JP7276106B2 - power storage device - Google Patents

Description

The present disclosure relates to power storage devices.

A power storage device described in Japanese Patent Application Laid-Open No. 2019-121450 includes an electrode laminate and a sealing member to which the peripheral surface of the electrode laminate is attached. The electrode laminate includes a plurality of bipolar electrodes, and the electrode laminate contains an electrolytic solution.

Each bipolar electrode includes an electrode plate, a positive electrode formed on one major surface of the electrode plate, and a negative electrode formed on the other major surface.

The sealing member includes an annular portion provided on each bipolar electrode and a tubular portion formed to surround the plurality of annular portions.

JP 2019-121450 A

In the power storage device configured as described above, depending on the state of the power storage device, gas is generated in the power storage device, and the internal pressure inside the power storage device increases. When the internal pressure in the power storage device increases, the electrolyte may leak from between the sealing member, the electrode laminate, and the sealing member, or the sealing member may be damaged.

Therefore, in order to suppress the occurrence of the above harmful effects, it is conceivable to provide a drain valve on the side surface of the sealing member. When the internal pressure in the power storage device rises, the drain valve opens to exhaust the gas in the power storage device to the outside, thereby suppressing an increase in the internal pressure in the power storage device. On the other hand, when the gas is ejected from the drain valve, the electrolytic solution is likely to leak out together with the gas. If the electrolyte leaking from the power storage device adheres to surrounding members, the surrounding members may corrode.

However, the conventional power storage device disclosed in Japanese Unexamined Patent Application Publication No. 2019-121450 does not have a configuration capable of detecting electrolyte leakage.

The present disclosure has been made in view of the problems described above, and an object of the present disclosure is to provide a power storage device having a drain valve that can detect leakage of electrolyte from the drain valve. is to provide

The electricity storage device includes an upper surface, a lower surface, and a plurality of side surfaces formed to connect the upper and lower surfaces, and includes an electricity storage module containing an electrolytic solution therein, and at least one side surface of the plurality of side surfaces. a drain valve provided, a cover member spaced apart from the side surface on which the drain valve is provided, and a liquid absorbing member provided on an inner surface of the cover member facing the power storage module. , and wiring provided on the inner surface and corroded by the electrolyte. The liquid absorbing member includes a tapered portion that tapers downward, and the wiring is arranged below the tapered portion.

According to the power storage device described above, the electrolytic solution ejected from the drain valve is sprayed onto the liquid absorbing member. The electrolytic solution sprayed onto the absorbing member moves downward inside the absorbing member. At least a portion of the electrolyte moving in the liquid absorbing member enters the tapered portion. The tapered portion is formed so as to taper downward, and the electrolytic solution is collected at the lower end portion of the tapered portion. Electrolyte drips downward from the lower end of the tapered portion. The wiring is arranged below the tapered portion, and the dripping electrolyte adheres to the wiring. If the electrolyte adheres to the wiring, the wiring will corrode and break. When the wiring is disconnected, the detector detects the disconnection of the wiring.

According to the power storage device according to the present disclosure, leakage of electrolyte from the drain valve can be detected in the power storage device including the drain valve.

1 is a schematic diagram schematically showing a vehicle 1 equipped with a power storage device 2 according to Embodiment 1. FIG. 2 is a perspective view schematically showing a power storage device 2; FIG. 3 is an exploded perspective view showing a power storage module 3 and restraints 8. FIG. 3 is a perspective view showing a storage cell 16; FIG. 4 is a perspective view showing a cover plate 46, a liquid absorbing member 5, a wiring unit 6, and the like. FIG. 3 is a perspective view showing a wiring unit 6; FIG. 3 is a side view of the power storage module 3 showing the configuration of the end side 15 and its surroundings. FIG.

A power storage device according to the present embodiment will be described with reference to FIGS. 1 to 7. FIG. Among the configurations shown in FIGS. 1 to 7, the same or substantially the same configurations are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 is a schematic diagram schematically showing a vehicle 1 equipped with a power storage device 2 according to the first embodiment. As shown in FIG. 1 , vehicle 1 includes power storage device 2 , ECU 18 , and notification unit 19 . ECU 18 controls the charge power upper limit (Win) and the discharge power upper limit (Wout) of power storage device 2 . The notification unit 19 includes, for example, a liquid crystal display unit such as a navigation device, and is a device for notifying the driver or the like of various types of information.

FIG. 2 is a perspective view schematically showing the power storage device 2. As shown in FIG. The power storage device 2 includes a power storage module 3 , a liquid absorbing member 5 , a wiring unit 6 , a detector 7 , and a restraint 8 .

The power storage module 3 is formed in a substantially rectangular parallelepiped shape. The storage module 3 includes a top surface 10 , a bottom surface 11 , long sides 12 , 13 and end sides 14 , 15 .

Long side surfaces 12 and 13 and end side surfaces 14 and 15 are arranged to connect upper surface 10 and lower surface 11 .

The long side surface 12 and the long side surface 13 are elongated in the width direction W, and the long side surface 12 and the long side surface 13 are arranged in the front-rear direction D. As shown in FIG. The end side surfaces 14 and 15 are formed to extend in the front-rear direction D, and the end side surfaces 14 and 15 are arranged so as to be arranged in the width direction W. As shown in FIG.

FIG. 3 is an exploded perspective view showing power storage module 3 and restraint 8. As shown in FIG. The power storage module 3 includes multiple power storage cells 16 and multiple current collector plates 17 . The plurality of storage cells 16 are arranged at intervals in the vertical direction. A current collector plate 17 is arranged between each storage cell 16 . Further, collector plates 17 are also arranged on the upper surface 10 and the lower surface 11 of the power storage module 3 .

The restraint 8 includes a top plate 20 , a bottom plate 21 , a plurality of pillars 22 and insulating plates 23 and 24 . The insulating plate 23 is arranged on the upper surface 10 of the storage module 3 , and the insulating plate 24 is arranged on the lower surface 11 of the storage module 3 .

The top plate 20 is arranged on the upper surface of the insulating plate 23 and the bottom plate 21 is arranged on the lower surface of the insulating plate 24 . A plurality of pillars 22 are provided to connect the top plate 20 and the bottom plate 21 . The pillars 22 are spaced apart along the long sides 12 and 13 of the power storage module 3 . In addition, the top plate 20, the bottom plate 21, and the pillars 22 are formed of a metal material.

The upper end of the pillar 22 is fixed to the top plate 20 with bolts or the like. A lower end of the column 22 is fixed to the bottom plate 21 by a bolt (not shown) or the like. By winding and tightening the bolt, a binding force is applied to the power storage module 3 arranged between the top plate 20 and the bottom plate 21 . As a result, the storage cells 16 and the collector plates 17 that are stacked in the vertical direction are restrained.

The insulating plate 23 ensures insulation between the top plate 20 and the power storage module 3 , and the insulating plate 24 ensures insulation between the bottom plate 21 and the power storage module 3 .

FIG. 4 is a perspective view showing the storage cell 16. As shown in FIG. Electric storage cell 16 includes electrode plates 30 and 31 , resin frame 32 , and electrode body 39 .

The storage cell 16 includes a top surface 33 , a bottom surface 34 , long sides 35 and 36 and end sides 37 and 38 . The electrode plate 30 is arranged on the upper surface 33 and the electrode plate 31 is arranged on the lower surface 34 . The resin frame 32 is formed in an annular shape, and the resin frame 32 defines long side surfaces 35 and 36 and end side surfaces 37 and 38 .

A housing space 40 is formed by the electrode plate 30 , the electrode plate 31 , and the resin frame 32 , and the electrode body 39 is housed in the housing space 40 . An electrolytic solution is also accommodated in the accommodation space 40 . The electrode assembly 39 includes a positive electrode mixture layer, a negative electrode mixture layer, and a separator. The positive electrode mixture layer is made of nickel hydroxide or the like. The negative electrode mixture layer is made of a hydrogen-adsorbing alloy or the like. The separator is made of, for example, a woven fabric or non-woven fabric made of a porous film made of polyolefin resin. The electrolytic solution is, for example, an alkaline solution such as an aqueous potassium hydroxide solution, and is enclosed in the housing space 40 . Thus, the storage cell 16 is configured as a nickel-metal hydride battery (Ni--MH battery).

A plurality of drain valves 41 are formed in the storage cell 16 . In this example shown in FIG. 4, end side 37 includes a plurality of drain valves 41 .

Returning to FIG. 3 , each collector plate 17 is made of a metal material, and each storage cell 16 is electrically connected in series by each collector plate 17 . The collector plate 17 positioned on the upper surface 10 of the electric storage module 3 is provided with a collector terminal (not shown), and the collector plate 17 positioned on the lower surface 11 is also provided with a collector terminal. . Each collector terminal is connected to a junction box or the like provided outside the power storage device 2 .

Returning to FIG. 2 , power storage device 2 includes a plurality of cover plates 45 , 46 , 47 , 48 . The cover plate 45 is arranged on the side of the end side 14 . A cover plate 46 is arranged on the end side 15 . Similarly, cover plate 47 is arranged on long side 12 and cover plate 48 is arranged on long side 13 .

A connection wiring 61 and a connection wiring 62 are connected to the wiring unit 6 . The connection wiring 61 and the connection wiring 62 are connected to the detection section 7 .

An electrical closed circuit 68 is formed by the wiring unit 6 , the detection section 7 , and the connection wirings 61 and 62 , and the detection section 7 applies a voltage to this closed circuit 68 .

The detection unit 7 detects voltage, and when an electrical disconnection occurs in the closed circuit 68, the disconnection can be detected.

FIG. 5 is a perspective view showing the cover plate 46, the absorbent member 5, the wiring unit 6, and the like. The cover plate 46 is formed in a plate shape and includes a main surface (inner surface) 50 and a main surface 51 . Main surface 50 is arranged to face end side surface 15 of power storage module 3 shown in FIG. 2 .

An upper frame 52 and a lower frame 53 are formed on the cover plate 46 , and the upper frame 52 and the lower frame 53 are formed to protrude from the main surface 50 toward the end side surface 15 . The upper frame 52 is formed to extend in the front-rear direction D along the upper side of the cover plate 46 . The lower frame 53 is formed to extend in the front-rear direction D along the lower side of the cover plate 46 .

The liquid absorbing member 5 is provided on the main surface 50 and arranged between the upper frame 52 and the lower frame 53 .

The liquid absorbing member 5 is made of sponge or the like. The liquid absorbing member 5 is formed in a plate-like shape. A notch 54 extending upward is formed in the lower side of the liquid absorbing member 5 .

A tapered portion 55 is formed at the upper end of the inner peripheral edge portion of the notch portion 54 . The tapered portion 55 is formed to protrude downward. The tapered portion 55 is formed so as to taper downward. The wiring unit 6 is arranged below the tapered portion 55 .

6 is a perspective view showing the wiring unit 6. FIG. The wiring unit 6 includes a housing case 60 , connection wirings 61 and 62 , terminals 63 and 64 and wiring 65 .

Hollow portions 66 and 67 are formed in the housing case 60 , and the hollow portions 66 and 67 are formed so as to reach from the bottom surface of the housing case 60 to the top surface.

A terminal 63 is inserted into the hollow portion 66 and a terminal 64 is inserted into the hollow portion 67 . The connection wiring 61 is connected to the lower end of the terminal 63 , and the connection wiring 62 is connected to the lower end of the terminal 64 .

A wire 65 connects the upper end of the terminal 63 and the upper end of the terminal 64 , and the wire 65 is arranged below the tapered portion 55 . The wiring 65 is made of a metal material, and is made of a metal that corrodes with the electrolyte.

FIG. 7 is a side view of the storage module 3 showing the configuration of the end side 15 and its surroundings. A plurality of drain valves 41 are arranged on the end side 15 .

The upper end portion of the liquid absorbing member 5 is positioned above the liquid drain valve 41 that is positioned highest among the plurality of liquid drain valves 41 .

In the power storage device 2 configured as described above, the power storage device 2 may be overcharged. In such a case, gas may be generated inside the storage cell 16 and the internal pressure inside the storage cell 16 may rise.

The drain valve 41 opens when the internal pressure in the storage cell 16 reaches or exceeds a predetermined pressure. When the drain valve 41 opens, the gas in the storage cell 16 is discharged to the outside, and the electrolytic solution in the storage cell 16 may also be ejected to the outside.

The electrolytic solution ejected from the liquid drain valve 41 is sprayed onto the liquid absorbing member 5 . In FIG. 5, the electrolytic solution sprayed onto the liquid absorbing member 5 soaks into the liquid absorbing member 5, then passes through the liquid absorbing member 5 and moves downward.

At least part of the electrolyte then enters the tapered portion 55 and drips downward from the lower end of the tapered portion 55 .

Here, since the tapered portion 55 is formed so as to taper downward, the electrolytic solution that has entered the tapered portion 55 is collected at the lower end portion of the tapered portion 55 .

Since the electrolytic solution is collected at the lower end of the tapered portion 55 , the electrolytic solution tends to drip downward from the lower end of the tapered portion 55 .

The electrolyte dripping down from the lower end of the tapered portion 55 adheres to the wiring 65 . If the electrolyte adheres to the wiring 65, the wiring 65 will corrode. Then, the wiring 65 is disconnected.

When the wiring 65 is disconnected, the voltage of the closed circuit 68 in FIG. 2 fluctuates. The detector 7 detects voltage fluctuations in the closed circuit 68 .

The detection unit 7 transmits the voltage fluctuation of the closed circuit 68 to the ECU 18 . The ECU 18 determines that the wiring 65 is disconnected when the voltage fluctuation of the closed circuit 68 is equal to or greater than a predetermined value. The predetermined value is set to be smaller than the amount of voltage fluctuation that occurs in the closed circuit 68 when the wiring 65 is broken.

When ECU 18 determines that line 65 is disconnected, ECU 18 reduces the absolute values of charge power upper limit value Win and discharge power upper limit value Wout for charging power storage device 2 . Further, ECU 18 provides notification unit 19 with information indicating that the absolute values of charge amount upper limit Win and discharge power upper limit Wout have been set small. It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to include all changes within the meaning and range of equivalents to the claims.

REFERENCE SIGNS LIST 1 vehicle 2 power storage device 3 power storage module 5 liquid absorbing member 6 wiring unit 7 detector 8 restraint tool 10, 33 upper surface 11, 34 lower surface 12, 13, 35, 36 long side surface 14, 15, 37, 38 end side, 16 power storage cell, 17 current collector, 19 reporting unit, 20 top plate, 21 bottom plate, 22 pillar, 23, 24 insulating plate, 30, 31 electrode plate, 32 resin frame, 39 electrode body , 40 housing space, 41 drainage valve, 45, 46, 47, 48 cover plate, 50, 51 main surface, 52 upper frame, 53 lower frame, 54 notch, 55 taper, 60 housing case, 61, 62 connection Wiring 63, 64 Terminal 65 Wiring 66, 67 Hollow portion 68 Closed circuit D Front-back direction W Width direction Wout Discharge amount upper limit.

Claims (1)

an electricity storage module including an upper surface, a lower surface, and a plurality of side surfaces formed to connect the upper surface and the lower surface, and containing an electrolytic solution therein;
a drainage valve provided on at least one of the plurality of sides;
a cover member spaced apart from the side surface on which the drain valve is provided;
a liquid absorbing member provided on an inner surface of the cover member facing the power storage module;
Wiring provided on the inner surface and corroded by the electrolyte;
a detection unit connected to the wiring for detecting disconnection of the wiring;
with
The liquid absorbing member includes a tapered portion that tapers downward,
The power storage device, wherein the wiring is arranged below the tapered portion.

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