JP7437864B2 - Storage method for power storage device pack and storage device for power storage device pack - Google Patents

Description

The present invention relates to a method for storing a power storage device pack that includes a plurality of power storage devices and a housing exterior body that houses these devices, and a storage device for a power storage device pack.

2. Description of the Related Art As a power storage device pack, a power storage device pack in which a power storage device such as a secondary battery or a capacitor is housed in an accommodating exterior body is known. Furthermore, as an electricity storage device included in this, there is an electricity storage device having a laminated part-containing electrode body (hereinafter also simply referred to as an electrode body) that includes an electrode laminated part in which a plurality of electrode plates are laminated. For example, a rectangular parallelepiped-shaped laminated electrode body in which multiple rectangular electrode plates are alternately laminated with separators or solid electrolyte layers interposed in between, or a strip-shaped electrode plate wound into a flat shape with a strip-shaped separator in between. These include flat, wound-type electrode bodies. For example, Patent Document 1 discloses such an electricity storage device pack (see FIGS. 1 to 3 of Patent Document 1, etc.).
Furthermore, some of these power storage device packs are removable and can be installed in a device during use, but removed from the device for charging or storage. For example, such removable power storage device packs are often used in power tools, drones, and the like.

Special Publication No. 2014-519180

By the way, when the electricity storage device pack is mounted on a device and used, and when it is removed from the device and stored, There are cases where it is desired to change the magnitude of the compressive load. Specifically, there are cases where it is desired to increase this compressive load during storage.
For example, if the electricity storage device is a lithium ion secondary battery that contains an electrolyte, as it is repeatedly charged, the electrolyte decomposes within the electrode body during charging and the gas generated accumulates inside the electrode body. As a result, the battery resistance increases. On the other hand, if the compressive load applied to the electrode lamination part of the electrode body of this battery in the electrode plate lamination direction is increased during storage, the gas accumulated inside the electrode body will be released outside the electrode body due to compression. This can suppress an increase in battery resistance.

The present invention has been made in view of the current situation, and provides an electricity storage device pack that is removably attached to equipment in use. Provided is a method for storing an electricity storage device pack that can increase compressive load, and a storage device for this electricity storage device pack.

In one aspect of the present invention for solving the above problems, a power storage device pack includes a plurality of power storage devices having an electrode body including a laminated part including an electrode laminated part in which a plurality of electrode plates are laminated, and an accommodating exterior body that accommodates the device therein, the accommodating exterior body has a removable structure that allows the electricity storage device pack to be repeatedly attached and detached from the equipment used, and the accommodating exterior body and The plurality of power storage devices can be repeatedly subjected to external compression that increases the compressive load in the electrode plate lamination direction applied to the electrode lamination portions of the plurality of power storage devices by applying an external force from outside the power storage device pack. A storage method in which the electricity storage device pack having a compressible structure is stored in a state in which it is removed from the equipment in use, wherein the external force is applied to the electricity storage device pack, and the electrode laminated portions of the plurality of electricity storage devices are stored. A power storage device pack comprising: an external compression step of performing the external compression to increase the compression load applied to each; and a storage step of storing the power storage device pack in a state where the compression load is increased by the external compression step. This is a method of preservation.

The above-described storage method for power storage device packs includes the above-mentioned external compression step and storage step. Therefore, the power storage device pack is removed from the device in use, and either as is or after charging, the compression applied to the electrode laminated portion of each power storage device by external compression is performed. The power storage device pack can be stored with an increased load.

In addition, the "removable structure" provided on the housing exterior body allows the power storage device pack to be attached to the device in order to use it, and the power storage device pack to be removed from the device for charging or storage. This is a structure provided in the housing exterior body to make it possible to repeat the process. For example, a structure in which the housing exterior body is provided with an engaging claw that engages with an engagement hole or an engagement recess formed in advance in the power storage device mounting portion of the equipment used, and attaches the power storage device pack to the power storage device mounting portion. Examples include.

The "compressible structure" of the housing exterior body and the plurality of power storage devices is the form and structure of the housing exterior body, the shape and structure of each of the plurality of power storage devices, and the structure inside the housing exterior body, which is adopted to enable repeated external compression. refers to the arrangement of each power storage device. This "compressible structure" includes a structure that increases the compressive load indirectly applied to the electrode stack of each power storage device through the housing exterior by applying a predetermined external force to the housing exterior. It also includes a structure in which the compressive load applied to the electrode stack of each power storage device is increased by applying an external force directly to each power storage device or to a stacked structure in which power storage devices are stacked, without using the housing exterior body.
"Electricity storage device packs" include energy storage device packs in which no compressive load is applied to the electrode lamination part of the electricity storage device in the electrode plate lamination direction unless a predetermined external force is applied to them; This also includes an electricity storage device pack in which a pre-compression load is applied to the electrode lamination portion of the electricity storage device in the electrode plate lamination direction even in this state.

In another aspect, the power storage device pack includes a plurality of power storage devices having a laminated part-containing electrode body that includes an electrode laminated part in which a plurality of electrode plates are laminated, and a housing exterior that houses the plurality of power storage devices therein. The housing exterior body has a removable structure that allows the power storage device pack to be repeatedly attached to and detached from the equipment used, and the housing exterior body and the plurality of power storage devices are The above-mentioned power storage device has a compressible structure that allows repeated external compression to be performed by applying an external force from outside the power storage device pack to increase the compressive load in the electrode plate lamination direction applied to the electrode laminated portions of the plurality of power storage devices. A storage device for storing a device pack in a state where it is removed from the equipment in use, wherein the external force is applied to the power storage device pack to increase the compressive load applied to the electrode laminated portions of the plurality of power storage devices, respectively. This is a storage device for a power storage device pack including an external compression mechanism section that performs the above-mentioned external compression.

Since the above-mentioned power storage device pack storage device includes the above-mentioned external compression mechanism, it is possible to remove the power storage device pack from the equipment in use and remove the compressive load applied to the electrode stack of each power storage device by external compression, either as is or after charging. The power storage device pack can be stored in an increased state.

FIG. 2 is a top view of a battery pack according to an embodiment. FIG. 2 is a partially cutaway sectional view of the battery pack according to the embodiment along the pack lateral direction and the pack height direction. FIG. 1 is a perspective view of a battery according to an embodiment. FIG. 2 is an explanatory diagram of the battery pack storage device according to the embodiment viewed from above. It is an explanatory view seen from the side of the battery pack preservation device concerning an embodiment. 3 is a flowchart of a method for storing a battery pack according to an embodiment. It is a graph showing the relationship between restraint time and resistance increase rate Rz for each battery with different restraint pressures. It is a graph showing the relationship between restraint time and electrode internal gas content rate Ga for each battery with different restraint pressures.

(Embodiment)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a top view of a battery pack (power storage device pack) 1 according to the present embodiment, and FIG. 2 shows a partially cutaway sectional view of the battery pack 1. Further, FIG. 3 shows a perspective view of the battery (power storage device) 10 included in the battery pack 1. This battery pack 1 is a battery pack that is installed in a device (not shown) such as a drone. In the following description, the pack longitudinal direction AH, pack lateral direction BH, and pack height direction CH of the battery pack 1 are defined as the directions shown in FIGS. 1 and 2.

The battery pack 1 includes a battery assembly 40 made up of a plurality of batteries 10, and a pack case (accommodating exterior body) 50 that accommodates the battery assembly 40 inside.
Among these, the battery 10 is a lithium ion secondary battery. The battery 10 includes a laminated part-containing electrode body (hereinafter also simply referred to as an electrode body) 11, a battery case 21 that houses the electrode body 11 inside, and a positive terminal 31 and a negative terminal 32 supported by the battery case 21. It is composed of etc. Further, an electrolytic solution 25 is housed in the battery case 21 , a part of which is impregnated into the electrode body 11 and a part of which remains at the bottom of the battery case 21 .

The electrode body 11 has a flat rectangular parallelepiped shape, and includes a rectangular positive electrode plate (electrode plate) 12, a rectangular negative electrode plate (electrode plate) 15, and a rectangular separator 18 made of a porous resin membrane. It is a laminated type electrode body in which the electrode bodies are alternately laminated with each other. This electrode body 11 consists of an electrode lamination section 11a in which a positive electrode plate 12 and a negative electrode plate 15 are laminated in the electrode plate lamination direction SH with a separator 18 in between. In the electrode laminated portion 11a, a portion on one side DH1 in the electrode body width direction DH (lower left direction in FIG. 3) is a positive electrode laminated current collector where a later-described positive electrode exposed portion 12d of the positive electrode plate 12 overlaps in the electrode plate lamination direction SH. The portion 11b on the other side DH2 in the electrode body width direction DH (upper right direction in FIG. 3) is a negative electrode laminated current collector portion 11c where a negative electrode exposed portion 15d, which will be described later, of the negative electrode plate 15 overlaps in the electrode plate lamination direction SH. It is. This electrode body 11 is housed in the battery case 21 in a sideways state so that the electrode body width direction DH coincides with the battery width direction EH and the electrode plate stacking direction SH coincides with the battery thickness direction FH. . The positive electrode terminal 31 is electrically connected to the positive electrode laminated current collector 11b of the electrode body 11, and the negative electrode terminal 32 is electrically connected to the negative electrode laminated current collector 11c of the electrode body 11.

The positive electrode plate 12 has a positive current collector foil 13 made of rectangular aluminum foil. A positive electrode active material layer 14 containing positive electrode active material particles capable of intercalating and deintercalating lithium ions is formed on both main surfaces of the positive electrode current collector foil 13, respectively. At the end of one side DH1 of the positive electrode plate 12 in the electrode body width direction DH, the positive electrode active material layer 14 is not present in the thickness direction, and the positive electrode current collector foil 13 is exposed in the thickness direction, forming a positive electrode exposed portion 12d. There is. As described above, the positive electrode exposed portions 12d of each positive electrode plate 12 overlap in the electrode plate lamination direction SH to form the positive electrode laminated current collector portion 11b.

The negative electrode plate 15 has a negative electrode current collector foil 16 made of rectangular copper foil. On both main surfaces of this negative electrode current collector foil 16, negative electrode active material layers 17 each containing negative electrode active material particles capable of intercalating and deintercalating lithium ions are formed. In the negative electrode plate 15, the end of the other side DH2 in the electrode body width direction DH has no negative electrode active material layer 17 in the thickness direction, and becomes a negative electrode exposed part 15d where the negative electrode current collector foil 16 is exposed in the thickness direction. ing. As described above, the negative electrode exposed portions 15d of each negative electrode plate 15 overlap in the electrode plate lamination direction SH to form the negative electrode laminated current collector portion 11c.

The battery case 21 is a flat rectangular parallelepiped box made of aluminum, and is welded to a case body member 22 having a bottomed rectangular cylindrical shape having an opening 22c at the top in such a manner as to close the opening 22c of the case body member 22. The case lid member 23 has a rectangular plate shape. A positive electrode terminal 31 made of a plurality of aluminum members is fixed to the case lid member 23 while being insulated from the case lid member 23 . The positive electrode terminal 31 is connected to the positive electrode laminated current collecting portion 11b of the electrode body 11 inside the battery case 21 for conduction, and extends through the case lid member 23 to the outside of the battery. Further, a negative electrode terminal 32 made of a plurality of copper members is fixed to the case lid member 23 while being insulated from the case lid member 23 . This negative electrode terminal 32 is connected to the negative electrode laminated current collecting portion 11c of the electrode body 11 inside the battery case 21 for conduction, and extends through the case lid member 23 to the outside of the battery.

In the battery assembly 40, a plurality of the batteries 10 described above are stacked in the battery thickness direction FH (the electrode plate stacking direction SH of the electrode stacking portion 11a). The batteries 10 constituting the battery assembly 40 are connected in series via a rectangular plate-shaped bus bar 45. The total positive terminals 41 of this battery assembly 40 are electrically connected to the pack positive terminal 71 of the battery pack 1, and the total negative terminals 42 of the battery assembly 40 are electrically connected to the pack negative terminal 72 of the battery pack 1. connected.

The pack case 50 has a first accommodating part 51 and a second accommodating part 61 each made of aluminum, and has an expandable structure. Specifically, the first accommodating portion 51 is shaped like a square cylinder with a bottom and has a first opening 51c that opens on one side IH1 in the expansion/contraction direction IH (the same direction as the pack lateral direction BH) in which the pack case 50 expands and contracts. It has a rectangular plate-shaped first bottom part 52 and four rectangular plate-shaped first side parts 53 , 54 , 55 , 56 rising vertically from the periphery of the first bottom part 52 .
On the other hand, the second accommodating part 61 has a bottomed square cylindrical shape having a second opening 61c that opens to the other side IH2 in the expansion/contraction direction IH, and has a rectangular plate-shaped second bottom part 62 and a second bottom part 62. It has four rectangular plate-shaped second side portions 63, 64, 65, and 66 rising vertically from the periphery. The second opening 61c of the second accommodating part 61 is arranged inside the first opening 51c of the first accommodating part 51, so that the second accommodating part 61 can move in the expansion/contraction direction IH. is fitted.

The aforementioned battery assembly 40 is accommodated inside these first accommodating section 51 and second accommodating section 61 . Specifically, in the battery assembly 40, the battery width direction EH (electrode body width direction DH) of each battery 10 coincides with the pack longitudinal direction AH, and the battery thickness direction FH (electrode plate stacking direction SH) of each battery 10 coincides with the pack longitudinal direction AH. It is arranged between the first bottom part 52 of the first accommodating part 51 and the second bottom part 62 of the second accommodating part 61 so that it coincides with the pack lateral direction BH (expansion/contraction direction IH). As a result, the electrode plate lamination direction SH of the electrode lamination portion 11a of each battery 10 and the expansion/contraction direction IH of the pack case 50 match.

Further, a pack positive terminal 71 and a pack negative terminal 72 are fixed to the pack case 50. The pack positive terminal 71 is electrically connected to all the positive terminals 41 of the battery assembly 40 inside the pack case 50, and extends through the pack case 50 to the outside of the pack. Further, the pack negative terminal 72 is electrically connected to all the negative terminals 42 of the battery assembly 40 inside the pack case 50, and extends through the pack case 50 to the outside of the pack.

Moreover, the pack case 50 has a detachable structure that can be repeatedly attached to and detached from the equipment used. Specifically, engaging claws 57 are provided on the first side portions 55 and 56 of the first housing portion 51 of the pack case 50, and these engaging claws 57 are connected to the battery mounting portion of the device in use. By engaging with an engagement recess (not shown) formed in the battery pack 1 (not shown), the battery pack 1 can be mounted and fixed on a device to be used. On the other hand, by removing the engagement claw 57 from the engagement recess of the device, the battery pack 1 can be removed from the device. Therefore, when using the device, a charged battery pack 1 is installed in the device, but when charging or storing the battery pack 1, the battery pack 1 is removed from the device and the battery pack 1 is loaded into the device. It is possible to charge a single unit.

Further, the battery pack 1 has a compressible structure that allows repeated external compression. That is, in the battery pack 1, when no external compression is performed, no restraining load is applied to the battery assembly 40, so that the electrode laminated portion 11a of the electrode body 11 of each battery 10 has a load in the electrode plate lamination direction SH. No compressive load Fc is applied.
On the other hand, when external compression is performed by applying a predetermined external force Fg to the battery pack 1 as described later (see FIGS. 4 and 5), specifically, when the first storage section 51 of the pack case 50 When a predetermined external force Fg directed toward the inner side IH3 in the stretching direction IH is applied to the first bottom part 52 and the second bottom part 62 of the second storage part 61, the pack case 50 contracts in the stretching direction IH, and the first bottom part 52 and The battery assembly 40 sandwiched between them can also be compressed in the expansion/contraction direction IH indirectly via the second bottom portion 62. As a result, each battery 10 constituting the battery assembly 40 is compressed in the battery thickness direction FH (electrode plate stacking direction SH), and a compressive load is applied to the electrode stacking portion 11a of the electrode body 11 of each battery 10 in the electrode plate stacking direction SH. Fc is applied respectively (compressive load Fc increases from zero).

Note that when this external force Fg is released, the compressive load Fc applied to the electrode laminated portion 11a of each battery 10 returns to zero.
In this manner, the battery pack 1 can be repeatedly subjected to external compression in which the external force Fg is applied to the pack case 50 to increase the compression load Fc applied to the electrode laminated portion 11a of each battery 10.

Next, a method for storing the above-mentioned battery pack 1 removed from the device used will be explained (see FIGS. 4 to 6). First, a battery pack storage device (storage device for power storage device pack, hereinafter also simply referred to as storage device) 100 used to store the battery pack 1 will be described. The storage device 100 includes an external compression mechanism section 110 that performs external compression on each battery 10 included in the battery pack 1. The external compression mechanism section 110 includes a placing section 111 on which the battery pack 1 is placed, a first fixing wall section 112 extending upward from the placing section 111, and a first fixing wall section 112 extending upward from the placing section 111. A second fixed wall part 113 facing the wall part 112 is disposed between the first fixed wall part 112 and the second fixed wall part 113, and is movable toward the first fixed wall part 112 while facing them. The movable wall portion 115 has a movable wall portion 115 and a bolt 116 for moving the movable wall portion 115.

The first fixed wall portion 112 is located on one side IH1 (left side in FIGS. 4 and 5) in the expansion/contraction direction IH (pack lateral direction BH) of the battery pack 1 placed on the placement portion 111, This is a portion of the pack case 50 that is brought into contact with the first bottom portion 52 of the first accommodating portion 51 .
On the other hand, the movable wall portion 115 is located on the other side IH2 (right side in FIGS. 4 and 5) in the expansion/contraction direction IH (pack lateral direction BH) of the battery pack 1 placed on the placement portion 111. Further, the bolt 116 passes through the second fixed wall part 113 while being screwed into a female screw part 113a bored in the second fixed wall part 113, and the tip end 116s of the bolt 116 comes into contact with the movable wall part 115. . When the head 116t of this bolt 116 is rotated to move the bolt 116 and the movable wall portion 115 in contact with it toward the first fixed wall portion 112 (towards the left in FIGS. 4 and 5), The movable wall portion 115 contacts the second bottom portion 62 of the second storage portion 61 of the pack case 50, and the first fixed wall portion 112 and the movable wall portion 115 move the pack case 50 in the expansion/contraction direction IH (pack lateral direction BH). Can be compressed.

When storing the battery pack 1, the battery pack 1 is first removed from the device in use, and the battery pack 1 is placed on the mounting section 111 of the external compression mechanism section 110. Note that, after removing the battery pack 1 from the device in use, the battery pack 1 may be charged, and then the battery pack 1 may be placed on the placement section 111 of the external compression mechanism section 110.
Then, in the "external compression step" S1, the head 116t of the bolt 116 of the external compression mechanism section 110 is rotated to move the bolt 116 and the movable wall section 115 toward the first fixed wall section 112, and the first fixed wall section 116 is moved toward the first fixed wall section 112. The pack case 50 of the battery pack 1 is sandwiched between the section 112 and the movable wall section 115 in the expansion/contraction direction IH (pack lateral direction BH). Further, when the bolt 116 and the movable wall portion 115 are moved toward the first fixed wall portion 112 and a predetermined external force Fg directed toward the inner side IH3 in the expansion/contraction direction IH is applied to the pack case 50, the first accommodation of the pack case 50 is performed. The part 51 and the second accommodating part 61 slide to contract the pack case 50 in the expansion/contraction direction IH, and each battery 10 constituting the battery assembly 40 built into the pack case 50 is moved in the battery thickness direction FH (electrode plate stacking direction). SH), and a compressive load Fc in the electrode plate lamination direction SH is applied to the electrode laminated portion 11a of the electrode body 11 of each battery 10 (the compressive load Fc increases from zero).

Next, in a "storage step" S2, the power storage device pack 1 is stored with the compression load Fc increased in the external compression step S1. In this embodiment, since the electricity storage device is the lithium ion secondary battery 10 containing the electrolyte 25, the electrolyte 25 decomposes within the electrode body 11 during charging and gas is generated, and this gas is transferred to the electrode body 11. It tends to accumulate inside. However, since this storage step S2 is performed with the compressive load Fc applied to the electrode stack 11a of the battery 10 increased, the gas accumulated inside the electrode body 11 is likely to be released outside the electrode body 11 due to compression. . Therefore, it is possible to suppress an increase in battery resistance due to gas accumulated in the electrode body 11.

When this battery pack 1 is installed in a device to be used, the above-mentioned external compression is released in a "compression release step" S3. That is, the head 116t of the bolt 116 of the external compression mechanism section 110 is reversely rotated to move the bolt 116 and the movable wall section 115 in a direction away from the first fixed wall section 112 (to the right in FIGS. 4 and 5). , the movable wall portion 115 is separated from the second bottom portion 62 of the second storage portion 61 of the pack case 50. As a result, the pack case 50 extends in the expansion/contraction direction IH, and the compressive load Fc applied to the electrode laminated portion 11a of each battery 10 becomes zero. Thereafter, the battery pack 1 is removed from the storage device 100.

(Test results)
Next, the results of tests conducted to verify the effects of the present invention will be explained. First, a plurality of batteries 10 were prepared, and the initial battery resistance R was measured for each battery. Specifically, after adjusting the battery 10 to SOC 50% (battery voltage 3.7V), it was discharged for 10 seconds at a constant current I of 2C, and the battery voltage V before and after discharge was measured to find the voltage change amount ΔV. , the battery resistance (IV resistance) R was determined by R=ΔV/I.
Next, these batteries 10 were subjected to a charge/discharge cycle test to cause the batteries 10 to deteriorate to some extent. Specifically, a charging/discharging device (not shown) is connected to the battery 10 in an unrestrained state (a state in which no compressive load Fc is applied to the electrode laminated portion 11a of the electrode body 11), and the SOC is 100% (with a constant current of 1C). One cycle of charging and discharging was charging to a battery voltage of 4.2 V) and then discharging at a constant current of 2 C to a SOC of 0% (battery voltage of 3.0 V), and this charging and discharging was repeated 300 times.
Thereafter, for each battery 10, the battery resistance R after the charge/discharge cycle test was measured in the same manner as the initial battery resistance R was measured. Furthermore, for each battery 10, the resistance increase rate Rz (%) with respect to the initial battery resistance R is calculated as the resistance increase rate Rz = ((Battery resistance R after charge/discharge cycle test)/(Initial battery resistance R) - 1) Each was calculated by ×100.

Next, for each battery 10 after the charge/discharge cycle test, after adjusting the SOC to 50%, the magnitude of the restraint pressure was changed for each battery 10 to 0 kpa (no restraint), 50 kpa, 180 kpa, or 1100 kpa, and the battery thickness direction FH ( The battery 10 was compressed in the electrode plate stacking direction SH), and each battery 10 was stored in this compressed state.
Further, after 12 hours and 48 hours had passed from the start of restraint, the battery resistance R was measured for each battery 10 in the same manner as the measurement described above, and the resistance increase rate Rz with respect to the initial battery resistance R was calculated. The results are shown in FIG.

In addition, for each battery 10 used in the test, the amount of gas accumulated in the electrode body 11 was measured after the aforementioned charge/discharge cycle test (before restraint), after 12 hours from the start of restraint, and after 48 hours, respectively. The amount was investigated. Specifically, the part where gas exists in the electrode body 11 of the battery 10 is investigated by ultrasonic measurement, and the gas content rate inside the electrode Ga=((area of the part where gas exists)/(electrode body) The gas content rate Ga (%) in the electrode body was calculated by (area))×100. The results are shown in FIG.

As is clear from the graphs in FIGS. 7 and 8, when the battery 10 is stored compressed in the battery thickness direction FH (electrode plate stacking direction SH), when the battery 10 is stored without being compressed (0 kpa, no restraint) Compared to this, the resistance increase rate Rz with respect to the initial battery resistance R decreases, and the gas content rate Ga within the electrode decreases. Specifically, the higher the restraint pressure and the longer the restraint time, the lower the resistance increase rate Rz and the lower the gas content Ga within the electrode. That is, it can be seen that the gas accumulated in the electrode body 11 is reduced by the charge/discharge cycle test, and the deterioration state of the battery 10, which has deteriorated (battery resistance R increases) by the charge/discharge cycle test, is improved.

The reason for this result is considered to be as follows. That is, when the battery 10 is charged, the electrolyte 25 decomposes within the electrode body 11 and gas is generated, so as the battery 10 in an unrestrained state is repeatedly charged, gas accumulates within the electrode body 11. go. Therefore, in the battery 10 after the charge/discharge cycle test, a large amount of gas remains in the electrode body 11. If a large amount of gas accumulates in the electrode body 11 in this way, the battery reaction will be inhibited, and thus the battery resistance R will increase. Therefore, in each battery 10 after the charge/discharge cycle test (before restraint), the gas content rate Ga in the electrode rose to about 95%, and the resistance increase rate Rz became about 35%.
On the other hand, when storing the battery 10, the higher the restraint pressure and the longer the restraint time of the battery 10, the more gas accumulated in the electrode body 11 during the charge/discharge cycle test will be released to the outside of the electrode body 11. , the battery resistance R becomes low. For this reason, it is considered that the higher the restraint pressure of the battery 10 and the longer the restraint time, the lower the gas content rate Ga within the electrode and the lower the resistance increase rate Rz.

As explained above, since the method for storing the battery pack 1 includes the external compression step S1 and the storage step S2, the battery pack 1 is removed from the device used, and the electrodes of each battery 10 are removed by external compression either as is or after charging. The battery pack 1 can be stored in a state where the compressive load Fc applied to the laminated portion 11a is increased.
Furthermore, since the battery pack storage device 100 includes the external compression mechanism section 110, the battery pack 1 can be stored in a state where the compression load Fc applied to the electrode lamination section 11a of each battery 10 is increased by external compression.

Although the present invention has been described above based on the embodiments, it goes without saying that the present invention is not limited to the embodiments and can be modified and applied as appropriate without departing from the gist thereof.
For example, in the embodiment, the battery pack 1 including the battery 10 made of a lithium ion secondary battery is exemplified as an electricity storage device pack including an electricity storage device, but the present invention is not limited to this. For example, the present invention may be applied to an all-solid battery pack including an all-solid battery or a capacitor pack including a lithium ion capacitor.
Further, in the embodiment, the rectangular parallelepiped box-shaped battery case 21 made of metal is used as the battery case of the battery 10, but the present invention is not limited to this. For example, a case made of laminate film may be used.

Further, in the storage device 100 of the embodiment, the external compression mechanism section 110 is illustrated as having a configuration in which the movable wall section 115 is moved toward the battery pack 1 by the bolt 116, but the present invention is not limited to this. The external compression mechanism part is configured to move the movable wall part, for example, by a mechanism of a clamp lever with an eccentric cam in which an eccentric cam is fixed to a rotating shaft member and a lever for rotating this rotating shaft member is provided. You can also use it as

1 Battery pack (power storage device pack)
10 Batteries (lithium ion secondary batteries, power storage devices)
11 Laminated part containing electrode body (electrode body)
11a Electrode lamination part 12 Positive electrode plate (electrode plate)
15 Negative electrode plate (electrode plate)
50 Pack case (accommodation exterior body)
100 Battery pack storage device (storage device for power storage device pack, storage device)
110 External compression mechanism section IH Stretching direction IH1 (Stretching direction) One side IH2 (Stretching direction) Other side IH3 (Stretching direction) Inside SH Electrode plate stacking direction Fg External force Fc Compression load S1 External compression step S2 Charging step S3 Decompression step

Claims (2)

The power storage device pack is
A plurality of electricity storage devices each having a laminated part-containing electrode body that includes an electrode laminated part in which a plurality of electrode plates are laminated;
an accommodating exterior body that accommodates the plurality of power storage devices therein;
The above-mentioned housing exterior body is
It has a removable structure that allows the power storage device pack to be repeatedly installed and removed from the equipment used, and
The housing exterior body and the plurality of power storage devices are
The above-mentioned power storage device pack has a compressible structure capable of repeatedly performing external compression that increases the compressive load in the electrode plate lamination direction applied to the electrode lamination portions of the plurality of power storage devices by applying an external force from outside the power storage device pack. A storage method in which the power storage device pack is stored in a state where it is removed from the equipment used, comprising:
an external compression step of applying the external force to the electricity storage device pack to increase the compression load applied to the electrode laminated portions of the plurality of electricity storage devices;
A method for storing an electricity storage device pack, comprising: storing the electricity storage device pack in a state where the compression load is increased by the external compression step. The power storage device pack is
A plurality of electricity storage devices each having a laminated part-containing electrode body that includes an electrode laminated part in which a plurality of electrode plates are laminated;
an accommodating exterior body that accommodates the plurality of power storage devices therein;
The above-mentioned housing exterior body is
It has a removable structure that allows the power storage device pack to be repeatedly installed and removed from the equipment used, and
The housing exterior body and the plurality of power storage devices are
The above-mentioned power storage device pack has a compressible structure capable of repeatedly performing external compression that increases the compressive load in the electrode plate lamination direction applied to the electrode lamination portions of the plurality of power storage devices by applying an external force from outside the power storage device pack. A storage device that stores an electricity storage device pack in a state where it is removed from the equipment used,
A storage device for a power storage device pack, comprising: an external compression mechanism section that applies the external force to the power storage device pack to increase the compressive load applied to the electrode laminated portions of the plurality of power storage devices.

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