JP7269072B2 - Storage element unit and design method for storage element unit - Google Patents

Description

The present invention relates to a power storage element unit and a design method for the power storage element unit.

For example, as proposed in Patent Literature 1, a power storage element unit having a plurality of power storage element modules is known. A plurality of power storage element modules are stored in a storage box in a stacked state. In this case, the battery capacity of the storage element unit can be adjusted by changing the number of storage element modules accommodated in the storage box.

JP 2018-181782 A

In general, the larger the battery capacity of the storage element unit, the higher the cost of the storage element unit. Therefore, using a power storage element unit having an excessively large battery capacity results in unnecessary costs. Therefore, it is preferable to appropriately adjust the battery capacity of the storage element unit according to the application. On the other hand, when adjusting the battery capacity of the storage element unit by changing the number of storage element modules housed in the storage box, it is necessary to develop a new storage box, which may increase the design cost.

An object of the present invention is to provide a power storage element unit and a method of designing the power storage element unit that can effectively solve such problems.

The storage element unit according to the present invention is
a plurality of energy storage element groups housed in the storage box and electrically connected in series;
The energy storage element group includes at least one energy storage element body that is electrically connected to another energy storage element group and extends in a planar direction, and at least one dummy body that extends in the same planar direction as the energy storage element body. have
The electric storage element body and the dummy body are electric storage element units having the same thickness in the thickness direction orthogonal to the surface direction.

In the electric storage element unit according to the present invention, the electric storage element body and the dummy body may be arranged in the thickness direction.

In the electric storage element unit according to the present invention, the electric storage element body and the dummy body may be in contact with each other in the thickness direction.

In the electric storage element unit according to the present invention, the electric storage element group may have an intermediate member positioned between the electric storage element body and the dummy body in the thickness direction.

In the electric storage element unit according to the present invention, at least part of the plurality of electric storage element groups may be arranged in the thickness direction.

In the electric storage element unit according to the present invention, at least part of the plurality of electric storage element groups may be arranged in a direction intersecting the thickness direction.

In the electric storage element unit according to the present invention, the electric storage element group may have a plurality of electric storage element bodies electrically connected in parallel with each other.

In the storage element unit according to the present invention, the number of storage element bodies in each storage element group may be the same, and the number of dummy bodies in each storage element group may be the same.

In the electric storage element unit according to the present invention, the electric storage element body and the dummy body may have the same dimension in the plane direction.

A method for designing a storage element unit according to the present invention includes:
The storage element unit is
a storage box and
a plurality of energy storage element groups housed in the storage box and electrically connected in series;
the energy storage element group has at least one energy storage element body electrically connected to another energy storage element group and at least one dummy body;
The design method is
obtaining information about the target electric capacity of the storage element unit;
determining the number of the storage element bodies and the number of the dummy bodies in each storage element group so as to satisfy the target electric capacity.

In the method for designing an electric storage element unit according to the present invention, the electric storage element body and the dummy body may extend in the same plane direction and have the same thickness in a thickness direction orthogonal to the plane direction.

In the method for designing an electric storage element unit according to the present invention, the electric storage element body and the dummy body may be arranged in the thickness direction.

ADVANTAGE OF THE INVENTION According to this invention, the battery capacity of an electrical storage element unit can be adjusted easily.

FIG. 1 is a diagram for explaining an embodiment, and is a perspective view showing a storage element unit. 2 is a perspective view showing the inside of the storage element unit of FIG. 1. FIG. 3 is a perspective view showing a storage element module assembly and storage element modules arranged in a storage box of the storage element unit of FIG. 1. FIG. FIG. 4 is a side view showing the electric storage element module combination of FIG. 3, showing the electric storage element module combination from the second direction. 5 is a perspective view showing a power storage element module included in the power storage element module assembly of FIG. 3. FIG. FIG. 6 is a perspective view showing the electric storage element module of FIG. 5, and is shown from the opposite side in the first direction of the electric storage element module. 7 is a perspective view showing a laminate included in the electric storage element module of FIG. 5. FIG. FIG. 8 is a diagram for explaining electrical connection of the plurality of electric storage element bodies in FIG. 7. FIG. FIG. 9 is a perspective view showing one electric storage element body of the laminate shown in FIG. FIG. 10 is a perspective view showing the power storage element module of FIG. 5, showing a state in which the cover is removed from the case. 11 is a configuration diagram schematically showing the main configuration of the storage element module of FIG. 5. FIG. 12 is a partial perspective view showing an enlarged interior of the storage element module of FIG. 5. FIG. 13 is a perspective view showing a case included in the power storage element module of FIG. 5. FIG. 14 is a partially enlarged view of FIG. 13. FIG. FIG. 15 is a configuration diagram schematically showing the main configuration of a power storage element module according to one modification. FIG. 16 is a configuration diagram schematically showing the main configuration of a power storage element module according to one modification. FIG. 17 is a configuration diagram schematically showing the main configuration of a power storage element module according to one modification.

An embodiment of the present invention will now be described with reference to specific examples shown in the drawings. In the drawings attached to this specification, for the convenience of illustration and ease of understanding, the scale and the ratio of vertical and horizontal dimensions are changed and exaggerated from those of the real thing.

1 to 12 are diagrams for explaining an embodiment according to the present invention. 1 is a perspective view showing a power storage element unit 10, FIG. 2 is a perspective view showing the inside of the power storage element unit, and FIG. 3 shows a power storage element module 20 included in the power storage element unit. It is a perspective view. The storage element unit 10 is used as a rechargeable secondary battery unit. The illustrated power storage element unit 10 is applied to, for example, a building such as a residence or a public facility, and is electrically connected to the wiring of the building and functions as a power supply for an electrical device installed in the building.

As shown in FIGS. 1 and 2 , the storage element unit 10 includes a storage box 11 , and a control module 14 and a plurality of storage element modules 20 housed in the storage box 11 . The storage box 11 has a frame 12 and a panel 13 fixed to the frame 12. - 特許庁The frame 12 is made of metal or resin, for example, and has a certain degree of strength. The frame 12 forms an arrangement space for the control module 14 and the power storage element module 20 . The panel 13 is, for example, a plate-like member made of resin or metal. The panel 13 closes the arrangement space of the control module 14 and the storage element module 20 .

The control module 14 has, for example, a function of controlling charging and discharging of the plurality of power storage element modules 20, a function of monitoring the state of charge (for example, the amount of charge) of the power storage element modules 20, and a function of monitoring whether the power storage element modules 20 are abnormal. have one or more of the functions Further, the control module 14 may transmit information such as the state of charge of the storage element module 20 and the result of monitoring whether there is an abnormality or the like to a control device installed outside the storage element unit 10 . Also, the control module 14 may have a switch that switches between electrical connection and disconnection between the wiring outside the storage element unit 10 (for example, the wiring of the building) and the storage element module 20 .

FIG. 2 shows the storage element unit 10 with the upper and front panels removed. In the illustrated electric storage element unit 10 , and in FIG. 3 , a plurality of electric storage element modules 20 are shown in a state of being accommodated in the storage box 11 . As shown in FIG. 3 , the storage element unit 10 may have two storage element module combinations 15 . The storage element module combination 15 has a plurality of storage element modules 20 stacked in the first direction DA. The two power storage element module assemblies 15 are arranged side by side in a second direction DB that is non-parallel to the first direction DA.

In the illustrated example, the first storage element module assembly 15A has three storage element modules 20 stacked in the first direction DA. The second energy storage element module combination 15B is adjacent to the first energy storage element module combination 15A from one side SB1 in the second direction DB. As shown in FIG. 2, the second power storage element module assembly 15B supports the control module 14 from one side SA1 in the first direction DA. FIG. 4 shows the first power storage element module assembly 15A from the other side in the second direction DB. 5 and 6 show one storage element module 20 included in the storage element module assembly 15. FIG. The plurality of power storage element modules 20 included in the power storage element unit 10 may have different configurations, or may have the same configuration. However, from the viewpoint of improving versatility, the plurality of power storage element modules 20 preferably have the same configuration, and at least the same components (for example, the power storage element body 30, the case 40, the cover 60, and the tabs, which will be described later). Block 70, electrode member 80) is preferably included. In the illustrated example, the plurality of power storage element modules 20 have the same configuration.

In order to clarify the directional relationship among the drawings, in some drawings, the first direction DA, the second direction DB, and the third direction DC are indicated by arrows as common directions among the drawings. The tip side of the arrow is one side SA1, SB2, SC3 of each direction DA, DB, DC. Also, an arrow directed to the depth of the paper along the direction perpendicular to the paper of the drawing is indicated by a symbol with an X in a circle, as shown in FIG. 4, for example. An arrow pointing forward from the paper surface of the drawing along a direction perpendicular to the paper surface of the drawing is indicated by a dot in a circle, for example, as shown in FIG. 8, which will be described later. Further, the drawings showing the parts (for example, the electric storage element module assembly 15 and the electric storage element modules 20) housed in the storage box 11 show the directions and orientations of the parts housed in the storage box 11. FIG. Similarly, in the diagrams showing the components (for example, the storage element body 30, the case 40, the cover 60, the tab block 70, and the electrode member 80, which will be described later) included in the storage element module 20, the storage box 11 accommodates the storage box 11. The directions and orientations of the element module 20 are shown.

In the illustrated example, the first direction DA, the second direction DB and the third direction DC are perpendicular to each other. Also, the first direction DA is parallel to the vertical direction. The one side SA1 in the first direction DA is the lower side in the vertical direction, and the other side opposite to the one side in the first direction DA is the upper side in the vertical direction.

The storage element module 20 has a container 18 and a laminate housed in the container 18 . FIG. 7 is a perspective view showing the stack housed in the housing 18. As shown in FIG. As shown in FIG. 7, the laminate of the storage element module 20 has a plurality of storage element bodies 30 stacked in the thickness direction. In the present embodiment, the thickness direction of the power storage element module 20 is parallel to the first direction DA. Moreover, although not shown in FIG. 7 , the laminate of the storage element module 20 has dummy bodies 36 positioned between the storage element bodies 30 . Each storage element body 30 preferably has the same configuration. Similarly, each dummy body 36 preferably has the same configuration as each other.

The storage element body 30 is a secondary battery having a predetermined output voltage, such as a lithium ion secondary battery. The dummy body 36 is a member that structurally replaces the storage element body 30 and does not contribute to the electrical characteristics of the storage element module 20 . As will be described later, the dummy body 36 is such that the battery capacity required for the storage element module 20 is the maximum number of storage element bodies 30 that can be accommodated in the storage element module 20 (hereinafter also referred to as the maximum number of storage elements 30 ). It can be provided in the storage element module 20 when it is smaller than the battery capacity realized when housed in the housing body 18 . The dummy body 36 has structural features similar to those of the storage element body 30 . The structural feature is, for example, a dimension in the thickness direction (hereinafter also simply referred to as thickness), and dummy body 36 has the same thickness as power storage element body 30 in the thickness direction. As the dummy body 36, for example, a plate-shaped member made of an insulating material can be used.

FIG. 8 is a diagram for explaining electrical connection of the plurality of power storage element bodies 30 of the power storage element module 20. As shown in FIG. At least some of the plurality of power storage element bodies 30 of the power storage element module 20 are electrically connected in series with each other. In the example of FIG. 8, eight power storage element bodies 30 are connected in series. In this case, eight dummy bodies 36 are arranged so as to correspond to the storage element bodies 30 connected in series with each other. As shown in a modified example to be described later, there may be a plurality of groups of a plurality of power storage element bodies 30 electrically connected in parallel, and the groups may be electrically connected to each other in series. In this case, dummy bodies 36 are arranged corresponding to each of a plurality of groups of power storage element bodies 30 electrically connected in parallel.

In the following description, with reference to one or a group of electrical storage element bodies 30 electrically connected in series, the unit of partitioning the storage element bodies 30 and the dummy bodies 36 included in the storage element module 20 is It is also called a storage element group 28 . In the example shown in FIG. 8, one power storage element group 28 includes one power storage element body 30 and one dummy body 36 aligned with the power storage element body 30 in the thickness direction. The number of storage element bodies 30 in each storage element group 28 is the same, and the number of dummy bodies 36 in each storage element group 28 is also the same. Eight storage element groups 28 are shown in FIG. The storage element bodies 30 of one storage element group 28 are electrically connected in series with the storage element bodies 30 of the other storage element groups 28 . Therefore, it can be said that the plurality of storage element groups 28 are connected in series with each other.

Each storage element group 28 has a predetermined output voltage. The output voltage of the storage element module 20 corresponds to the sum of the output voltages of the storage element groups 28 connected in series. Therefore, the output voltage of the storage element module 20 can be adjusted by changing the number of the storage element groups 28 connected in series. As described above, the dummy body 36 is made of an insulating material or the like, so the dummy body 36 does not contribute to the electrical characteristics of the storage element group 28 . The electrical characteristics of the storage element group 28 are determined by the storage element bodies 30 included in the storage element group 28 . For example, the output voltage of the storage element group 28 is equal to the output voltage of the storage element bodies 30 included in the storage element group 28 .

The dummy body 36 has the same thickness as the electric storage element body 30 . Therefore, the dummy body 36 functions in the same manner as when it is assumed that the power storage element body 30 is arranged at the position of the dummy body 36 with respect to the thickness of the power storage element body 30 . For example, the thickness of the storage element group 28 including one storage element body 30 and one dummy body 36 is the same as the thickness of the storage element group 28 including two storage element bodies 30 . Moreover, when the dummy body 36 has the same length and width as the storage element body 30, the dummy body 36 can substitute for the storage element body 30 in terms of length and width as well. Thus, the dummy body 36 can replace the storage element body 30 with respect to structural features.

Each power storage element group 28 has a predetermined battery capacity. The battery capacity of the storage element group 28 corresponds to the total battery capacity of the storage element bodies 30 connected in parallel in the storage element group 28 . Therefore, by changing the number of power storage element bodies 30 connected in parallel, the battery capacity of the power storage element group 28 can be adjusted. For example, in the example of FIG. 8, by replacing the dummy body 36 included in each storage element group 28 with the storage element body 30, the battery capacity of each storage element group 28 can be increased. Thereby, the battery capacity of the entire power storage element module 20 can be increased.

Next, an example of a specific structure of the electric storage element body 30 will be described. FIG. 9 is a perspective view showing the storage element body 30. FIG. As shown in FIG. 9, the electric storage element body 30 may have a flat shape extending in the plane direction. In the present embodiment, the surface of the power storage element body 30 extends along the above-described second direction DB and third direction DC. In addition, the power storage element body 30 may have a substantially rectangular shape in plan view (observation from the first direction DA). The power storage element body 30 has a short side in the second direction DB and a long side in the third direction DC.

The power storage element body 30 includes a plurality of electrode plates 32 including positive and negative electrode plates, an exterior body 33 that accommodates the plurality of electrode plates 32 , and an exterior body 33 that is electrically connected to the electrode plates 32 and extends to the outside of the exterior body 33 . and a pair of tabs 35 protruding. A pair of tabs 35 functions as a positive terminal or a negative terminal, respectively. The illustrated tab 35 has a proximal end portion 35A extending from the outer body 33 and a distal end portion 35B bent with respect to the proximal end portion 35A.

As shown in FIGS. 7 to 9, the storage element body 30 may have a central portion 31C located in the center and a peripheral edge portion 31E surrounding the central portion 31C. The central portion 31C is thicker than the peripheral portion 31E. In the illustrated example, the power storage element body 30 bulges out toward one side in the first direction DA at the central portion 31C. Like the electric storage element body 30, the dummy body 36 may also have a central portion 31C located in the center and a peripheral edge portion 31E surrounding the central portion 31C. The power storage element bodies 30 and dummy bodies 36 adjacent in the thickness direction, or two power storage element bodies 30 adjacent in the thickness direction, have their central portions 31C at least partially facing each other in the thickness direction (in the first direction DA). So it's layered.

The power storage element body 30 and the dummy body 36 may have substantially symmetrical configurations with respect to planes along the first direction DA and the third direction DC passing through the center in the second direction DB as reference planes. Moreover, the power storage element body 30 and the dummy body 36 may have a generally symmetrical configuration with respect to a plane along the first direction DA and the second direction DB passing through the center in the third direction DC as a reference plane. .

The exterior body 33 of the power storage element body 30 may have a first exterior material 34A and a second exterior material 34B. The first exterior material 34A and the second exterior material 34B are connected, for example, thermally welded to each other at their circumferential edges. The first exterior member 34A has a bulging portion 34AP. The first exterior material 34A and the second exterior material 34B form a space for accommodating the electrode plate 32 inside the first exterior material 34A. In addition, the bulging portion 34AP defines the central portion 31C of the power storage element body 30 . On the other hand, the second exterior material 34B is formed in a flat plate shape. The tab 35 extends out of the exterior body 33 through between the first exterior member 34A and the second exterior member 34B. The exterior body 33 has a substantially rectangular shape in plan view (observation from the first direction DA). The exterior body 33 has a lateral direction in the second direction DB and a longitudinal direction in the third direction DC.

34 A of 1st exterior materials are formed with bulging part 34AP by embossing, for example. Generally, the first exterior material 34A and the second exterior material 34B have a metal layer and an inner layer laminated inside the metal layer. The inner layer is an insulating layer, preferably thermoplastic. By heating and pressurizing the first exterior material 34A and the second exterior material 34B, which are laminated so that the inner layers having thermoplasticity face each other, the first exterior material 34A and the second exterior material 34B are formed into the peripheral edge portion. It can be heat welded at 31E. In addition, since the first exterior material 34A and the second exterior material 34B include metal layers, the exterior body 33 can be provided with rigidity. On the other hand, an unintended short circuit or the like may occur when the tab 35 of another power storage element body 30 comes into contact with the exterior body 33 including the metal layer. However, in the present embodiment, measures are taken to prevent such a short circuit from occurring. Specifically, a tab block 70 and an electrode member 80, which will be described later, are provided.

The dummy body 36 may or may not have an exterior body 33 similar to that of the storage element body 30 .

Next, an example of arrangement of the storage element bodies 30 and the dummy bodies 36 will be described. As shown in FIG. 8, the storage element body 30 and the dummy body 36 may be arranged in contact with each other in the thickness direction. Moreover, the electric storage element body 30 and the dummy body 36 may have symmetrical shapes in the thickness direction with respect to the contact surface between them. Moreover, the storage element group 28 including the storage element bodies 30 and the dummy bodies 36 may also be arranged in the thickness direction. In this case, two power storage element groups 28 adjacent in the thickness direction may or may not be in contact with each other.

The dimensions of the storage element body 30 will be described in detail below. Dummy body 36 has the same thickness T2 as thickness T1 of power storage element body 30 . “The same thickness” means that the thickness T2 of the dummy body 36 is 0.8×T1 or more and 1.2×T1 or less. Moreover, the dummy body 36 may have the same length L2 as the length L1 of the storage element body 30 . "The same length" means that the length L2 of the dummy body 36 is 0.8×L1 or more and 1.2×L1 or less. "Length" is the dimension in the third direction DC. Moreover, the dummy body 36 may have the same width W2 as the width W1 of the storage element body 30 . “The same width” means that the width W2 of the dummy body 36 is 0.8×W1 or more and 1.2×W1 or less. "Width" is a dimension in the second direction DB.

Next, an example of the configuration of the storage element module 20 will be described in further detail.

As shown in FIGS. 10 to 12, the storage element module 20 has a case 40 and a cover 60 as a container 18 for containing a plurality of cells. The cover 60 can be removed from the case 40 . The storage element module 20 also has a tab block 70 and an electrode member 80 held by the case 40 and a first end cover 21 and a second end cover 22 fixed to the case 40 . In the illustrated example, the container 18 of the storage element module 20 that accommodates the plurality of storage element groups 28 includes, as main components, a first end cover 21, a second end cover 22, a case 40, a cover 60 , tab block 70 and electrode member 80 .

Here, FIG. 10 is a perspective view showing the power storage element module 20 with the cover 60 removed from the case 40, and FIG. 11 is a side view schematically showing the main configuration of the power storage element module 20. FIG. 12 is a perspective view showing a portion covered by the first end cover 21 and the cover 60 of the power storage element module 20 with the first end cover 21 and the cover 60 removed. 13 is a perspective view showing the case 40. FIG.

The case 40 that accommodates the plurality of power storage element groups 28 has, as an overall configuration, a bottom portion 42 that supports the plurality of power storage element groups 28 from one side SA1 in the first direction DA, and a bottom portion 42 that rises from the bottom portion 42 in the first direction DA. and a side wall portion 44 . The case 40 opens on the other side in the first direction DA. That is, the case 40 has an opening 40 a at a position facing the bottom 42 . The side wall portion 44 surrounds the storage element body 30 and the storage element group 28 from the second direction DB and the third direction DC. More specifically, the side wall portion 44 extends along the outer edge of the storage element group 28 when viewed from the first direction DA. However, the notch C is provided in the side wall portion 44 . The notch C is provided in the notch forming wall portion 45 extending along the second direction DB in the side wall portion 44 . The tab 35 extends into the notch C. As shown in FIG.

The side wall portion 44 faces the storage element group 28 from a direction orthogonal to the first direction DA, for example, the second direction DB or the third direction DC. The side wall portion 44 restricts relative movement of the storage element group 28 with respect to the case 40 in a direction orthogonal to the first direction DA, such as the second direction DB or the third direction DC. Thereby, the plurality of power storage element groups 28 can be stably held within the case 40 . On the other hand, the case 40 has an opening 40a in the first direction DA, which allows the storage element group 28 to move relative to the case 40 in the first direction DA.

The cover 60 is held by the case 40 so as to be movable in the first direction DA, and covers the opening 40a of the case 40 . The cover 60 covers the power storage element group 28 accommodated in the case 40 from the other side in the first direction DA.

As shown in FIG. 10 , the cover 60 has a cover body 61 and a fixing portion 62 extending from the cover body 61 . The fixed portion 62 can be engaged with a receiving portion 49 provided on the side wall portion 44 of the case 40 . The cover 60 is held by the case 40 by engaging the fixing portion 62 with the receiving portion 49 . In the illustrated example, the fixed portion 62 engages the receiving portion 49 movably in the first direction DA.

As shown in FIG. 10, the cover 60 has fixing portions 62 at positions spaced apart in the second direction DB. In addition, the cover 60 has fixing portions 62 at respective positions spaced apart in the third direction DC. A plurality of fixing portions 62 are provided at positions facing the side wall portion 44 along the first direction DA. In the illustrated example, four fixing portions 62 are provided separately on each portion of the side wall portion 44 extending in the third direction DC. Therefore, in the illustrated example, eight fixing portions 62 are provided on one cover 60 .

Note that the storage element groups 28 adjacent to each other in the first direction DA may be fixed to each other via the bonding layer 38 (see FIG. 11). According to this example, the use of the bonding layer 38 allows the plurality of storage element groups 28 to be stably held within the case 40 . In addition, by changing the thickness of the bonding layer 38 according to the thickness of the energy storage element group 28, variations in the thickness of the energy storage element group 28 can be effectively reduced without adjusting the spacing using a spacer or the like.

The cover 60 is formed using an insulating material, for example. The cover 60 as a whole can be integrally molded from insulating resin. Similarly, the case 40 is also formed using an insulating material, for example. The case 40 as a whole, including the parts to be described later, can be integrally molded from an insulating resin.

Next, the notch C provided in the side wall portion 44 of the case 40 and the structure of the side wall portion 44 related to the notch C will be described, and then the tab block 70 and the electrode member 80 will also be described.

For example, as shown in FIG. 13, the side wall portion 44 is provided with a pair of notches C. As shown in FIG. Each notch C is formed in a notch forming wall portion 45 extending along the second direction DB in the side wall portion 44 . The notch C is provided at a center position of the corresponding notch forming wall portion 45 in the second direction DB. As shown in FIGS. 10 and 12 , the pair of tabs 35 of the storage element body 30 extend into the notch C from the internal space of the case 40 . Due to the symmetry of the shape of the storage element body 30 described above, regardless of the arrangement of the storage element body 30 in the case 40, one tab 35 fits into one notch C, and the other tab 35 fits into the other notch C. go inside. More specifically, regardless of whether the center portion 31C of the electricity storage element body 30 protrudes toward one side SA1 or the other side in the first direction DA, the tab serving as the positive electrode terminal of the electricity storage element body 30 One tab 35 enters one notch C and the other tab 35 enters the other notch C regardless of whether 35 extends toward one side SB1 or the other side in the second direction DB. .

In the illustrated example, the side wall portion 44 further includes a notch guide wall portion 46 connected to the notch forming wall portion 45 . The notch guide wall portion 46 extends outward in the third direction DC from a position adjacent to the notch C of the notch forming wall portion 45 . In other words, the notch guide wall portion 46 extends away from the space of the case 40 that accommodates the power storage element body 30 . The notch guide wall portion 46 extends in the third direction DC. With respect to one notch C, notch guide wall portions 46 are provided on both sides of the notch C in the second direction DB. Therefore, each tab 35 is arranged between a pair of notch guide wall portions 46 and extends in the third direction DC while being guided by the notch guide wall portions 46 . With such a notch guide wall portion 46 , it is possible to stably hold the power storage element bodies 30 of the power storage element group 28 in the case 40 . In particular, since the position of the tab 35 functioning as a terminal is stabilized, the vibration resistance of the storage element module 20 and the storage element unit 10 can be effectively improved.

As shown in FIG. 14, each notch guide wall portion 46 has a first rib 46a and a second rib 46b. The first rib 46a and the second rib 46b are provided on the outer surface of the corresponding notch guide wall portion 46 in the second direction DB (the side away from the center of the case 40 in the second direction DB). The first rib 46a and the second rib 46b each protrude outward in the second direction DB from the corresponding notch guide wall portion 46 . The first rib 46a and the second rib 46b extend in the first direction DA. In the illustrated example, the first rib 46a and the second rib 46b extend over the entire length of the notch guide wall portion 46 along the first direction DA. The second rib 46b is located outside the first rib 46a in the third direction DC (on the side away from the center of the case 40 in the second direction DB, in other words, it accommodates the power storage element body 30 of the case 40 in the second direction DB). side away from the space). The first rib 46a is positioned between the notch guide wall portion 46 and the second rib 46b in the third direction DC.

A first recess 48a and a second recess 48b are formed in the notch guide wall portion 46 by such ribs 46a and 46b. The first concave portion 48a is formed between the notch guide wall portion 46 and the first rib 46a. The second recess 48b is formed between the first rib 46a and the second rib 46b. The first recess 48a and the second recess 48b open outward in the second direction DB (the side away from the center of the case 40 in the second direction DB). Therefore, the notch guide wall portion 46 is positioned facing the openings of the first recessed portion 48a and the second recessed portion 48b. The first recess 48a and the second recess 48b extend along the second direction DB. In the illustrated example, the first recess 48a and the second recess 48b extend over the entire length of the notch guide wall portion 46 along the first direction DA.

Next, the tab block 70 will be explained. The tab block 70 is arranged between the tabs of two storage element groups 28 adjacent to each other in the first direction DA, which is the thickness direction of the storage element body 30 . Tab block 70 is formed of an insulating material. The tab block 70 can be, for example, a resin molding. The tab block 70 insulates between the tabs 35 of the two storage element bodies 30 stacked adjacent to each other in the first direction DA. Further, the tab block 70 described below also has a function of positioning the storage element body 30 with respect to the case 40 .

In addition, as shown in FIG. 12, the projections 76 of a plurality of tab blocks 70 arranged in the first direction DA are contained in one first recess 48a extending along the first direction DA. The case 40 allows the tab block 70 to move relative to the case 40 in the first direction DA, and restricts the tab block 70 to move relative to the case 40 in the second direction DB or the third direction DC. , holding a plurality of tab blocks 70 .

Tab block 70 is formed using an insulating material. The insulating base portion 71, the inner portion 72, the outer portion 73, and the connection guide portion 74 of the tab block 70 may be integrally molded using insulating resin.

By the way, as schematically shown in FIG. 11, the tab block 70 is located at a position shifted from the central portion 31C of the electric storage element body 30 along the direction orthogonal to the first direction DA, which is the thickness direction of the electric storage element body 30. is provided. In the illustrated example, the tab block 70 is provided at a position shifted from the central portion 31C along the third direction DC orthogonal to the first direction DA. That is, the tab block 70 does not overlap the central portion 31C of the power storage element body 30 when projected in the first direction DA. Particularly in the illustrated example, the tab block 70 overlaps only the peripheral edge portion 31E of the storage element body 30 in the projection in the first direction DA, and the tabs of the adjacent two storage element bodies 30 to be insulated. Located between 35.

By interposing the insulating tab block 70 between the tabs 35 of the two storage element groups 28 at positions displaced from the central portion 31C, the tabs 35 of the two adjacent storage element groups 28 to be insulated can be separated from each other. can be insulated.

Further, the case 40 allows the tab block 70 to move relative to the case 40 in the first direction DA. On the other hand, the case 40 restricts relative movement of the tab block 70 with respect to the case 40 in directions not parallel to the first direction DA, especially in the second direction DB and the third direction DC orthogonal to the first direction DA. Since the case 40 supports the tab block 70 in this way, the tab block 70 supported by the case 40 follows the thickness variation of the electric storage element body 30 and moves in the first direction, which is the thickness direction of the electric storage element body 30 . You can move to DA. Thereby, the insulation using the tab block 70 can be stably ensured.

Further, the tab block 70 is at least partially located in a notch C formed in the side wall portion 44 of the case 40 . According to such a configuration, it is possible to insulate the tabs 35 of two adjacent power storage element bodies 30 that are arranged close to each other with a simple configuration.

Further, tab block 70 is supported by side wall portion 44 , and electric storage element body 30 is housed in a space defined by side wall portion 44 that supports tab block 70 . Therefore, it is possible to stably insulate the tabs 35 of two adjacent storage element groups 28 that are arranged close to each other with a simple configuration.

Further, the side wall portion 44 has a first recessed portion 48a extending in the first direction DA, which is the thickness direction of the electric storage element body 30, and the tab block 70 is inserted into the first recessed portion 48a and extends relative to the first recessed portion 48a. It has a convex portion 76 that is relatively movable in the first direction DA. According to such a configuration, the tab block 70 can move in the first direction DA following variations in thickness of the storage element body 30 and the dummy body 36 . As a result, it is possible to stably secure insulation while adopting a simple configuration.

However, the present invention is not limited to the example described above, and the protrusion 76 formed by the connecting projecting piece 75 of the tab block 70 may be inserted into the second recess 48b instead of the first recess 48a. Further, unlike the example described above, the tab block 70 has a recess extending in the first direction DA, which is the thickness direction of the electric storage element body 30, and the side wall portion 44 is inserted into the recess and extends in the first direction with respect to the recess. You may make it have the convex part which can be relatively moved to the direction DA. Similar effects can be achieved by these modifications as well.

Furthermore, in the illustrated example, the power storage element body 30 is configured such that the first exterior material 34A having the bulging portion 34AP faces one side SA1 in the first direction DA and the second exterior material 34B faces the other side in the first direction DA. a power storage element group 28 having power storage element bodies 30 in which the second exterior material 34B faces one side SA1 in the first direction DA and the first exterior material 34A faces the other side in the first direction DA; are alternately stacked in the first direction DA. Then, as shown in FIG. 11, the tab block 70 is arranged between two cells laminated so that the first exterior members 34A face each other. According to such a configuration, while ensuring the insulation of the tabs 35 of the two adjacent energy storage element groups 28, the center portions 31C of the two energy storage element groups 28 can be arranged so as to be close to each other in the first direction DA. can be done. That is, the thickness in the first direction DA of the plurality of stacked power storage element groups 28 can be reduced. Moreover, the accumulator element bodies 30 of the plurality of accumulator element groups 28 and the peripheral edge portions 31E of the dummy bodies 36 can be prevented from bending, and the posture can be maintained. As a result, the insulation between the two storage element groups 28 can be stably ensured, and unintended damage or the like to the storage element bodies 30 and the dummy bodies 36 can be effectively avoided.

As shown in FIG. 11, in such a configuration, the thickness Tx of the tab block 70 along the first direction DA is two times the projection length Lx of the central portion 31C of the storage element body 30 in the first direction DA. It is preferably not more than double. By setting the thickness Tx of the tab block 70 within such a range, the thickness of the electric storage element module 20 can be reduced. In addition, from the viewpoint of preventing the peripheral edge portion 31E of the storage element body 30 from bending, the thickness Tx of the tab block 70 along the first direction DA is equal to the protrusion length of the central portion 31C of the storage element body 30 in the first direction DA. It is preferably greater than Lx. In the illustrated example, the projection length Lx of the central portion 31C of the storage element body 30 in the first direction DA matches the projection length of the bulging portion 34AP of the first exterior material 34A in the first direction DA. do.

The tab block 70 is arranged between the tabs 35 that should not be electrically connected among the tabs 35 of the two power storage element groups 28 that are adjacent in the thickness direction. On the other hand, the electrode member 80 is arranged between the tabs 35 to be electrically connected among the tabs 35 of the two power storage element groups 28 adjacent in the thickness direction, and is electrically connected to the tabs 35 . ing. The thickness of the electrode member 80 along the first direction DA may be thinner than the thickness of the insulating base portion 71 of the tab block 70 . In addition, as shown in FIG. 11, the electrode member 80 may be positioned within the region where the tab block 70 is arranged in the first direction DA. That is, the tab block 70 secures a space for arranging the electrode member 80 in the outer portion 73, and separates the two storage element groups 28 from each other in the first direction DA in the insulating base portion 71 or the inner portion 72. The insulation of the tabs 35 of the storage element bodies 30 of the storage element groups 28 is ensured.

The case 40 allows the electrode member 80 to move relative to the case 40 in the first direction DA, and restricts the electrode member 80 to move relative to the case 40 in a direction orthogonal to the first direction DA. may support According to such a configuration, the electrode member 80 held in the case 40 can move in the stacking direction in accordance with variations in the thicknesses of the electric storage element bodies 30 and the dummy bodies 36 . A stable electrical connection with the storage element body 30 can be ensured.

Further, the electrode member 80 may be supported by the side wall portion 44 forming the cutouts C through which the tabs 35 of the plurality of power storage element bodies 30 pass. Thereby, the tabs 35 of the storage element bodies 30 of the two adjacent storage element groups 28 can be electrically connected with a simple configuration. Further, since the tab 35 extends from the side wall portion 44 of the case 40, the electrical connection with the storage element body 30 can be stably ensured.

Next, a method for designing the storage element unit 10 according to this embodiment will be described. Here, a method for determining the storage element bodies 30 and the dummy bodies 36 that constitute the storage element module 20 of the storage element unit 10 will be described.

First, information about the target voltage V1 [V] of each storage element module 20 of the storage element unit 10 is acquired. Also, information about the output voltage V2 [V] of the storage element body 30 is acquired. Subsequently, based on the target voltage V1 and the output voltage V2, the number of the storage element groups 28 to be electrically connected in series in the storage element module 20, that is, the number of storage element bodies 30 to be electrically connected in series. determine the number of For example, when the target voltage V1 is eight times the output voltage V2, the number of storage element groups 28 is determined to be eight.

Subsequently, information on the target electric capacity U1 [Wh] of each storage element module 20 of the storage element unit 10 is obtained. Also, information on the electric capacity U2 [Wh] of the storage element body 30 is acquired. Subsequently, based on the target electric capacity U1 and electric capacity U2, the number of electric storage element bodies 30 to be electrically connected in parallel in each electric storage element group 28 is determined. For example, when the target electric capacity U1 is equal to or smaller than the electric capacity U2, the number of electric storage element bodies 30 in each electric storage element group 28 is determined to be one. Also, when the target electric capacity U1 is larger than the electric capacity U2 and is equal to or less than two times the electric capacity U2, the number of electric storage element bodies 30 in each electric storage element group 28 is determined to be two. Here, the case where the target electric capacity U1 is equal to or smaller than the electric capacity U2 and the number of electric storage element bodies 30 in each electric storage element group 28 is one will be described.

Subsequently, a container 18 capable of accommodating a laminate in which eight energy storage element groups 28 each including at least one energy storage element body 30 are electrically connected in series is searched. Here, the housing body 18 (hereinafter referred to as a lamination body 18) is configured to house a laminate in which eight storage element groups 28 including two storage element bodies 30 electrically connected in parallel are electrically connected in series. It is assumed that a container 18 for 2x8) has already been developed. Further, the housing body 18 (hereinafter referred to as the housing body 18 for 1×8) is configured to house a laminate in which eight storage element groups 28 each including only one storage element body 30 are electrically connected in series. ) has not yet been developed.

In this case, when a container 18 for 2×8 is adopted and a plurality of energy storage element groups 28 are accommodated in the container 18 so that each energy storage element group 28 has one energy storage element body 30, one energy storage element A space for one storage element body 30 per group 28 is left over. As a result, it is conceivable that the arrangement of the storage element body 30 inside the container 18 becomes unstable. For example, it may be difficult to align the tab block 70 and the electrode member 80 with respect to the electric storage element assembly 30 . On the other hand, when a container 18 for 2×8 is adopted and a plurality of energy storage element groups 28 are accommodated in the container 18 so that each energy storage element group 28 has two energy storage element bodies 30, the energy storage element module 20 becomes larger than the target electric capacity U1. That is, the battery capacity of the storage element module 20 becomes excessively large, resulting in unnecessary costs.

Moreover, when adopting the containing body 18 for 1*8, the cost for newly developing the containing body 18 for 1*8 will arise.

Here, in the present embodiment, storage element group 28 includes dummy body 36 having the same thickness as storage element body 30 in addition to storage element body 30 . Therefore, it is possible to optimize the arrangement of each member inside the containing body 18 while adopting the containing body 18 that has already been developed. For example, a container 18 for 2×8 is adopted, and a plurality of storage element groups 28 are housed in the storage element group 28 so that each storage element group 28 has one storage element body 30 and one dummy body 36. . As a result, it is possible to prevent an extra space from being created inside the containing body 18, and the arrangement of each member inside the containing body 18 becomes stable. In addition, since the extra power storage element bodies 30 are not housed in the housing body 18, unnecessary costs associated with the power storage element bodies 30 can be suppressed. Moreover, since the container 18 that has already been developed is used, the waste associated with the development cost of the container 18 can be suppressed.

Various modifications can be made to the above-described embodiment. Modifications will be described below with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding portions in the above-described embodiment are used for the portions that can be configured in the same manner as in the above-described embodiment, Duplicate explanations are omitted. Further, when it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified example, the explanation thereof may be omitted.

In the above embodiment, in each storage element group 28, the storage element body 30 and the dummy body 36 are in contact with each other in the thickness direction. However, the present invention is not limited to this, and in each storage element group 28, storage element bodies 30 and dummy bodies 36 do not have to be in contact with each other in the thickness direction. For example, as shown in FIG. 15, the storage element group 28 may have an intermediate member 29 located between the storage element body 30 and the dummy body 36 in the thickness direction. The intermediate member 29 is, for example, a plate-like member having insulation. Intermediate member 29 may have a thickness adjusted so that the sum of the thickness of intermediate member 29 and the thickness of dummy body 36 is the same as the thickness of power storage element body 30 .

Further, in the above-described embodiment, in each storage element group 28, the storage element bodies 30 and the dummy bodies 36 are arranged side by side in the thickness direction. However, it is not limited to this, and the electric storage element body 30 and the dummy body 36 may be arranged in a direction intersecting the thickness direction. For example, as shown in FIG. 16, the storage element body 30 and the dummy body 36 may be arranged in the second direction DB. Moreover, although not shown, the storage element groups 28 may be arranged in a direction crossing the thickness direction. Also in this case, the storage element groups 28 are electrically connected in series.

Further, in the above-described embodiment, the example in which the number of storage element bodies 30 included in the storage element group 28 including the dummy body 36 is one has been shown. However, the present invention is not limited to this, and the storage element group 28 including the dummy bodies 36 may have a plurality of storage element bodies 30 . For example, as shown in FIG. 17, the storage element group 28 may include three storage element bodies 30 and one dummy body 36 arranged in the thickness direction. In this case, the three power storage element bodies 30 of each power storage element group 28 are electrically connected to each other. In addition, each storage element group 28 is electrically connected in series with each other. That is, three power storage element bodies 30 included in one power storage element group 28 are electrically connected in series to three power storage element bodies 30 included in another power storage element group 28 .

In the example shown in FIG. 17, it is assumed that the number of storage element groups 28 that can be housed in the storage body 18 of the storage element module 20 is eight. In this case, as the housing body 18, the housing body 18 is capable of housing a laminate in which eight storage element groups 28 including four storage element bodies 30 electrically connected in parallel are electrically connected in series. (hereinafter also referred to as container 18 for 4×8) is used.

In the example shown in FIG. 17 , the target electric capacity U1 [Wh] of the power storage element module 20 is larger than twice the electric capacity U2 of one power storage element body 30 and equal to the electric capacity U2 of one power storage element body 30. 3 times or less. In this case, the number of power storage element bodies 30 included in each power storage element group 28 is preferably three. On the other hand, the number of storage element bodies 30 in each storage element group 28 assumed for the container 18 is four. In this case, as shown in FIG. 17, each storage element group 28 is provided with three storage element bodies 30 and one dummy body 36 . Thereby, it is possible to suppress the generation of extra space inside the container 18 . Moreover, compared to the case where each storage element group 28 has four storage element bodies 30, it is possible to suppress unnecessary costs associated with the storage element bodies 30. FIG.

Although several modifications of the above-described embodiment have been described above, it is of course possible to apply a plurality of modifications in appropriate combination.

DA First direction SA1 One side DB Second direction SB1 Other side DC Third direction SC1 One side C Notch V Space 10 Storage element unit 11 Storage box 12 Frame 13 Panel 14 Control module 15 Storage element module assembly 15A First storage Element module assembly 15B Second storage element module assembly 18 Container 20 Storage element module 20A First storage element module 20B Second storage element module 21 First end cover 22 Second end cover 25 Heat transfer member 28 Energy storage element group 30 Energy storage element body 31E Peripheral edge 31C Central part 32 Electrode plate 33 Exterior body 34A First exterior material 34AP Swelling part 34B Second exterior material 35 Tab 35A Base end 35B Tip end 36 Dummy body 38 Joining layer 40 Case 40a Opening 42 Bottom 44 Side wall 45 Notch forming wall 46 Notch guide wall 46a First rib 46b Second rib 48a First recess 48b Second recess 49 Receiving portion 60 Cover 61 Cover body 62 Fixing portion 70 Tab block 71 Insulating base portion 72 Inner portion 73 Outer portion 74 Connection guide portion 75 Connection protruding piece 76 Protruding portion 80 Electrode member

Claims (10)

a storage box and
a plurality of energy storage element groups housed in the storage box and electrically connected in series;
The energy storage element group includes at least one energy storage element body that is electrically connected to another energy storage element group and extends in a planar direction, and at least one dummy body that extends in the same planar direction as the energy storage element body. have
the electricity storage element body and the dummy body have the same thickness in a thickness direction perpendicular to the surface direction;
The electricity storage element body and the dummy body are arranged in the thickness direction,
The electric storage element unit , wherein the electric storage element body and the dummy body are in contact with each other in the thickness direction . a storage box and
a plurality of energy storage element groups housed in the storage box and electrically connected in series;
The energy storage element group includes at least one energy storage element body that is electrically connected to another energy storage element group and extends in a planar direction, and at least one dummy body that extends in the same planar direction as the energy storage element body. have
the electricity storage element body and the dummy body have the same thickness in a thickness direction perpendicular to the surface direction;
An electric storage element unit, wherein the electric storage element group includes a plurality of electric storage element bodies electrically connected in parallel with each other . 3. The storage element unit according to claim 2 , wherein said storage element body and said dummy body are arranged in said thickness direction. 4. The storage element unit according to claim 3 , wherein said storage element body and said dummy body are in contact with each other in said thickness direction. 4. The storage element unit according to claim 3 , wherein said storage element group has an intermediate member located between said storage element body and said dummy body in said thickness direction. The storage element unit according to any one of claims 1 to 5 , wherein at least some of the plurality of storage element groups are arranged in the thickness direction. The storage element unit according to any one of claims 1 to 6 , wherein at least some of the plurality of storage element groups are arranged in a direction intersecting the thickness direction. 8. The storage element unit according to claim 1, wherein the storage element groups have the same number of storage element bodies, and the storage element groups have the same number of dummy bodies. 9. The storage element unit according to claim 1, wherein said storage element body and said dummy body have the same dimension in said plane direction . A design method for a power storage element unit according to any one of claims 1 to 9 ,
obtaining information about the target electric capacity of the storage element unit;
and determining the number of the storage element bodies and the number of the dummy bodies in each storage element group so as to satisfy the target electric capacity.

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