JP2020102345A - Power storage device - Google Patents

Abstract

To provide a power storage device including a power storage cell and a plurality of power storage cells adjacent to the power storage cell, where temperature rise to a high temperature of the plurality of power storage cells is inhibited from being caused at the same timing as temperature rise to a high temperature of the power storage cell.SOLUTION: A power storage device comprises: a first power storage cell 7A; a second power storage cell 7B provided at an interval with the first power storage cell 7A; a third power storage cell 7C provided at an interval with the first power storage cell 7A and provided on the opposite side to the second power storage cell 7B with respect to the first power storage cell 7A; a first plate 10 provided between the first power storage cell 7A and the second power storage cell 7B; and a second plate 11 provided between the first power storage cell 7A and the third power storage cell 7C. Thermal conductivity of the first plate 10 differs from thermal conductivity of the second plate 11.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a power storage device.

The power storage device includes a plurality of power storage cells arranged in one direction. In recent years, various power storage devices have been proposed in order to ensure the heat dissipation of each power storage cell.

For example, the power storage device described in Japanese Unexamined Patent Application Publication No. 2017-076504 includes a plurality of power storage cells, a pair of brackets that sandwich the plurality of power storage cells, a plate-shaped heat transfer plate disposed between adjacent power storage cells, and And a heat conducting member.

Specifically, the plurality of power storage cells include a first power storage cell, a second power storage cell, and a third power storage cell, and the first power storage cell is arranged between the second power storage cell and the third power storage cell. Has been done.

A heat transfer plate and a heat conducting member are arranged between the first power storage cell and the second power storage cell and between the second power storage cell and the third power storage cell.

The heat conducting member includes a first heat conducting portion and a second heat conducting portion formed in a frame shape. The 2nd heat conduction part is arranged in the frame of the 1st heat conduction part. The second heat conducting portion is a solid and elastic member formed by hardening a liquid heat conducting material (TIM: Thermal Interface Material).

In the power storage device configured as described above, even if each power storage cell thermally expands, the second heat conducting member disposed adjacent thereto deforms to absorb the thermal expansion amount of each power storage cell. You can As a result, the movement of the storage cells is suppressed.

JP, 2017-076504, A

In the power storage device configured as described above, for example, an internal short circuit may occur in the first power storage cell. At that time, the temperature of the first power storage cell may be high.

When the temperature of the first power storage cell rises, the heat of the first power storage cell is transferred to the second power storage cell and the third power storage cell through the heat transfer plate and the heat conducting member.

Here, the heat transfer plate and the heat conductive member arranged between the first power storage cell and the second power storage cell and the heat transfer plate and the heat conductive member arranged between the first power storage cell and the third power storage cell have the same configuration. Is.

Therefore, both the second power storage cell and the third power storage cell similarly increase in temperature. As a result, the temperature of the second storage cell and the third storage cell becomes high, and the high temperature gas is ejected from each storage cell at the same timing.

If the high temperature gas is ejected from the two power storage cells adjacent to the first power storage cell at the same timing, it is necessary to provide the power storage device with an exhaust duct having a large exhaust capacity.

Further, generally, the power storage device includes a housing case that houses a plurality of power storage cells. When the second power storage cell and the third power storage cell exhaust the high temperature gas at the same timing as described above, the internal pressure in the storage case is increased. Is likely to be very high. Therefore, it is necessary to provide a valve or the like in the housing case itself so that the internal pressure in the housing case does not become too high.

As described above, the temperature of a plurality of power storage cells becomes high at the same timing, which may cause various problems.

The present disclosure has been made in view of the above problems, and an object thereof is an electricity storage device in which a plurality of electricity storage cells that have become high in temperature and an adjacent plurality of electricity storage cells are prevented from becoming high temperature at the same timing. Is to provide.

The power storage device is provided with a first power storage cell, a second power storage cell spaced apart from the first power storage cell, a second power storage cell spaced apart from the first power storage cell, and a second power storage cell with respect to the first power storage cell. A third storage cell provided on the opposite side of the cell, a first plate provided between the first storage cell and the second storage cell, and a first plate provided between the first storage cell and the third storage cell Two plates are provided, and the thermal conductivity of the first plate and the thermal conductivity of the second plate are different.

According to the above power storage device, when the first power storage cell has a high temperature, the timing at which the second power storage cell has a high temperature and the timing at which the third power storage cell has a high temperature can be shifted.

According to the power storage device of the present disclosure, it is possible to prevent a plurality of power storage cells adjacent to a power storage cell having a high temperature from reaching a high temperature at the same timing.

FIG. 3 is a cross-sectional view schematically showing power storage device 1. 3 is a perspective view showing a storage cell 7. FIG. 3 is a cross-sectional view showing the heat absorption plate 10. FIG. It is a graph which shows the temperature transition of electricity storage cells 7A, 7B, and 7C. 6 is a graph showing changes in internal pressure in the storage case 2. FIG. 6 is a cross-sectional view showing a power storage device 1A according to a comparative example. FIG. 9 is a cross-sectional view schematically showing a power storage device 1B according to Modification 1. 9 is a cross-sectional view schematically showing a power storage device 1C according to Modification 2. FIG. FIG. 11 is a cross-sectional view schematically showing a power storage device 1D according to Modification 3. It is a partial cross section figure which shows the structure of the cooling plate 4D and its circumference.

The power storage device according to the present embodiment will be described with reference to FIGS. 1 to 10. Among the configurations shown in FIGS. 1 to 10, the same or substantially the same configurations are designated by the same reference numerals, and the duplicated description will be omitted. Note that in the structure described in the embodiment, a structure corresponding to a structure described in a claim may be described in parentheses together with a structure in the claim.

FIG. 1 is a cross-sectional view schematically showing power storage device 1. Power storage device 1 is provided, for example, on the upper surface of floor panel 9 of the vehicle. Power storage device 1 includes a housing case 2, a power storage module 3, a cooling plate 4, and an exhaust duct 8.

The housing case 2 may be made of metal such as aluminum or aluminum alloy, or may be made of resin containing carbon fiber. The electricity storage module 3 and the cooling plate 4 are housed in the housing case 2. The exhaust duct 8 communicates the inside of the housing case 2 with the outside of the vehicle.

Cooling plate 4 is arranged on the bottom surface side of power storage module 3, and power storage module 3 is arranged on the upper surface of cooling plate 4. The cooling plate 4 is made of, for example, metal.

The electricity storage module 3 includes end plates 5 and 6, a plurality of electricity storage cells 7, a plurality of heat absorbing plates 10, and a plurality of heat insulating plates 11.

The plurality of electricity storage cells 7 are arranged at intervals in the arrangement direction D1, and the electricity storage module 3 is elongated in the arrangement direction D1. The end plate 5 is arranged on one end side of the electricity storage module 3, and the end plate 6 is arranged on the other end side of the electricity storage module 3.

The plurality of power storage cells 7, the plurality of heat absorbing plates 10, and the plurality of heat insulating plates 11 are arranged between the end plates 5 and 6. The end plate 5 and the end plate 6 are connected to each other by a metal restraining band (not shown).

The plurality of power storage cells 7 and the like arranged between the end plates 5 and 6 are fixed between the end plates 5 and 6 by the restraining force applied from the end plates 5 and 6. There is.

FIG. 2 is a perspective view showing the electricity storage cell 7. The electricity storage cell 7 includes a cell case 15 and an electrode body 16. The cell case 15 is made of aluminum or an aluminum alloy. In the example shown in FIG. 2, the cell case 15 is formed in a flat rectangular parallelepiped shape. The cell case 15 includes an upper surface 20, a lower surface 21, main surfaces 22 and 23, and side surfaces 24 and 25.

The main surface 22 and the main surface 23 are arranged in the arrangement direction D1. The side surface 24 and the side surface 25 are arranged in the width direction W of the electricity storage cell 7.

A positive electrode terminal 26 and a negative electrode terminal 27 are provided on the upper surface 20, and an explosion-proof valve 28 is formed on the upper surface 20. When the internal pressure inside the cell case 15 becomes high, the explosion-proof valve 28 breaks and connects the internal space of the cell case 15 and the outside of the cell case 15.

The positive electrode terminal 26 and the negative electrode terminal 27 are electrically connected to the electrode body 16 provided in the cell case 15. The electrode body 16 includes a positive electrode sheet, a separator, and a negative electrode sheet. An electrolytic solution (not shown) is also stored in the cell case 15.

Returning to FIG. 1, the heat absorbing plate 10 is provided on one of the main surfaces 22 and 23 of the electricity storage cell 7, and the heat insulating plate 11 is provided on the other main surface.

Further, the heat absorbing plate 10 and the heat insulating plate 11 are arranged alternately as going from the end plate 5 to the end plate 6.

For example, the plurality of power storage cells 7 include a power storage cell (first power storage cell) 7A, a power storage cell (second power storage cell) 7B, and a power storage cell (third power storage cell) 7C. Power storage cell 7B is provided with a space from power storage cell 7A, and power storage cell 7C is provided on the opposite side of power storage cell 7A from power storage cell 7B.

A heat absorption plate 10 is arranged between the electricity storage cells 7A and 7B, and a heat insulating plate 11 is arranged between the electricity storage cells 7A and 7C.

FIG. 3 is a cross-sectional view showing the heat absorbing plate 10. The heat absorption plate 10 includes, for example, a metal plate 30 and an insulating coating 31 that covers the surface of the metal plate 30. The insulating coating 31 is made of resin, and for example, polypropylene resin or polyethylene resin can be adopted.

The heat insulating plate 11 is formed of, for example, a composite layer containing fibers and silica airgel. Silica airgel has a nano-sized porous structure. Therefore, the heat absorbing plate 10 has a higher thermal conductivity than the heat insulating plate 11.

In FIG. 1, the cooling plate 4 may be a metal plate, or may be an apparatus having a refrigerant pipe through which a refrigerant flows. Then, the cooling plate 4 cools the electricity storage cells 7 arranged on the upper surface of the cooling plate 4. An insulating sheet or the like is provided between each storage cell 7 and the cooling plate 4.

In power storage device 1 configured as described above, for example, when a large impact force is applied to power storage cell 7A, an internal short circuit or the like may occur in an electrode body or the like in power storage cell 7A.

When an internal short circuit or the like occurs in the electrode body, the temperature inside the storage cell 7A rapidly rises and the storage cell 7A becomes high in temperature. Further, high temperature gas is generated in the storage cell 7A, and the internal pressure in the cell case 15 of the storage cell 7A rises. When the internal pressure in the cell case 15 rises, the exothermic reaction in the electricity storage cell 7A is promoted, and high temperature gas is further generated. Then, when the internal pressure of the cell case 15 of the electricity storage cell 7A becomes higher than a predetermined pressure, the explosion-proof valve 28 shown in FIG. 2 breaks. When the explosion-proof valve 28 breaks, a large amount of high temperature gas is ejected from the electricity storage cell 7A from the explosion-proof valve 28, and the internal pressure in the electricity storage cell 7A decreases. When the internal pressure in the electricity storage cell 7A decreases, the exothermic reaction in the electricity storage cell 7A easily becomes calm.

Therefore, the temperature rise of the electricity storage cell 7A subsides, and the temperature of the electricity storage cell 7A starts to decrease over time. Further, the amount of gas ejected from the electricity storage cell 7A also decreases with the passage of time.

FIG. 4 is a graph showing changes in temperature of the storage cells 7A, 7B, 7C. In FIG. 4, the vertical axis represents temperature and the horizontal axis represents time. The graph line L1 shows the temperature transition of the electricity storage cell 7A, and the graph line L2 shows the temperature transition of the electricity storage cell 7B. Similarly, the graph line L3 shows the temperature transition of the electricity storage cell 7C.

Then, time T1 is a timing at which an internal short circuit occurs in the storage cell 7A and the temperature of the storage cell 7A starts to rise.

As shown by the graph line L1, it can be seen that the temperature of the electricity storage cell 7A sharply rises between the time T1 and the time T2. After that, it can be seen that the temperature of the electricity storage cell 7A decreases with the passage of time.

FIG. 5 is a graph showing a transition of the internal pressure in the housing case 2. In FIG. 5, the vertical axis represents the internal pressure in the housing case 2, and the horizontal axis represents time. Time T10 indicates the timing at which the high temperature gas is ejected from the electricity storage cell 7A.

When the high temperature gas starts to spout from the electricity storage cell 7A, the internal pressure in the housing case 2 rises. At this time, the exhaust duct 8 exhausts the high temperature gas from the power storage cell 7A to the outside, while the amount of the high temperature gas ejected from the power storage cell 7A is larger, so the internal pressure in the housing case 2 rises.

On the other hand, at time T11, the ejection amount of the hot gas ejected from the electricity storage cell 7A decreases, and the internal pressure in the housing case 2 starts to decrease.

Returning to FIG. 1, since the heat absorption plate 10 has a higher thermal conductivity than the heat insulating plate 11 when the temperature of the electricity storage cell 7A is high, when the temperature of the electricity storage cell 7A rises, the heat absorption plate 10 changes from the electricity storage cell 7A to the heat absorption plate 10. The amount of heat transferred is larger than the amount of heat transferred from the electricity storage cell 7 to the heat insulating plate 11.

As a result, the amount of heat transferred to the storage cell 7B through the heat absorbing plate 10 is larger than the amount of heat transferred to the storage cell 7C through the heat insulating plate 11.

Therefore, the temperature of the storage cell 7B starts to rise with the passage of time. When the temperature of power storage cell 7B rises, an exothermic reaction is promoted in power storage cell 7B, and the temperature of power storage cell 7B rapidly rises. When the temperature of power storage cell 7B rises, a high temperature gas is generated in power storage cell 7B, and the internal pressure in power storage cell 7B increases. When the internal pressure in power storage cell 7B becomes equal to or higher than a predetermined value, explosion-proof valve 28 of power storage cell 7B breaks, high-temperature gas is ejected from power storage cell 7B, and the internal pressure in power storage cell 7B decreases. When the internal pressure in power storage cell 7B decreases, the exothermic reaction is suppressed, the temperature rise of power storage cell 7B slows down, and the temperature of power storage cell 7B begins to decrease over time.

In FIG. 4, the temperature of the storage cell 7B rises sharply between time T3 and time T4. After time T4, the temperature of power storage cell 7B starts to decrease. In FIG. 5, at time T12, the high temperature gas is ejected from the electricity storage cell 7B, and the internal pressure in the housing case 2 rises. Then, at time T13, the ejection of the high-temperature gas from the electricity storage cell 7B becomes calm, and the internal pressure in the housing case 2 starts to decrease.

Returning to FIG. 1, the heat insulating plate 11 has a lower thermal conductivity than the heat absorbing plate 10, but the heat from the power storage cell 7A is transferred to the power storage cell 7C with the passage of time, and the temperature of the power storage cell 7C rises. To do.

At this time, since the thermal conductivity of the heat insulating plate 11 is lower than the thermal conductivity of the heat absorbing plate 10, the heat from the power storage cell 7A causes the temperature of the power storage cell 7C to start rising. Therefore, it is later than the timing at which the temperature of the storage cell 7B starts to rise.

Then, when the temperature of the electricity storage cell 7C rises, as in the case of the electricity storage cells 7A and 7B, the exothermic reaction is promoted in the electricity storage cell 7C, the temperature of the electricity storage cell 7C rapidly rises, and the high temperature in the electricity storage cell 7C. Gas is generated. As a result, the explosion-proof valve 28 of the electricity storage cell 7C is broken, and hot gas is ejected from the electricity storage cell 7C. When the high temperature gas is ejected from the electricity storage cell 7C, the temperature of the electricity storage cell 7C starts to decrease with the lapse of time thereafter, and the amount of the high temperature gas ejected from the electricity storage cell 7C is reduced.

In FIG. 4, at time T5, the temperature of power storage cell 7C begins to rise rapidly. At this time, the temperature of the storage cell 7B is starting to drop. Then, the temperature of the electricity storage cell 7C rises from the time T5 to the time T6, and thereafter, the temperature of the electricity storage cell 7C decreases with the passage of time.

In FIG. 5, at time T14, the high temperature gas is ejected from the electricity storage cell 7C and the internal pressure in the housing case 2 rises. At this time, the ejection of the high-temperature gas from the electricity storage cell 7B has calmed down. Therefore, at the timing when the high temperature gas is ejected from the electricity storage cell 7C, the internal pressure in the housing case 2 is lowered to some extent.

Therefore, even if the high temperature gas is ejected from the electricity storage cell 7C, the internal pressure in the housing case 2 is prevented from becoming too high. After that, from time T15, the ejection of the high-temperature gas from the electricity storage cell 7C has subsided, and the internal pressure in the housing case 2 has dropped.

In the example shown in FIG. 5, the internal pressure in power storage device 1 is maximum internal pressure P1 at time T11.

FIG. 6 is a cross-sectional view showing a power storage device 1A according to a comparative example. Power storage device 1A is substantially the same as power storage device 1 except for the configuration of power storage module 3.

Power storage device 1A includes a power storage module 3A. The power storage module 3A includes a plurality of power storage cells 7, and a heat insulating plate 11 is provided between the power storage cells 7.

That is, the heat insulating plates 11 are all provided between the power storage cells 7 that are adjacent to each other in the array direction D1, and the heat insulating plates 11 are not provided in the power storage device 1A.

Power storage device 1A includes power storage cells 7D, 7E, 7F corresponding to power storage cells 7A, 7B, 7C of power storage device 1.

A heat insulating plate 11A is provided between the power storage cells 7D and 7E, and a heat insulating plate 11B is provided between the power storage cells 7D and 7F. The heat insulating plate 11A and the heat insulating plate 11B have substantially the same configuration.

In this electricity storage device 1A, when an internal short circuit occurs in the electrode body of electricity storage cell 7D, the temperature of electricity storage cell 7D rises.

Here, when the temperature of power storage cell 7D rises, heat from power storage cell 7D is transferred to power storage cell 7E through heat insulating plate 11A, and heat from power storage cell 7D is transferred to power storage cell 7F through heat insulating plate 11B.

At this time, since the heat insulating plate 11A and the heat insulating plate 11B are substantially the same, a large difference is unlikely to occur between the amount of heat transferred to the power storage cell 7E and the amount of heat transferred to the power storage cell 7F.

As a result, the temperature of the electricity storage cells 7E and 7F rises in the same manner as each other. Along with this, a large difference is unlikely to occur between the timing at which the high temperature gas is ejected from the electricity storage cell 7E and the timing at which the high temperature gas is ejected from the electricity storage cell 7F.

The graph line L12 shown in FIG. 5 shows the time transition of the internal pressure in the housing case 2 of the power storage device 1A.

In graph line L12, at time T10, high-temperature gas is ejected from power storage cell 7D, the internal pressure in power storage device 1A rises, and at time T11, the internal pressure in power storage device 1A starts to drop. In this way, between time T10 and time T11, the transition of the internal pressure of power storage device 1A and the transition of the internal pressure of power storage device 1 substantially match.

At time T16, the high temperature gas is ejected from the electricity storage cell 7E, and the internal pressure in the electricity storage device 1A starts to rise. In the example shown in FIG. 5, at time T17, the ejection of the high-temperature gas from power storage cell 7E subsides, and from time T17, the internal pressure in power storage device 1A begins to drop. On the other hand, at time T18 immediately after time T17, high temperature gas is ejected from the electricity storage cell 7F.

As described above, in power storage device 1A, high-temperature gas is ejected at timings close to power storage cells 7E and 7F arranged on both sides of power storage cell 7D that initially has a high temperature. As a result, at time T19, the internal pressure in power storage device 1A becomes maximum internal pressure P2.

Here, the maximum internal pressure P1 of power storage device 1 is lower than the maximum internal pressure P2 of power storage device 1A. That is, in the power storage device 1 according to the present embodiment, the maximum internal pressure P1 should be kept low because the timings at which the high temperature gas is ejected from the power storage cell 7A that has reached a high temperature and the two adjacent power storage cells 7B and 7C are different. You can

By suppressing the maximum internal pressure P1 to be low, it is possible to suppress an increase in the exhaust capacity required for the exhaust duct 8 and reduce the cost of the exhaust duct 8.

Further, when the maximum internal pressure P1 is high, it is necessary to increase the rigidity of the housing case 2 of the power storage device 1, while in the present embodiment, the maximum internal pressure P1 can be suppressed to a low value. Manufacturing cost can be reduced.

Thus, in the first embodiment, when heat storage cell 7A reaches a high temperature, heat absorption plate 10 and heat insulation plate 11 are used to transfer the amount of heat transferred from power storage cell 7A to power storage cell 7B to the power storage cell 7A. The amount of heat transferred to the storage cell 7B is different.

(Modification 1)
FIG. 7 is a cross-sectional view schematically showing a power storage device 1B according to Modification 1. Power storage device 1B includes a power storage module 3B, and is configured in the same manner as power storage device 1 except for the power storage module 3B.

The power storage module 3B includes a plurality of power storage cells 7 and a plurality of heat insulating plates 11, and the plurality of power storage cells 7 include a power storage cell 7A, a power storage cell 7B, and a power storage cell 7C.

The electricity storage cells 7A and 7B are in contact with each other, and the heat insulating plate 11 is disposed between the electricity storage cells 7A and 7C.

Therefore, for example, when the temperature of power storage cell 7A becomes high, the amount of heat transferred from power storage cell 7A to power storage cell 7B is larger than the amount of heat transferred from power storage cell 7A to power storage cell 7C. As a result, even if the electricity storage cells 7B and 7C become high in temperature over time, the electricity storage cell 7B becomes high in temperature and the timing at which high temperature gas is ejected from the electricity storage cell 7B and the electricity storage cell 7C become high in temperature. The timing at which the exhaust gas is ejected from the electricity storage cell 7C can be shifted.

An insulating film much thinner than the heat insulating plate 11 is arranged between the electricity storage cells 7A and 7B to ensure insulation between the electricity storage cells 7A and 7B. Good. This insulating film has a higher thermal conductivity than the heat insulating plate 11.
(Modification 2)
FIG. 8 is a sectional view schematically showing a power storage device 1C according to Modification 2. Power storage device 1C includes a power storage module 3C, and is configured in the same manner as power storage device 1 except for the power storage module 3C.

The power storage module 3C includes a plurality of power storage cells 7 and a plurality of heat insulating plates 18 and 19. The thickness of the heat insulating plate 18 in the arrangement direction D1 is smaller than the thickness of the heat insulating plate 19.

In each electricity storage cell 7, the heat insulating plate 18 is provided on one of the main surfaces 22 and 23 arranged in the arrangement direction D1, and the heat insulating plate 19 is provided on the other main surface.

Therefore, for example, a heat insulating plate 18 is provided between the power storage cells 7A and 7B, and a heat insulating plate 19 is provided between the power storage cells 7A and 7C.

Since the heat insulating plate 18 is thinner than the heat insulating plate 19, the amount of heat transferred from the power storage cell 7A to the power storage cell 7B is greater than the amount of heat transferred from the power storage cell 7A to the power storage cell 7C when the power storage cell 7A has a high temperature. ..

As a result, even if the electricity storage cells 7B and 7C become high in temperature over time, the electricity storage cell 7B becomes high in temperature and the timing at which high temperature gas is ejected from the electricity storage cell 7B and the electricity storage cell 7C become high in temperature. The timing at which the exhaust gas is ejected from the cell 7C can be shifted.
(Modification 3)
FIG. 9 is a cross-sectional view schematically showing a power storage device 1D according to Modification 3. Power storage device 1D includes a power storage module 3D and a cooling plate 4D, and the configurations other than power storage module 3D and cooling plate 4D are the same as those of power storage device 1.

In the example shown in FIG. 9, power storage module 3D includes power storage cells 7G, 7H, 7I, 7J, 7K, 7L, 7M, 7N. The storage cells 7G, 7H, 7I, 7J, 7K, 7L, 7M, 7N are sequentially arranged from the end plate 5 toward the end plate 6.

FIG. 10 is a partial cross-sectional view showing the configuration of the cooling plate 4D and its surroundings. The cooling plate 4D includes the housing 40, and the refrigerant C flows in the housing 40.

The housing 40 includes an upper wall 41, and the storage cells 7G, 7H, 7I, 7J, 7K, 7L, 7M, 7N are arranged on the upper surface of the upper wall 41.

The upper wall 41 is formed with thin portions 42A, 42B and thick portions 43A, 43B, 43C. The thin portions 42A, 42B and the thick portions 43A, 43B, 43C are arranged alternately in the arrangement direction D1, and the thin portions 42A, 42B and the thick portions 43A, 43B, 43C extend in the width direction W. Is formed in. The thin portions 42A, 42B are thinner than the thick portions 43A, 43B, 43C.

The storage cell 7G is arranged on the upper surface of the thick portion 43A, and the storage cells 7H, 7I are arranged on the upper surface of the thin portion 42A. Storage cells 7J and 7K are provided on the upper surface of thick portion 43B, and storage cells 7L and 7M are provided on the upper surface of thin portion 42B. The electricity storage cell 7N is provided on the upper surface of the thick portion 43C.

In the power storage device 1D configured as described above, when the coolant C flows in the housing 40, the power storage cells 7G, 7H, 7I, 7J, 7K, 7L, 7M, 7N are cooled through the upper wall 41.

At this time, the storage cells 7G, 7J, 7K, 7N are cooled through the thick portions 43A, 43B, 43C, and the storage cells 7H, 7I, 7L, 7M are cooled through the thin portions 42A, 42B. At this time, since the thin portions 42A, 42B are thinner than the thick portions 43A, 43B, 43C, the storage cells 7H, 7I, 7L, 7M are more easily cooled than the storage cells 7G, 7J, 7K, 7N.

Then, for example, it is assumed that an internal short circuit occurs in the electricity storage cell 7K and the electricity storage cell 7K becomes high in temperature. At this time, heat is transferred from power storage cell 7K to power storage cell 7L and power storage cell 7J. Since the power storage cell 7L is more easily cooled than the power storage cell 7J, the power storage cell 7L is unlikely to have a higher temperature than the power storage cell 7J, and the timing at which the power storage cell 7J becomes high and the timing at which the power storage cell 7L becomes high can be shifted. it can.

As a result, even if the high temperature gas is ejected from the electricity storage cell 7J and the electricity storage cell 7L, the high temperature gas is ejected from the electricity storage cell 7L after a predetermined time has elapsed after the high temperature gas was ejected from the electricity storage cell 7J. Become. In the above example, the timing at which the storage cell 7J is at a high temperature and the timing at which the storage cell 7L is at a high temperature are shifted by making the thickness of the upper wall 41 of the cooling plate 4D different, but the same effect is obtained. Other configurations can be employed to obtain For example, while the thickness of the upper wall 41 of the cooling plate 4D is made uniform, a heat mass may be applied to a portion of the side surface of the housing 40 adjacent to the storage cells 7H, 7I, 7L, 7M. ..

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1, 1A, 1B, 1C, 1D power storage device, 2 housing case, 3, 3A, 3B, 3C, 3D power storage module, 4, 4D cooling plate, 5, 6 end plate, 7, 7A, 7B, 7C, 7D, 7E, 7F, 7G, 7H, 7I, 7J, 7K, 7L, 7M, 7N electricity storage cell, 8 exhaust duct, 9 floor panel, 10 heat absorption plate, 11, 11A, 11B, 18, 19 heat insulation plate, 15 cell case, 16 electrode body, 20 upper surface, 21 lower surface, 22,23 main surface, 24, 25 side surface, 26 positive electrode terminal, 27 negative electrode terminal, 28 explosion proof valve, 30 metal plate, 31 insulating coating, 40 housing, 41 upper wall, 42A , 42B thin part, 43A, 43B, 43C thick part.

Claims (1)

A first storage cell,
A second storage cell provided at a distance from the first storage cell;
A third storage cell provided at a distance from the first storage cell and provided on the opposite side of the second storage cell with respect to the first storage cell;
A first plate provided between the first power storage cell and the second power storage cell;
A second plate provided between the first power storage cell and the third power storage cell;
Equipped with
The power storage device in which the thermal conductivity of the first plate and the thermal conductivity of the second plate are different.