition 51 and the second partition 52. In the first partition, heat exchange is performed between the battery module 10 and the water jacket 40. The battery module 10 and the bottom plate 321 may be in direct contact or may be in indirect contact via a heat transfer material.

[0094] The second partition 52 is provided above the water jacket 40, outside the first partition 51 and on both left and right sides of the first partition 51. That is, the second partition 52 has a left gap 521 between the two battery modules 10 on the left and the side frame 322 on the left, and a right gap 522 between the two battery modules 10 on the right and the side frame 322 on the right.

[0095] In addition, the battery case 31 has a front gap 523 between the two battery modules 10 located on the front side and the front cross beam 333, a central front gap 524 between the two battery modules 10 located on the front side and the central cross beam 334, a central rear gap 526 between the two battery modules 10 located on the rear side and the central cross beam 334, and a rear gap 527 between the two battery modules 10 located on the rear side and the rear cross beam 335. The front gap 523, the central front gap 524, the central rear gap 526, and the rear gap 527 form an air passage that is orthogonal to the extension direction of the left gap 521 and the right gap 522 constituting the second partition 52 and connects the left gap 521 and the right gap 522.

[0096] Water jacket 40 and Fig.11The battery cooling system 100 shown is connected to the battery cooling circuit 18. The battery cooling system 100 includes: the battery cooling circuit 18, which circulates the first cooling medium (for example, LLC) flowing through the water jacket 40; the heat pump circuit 19, which circulates the second cooling medium (for example, cooling medium for air conditioning) different from the first cooling medium; the cooler 42, which can exchange heat between the first cooling medium and the second cooling medium; the fan 13; and the control unit 14, which controls them.

[0097] The battery cooling circuit 18 is provided outside the battery case 31 and connected to the battery case 31 through piping. The battery cooling circuit 18 includes a main flow path 45 including a water jacket 40, a radiator 41, a cooler 42, a heater 43, and an electric pump 44, and a bypass flow path 47 that bypasses the radiator 41 of the main flow path 45.

[0098] The bypass flow path 47 connects the branch portion 46a between the water jacket 40 and the radiator 41 and the confluence portion 46b between the radiator 41 and the cooler 42. A three-way valve 48 is provided at the branch portion 46a. The control unit 14 switches the three-way valve 48 between a bypass disconnection state and a bypass connection state. When the three-way valve 48 is in the bypass disconnection state, the first cooling medium sent from the electric pump 44 circulates in the water jacket 40, the radiator 41, the cooler 42 and the heater 43. On the other hand, when in the bypass connection state, the first cooling medium sent from the electric pump 44 bypasses the radiator 41 and circulates in the water jacket 40, the cooler 42 and the heater 43. The heater 43 is controlled by the control unit 14 to be in the connection state and the disconnection state.

[0099] The battery cooling circuit 18 is driven by the control unit 14 in a stop mode, a heating mode, a normal mode, and a cooling mode. The stop mode is set, for example, when the vehicle is parked. In the stop mode, the electric pump 44 does not operate. The heating mode is set, for example, when the battery is at a low temperature. In the heating mode, by setting the three-way valve 48 to the bypass on state, the battery can be heated by heating the first cooling medium by the heater 43 while cutting off the heat dissipation from the radiator 41. The normal mode is set, for example, when the vehicle is running. In the normal mode, by setting the three-way valve 48 to the bypass off state, the battery can be cooled by dissipating the heat of the cooling medium from the radiator 41. The cooling mode is set, for example, when the temperature of the battery is high when the vehicle is running, or when the vehicle is charged (including fast charging). In the cooling mode, in addition to dissipating the heat of the cooling medium from the radiator 41, the battery can be further cooled by heat exchange between the first cooling medium and the second cooling medium of the heat pump circuit 19 in the cooler 42. During charging or the like, since the heat exchange capacity of the radiator 41 is limited, heat exchange by the cooler 42 becomes effective.

[0100] The heat pump circuit 19 is, for example, a refrigeration cycle for air conditioning of a vehicle. The heat pump circuit 19 includes a main flow path 70 and a battery cooling flow path 80 branching from the main flow path 70. The main flow path 70 includes a compressor 71, a condenser 72, a first stop valve 73, a first expansion valve 74, and a first evaporator 75 in order in the flow direction of the second cooling medium.

[0101] The battery cooling flow path 80 connects a first branch portion 77 located between the condenser 72 and the first stop valve 73 and a first junction portion 78 located between the first evaporator 75 and the compressor 71 .

[0102] The battery cooling flow path 80 is provided with a second branching portion 83 that branches the battery cooling flow path 80 into an evaporator flow path 81 and a cooler flow path 82, and a second converging portion 84 that merges the evaporator flow path 81 and the cooler flow path 82. The cooler flow path 82 includes a second stop valve 85, a second expansion valve 86, and a cooler 42 in the flow direction of the second cooling medium from the second branching portion 83. The evaporator flow path 81 includes a third stop valve 87, a third expansion valve 88, and a second evaporator 17 in the flow direction of the second cooling medium from the second branching portion 83.

[0103] The heat pump circuit 19 controls the first stop valve 73, the second stop valve 85, and the third stop valve 87 to be turned on and off by the control unit 14. When there is a cooling request in the vehicle cabin, the control unit 14 controls the first stop valve 73 to be turned on and the first evaporator 75 to be turned on, and when there is no cooling request in the vehicle cabin, the control unit 14 controls the first stop valve 73 to be turned off and the first evaporator 75 to be turned off.

[0104] In addition, the control unit 14 controls the cooler 42 to be in the on state by turning on the second stop valve 85 when the temperature of the laminated single cell 21 (hereinafter referred to as the single cell temperature) is higher than the single cell cooling start temperature (first threshold value), and controls the cooler 42 to be in the off state by turning on the second stop valve 85 when the single cell temperature is lower than the single cell cooling start temperature. Thus, when the single cell temperature is high, the first cooling medium flowing in the battery cooling circuit 18 is cooled by the cooler 42, thereby improving the cooling capacity of the water jacket 40.

[0105] return Figure 5 When the first cooling medium is supplied to the water jacket 40, the battery module 10 of the first partition 51 is cooled via the bottom plate 321. At this time, the laminated single cell 21 itself abutting against the bottom plate 321 is well cooled, while the electrode tab 212 of the laminated single cell 21 away from the bottom plate 321 is difficult to be cooled, and the temperature of the electrode tab 212 may exceed the threshold value, thereby limiting the current of the battery.

[0106] Therefore, when the temperature of the electrode tab 212 of the laminated single cell 21 (hereinafter referred to as the tab temperature) becomes equal to or higher than the tab cooling start (second threshold) temperature, the control unit 14 controls the second evaporator 17 to be in the on state by controlling the third stop valve 87 to be in the on state, and controls the fan 13 to be in the on state. On the other hand, when the tab temperature is lower than the tab cooling start temperature, the control unit 14 controls the second evaporator 17 to be in the off state by controlling the third stop valve 87 to be in the off state, and controls the fan 13 to be in the off state.

[0107] In the present disclosure, the fan 13 and the second evaporator 17 are provided inside the battery case 31. When the fan 13 is driven, air circulates in the first partition 51 and the second partition 52. Since the electrode tab 212 is in contact with the air circulating in the battery case 31, when the air passes through the second evaporator 17, the heat of the cell terminal is dissipated to the second evaporator 17. Thus, the electrode tab 212 of the laminated cell 21 can be appropriately cooled.

[0108] Two fans 13 are provided inside the battery housing 31 of the present embodiment, one of which is provided in the right gap 522 of the second partition 52 and behind the central cross beam 334, and the other is provided in the left gap 521 of the second partition 52 and in front of the central cross beam 334. The two fans 13 are configured to send air in opposite directions in the front-rear direction. In addition, the second evaporator 17 can be provided at any position as long as it is provided on the battery housing 31 or provided inside the battery housing 31, but in the present embodiment, the second evaporator 17 is provided behind the fan 13 provided in the left gap 521 and adjacent to the fan 13.

[0109] In this embodiment, if Fig.10 As shown, the fan 13 on the right sends air forward, and the fan 13 on the left sends air backward. The air sent from the fan 13 flows forward or backward in the gap around the central crossbeam 334. Therefore, the front of the fan 13 on the right in the right gap 522 becomes a positive pressure area, and the rear becomes a negative pressure area. On the contrary, the front of the fan 13 on the left in the left gap 521 becomes a negative pressure area, and the rear becomes a positive pressure area. As a result, a pressure distribution is formed in the battery case 31 in the left-right direction, which is a negative pressure area from the positive pressure area of ​​the second partition 52 → the first partition 51 (battery module 10) → the second partition 52, so that the air in the battery case 31 can circulate smoothly.

[0110] That is, Fig.10As shown by the arrows, inside the battery case 31, the air sent out from the right fan 13 flows from the front of the right gap 522 (positive pressure area of ​​the right fan 13) through the upper parts of the two battery modules 10 located on the front side (upper gap 15), flows to the front of the left gap 521 (negative pressure area of ​​the left fan 13), and is sucked into the left fan 13. In addition, the air sent out from the left fan 13 flows from the rear of the left gap 521 (positive pressure area of ​​the left fan 13) through the upper parts of the two battery modules 10 located on the rear side (upper gap 15), flows to the rear of the right gap 522 (negative pressure area of ​​the right fan 13), and is sucked into the right fan 13. In this way, the upper part of the laminated single cell 21 (the upper part of the battery module 10) can be cooled.

[0111] In addition, the junction box 11 mounted on the upper frame 34 is arranged above the two battery modules 10 located on the front side, so the junction box 11 is also cooled. In particular, by making the conductive member of the junction box 11 contact with the air circulating in the first partition 51 and the second partition 52, the current limitation caused by the heat of the conductive member can be avoided.

[0112] In addition, part of the air sent from the right fan 13 flows from the front of the right gap 522 (the positive pressure area of ​​the right fan) to the front of the left gap 521 (the negative pressure area of ​​the left fan 13) through the front gap 523 and the central front gap 524, and is sucked into the left fan 13. In addition, part of the air sent from the left fan 13 flows to the rear of the right gap 522 (the negative pressure area of ​​the right fan 13) through the rear gap 527 and the central rear gap 526, and is sucked into the right fan 13. In this way, the electrode tab 212 of the laminated single cell 21 can be cooled.

[0113] More specifically, Fig. 9 As shown, the air passing through the air passages of the front gap 523, the central front gap 524, the rear gap 527, and the central rear gap 526 advances in the space 25 formed between the electrode tab 212 of the laminated cell 21 and the bus bar cover 23 and extending in the stacking direction, while cooling the electrode tab 212 of the laminated cell 21. As described above, by connecting the space 25 formed between the electrode tab 212 of the laminated cell 21 and the bus bar cover 23 in the stacking direction, the electrode tab 212 of the laminated cell 21 located near the cross beams 333 to 335 can be appropriately cooled.

[0114] In the battery pack 1 thus configured, the electrode tabs 212 of the laminated cells 21 are in contact with the air circulating in the battery case 31 in the first partition 51, so that the heat of the electrode tabs 212 of the laminated cells 21 can be dissipated through the air to the second evaporator 17. As a result, the temperature of the electrode tabs 212 can be lowered, so that current limitation due to the temperature of the electrode tabs 212 can be suppressed, and the capacity of the battery can be effectively used.

[0115] In addition, since the upper portion of the laminated single cell 21 dissipates heat to the second evaporator 17 via the air, and the lower portion of the laminated single cell 21 dissipates heat to the water jacket 40 located below the laminated single cell 21 in the first partition 51, the temperature deviation between the upper and lower portions of the laminated single cell 21 can be suppressed.

[0116] Fig.12 and Fig.13 This is a line diagram for explaining battery cooling control. Fig.12 is a timing chart of battery cooling control when rapid charging is started in a state where the battery temperature is lower than the battery cooling start temperature by a predetermined amount or more, and Fig.13 This is a timing chart of the battery cooling control when the rapid charging is started in a state where the cell temperature is close to the cell cooling start temperature.

[0117] The control unit 14 operates the battery cooling circuit 18 in the normal mode in conjunction with the start of the fast charge. Fig.12 As shown, when the fast charging starts and the tab temperature of the laminated single cell 21 reaches the tab cooling start temperature, the control unit 14 controls the second evaporator 17 and the fan 13 to be turned on. That is, when the tab temperature of the laminated single cell 21 is above the tab cooling start temperature, the control unit 14 controls the second evaporator 17 to be turned on by controlling the third stop valve 87 of the heat pump circuit 19 to be turned on, and controls the fan 13 to be turned on. As a result, the rise in the temperature inside the housing is suppressed and the rise in the tab temperature becomes gentle, preventing the tab temperature from reaching the upper limit of the tab temperature.

[0118] Next, when the cell temperature of the laminated cell 21 reaches the cell cooling start temperature, the control unit 14 controls the cooler 42 to be in the on state (the cooling mode described above). That is, when the cell temperature of the laminated cell 21 is above the cell cooling start temperature, the control unit 14 controls the cooler 42 to be in the on state by controlling the second stop valve 85 of the heat pump circuit 19 to be in the on state. As a result, the temperature of the first cooling medium (LLC temperature in the figure, hereinafter referred to as the first cooling medium temperature) decreases, and the rise of the cell temperature is suppressed, so that the cell temperature is prevented from reaching the cell upper limit temperature.

[0119] When the fast charge is completed and the tab temperature of the laminated cell 21 is lower than the tab cooling start temperature, the control unit 14 controls the second evaporator 17 and the fan 13 to be turned off. Next, when the cell temperature of the laminated cell 21 is lower than the cell cooling start temperature, the control unit 14 controls the cooler 42 to be turned off.

[0120] On the other hand, Fig.13 As shown, when the fast charging starts and the cell temperature of the laminated cell 21 reaches the cell cooling start temperature, the control unit 14 controls the cooler 42 to be in the on state. That is, when the cell temperature of the laminated cell 21 is higher than the cell cooling start temperature, the control unit 14 controls the cooler 42 to be in the on state by controlling the second stop valve 85 of the heat pump circuit 19 to be in the on state. As a result, the first cooling medium temperature (LLC temperature in the figure) decreases, and the cell temperature is suppressed from rising, thereby preventing the cell temperature from reaching the cell upper limit temperature.

[0121] Next, when the tab temperature of the laminated cell 21 reaches the tab cooling start temperature, the control unit 14 controls the second evaporator 17 and the fan 13 to be turned on. That is, when the tab temperature of the laminated cell 21 is above the tab cooling start temperature, the control unit 14 controls the second evaporator 17 to be turned on by controlling the third stop valve 87 of the heat pump circuit 19 to be turned on, and controls the fan 13 to be turned on. As a result, the rise in the temperature inside the housing is suppressed and the rise in the tab temperature becomes gentle, preventing the tab temperature from reaching the tab upper limit temperature.

[0122] When the fast charge is completed and the tab temperature of the laminated cell 21 is lower than the tab cooling start temperature, the control unit 14 controls the second evaporator 17 and the fan 13 to be turned off. Next, when the cell temperature of the laminated cell 21 is lower than the cell cooling start temperature, the control unit 14 controls the cooler 42 to be turned off.

[0123] As described above, in the cooling control of the above-mentioned storage battery, the objects for monitoring temperature are different in the cooling of the laminated single cell 21 by the water jacket 40 and the cooling of the electrode tab 212 by the air. The control unit 14 controls the storage battery cooling circuit 18 according to the temperature of the laminated single cell 21, and in the first section 51, the ability of the water jacket 40 to cool the laminated single cell 21 changes according to the temperature of the laminated single cell 21. On the other hand, the control unit 14 controls the second evaporator 17 and the fan 13 according to the temperature of the electrode tab 212, and the ability of the air inside the storage battery case 31 to cool the electrode tab 212 changes according to the temperature of the electrode tab 212. Therefore, compared with the case where the object for monitoring temperature for the operation of the cooler 42 and the object for monitoring temperature for the operation of the second evaporator 17 and the fan 13 are the same object, it is possible to maintain the temperature of the laminated single cell 21 at an appropriate temperature while further effectively suppressing the current limitation due to the temperature of the electrode tab 212.

[0124] In addition, the method for measuring the temperature is not limited to the case where the temperature of the laminated single cell 21 and the electrode tab 212 are directly measured by bringing the temperature sensor into contact with the laminated single cell 21 and the electrode tab 212. The temperature of the laminated single cell 21 and the electrode tab 212 may be estimated based on the temperature of the portion reflecting the temperature of the laminated single cell 21 and the electrode tab 212. For example, the temperature of the electrode tab 212 may be estimated based on the temperature of the air around the single cell terminal. In addition, the temperature of the laminated single cell 21 may be estimated based on the temperature of the cooling medium on the outlet side of the water jacket 40.

[0125] [Second embodiment]

[0126] Next, refer to Fig.14 and Fig.15 A battery pack 1A according to the second embodiment will be described. In the following, only the differences from the battery pack 1 according to the first embodiment will be described. In the drawings, the same reference numerals are given to the same configurations as those in the first embodiment, and description thereof will be omitted.

[0127] like Fig.14 As shown, the battery pack 1A of the second embodiment includes eight battery modules 10A, a junction box 11, an auxiliary machine 12, and a battery case 31 for accommodating them. The eight battery modules 10A are arranged in two rows in the front-to-back direction and in four rows in the left-to-right direction. In addition, the number of battery modules 10A can be set arbitrarily as long as there are two or more, and the arrangement is not particularly limited.

[0128] In the battery module 10A, a pair of end plates arranged at both ends of the stacking direction of the cell stack 20A in which a plurality of square cells 21A are stacked are connected by a pair of restraining members 38A arranged on the side, and the positive terminal 21a1 and the negative terminal 21b1 provided on the upper part of the square cell 21A are covered by the bus bar cover 23A. Between the positive terminal 21a1 and the negative terminal 21b1 and the bus bar cover 23A, a space 25 for air to pass is connected in the stacking direction.

[0129] That is, in the battery module 10A of the second embodiment, the positive electrode terminal 21a1 and the negative electrode terminal 21b1 are provided on the upper part of the square cell 21A. In addition, cylindrical cells may be stacked instead of the square cell 21A.

[0130] In the battery pack 1A thus constructed, Fig.14 As shown by the arrows, when the second evaporator 17 and the fan 13 of the battery case 31 equipped with the battery module 10A are driven, the Fig.10 Similarly, the air sent out from the right fan 13 flows from the front of the right gap 522 (positive pressure area of ​​the right fan 13) through the upper parts of the four battery modules 10 located on the front side (upper gap 15), flows to the front of the left gap 521 (negative pressure area of ​​the left fan 13), and is sucked into the left fan 13. In addition, the air sent out from the left fan 13 flows from the rear of the left gap 521 (positive pressure area of ​​the left fan 13) through the upper parts of the four battery modules 10 located on the rear side (upper gap 15), flows to the rear of the right gap 522 (negative pressure area of ​​the right fan 13), and is sucked into the right fan 13. The air passing through the upper gap 15 cools the positive electrode terminal 21a1 and the negative electrode terminal 21b1 of the square cell 21A while advancing in the space 25 formed between the positive electrode terminal 21a1 and the negative electrode terminal 21b1 of the square cell 21A and the bus bar cover 23A and extending in the stacking direction. Thus, the upper portion of the square cell 21A (the upper portion of the battery module 10A) can be cooled, and the positive electrode terminal 21a1 and the negative electrode terminal 21b1 can be cooled.

[0131] Furthermore, in the present embodiment, part of the air sent by the fan 13 also passes through the front gap 523, the central front gap 524, the rear gap 527, and the central rear gap 526. The air passing through the front gap 523, the central front gap 524, the rear gap 527, and the central rear gap 526 cools the side surfaces of the opposite-type cells 21A (the side surfaces of the battery module 10A).

[0132] As described above, in the battery pack 1A, the positive terminal 21a1 and the negative terminal 21b1 of the square cell 21A are also in contact with the air circulating in the battery case 31 in the first partition 51, so that the heat of the positive terminal 21a1 and the negative terminal 21b1 of the square cell 21A can be dissipated through the air to the second evaporator 17 of the second partition 52. As a result, the temperature of the positive terminal 21a1 and the negative terminal 21b1 can be lowered, so that the current limitation due to the temperature of the positive terminal 21a1 and the negative terminal 21b1 can be suppressed, and the capacity of the battery can be effectively used.

[0133] In addition, the upper part of the square single cell 21A dissipates heat to the second evaporator 17 via the air, and the lower part of the square single cell 21A dissipates heat to the water jacket 40 located below the square single cell 21A in the first partition 51, thereby suppressing the temperature deviation between the upper and lower parts of the square single cell 21A.

[0134] Above, various embodiments have been described with reference to the accompanying drawings, but the present invention is certainly not limited to this example. It should be understood by those skilled in the art that various variations or modifications can be conceived within the scope of the technical solution, and these variations or modifications certainly also belong to the technical scope of the present invention. In addition, the various constituent elements in the above-mentioned embodiments may also be arbitrarily combined within the scope of the gist of the invention.

[0135] For example, the second evaporator 17 and the fan 13 are not limited to being provided inside the battery case 31, but may be provided on the battery case 31. By providing the fan 13 on the battery case 31, it is possible to take air from outside the battery case 31 into the inside. In addition, the number of fans 13 is not limited to two, and one, or three or more may be provided.

[0136] In addition, the water jacket 40 is not limited to the case formed by the bottom plate 321 and the cover plate 36 , and may be a separate water jacket provided externally or may be provided inside the battery case 31 .

[0137] At least the following matters are described in this specification. In addition, although corresponding components and the like in the above-mentioned embodiment are shown in brackets, the present invention is not limited thereto.

[0138] (1) A battery pack (battery pack 1, 1A), wherein:

[0139] The battery pack has:

[0140] A plurality of cells (laminated cell 21, square cell 21A) having a positive electrode terminal (positive electrode tab 21a, positive electrode terminal 21a1) and a negative electrode terminal (negative electrode tab 21b, negative electrode terminal 21b1);

[0141] a plurality of battery modules (battery modules 10, 10A) in which the plurality of single cells are stacked;

[0142] A battery housing (battery housing 31 ) for accommodating the plurality of battery modules;

[0143] a water jacket (water jacket 40 ), which is disposed in the battery housing or inside thereof and allows a first cooling medium to flow through and perform heat exchange with the plurality of battery modules;

[0144] a heat exchanger (second evaporator 17 ), which is disposed in the battery housing or inside thereof and allows the second cooling medium to flow through and perform heat exchange with the air inside; and

[0145] The fan (fan 13) is disposed in the battery case or inside thereof and circulates the air inside.

[0146] According to (1), the cell terminals are in contact with the air circulated in the battery housing by the fan, so that the heat of the cell terminals can be dissipated to the heat exchanger when the air passes through the heat exchanger. In addition, the cell body dissipates heat to the water jacket. As a result, the temperature of the cell terminals and the temperature of the cells can be lowered, so that the current limitation imposed by the temperature of the cell terminals can be suppressed, and the current limitation imposed by the temperature of the cells can be suppressed. As a result, the current limitation of the battery can be suppressed, and the capacity of the battery can be appropriately utilized.

[0147] (2) The battery pack according to (1), wherein:

[0148] The water jacket cools the plurality of battery modules from below,

[0149] The battery housing has:

[0150] a first partition (first partition 51 ), which is provided with the plurality of battery modules and performs heat exchange between the plurality of battery modules and the water jacket;

[0151] a second partition (second partition 52 ), which is located above the water jacket and is not equipped with the plurality of battery modules; and

[0152] A gap (upper gap 15 ) is provided between the plurality of cells and the inner wall of the battery case and allows air to pass through.

[0153] According to (2), air can be circulated appropriately.

[0154] (3) The battery pack according to (2), wherein:

[0155] The battery housing contains a junction box (junction box 11).

[0156] The junction box is configured so that air circulated in the first section and the second section by the fan comes into contact with a conductive component of the junction box.

[0157] According to (3), since the conductive member of the junction box is also cooled by the flow of air in the battery case, it is possible to suppress the current limitation during rapid charging or the like.

[0158] (4) The battery pack according to (2), wherein:

[0159] The second partition is located outside the first partition and on both sides of the first partition.

[0160] The heat exchanger and the fan are disposed in the second partition.

[0161] According to (4), since the heat exchanger and the fan are provided in the second partition used for the collision stroke where no battery module is configured, the space in the battery pack can be used more effectively compared to the case where the fan is provided on the battery module (the first partition), and an increase in the height of the battery pack can be suppressed.

[0162] (5) The battery pack according to (4), wherein:

[0163] The fans are respectively arranged in the second partitions,

[0164] The second partitions respectively have:

[0165] a positive pressure region located on the side of the fan from which air is discharged, relative to the fan; and

[0166] a negative pressure region, which is located on the side of the fan where the air is introduced into the fan,

[0167] The positive pressure region of the second subarea on one side and the negative pressure region of the second subarea on the other side are opposed to each other via the first subarea.

[0168] The negative pressure region of the second subregion on one side and the positive pressure region of the second subregion on the other side face each other with the first subregion interposed therebetween.

[0169] According to (5), a pressure distribution of the positive pressure region of the second section → the first section (battery module) → the negative pressure region of the second section is formed, and the circulation of air in the battery case can be made smoother.

[0170] (6) The battery pack according to (1), wherein:

[0171] The plurality of battery modules include a terminal insulation cover (bus bar cover 23, 23A) that covers a cell terminal (electrode tab 212) of at least one of the positive electrode terminal and the negative electrode terminal of the cell.

[0172] A space (space 25 ) extending in the stacking direction of the single cells is provided between the terminal insulating cover and the single cell terminal.

[0173] According to (6), since the space around the cell terminals serves as an air passage, the cell terminals can be effectively cooled while insulating the cell terminals.

[0174] (7) The battery pack according to (2), wherein:

[0175] The second partition is located outside the first partition and on both sides of the first partition.

[0176] An air passage (front gap 523, central front gap 524, central rear gap 526, rear gap 527) is formed between adjacent battery modules or between the battery modules and cross beams (front cross beam 333, central cross beam 334, rear cross beam 335) and is orthogonal to the extension direction of the second partition and connects the second partition on one side with the second partition on the other side.

[0177] When there are cell terminals on both sides of a cell, the position of one terminal is close to other battery modules or a cross beam. According to (7), by providing an air passage between adjacent battery modules or between a battery module and a cross beam, the cell terminal on the side close to other battery modules or a cross beam can be effectively cooled compared to a case where no air passage is provided and the battery modules are in close contact with each other.

[0178] (8) A battery cooling system (battery cooling system 100), wherein:

[0179] The battery cooling system comprises:

[0180] The battery pack according to any one of (1) to (7);

[0181] a cooling medium circuit (battery cooling circuit 18 ) for circulating the first cooling medium flowing in the water jacket;

[0182] a heat pump circuit (heat pump circuit 19) for circulating the second cooling medium flowing through the heat exchanger;

[0183] A second heat exchanger (cooler 42), which is capable of performing heat exchange between the first cooling medium and the second cooling medium; and

[0184] A control unit (control unit 14 ) controls the heat exchanger, the second heat exchanger, and the fan.

[0185] According to (8), the first cooling medium transfers heat to the heat pump circuit via the second cooling medium in the second heat exchanger, and the air in the battery case also transfers heat to the heat exchanger of the heat pump circuit. Therefore, the interior of the battery case can be appropriately cooled by a single heat pump circuit.

[0186] (9) The battery cooling system according to (8), wherein:

[0187] The control unit controls the second heat exchanger to be in an on state when the temperature of the battery cell is higher than a first threshold value (battery cell cooling start temperature),

[0188] The control unit controls the heat exchanger and the fan to be turned on when the terminal temperature of the battery cell is higher than a second threshold value (tab cooling start temperature).

[0189] According to (9), the objects for monitoring temperature in the cooling of the single cell by the water jacket and the cooling of the single cell terminal by the air are different, the ability of the water jacket to cool the single cell changes according to the temperature of the single cell, and the ability of the air in the battery case to cool the single cell terminal changes according to the temperature of the single cell terminal. As a result, the temperature of the single cell can be maintained at an appropriate temperature while further effectively suppressing the current limitation imposed by the temperature of the single cell terminal. In addition, the method for measuring the temperature is not limited to the case where the temperature of the single cell and the temperature of the single cell terminal are directly measured by making the temperature sensor contact with the single cell and the single cell terminal, and the temperature of the single cell and the single cell terminal can also be estimated based on the temperature of the part reflecting the temperature of the single cell and the single cell terminal. For example, the temperature of the single cell terminal can also be estimated based on the temperature of the air around the single cell terminal. In addition, the temperature of the single cell can also be estimated based on the temperature of the cooling medium on the outlet side of the water jacket.

[0190] (10) The battery cooling system according to (8), wherein:

[0191] The heat pump circuit includes a branch portion (second branch portion 83 ) that branches off the flow path to the heat exchanger, upstream of the flow path to the second heat exchanger.

[0192] According to (10), by providing the branch portion upstream of the second heat exchanger, the cold second cooling medium before heat exchange in the second heat exchanger can be supplied to the heat exchanger.

Claims

1. A battery pack, wherein: The battery pack has: A plurality of battery cells having a positive terminal and a negative terminal; a plurality of battery modules on which the plurality of single cells are stacked; A battery housing, which accommodates the plurality of battery modules; a water jacket disposed in the battery housing or inside thereof and allowing a first cooling medium to flow through and perform heat exchange with the plurality of battery modules; a heat exchanger disposed in the battery housing or inside thereof and allowing the second cooling medium to flow through and perform heat exchange with the air inside; and A fan is disposed in the battery case or inside thereof and circulates the air inside.

2. The battery pack according to claim 1, wherein: The water jacket cools the plurality of battery modules from below, The battery housing has: a first partition, which is provided with the plurality of battery modules and performs heat exchange between the plurality of battery modules and the water jacket; a second partition, which is located above the water jacket and is not equipped with the plurality of battery modules; as well as A gap is provided between the plurality of cells and an inner wall of the battery case and is capable of allowing air to pass through.

3. The battery pack according to claim 2, wherein: A junction box is housed in the battery housing. The junction box is configured so that air circulated in the first section and the second section by the fan comes into contact with a conductive component of the junction box.

4. The battery pack according to claim 2, wherein: The second partition is located outside the first partition and on both sides of the first partition. The heat exchanger and the fan are disposed in the second partition.

5. The battery pack according to claim 4, wherein: The fans are respectively arranged in the second partitions, The second partitions respectively have: a positive pressure region located on the side of the fan from which air is discharged, relative to the fan; and a negative pressure region, which is located on the side of the fan where the air is introduced into the fan, The positive pressure region of the second subarea on one side and the negative pressure region of the second subarea on the other side are opposed to each other via the first subarea. The negative pressure region of the second subregion on one side and the positive pressure region of the second subregion on the other side face each other with the first subregion interposed therebetween.

6. The battery pack according to claim 1, wherein: The plurality of battery modules include a terminal insulation cover that covers at least one of the positive electrode terminal and the negative electrode terminal of the single cell. A space extending in a stacking direction of the single cells is provided between the terminal insulating cover and the single cell terminal.

7. The battery pack according to claim 2, wherein: The second partition is located outside the first partition and on both sides of the first partition. An air passage is formed between adjacent battery modules or between the battery module and the crossbeam, the air passage being orthogonal to the extending direction of the second section and connecting the second section on one side with the second section on the other side.

8. A battery cooling system, wherein: The battery cooling system comprises: The battery pack according to any one of claims 1 to 7; a cooling medium circuit for circulating the first cooling medium flowing through the water jacket; a heat pump circuit for circulating the second cooling medium flowing through the heat exchanger; a second heat exchanger capable of performing heat exchange between the first cooling medium and the second cooling medium; as well as A control unit controls the heat exchanger, the second heat exchanger, and the fan.

9. The battery cooling system according to claim 8, wherein: The control unit controls the second heat exchanger to be in an on state when the temperature of the single battery cell is higher than a first threshold value, The control unit controls the heat exchanger and the fan to be turned on when the terminal temperature of the battery cell is higher than a second threshold value.

10. The battery cooling system according to claim 8, wherein: The heat pump circuit includes a branch portion that branches off a flow path that flows toward the heat exchanger, upstream of a flow path that flows toward the second heat exchanger.

Images