Power storage device

Abstract

To provide a power storage device capable of suppressing reduction in battery capacity of the power storage device in simple configuration.SOLUTION: A power storage device comprises: a rectangular parallelepiped cell laminate 17 configured by laminating a plurality of tabular battery cells 16 each including a power generating element 14 and a package 15 in which the power generating element 14 is stored; a housing 33 including a front cover body 29, a back face part 33a, a top face part 33e, a bottom face part 33d and side face parts 33b and 33c; pressurization means 19 which is stored in the housing 33 and pressurizes the cell laminate 17 so as to compress it; a pair of leg members 20a and 20b fixed on a floor F and supporting a bottom face part 184; and a wall fixture member 21 including a long tabular back face fixing part 211 to be fixed on a wall W. The leg members 20a and 20b include base parts 20a1 and 20b1 which are positioned on the floor F, and two bent parts 20a2 and 20a3; 20b2 and 20b3 which are vertical to the base parts 20a1 and 20b1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage device including a secondary battery such as a lithium ion battery and a nickel metal hydride battery. [Background technology]

[0002] In recent years, power storage devices have become widespread for the purpose of combining with renewable energy and supplying power in the event of a disaster. In a power storage device, internal components such as a battery module, a control circuit, and a conversion circuit are housed in a housing. For example, the inside of the housing is configured in a shelf shape, and a plurality of battery modules weighing 10 to 30 kg and having a capacity of 0.5 to 3.0 kWh are housed on each shelf. The battery modules are electrically connected to the control circuit and the conversion circuit by wiring. In order to ensure safety, such a power storage device is required not to fall or move due to an earthquake or the like. Therefore, various techniques for fixing a power storage device to a building have been proposed, for example, in Patent Documents 1 to 5. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-196857 A [Patent Document 2] JP 2017-155459 A [Patent Document 3] JP 2016-18608 A [Patent Document 4] JP 2016-85895 A [Patent Document 5] JP 2019-109986 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional techniques described in the above Patent Documents 1 to 3, after the storage device is installed in a building, the storage device is placed on the floor of the building and is screwed to the wall of the building via metal fittings attached to the back and side parts of the storage device. When the storage device is transported by a transport vehicle such as a truck or a ship, there is no wall in the cargo compartment of the transport vehicle or ship to fix the storage device, so the storage device is loaded with the bottom part of the storage device facing down. In this state, when the vibration during transportation and the inertial force due to an earthquake after installation act on the storage device, the storage capacity of the storage device may decrease. In order to suppress such a decrease in storage capacity, a design is required to protect the battery module against the transmission path and vibration mode of each vibration. As one of the measures to protect the storage device from multiple vibration modes, it is possible to attach a buffer mechanism corresponding to each vibration mode to the battery module. In order to deal with all vibration modes using such a buffer mechanism, the number of buffer mechanisms attached to the battery module increases, which increases the number of materials and parts used in the storage device, resulting in a complex structure.

[0005] The conventional technology described in Patent Document 4 discloses a technique for increasing the initial capacity of a storage battery by applying a compressive force to a stack of multiple battery cells that constitute a battery module. However, no consideration is given to measures against vibrations during transportation or the action of inertial forces during earthquakes, and no measures are proposed for the mounting structure.

[0006] Furthermore, the conventional technologies described in Patent Documents 1 to 4 above do not provide sufficient countermeasures against vibration of the battery modules in the energy storage device, and therefore acceleration caused by vibrations of the energy storage device during earthquakes and transportation may reduce the battery capacity of the energy storage device and may accelerate the rate at which the battery capacity will decrease in the future. There is a demand for an energy storage device that can solve these technical problems of the conventional technologies with a simple configuration.

[0007] The prior art described in the above Patent Document 5 proposes a small-sized power storage device that can be wall-mounted by a metal fitting on the back side. In this prior art, as the battery capacity increases, the weight of the power storage device also increases, and sufficient mechanical strength cannot be ensured in a wall-mounted structure, so that the installation target is limited to small-sized power storage devices. Although the packaging state of the power storage device, that is, the so-called packing state, is not described, it is considered that the power storage device is stored in a packing box in a horizontally lying position in order to stably load the power storage device. If the power storage device is loaded in such a horizontally lying position, the vibration during transportation is transmitted to the power storage device in a form different from the vibration of an earthquake when the power storage device is wall-mounted. Therefore, there is a problem that the structure is likely to become complicated, such as the number of fixing points of the storage battery module and wiring in the housing increasing, in order to respond to the vibration modes for the two types of positions of the power storage device, that is, the state in which the power storage device is laid on its side and the state in which it is wall-mounted. [Means for solving the problem]

[0008] The power storage device according to the present disclosure includes a cell stack in which a plurality of battery cells are stacked, the battery cells having a power generating element and a packaging body that houses the power generating element; A housing that houses the cell stack, A front part and a back surface portion located on the opposite side of the cell stack from the front surface portion; an upper surface portion that faces the cell stack from above and extends between the front surface portion and the rear surface portion; A bottom surface portion extending between the front surface portion and the rear surface portion and facing the cell stack from below; A housing having two side surfaces facing the cell stack from the sides between the front surface and the rear surface; a pressure applying unit that is located within the housing and applies pressure to the plurality of battery cells so as to compress them in the stacking direction; A pair of leg members that can be fixed to a first fixing surface that faces the bottom surface and are respectively disposed at positions close to the two side surfaces of the bottom surface; A rear fixing portion that can be fixed to a second fixing surface that faces the rear portion. 、 and A pair of leg member fixing parts, one of the pair of leg member fixing parts being The above A pair leg parts On the other hand Connected to The other of the pair of leg member fixing parts is connected to the other of the pair of leg members. R , a pair of and a wall fixing member having a leg member fixing portion. Effect of the Invention

[0009] According to the electricity storage device according to the present disclosure, it is possible to provide an electricity storage device that has a simple configuration, improves installation ease, and can suppress a decrease in electricity storage capacity. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an example of installation in which a power storage device according to an embodiment of the present disclosure is attached to a wall and a floor of a wooden house. [Diagram 2] FIG. 11 is a perspective view showing an example of installation in which the power storage device is attached to a wall of a house made of a concrete structure. [Diagram 3] 1 is an exploded perspective view of an electricity storage device according to an embodiment of the present disclosure. [Figure 4] 11 is a perspective view showing a state in which the battery module is housed in the housing from which the front cover body has been removed and moved toward the wall. FIG. [Diagram 5] FIG. 2 is a perspective view showing a state in which a front cover body is attached to a housing. [Figure 6] FIG. 2 is a perspective view showing a wall fixing member and a leg member. [Figure 7] FIG. 2 is a cross-sectional view showing the internal structure of the battery module. [Figure 8] FIG. 2 is an exploded perspective view of the battery module. [Figure 9] FIG. 2 is a perspective view showing the appearance of a battery cell. [Figure 10] 4 is a flowchart for explaining a procedure for attaching a battery module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the power storage device according to the present disclosure will be described with reference to the accompanying drawings.

[0012] Fig. 1 is a perspective view showing an installation example in which a power storage device 1 according to an embodiment of the present disclosure is installed on a wall W1 and a floor F1 of a wooden house. Fig. 2 is a perspective view showing an installation example in which a power storage device 1 is installed on a wall W2 and a floor F2 of a house made of a concrete structure. As power storage devices are becoming more widespread for the purpose of combining with renewable energy and supplying power during disasters, an example of an embodiment of a power storage device that has high safety against vibrations during earthquakes and transportation, has a simple configuration, and is easy to install when installing the power storage device 1 not only in wooden houses but also in concrete houses will be described below.

[0013] The locations to which the power storage device 1 of this embodiment is to be installed include a wall W1 that is the second fixed surface and a floor F1 that is the first fixed surface of a wooden house shown in Fig. 1, and a wall W2 and a floor F2 of a house with a concrete structure shown in Fig. 2. In the following description, the walls W1 and W2 will be referred to collectively without distinction and will be referred to as the wall W, and the floors F1 and F2 will be referred to collectively without distinction and will be referred to as the floor F.

[0014] First, a schematic structure of an example of a target mounting location of a building to which the energy storage device 1 of this embodiment is attached will be described. As shown in Fig. 1, a wall W1 of a wooden house is configured with a plurality of studs 2 arranged horizontally and parallel to each other at equal intervals with battens 3, and an exterior wall panel 4 is fixed to each stud 2 from the outdoor side with nails or the like, and a fireproof covering panel 5 also called a fireproof board is fixed from the indoor side with nails or the like. The floor F1 is configured by laying a floor surface material 61 made of compressed plywood or the like. 2, wall W2 of a concrete house has multiple studs 6 made of shaped steel material set up in parallel at equal horizontal intervals, sound absorbing material 8 such as glass wool arranged between each stud 6, concrete wall material 9 arranged on each stud 6 from the outdoor side, base material 10 such as gypsum board and top surface material 11 such as hard gypsum board arranged from the indoor side, and furthermore bonding material 12 made of fire-retardant resin or the like is attached to the top surface material 11 so as to cover the joints between the top surface materials 11, and baseboards 13 are attached. Floor F2 is constructed by laying floor surface material 141 made of compressed plywood or the like, similar to floor F1 of the wooden house described above.

[0015] The energy storage device 1 is installed immediately before and adjacent to the baseboard 13 at the corner where the wall W and floor F are close to each other as described above, and the same common configuration applies to both wooden and concrete buildings, and as described below, it has high mechanical strength against external forces such as vibrations and shocks during earthquakes and transportation, and is also easy to install in terms of reducing the effort required for installation, and is realized by a simple configuration with a small number of parts.

[0016] Fig. 3 is an exploded perspective view of the energy storage device 1 according to the embodiment of the present disclosure. Fig. 4 is a perspective view showing a state in which the battery module 30 is housed in the housing 33 from which the front cover body 29 has been removed and moved toward the wall W. Fig. 5 is a perspective view showing a state in which the front cover body 29 is attached to the housing 33. Fig. 6 is a perspective view showing the wall fixing member 21 and the leg members 20a, 20b. Note that the perspective view of the leg member 20a is a view in which a part of the leg member 20a is virtually removed in order to show the base portion 20a1. Fig. 7 is a cross-sectional view showing the internal structure of the battery module 30.

[0017] As shown in Figures 3, 4 and 7, the energy storage device 1 of this embodiment comprises a rectangular cell stack 17 in which a plurality of plate-shaped battery cells 16, each having a power generation element 14 and a packaging body 15 that houses the power generation element 14, a rectangular storage case 18 that houses the cell stack 17, a housing 33 that houses the storage case 18 that houses the cell stack 17, a pressure means 19 that pressurizes each of the side surfaces 17a, 17b on both sides of the stacking direction D of the cell stack 17 so that the plurality of battery cells 16 are compressed in the stacking direction D, a pair of leg members 20a, 20b that are fixed to the floor F and support positions near both ends of the bottom portion 33d (see Figures 3 and 4) of the housing 33 in the stacking direction D, and a wall fixing member 21 having a longitudinal plate-shaped rear fixing portion 211 that is fixed to the wall W opposite the rear portion 33a of the housing 33.

[0018] The housing 33 has a front cover body 29 which is the front portion, a back portion 33a which is located on the opposite side of the cell stack 17 from the front cover body 29, a top portion 33e which faces the cell stack 17 from above between the front cover body 29 and the back portion 33a, a bottom portion 33d which faces the cell stack 17 from below between the front cover body 29 and the back portion 33a, and two side portions 33b, 33c which face the cell stack 17 from the side between the front cover body 29 and the back portion 33a.

[0019] As shown in FIG. 6, each of the pair of leg members 20a, 20b has a longitudinal plate-shaped base 20a1, 20b1 located on floor F, two bent portions 20a2, 20a3; 20b2, 20b3 each perpendicular to base portions 20a1, 20b1, which are connected to both side edges in the width direction perpendicular to the longitudinal direction of base portions 20a1, 20b1, and flange portions 20a4, 20a5; 20b4, 20b5 connected perpendicularly to the upper edges of each pair of bent portions 20a2, 20a3; 20b2, 20b3 and screwed to positions near both ends in the stacking direction D of the bottom portion 33d of housing 33, and is formed in a roughly U-shape. These leg members 20a, 20b have base portions 20a1, 20b1, bent portions 20a2, 20a3; 20b2, 20b3, and flange portions 20a4, 20a5; 20b4, 20b5, and therefore have a large second moment of area in a cross section perpendicular to the longitudinal direction and large bending rigidity against the overturning moment acting on the storage battery device 1 due to earthquakes or vibrations.

[0020] As shown in Fig. 6, the wall fixing member 21 is a pair of approximately L-shaped leg member fixing parts 212, 213 that are connected to both ends of the rear fixing part 211 in the longitudinal direction and are bent perpendicularly to the rear fixing part 211, and has a pair of leg member fixing parts 212a, 213a to which one of the two bent parts 20a2, 20a3; 20b2, 20b3 of each leg member 20a, 20b that is arranged on the outside of the stacking direction D of the cell stack 17 is screwed and fixed. Each leg member fixing part 212a, 213a has a plurality of tapping holes 212b, 213b formed therein, into which a tapping screw is inserted through one of the bent parts 20a2, 20b3 that is arranged on the outside of each leg member 20a, 20b and screwed. Each tapping hole 212b, 213b is burred to increase the screwing strength of the tapping screw.

[0021] Fig. 8 is an exploded perspective view of the battery module 30. Fig. 9 is a perspective view showing the appearance of the battery cell 16. The storage case 18 has a front portion 181, a back portion 182 located on the opposite side of the cell stack 17 from the front portion 181, a top portion 183 facing the cell stack 17 from above between the front portion 181 and the back portion 182, a bottom portion 184 facing the cell stack 17 from below between the front portion 181 and the back portion 182, and two side portions 185, 186 facing the cell stack 17 from the sides between the front portion 181 and the back portion 182.

[0022] The battery module 30 includes a cell stack 17 , a current collecting member 40 , a housing case 18 , and a pressurizing means 19 .

[0023] In the cell stack 17, a plurality of battery cells 16 are stacked on top of each other in the stacking direction D. The plurality of battery cells 16 are stacked so that their outer shapes are approximately the same when viewed from the stacking direction D, forming the cell stack 17 having an approximately rectangular parallelepiped appearance. In the cell stack 17, the positive electrode terminal 161 and the negative electrode terminal 162 of each battery cell 16 protrude from the end face 17c of the cell stack 7. The shape of the battery cell 16 when viewed from the stacking direction D of the cell stack 17 may be, for example, rectangular, square, circular, elliptical, or other shapes. In this embodiment, the battery cell 16 is approximately rectangular when viewed from the stacking direction D, as shown in FIG. 8. As an example of the dimensions of the battery cell 16 when viewed from the stacking direction D, the length of the long side is 50 mm to 500 mm, and the length of the short side is 50 mm to 300 mm. The thickness of the battery cells 16 in the stacking direction D is, for example, 0.1 mm to 2 mm.

[0024] As shown in FIG. 9, the battery cell 16 includes a power generating element 14, a packaging body 15, a positive electrode terminal 161, and a negative electrode terminal 162. The power generating element 14 is a member for storing and discharging electric charge by utilizing an electrochemical reaction. The power generating element 14 includes, for example, a positive electrode connected to the positive electrode terminal 161, a negative electrode connected to the negative electrode terminal 162, and a separator located between the positive electrode and the negative electrode. The power generating element 14 can supply electric power generated by an electrochemical reaction in which cations and anions are exchanged between the positive electrode and the negative electrode through the separator (not shown) to an external device by electrically connecting the positive electrode terminal 161 and the negative electrode terminal 162 to the external device. The positive electrode and the negative electrode are made of, for example, an electrochemically active material.

[0025] The current collecting member 40 is a member that electrically connects the multiple battery cells 16 to each other. The current collecting member 40 may be configured to electrically connect the multiple battery cells 16 in parallel. That is, the current collecting member 40 may electrically connect the positive electrode terminals 161 of the multiple cell stacks 17 to each other and electrically connect the negative electrode terminals 162 of the multiple battery cells 16 to each other. This can increase the power storage capacity of the battery module 30.

[0026] The current collecting member 40 may be configured to electrically connect the positive electrode terminals 161 and the negative electrode terminals 162 of the multiple battery cells 16 so that the multiple cell stacks 17 are electrically connected in series. This makes it possible to increase the output voltage of the battery module 30.

[0027] The housing 33 is a member for housing the battery module 30 and protecting the battery module 30 from the external environment. The housing 33 may be a member for protecting the battery module 30 from an external force from the external environment. In this embodiment, the housing 33 is a box body having a rectangular parallelepiped shape with one side open, as shown in FIG. 4, for example. The housing 33 may be formed, for example, by forming one member into a rectangular parallelepiped shape with one side open. The housing 33 may be formed, for example, by combining two or more members together as in this embodiment.

[0028] The housing 33 may be made of, for example, a metal material. This increases the rigidity of the housing 33, and makes it difficult for external forces from the external environment to be transmitted to the battery module 30. As a result, the battery module 30 can be protected from the external environment. For example, an aluminum alloy, stainless steel, or the like may be used as a metal material used for the housing 33. This makes it easier for heat generated in the cell stack 17 to be transmitted to the housing 33, improves heat dissipation, and makes it difficult for heat to be stored in the cell stack 17. As a result, the cell stack 17 can be protected from heat, deterioration of the cell stack 17 due to heat can be suppressed, and the lifespan can be improved.

[0029] Storage case 18 may have, for example, a plurality of members. The plurality of members may be realized by, for example, plate-like members that respectively constitute front surface portion 181, rear surface portion 182, top surface portion 183, bottom surface portion 184, and two side surface portions 185, 186 as described above. Front surface portion 181, rear surface portion 182, top surface portion 183, bottom surface portion 184, and two side surface portions 185, 186 may include a metal material and a resin material.

[0030] The two side surface portions 185, 186 are members for protecting the end faces 17a, 17b of the cell stack 17 in the stacking direction D.

[0031] Main panels 51 are disposed on the inner sides of the side surface portions 185, 186 so as to face each other. The main panels 51 may be made of, for example, a resin material. Examples of the resin material used for the main panels 51 include heat-resistant resin materials such as polyethylene terephthalate (PET). This makes it possible to electrically insulate the cell stack 17 from the external environment, thereby preventing a short circuit between the cell stack 17 and the external environment and improving safety. As a result, the life of the cell stack 17 can be improved.

[0032] Each side portion 185, 186 is a member for protecting side portions 17a, 17b of the cell stack 17 that are connected to the upper surface and aligned along the stacking direction D. The two side portions 185, 186 face the side portions 17a, 17b of the cell stack 17, respectively.

[0033] Each side surface portion 185, 186 may be in contact with the side surfaces 17a, 17b of the cell stack 17, respectively. This allows heat generated in the cell stack 17 to be easily transferred to the outside via 185, 186, thereby reducing the thermal effect of the cell stack 17 and improving the lifespan of the cell stack 17. Furthermore, by including the cell stack 17 of the above embodiment, the battery module 30 of this embodiment can improve the lifespan of the cell stack 17 even if only one of the side surface portions 185, 186 is in contact with the opposing side surface 17a (or 17b) of the cell stack 17.

[0034] Each of the side surface portions 185, 186 may be rectangular when viewed in a direction perpendicular to the side surfaces 17a, 17b of the cell stack 17 (i.e., stacking direction D). In this case, the side surface portions 185, 186 may have long sides of 200 mm to 600 mm and short sides of 50 mm to 300 mm, for example. Each of the side surface portions 165, 166 may have a thickness of 0.5 mm to 5 mm, for example.

[0035] Each side portion 185, 186 may be made of, for example, a metal material. Examples of the metal material used for the side portion 185, 186 include aluminum alloy, stainless steel, etc. This makes it easier for heat generated in the cell stack 17 to be transferred to the outside via each side portion 185, 186, thereby suppressing deterioration of the cell stack 17 due to heat and extending its lifespan.

[0036] Each of the side portions 185, 186 may be made of, for example, a resin material. Examples of the resin material used for each of the side portions 185, 186 include a heat-resistant resin material such as polyethylene terephthalate (PET). This makes it possible to electrically insulate the cell stack 17 from the external environment, thereby preventing a short circuit between the cell stack 17 and the external environment. As a result, the life of the cell stack 17 can be extended.

[0037] Bottom surface portion 184 is a member for protecting the lower surface opposite to the upper surface of cell stack 17. Bottom surface portion 184 may be formed by bending a part of front surface portion 181 or side surface portions 185, 186.

[0038] The bottom surface portion 184 may be in contact with a bottom surface 17f opposite to the top surface 17c of the cell stack 17. This makes it easier for heat generated in the cell stack 17 to be conducted to the outside via the bottom surface portion 184, thereby making it possible to extend the life of the cell stack 17.

[0039] The bottom surface portion 184 may be rectangular when viewed in a direction perpendicular to the lower surface 17f of the cell stack 17. In this case, the bottom surface portion 184 may have, for example, long sides of 200 mm to 600 mm and short sides of 50 mm to 300 mm. The bottom surface portion 184 may also have a thickness of, for example, 0.5 mm to 5 mm.

[0040] The bottom surface portion 184 may be made of, for example, a metal material. Examples of the metal material used for the bottom surface portion 184 include aluminum alloys and stainless steel. This makes it easier for heat generated in the cell stack 17 to be transferred to the outside via the bottom surface portion 184, thereby making it possible to extend the life of the cell stack 17.

[0041] The bottom surface portion 184 may be made of, for example, a resin material. Examples of the resin material used for the bottom surface portion 184 include heat-resistant resin materials such as polyethylene terephthalate (PET). This makes it possible to electrically insulate the cell stack 17 from the external environment, thereby reducing the risk of short-circuiting between the cell stack 17 and the external environment. This in turn makes it possible to extend the life of the cell stack 17.

[0042] The cell stack 17 may be held in the housing 33 by being pressed at the side surfaces 17a and 17b in the stacking direction D. The cell stack 17 may be held by being pressed by a pressing plate 54 and an elastic body 55.

[0043] For example, a metal material may be used as the pressure plate 54. This makes it possible to easily transfer heat generated from the cell stack 17 to the outside. As a result, it is possible to improve the life of the cell stack 17. Examples of metal materials used for the pressure plate 54 include aluminum alloys and stainless steel.

[0044] For example, an insulating resin material may be used as the pressure plate 54. This can electrically insulate the cell stack 17 from the external environment, thereby reducing the possibility of a short circuit between the cell stack 17 and the external environment. Examples of the resin material used for the pressure plate 54 include thermosetting resins such as epoxy resin, phenol resin, and melamine resin.

[0045] For example, a resin material and a metal material may be used as the pressing plate 54. The resin material may be used, for example, for the portion of the pressing plate 54 that comes into contact with the cell stack 17. This makes it possible to electrically insulate the cell stack 17 from the pressing plate 54. As a result, it is possible to reduce the possibility of a short circuit between the cell stack 17 and the external environment. Furthermore, by using a metal material for the pressing plate 54, it is possible to make the pressing plate less susceptible to damage.

[0046] The elastic body 55 is located between the pressing plate 54 and the main plate 51 of the housing 33. The elastic body 55 is provided to apply a compressive force to the cell stack 17 by applying pressure to the pressing plate 54. The elastic body 55 can be, for example, a spring. The spring can be, for example, a spiral compression coil spring or a torsion spring. The spring can also be, for example, a curved leaf spring. The spring can be made of, for example, a metal material. Examples of metal materials used for the spring include spring steel and stainless steel. The dimensions of the spring, for example, in the case of a spiral shape, can be a diameter of 5 mm to 50 mm, a length of 10 mm to 50 mm, and a pitch of 1 mm to 10 mm.

[0047] For example, a plate-shaped rubber material may be used as the elastic body 55. The rubber material may have the same shape as the pressing plate 54. The rubber material may be, for example, natural rubber or synthetic rubber.

[0048] Furthermore, pressure may be applied by the housing 33 to the end faces 17c, 17d of the cell stack 17 in a second direction E perpendicular to the stacking direction D. The housing 33 may apply a compressive force in a direction in which the main panel 51 presses the side faces 17a, 17b of the cell stack 17 by, for example, screwing the main panel 51 and the side portions 185, 186 together.

[0049] The battery module 30 can provide an electrochemical cell module with excellent durability by including the cell stack 17. Furthermore, the battery module 30 can prevent external forces from the external environment from being transmitted to the cell stack 17 by the highly rigid housing 33. This makes it possible to provide an electrochemical cell module with even greater durability.

[0050] Therefore, in the energy storage device 1 of the present disclosure, even if the fixing object during transportation or after installation is different from the floor F or the wall W, by fixing the housing 33 with common members, namely the leg members 20a, 20b and the wall fixing member 21, the load transmission path can be made the same during transportation and after installation, so there is no need to provide separate parts for reinforcement, etc., or to change to a different reinforcement structure, and the energy storage device 1 can have a simple structure.

[0051] The wall fixing member 21 has a pair of leg member fixing portions 212, 213 that are connected to both longitudinal ends of the rear fixing portion 211 and are bent perpendicularly to the rear fixing portion 211, and has a pair of leg member fixing portions 212a, 213a to which one of the two bent portions 20a2, 20a3; 20b2, 20b3 that is positioned on the outside in the stacking direction D of the cell stack 17 is fixed, respectively. 0

[0052] The energy storage device 1 further includes a flat reinforcing member 22 fixed to a wall W facing the rear portion 33a of the housing 33. The reinforcing member 22 is fixed to the wall W by screws at multiple points while being supported by an upper surface of a baseboard 13 disposed substantially horizontally at the lower end of the wall W near the floor F.

[0053] The energy storage device 1 further includes a cable 23, which is an electric wire electrically connected to the cell stack 17. The reinforcing member 22 has an electric wire through hole 24 for inserting the cable 23. The cable 23 may be a parallel cable wire in which multiple metal core wires are covered with an insulating material such as synthetic resin.

[0054] The energy storage device 1 further includes a rear cover member 25 that is concave in front view and extends along the upper edge portion of the rear portion 33a of the housing 33 and along two side portions 33b, 33c on both sides of the rear portion 33a in the stacking direction D of the cell stack 17.

[0055] It further includes a plurality of first screw members 26 which penetrate the reinforcing member 22 and are screwed to the wall W at a first interval ΔL1, and a plurality of second screw members 27 which penetrate the wall fixing member 21 and are screwed to the reinforcing member 22 at a second interval ΔL2 which is larger than the first interval ΔL1.

[0056] (effect) When the electricity storage device 1 vibrates in the up-down direction Y and in the front-rear direction X perpendicular to the wall W due to an earthquake, the wall fixing member 21 is formed in a substantially U-shape when viewed from the direction along the up-down direction Y, and the leg member fixing parts 212, 213 have surfaces that are aligned with the vibration directions of the up-down direction Y and the front-rear direction X, so that deformation is unlikely to occur. This increases the fixing strength.

[0057] The weight of the power storage device 1 is very heavy, about 40kg to 100kg for a storage capacity of 3 to 6kWh used in a typical detached house. Since the wall fixing member 21 has leg member fixing parts 212, 213 perpendicular to the wall W on which the power storage device 1 is to be installed, the power storage device 1 can be slid along the floor F toward the wall W, thereby positioning the power storage device 1 to be screwed to the wall fixing bracket. This improves ease of installation when installing a storage battery in a narrow space inside a house.

[0058] Since the reinforcing member 22 reinforces the wall W, the load applied to the wall W when an earthquake load is applied can be reduced, and damage to the wall W can be suppressed. By disposing the first screw members 26 on the outer periphery of the reinforcing member 22, the first interval ΔL1 between the first screw members 26 can be widened, and a sufficient number of the first screw members 26 can be driven while distributing the load applied to the wall W, so that the energy storage device 1 can be firmly fixed to the wall W. If the first screw members 26 are driven densely in a narrow range, the pull-out strength of the wall W decreases, and the first screw members 26 in the wall W are in a state of compressive failure similar to the case of driving in a large number of wedges, making the wall W more likely to be damaged. The first interval ΔL1 is set so as to prevent such a problem from occurring.

[0059] Since the electric wire hole 24 formed in the wall W for inserting the cable 23 therethrough can be protected by the reinforcing member 22, damage to the wall W caused by the electric wire hole 24 in the wall W being pulled by the cable 23 and breaking during construction or an earthquake, which would otherwise cause the periphery of the electric wire hole to break and expand, can be suppressed, and the wall W can be protected.

[0060] By shielding rear surface portion 33a of power storage device 1 and cable 23 from the surroundings, it is possible to prevent electric shock accidents caused by residents accidentally touching the rear surface of power storage device 1 while cleaning or the like.

[0061] As described above, according to this embodiment, it is possible to suppress the load applied to the wall W when an earthquake load or the like is applied, while ensuring sufficient fixing strength for the energy storage device 1. In particular, in the case of a wooden house, the first screw members 26 can be driven into wood screws or the like at any position, so that the reinforcing members 22 can be fixed to the pillars or studs 2 behind the wall by the first screw members 26 while increasing the degree of freedom in arranging the energy storage device 1. This allows the energy storage device 1 to be fixed firmly with good workability.

[0062] As described above, the energy storage device 1 is disposed on the floor F via the two leg members 20a, 20b, and each of the leg members 20a, 20b is screwed to the leg member fixing portions 212, 213 of the wall fixing member 21. Therefore, the inertial load of the energy storage device 1 due to vibrations such as an earthquake is distributed and transmitted to the floor F via each of the leg members 20a, 20b, and is also distributed and transmitted to the wall W via the wall fixing member 21 and the reinforcing member 22. This prevents excessive reaction forces from the leg members 20a, 20b and each of the leg member fixing portions 212, 213 from acting on the storage case 18 of the energy storage device 1, and therefore prevents large impact forces from acting on the cell stack 17 contained in the storage case 18 from both sides in the stacking direction D via the pressure means 19.

[0063] When an impact force acts on the cell stack 17 from both sides in the stacking direction D, a large compressive force acts on the multiple battery cells 16 that make up the cell stack 17. As described above, each battery cell has a configuration in which the power generating element 14 is sandwiched between positive and negative electrodes on both sides via a separator, so that a high compressive force acts locally from the pressure means 19 on the battery cells 16 located on both sides of the cell stack 17 in the stacking direction D.

[0064] When the main surface of the battery cell 16 is viewed microscopically, there are minute projections and recesses, and the battery cells 16 are in contact with each other only at the projections, and the contact area is much smaller than the area of ​​the entire main surface. Since the pressure of the restraining device is supported by the contact between the projections, even if the load applied to the main surface changes by only a few grams due to the above-mentioned compression amount, the pressure becomes extremely high at the projections, and the projections undergo plastic deformation. Due to this phenomenon, the thickness of the battery cell 16 in the stacking direction D decreases, just as the apparent volume of the sand decreases when a box containing sand is shaken, and this may reduce the compression load applied by the pressure means 19, leading to a decrease in battery capacity. The electricity storage device 1 according to this embodiment can prevent such problems.

[0065] A predetermined compressive load is applied to the battery cells 16 by pressure means 19 such as a compression coil spring in order to suppress fluctuations in resistance such as internal resistance and to maintain battery capacity over the long term. This compressive load must be kept within a certain range, as battery capacity is impaired if it is too high or too low.

[0066] However, when the main surfaces of the battery cells 16 are viewed microscopically, they are found to have minute projections and recesses, and the battery cells are in contact with each other only at their projections, with the contact area being much smaller than the area of ​​the entire main surfaces. Because the pressure of the restraining device is supported by the contact between the projections, even a change in the applied load of just a few grams will result in extremely high pressure at the projections, causing plastic deformation of the projections. This phenomenon reduces the thickness of the battery cells 16 in the stacking direction D, which in turn reduces the compressive load applied by the pressure means 19, potentially resulting in a reduction in battery capacity.

[0067] Meanwhile, the energy storage device 1 is fixed to a pallet during transportation, and once installed, is fixed to various objects such as an indoor wall W or an outdoor foundation. The energy storage device 1 is subjected to vibrations during transportation during transportation, and after installation, is subjected to vibrations due to earthquakes, etc. This vibration reduces the thickness of the battery cells 16 as described above, and because the elastic recovery force of the spring is proportional to the amount of displacement, there is a possibility that the compressive load of the cell stack 17 will change.

[0068] If the input path of the vibration applied to the energy storage device 1 is different, the difference in the path will result in a difference in the vibration mode, which will affect the thickness of the group of battery cells 16 in the stacking direction D and result in a different amount of reduction in the compressive load. Therefore, vibration-damping components and structures that correspond to each input path of the vibration to the energy storage device 1 are required.

[0069] (How to install) Fig. 10 is a flowchart showing the procedure for installing the energy storage device 1 according to an embodiment of the present disclosure. With reference to Figs. 3 to 5 as well, when the installation work for the energy storage device 1 is started, in step S1, the installer fixes the reinforcing member 22 to the wall W at a preselected installation position with the first screw members 26 as shown in Fig. 3, and then fixes the wall fixing member 21 onto the reinforcing member 22 and the baseboard 13 with the second screw members 27.

[0070] Next, in step S2, the battery module 1a with the front cover body 29 removed is carried in a state housed in the housing 33 immediately before the wall fixing member 21. The leg members 20a, 20b are fixed in advance by screws to the bottom surface portion 33d of the housing 33. Such a housing 33 is slid between the leg member fixing parts 212, 213 along the leg member fixing parts 212, 213 toward the wall W, and the leg member fixing parts 212, 213 are fixed to the leg members 20a, 20b by screws as shown in FIG.

[0071] Next, in step S3, the rear cover member 25 is inserted from directly above the battery module 1a into the gap between the battery module 1a and the wall W, and the rear cover member 25 is fixed to the leg member fixing portions 212, 213 with rivets 31. After that, in step S4, the front cover body 29 is attached to the battery module 1a as shown in FIG. 5, and the installation work of the energy storage device 1 is completed.

[0072] As described above, the electricity storage device 1 is attached to the wall W and the floor F by the wall fixing member 21 to which the leg members 20a, 20b are connected, so that the electricity storage device 1 can be easily fixed firmly to the wall W and the floor F with a small number of parts.

[0073] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-mentioned embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure. It goes without saying that all or part of the components of each of the above-mentioned embodiments can be appropriately combined within the scope of not contradicting each other. [Explanation of symbols]

[0074] 1. Energy storage device 2 Studs 3. Batten 4. Exterior wall panels 5. Fireproof Panel 6 Studs 61 Floor materials 8. Sound-absorbing materials 9. Concrete wall materials 10 Base material 11 Surface covering 12 Bonding material 13 Baseboard 14 Power generation elements 15 Packaging 16 Battery Cells 17 Cell stack 17a,17b side 18 Storage Case 181 Front part 182 Back part 183 Top part 184 Bottom part 185,186 side part 19 Pressurizing means 20a,20b Leg members 20a1,20b1 base 20a2,20a3;20b2,20b3 Bend part 21 Wall fixing members 211 Rear fixed part 22 Reinforcement members 23 Cable 24 Electrical wire hole 25 Rear cover member 26 First screw member 27 Second screw member 29 Front cover body 30 Battery Module 33 Case 33a Back part 33e Top part 33d bottom part 33b,33c Side part D Stacking direction W;W1,W2 Wall F;F1,F2 floor

Claims

1. a cell stack in which a plurality of battery cells each having a power generating element and a packaging body for accommodating the power generating element are stacked; A housing that houses the cell stack, A front part and a back surface portion located on the opposite side of the cell stack from the front surface portion; an upper surface portion that faces the cell stack from above and extends between the front surface portion and the rear surface portion; A bottom surface portion extending between the front surface portion and the rear surface portion and facing the cell stack from below; a housing having two side surfaces facing the cell stack from the sides between the front surface and the rear surface; a pressure applying unit that is located within the housing and applies pressure to the plurality of battery cells so as to compress them in the stacking direction; A pair of leg members that can be fixed to a first fixing surface that faces the bottom surface portion and are respectively disposed at positions close to the two side surfaces of the bottom surface; a wall fixing member having a rear fixing portion that can be fixed to a second fixing surface opposite the rear portion, and a pair of leg member fixing portions, one of the pair of leg member fixing portions being connected to one of the pair of leg members and the other of the pair of leg member fixing portions being connected to the other of the pair of leg members.

2. The leg member has an elongated shape extending in a longitudinal direction along the first fixing surface, The power storage device according to claim 1 , wherein the leg member fixing portions are connected to both side edge portions of the rear surface fixing portion in a width direction perpendicular to the longitudinal direction, and are bent perpendicular to the rear surface fixing portion.

3. The energy storage device described in claim 2, wherein the pair of leg members each have a base and two bent portions that are connected to both side edges in a width direction perpendicular to the longitudinal direction of the base and are perpendicular to the base, and the pair of leg member fixing portions are each fixed to one of the two bent portions that is positioned on the outside in the stacking direction of the cell stack.

4. The power storage device according to claim 3 , further comprising a reinforcing member fixable to the second fixing surface opposed to the rear surface portion.

5. Further comprising an electric wire electrically connected to the cell stack; The power storage device according to claim 4 , wherein the reinforcing member has an electric wire through hole for inserting the electric wire therethrough.

6. 6. The power storage device according to claim 1, further comprising a concave cover member extending along an upper edge portion and a side surface portion on the rear surface side.

7. a plurality of first screw members extending through the reinforcing member and attached to the wall at first intervals; The storage device according to any one of claims 4 to 6, further comprising: a plurality of second screw members that penetrate the wall fixing member and are attached to the reinforcing member at second intervals that are larger than the first intervals.

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