Power storage device, power storage module, and mobile body

Abstract

A power storage device according to the present invention comprises an electrode part, an exterior member that covers the electrode part, and a terminal part. The exterior member has: a housing part that houses the electrode part; and a flange part that is connected to the outer edge of the housing part and to which a first sheet part and a second sheet part are directly or indirectly adhered. The flange part has: a first sealing part at which the first sheet part and the second sheet part are adhered to the electrode part; a second sealing part at which the first sheet part and the second sheet part are directly adhered; and a fastening part that is formed continuously over at least the entire length of the second sealing part and that imparts an adhesive force through a fastening member that penetrates and fastens the first sheet part and the second sheet part.

Description

Power storage device, power storage module, and moving body

[0001] The present invention relates to a power storage device, a power storage module including the power storage device, and a moving body including the power storage module.

[0002] A conventional power storage device is disclosed in Patent Document 1. In this power storage device, a power storage element is enclosed in an exterior member. The power storage element has a configuration in which a positive electrode plate and a negative electrode plate are arranged to face each other via a separator, and an electrolyte is disposed between the positive electrode plate and the negative electrode plate. The power storage device has a configuration in which the power storage element is housed inside an exterior material formed of a resin film including a metal layer or a barrier layer. By covering the power storage element and the electrolyte with the resin film and sealing the outer edge portion, the power storage element is sealed by the exterior material.

[0003] In addition, a plurality of power storage devices having such a configuration are arranged side by side, and the power storage devices are connected in parallel or in series, and a power storage module housed in a module, a pack, or directly in a moving body is also used.

[0004] Japanese Patent No. 3852110

[0005] In recent years, the power storage capacity of power storage devices has been increasing. Along with the increase in the power storage capacity, the internal pressure acting on the exterior material due to gas generation, particularly during rapid charging, of the power storage element tends to increase. When the internal pressure rapidly increases, an excessive force acts on the exterior material sealing portion, and there may be a decrease in the sealing performance and local unsealing, which may cause problems in the power storage device. In addition, thermal runaway may occur in battery failures such as internal short circuits, and when thermal runaway occurs, the battery temperature rapidly rises, and there is also a possibility of unsealing, smoking, and ignition.

[0006] An object of the present invention is to provide a power storage device that maintains the sealing performance even when the internal pressure and temperature increase by repeating rapid charging, and also maintains the sealing performance even when thermal runaway occurs during abnormalities such as internal short circuits and nail punctures.

[0007] An exemplary energy storage device of the present invention comprises an electrode portion in which positive electrode plates and negative electrode plates are alternately stacked with an intermediate member in between; an outer casing member having a first packaging material and a second packaging material that cover the electrode portion from both outer sides in the stacking direction of the electrode portion; and terminal portions electrically connected to the positive electrode plate and the negative electrode plate, respectively. The outer casing member has a housing portion for housing the electrode portion and a sealing band portion connected to at least a part of the outer edge of the housing portion so that the first packaging material and the second packaging material are directly or indirectly bonded together. The sealing band portion has a fastening portion that applies a fastening force in the stacking direction to the first packaging material and the second packaging material by a fastening member that fastens through the first packaging material and the second packaging material.

[0008] According to the present invention, it is possible to provide an energy storage device that maintains sealing performance even when the internal pressure rises due to repeated rapid charging, and also maintains sealing performance even when thermal runaway occurs due to internal short circuits, nail penetration, etc.

[0009] Figure 1 is a front view of the energy storage device. Figure 2 is a cross-sectional view of the energy storage device shown in Figure 1, taken along line II-II. Figure 3 is an enlarged cross-sectional view of the energy storage device shown in Figure 1, taken along line III-III. Figure 4 is a cross-sectional view showing the laminated structure of the resin sheets. Figure 5 is an exploded perspective view of the energy storage device. Figure 6 is a perspective view of the energy storage module. Figure 7 is a side view of the electric vehicle. Figure 8 is a top view of the electric vehicle. Figure 9 is a front view of the energy storage device of the first modified example. Figure 10 is a front view of the energy storage device of the second modified example. Figure 11 is a cross-sectional view of the energy storage device shown in Figure 10, taken along line XI-XI. Figure 12 is a top view of the terminal section. Figure 13 is a front view of the energy storage device of the third modified example.

[0010] The following describes an energy storage device according to one embodiment of the present invention with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments and can be arbitrarily modified within the scope of the technical concept of the present invention.

[0011] In this specification, the energy storage device 1 is defined as having the Y-direction as vertical, the X-direction as horizontal, and the Z-direction as front-back, based on the state shown in Figures 1 and 2. In the energy storage device 1, the Z-direction is the front-back direction. These directions are assigned for convenience to facilitate explanation and do not represent the actual directions of use.

[0012] <Energy Storage Device 1> Figure 1 is a front view of energy storage device 1. Figure 2 is a cross-sectional view of energy storage device 1 shown in Figure 1, taken along line II-II. Figure 3 is an enlarged cross-sectional view of energy storage device 1 shown in Figure 1, taken along line III-III.

[0013] As shown in Figure 1, in a front view, the energy storage device 1 is rectangular in shape with the X direction as its longitudinal direction. As shown in Figures 1, 2, and 3, the energy storage device 1 includes an outer casing member 10, an energy storage element 20, and a terminal portion 30. The energy storage device 1 has a configuration in which the energy storage element 20 is housed in a housing portion 11 provided in the outer casing member 10, such as a primary battery, secondary battery, or electric double-layer capacitor (including EDLC). Examples of the energy storage device 1 include lithium-ion batteries, lithium-ion polymer batteries, lithium-ion all-solid-state batteries, lithium-ion capacitors, lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver-zinc oxide batteries, metal-air batteries, and polyvalent cation batteries.

[0014] <Energy Storage Element 20> In the energy storage device 1, the energy storage element 20 is housed in the housing section 11 together with the electrolyte. The energy storage element 20 has a positive electrode plate 21, a negative electrode plate 22, and a separator 23. In the energy storage element 20, the positive electrode plate 21 and the negative electrode plate 22 are formed by facing each other with an insulating separator 23 in between. In the energy storage device 1, the energy storage element 20 is formed by stacking multiple layers of sheet-like positive electrode plate 21, separator 23, negative electrode plate 22, and separator 23 in the Z direction. In the energy storage device 1, the positive electrode plate 21 and the negative electrode plate 22 are housed in the housing section 11 together with the electrolyte in such a way that the direction in which they are stacked is the Z direction of the energy storage device 1.

[0015] In this embodiment, a liquid electrolyte is used as the electrolyte, and it is filled inside the containment section 11. A solid electrolyte or a gel-like electrolyte may also be used as the electrolyte. The separator 23 is an example of an intermediate member placed between the positive electrode plate 21 and the negative electrode plate 22. When a solid electrolyte is used as the electrolyte, the solid electrolyte is the intermediate member, and there is no separator.

[0016] <Terminal section 30> The terminal section 30 has a positive terminal 31 and a negative terminal 32. The positive terminal 31 is connected to the positive plate 21, and the negative terminal 32 is connected to the negative plate 22. The positive terminal 31 and the negative terminal 32 are electrically conductive. As shown in Figures 1 and 2, the positive terminal 31 and the negative terminal 32 pass through the first sealing portion 121 of the sealing band 12 and protrude to the outside of the exterior member 10. In the energy storage device 1, the positive terminal 31 and the negative terminal 32 are input / output terminals for charging and discharging the energy storage element 20. In a front view, in the energy storage device 1, the positive terminal 31 and the negative terminal 32 protrude outward from both ends in the X direction.

[0017] <Exterior Member 10> The first packaging material 141 and the second packaging material 142 of the exterior member 10 are made of a resin sheet 40 having at least one insulating layer. Figure 4 is a cross-sectional view showing the laminated structure of the resin sheet 40. As shown in Figure 4, the resin sheet 40 is formed by laminating at least a base layer 41, a barrier layer 42, and a heat-adhesive resin layer 43 in order. The thickness of the resin sheet 40 is preferably 50 μm or more considering the strength of the exterior member 10, and preferably 400 μm or less considering the weight reduction of the energy storage device 1. The thicker the barrier layer 42, the higher the strength and thermal conductivity. Therefore, if the strength and thermal conductivity of the exterior member 10 are required even if the weight of the energy storage device 1 increases, the thickness of the resin sheet 40 may be 1 mm to 2 mm or more.

[0018] The base layer 41 is insulating and is formed from a resin film such as nylon, polyester, or polyethylene terephthalate. The thickness of the base layer 41 is, for example, 10 μm to 75 μm. To improve heat resistance, it is more desirable to form the base layer 41 from a uniaxially oriented film or a biaxially oriented film. The thicker the base layer 41, the less favorable the thermal conductivity in the Z direction becomes. For example, if sufficient thermal conductivity can be ensured by the barrier layer 42, the thickness of the base layer 41 may be about 50 μm.

[0019] Furthermore, to improve pinhole resistance, insulation, etc., multiple resin films of different materials may be laminated to form the base layer 41. In this case, the multiple resin films are bonded together with a polyurethane-based, acrylic-based, silicone-based adhesive or an acid-modified resin. In this embodiment, the resin sheet 40 is formed by laminating polyethylene terephthalate (thickness 12 μm) and nylon (thickness 15 μm) with an adhesive (thickness 4 μm).

[0020] The barrier layer 42 prevents the intrusion of water vapor, oxygen, light, etc. As the barrier layer 42, for example, metal foil such as aluminum, aluminum alloy, stainless steel, titanium, iron, or high-strength steel can be used. The thickness of the barrier layer 42 is formed to be, for example, 10 μm or more and 500 μm or less. The base layer 41 and the barrier layer 42 are bonded together with a polyurethane-based, acrylic-based, silicone-based adhesive or an acid-modified resin, etc. (not shown). In the resin sheet 40 of this embodiment, the barrier layer 42 is formed of aluminum foil with a thickness of 40 μm.

[0021] The heat-adhesive resin layer 43 can be any resin that has heat-adhesive properties, and is formed from, for example, a heat-adhesive resin such as polypropylene, acid-modified polypropylene, low-density polyethylene, or linear low-density polyethylene. Multiple layers of resins of different materials may be laminated to form the heat-adhesive resin layer 43. The thickness of the heat-adhesive resin layer 43 is formed to be, for example, 10 μm or more and 100 μm or less. The heat-adhesive resin layer 43 is formed by extrusion onto the barrier layer 42. The film forming the heat-adhesive resin layer 43 may be bonded to the barrier layer 42 via an adhesive. Depending on the size of the energy storage element 20 housed in the housing 11, and the weight of the energy storage element 20 and the electrolyte, the thickness of the heat-adhesive resin layer 43 may be 100 μm or more and 500 μm or less.

[0022] In the resin sheet 40 of this embodiment, the heat-adhesive resin layer 43 is formed by sequentially extruding acid-modified polypropylene (thickness 40 μm) and polypropylene (thickness 40 μm) onto the barrier layer 42. In the second sealing portion 122 of the sealing band portion 12, the heat-adhesive resin layer 43 of the first packaging material 141 and the heat-adhesive resin layer 43 of the second packaging material 142 are brought into contact with each other and bonded by heat sealing through heating and pressurization.

[0023] Figure 5 is an exploded perspective view of the energy storage device 1. The exterior member 10 is formed integrally from a first packaging material 141 and a second packaging material 142 in a continuous manner in the Y direction. The first packaging material 141 has a housing portion 11 and a flange portion 15. The first packaging material 141 and the second packaging material 142 are made of resin sheets. The first packaging material 141 is formed, for example, by cold forming to create a housing portion 11 recessed to a predetermined depth relative to the flange portion 15. The housing portion 11 has a substantially rectangular opening 11a on one side to house the energy storage element 20. The flange portion 15 is formed to protrude outward from one of the short and long sides of the opening 11a. The second packaging material 142 is formed in the shape of a rectangular sheet. A sealing band portion 12 is formed by, for example, heat bonding the second packaging material 142 to the flange portion 15. The second packaging material 142 also forms a lid portion 16 that covers the opening 11a.

[0024] <Sealing Band 12> Next, the details of the sealing band 12 will be described. The sealing band 12 has two first sealing parts 121, a second sealing part 122, and a fastening part 123. In a front view, the sealing band 12 is strip-shaped and configured to connect to one of the long sides and both of the short sides of the housing part 11. In the sealing band 12, the first packaging material 141 and the second packaging material 142 are in close contact. Here, close contact means that gases generated by the evaporation of the electrolyte sealed in the housing part 11 and gases generated by rapid charging etc. do not leak to the outside, and that contact is made while blocking water vapor from the outside.

[0025] In the sealing band portion 12, the first sealing portion 121 is the portion that overlaps with the positive terminal 31 or the negative terminal 32 in the front and back. The second sealing portion 122 is the portion of the sealing band portion 12 other than the first sealing portion 121.

[0026] In other words, in a front view, the portion of the sealing band 12 that connects to both short sides of the housing 11 and overlaps with the positive terminal 31 or negative terminal 32 in the front and rear directions is the first sealing portion 121. The entire portion of the sealing band 12 that connects to one of the long sides of the housing 11, and the portion of the short side other than the first sealing portion 121, constitutes the second sealing portion 122.

[0027] In the first sealing portion 121, the positive terminal 31 and negative terminal 32 of the terminal portion 30 are sandwiched between the flange portion 15 and the lid portion 16 via a heat-adhesive tab film 50. In this state, the flange portion 15 and the lid portion 16 are heated and pressurized. As a result, the first packaging material 141 and the second packaging material 142 are indirectly melted and bonded together. This improves the sealing performance around the first sealing portion 121.

[0028] As a result, in the first sealing portion 121, the first packaging material 141 and the second packaging material 142 are in close contact with the positive terminal 31 and the negative terminal 32 of the terminal portion 30.

[0029] Furthermore, in the second sealing section 122, the heat-adhesive resin layers 43 of the first packaging material 141 and the second packaging material 142 are in direct contact. In this state, the first packaging material 141 and the second packaging material 142 are heat-bonded by heating and pressurizing them. In other words, in the second sealing section 122, the first packaging material 141 and the second packaging material 142 are directly melted and bonded together.

[0030] Furthermore, in the sealing band portion 12, the fastening portion 123 is formed along the entire length of the second sealing portion 122. The fastening portion 123 is formed by sewing the first packaging material 141 and the second packaging material 142 together with a wire 124 having a higher heat resistance temperature than the resin sheet 40. The wire 124 is an example of a fastening member. Examples of the wire 124 include fine stainless steel wire, fine tungsten wire, and fine aramid fiber wire. However, it is not limited to these, and a wide range of wires with a higher heat resistance temperature than the resin sheet 40, or flame-retardant wires, can be used as the wire 124. As shown in Figure 1, the fastening portion 123 sews the first packaging material 141 and the second packaging material 142 together, including the tab film 50, but it is not limited to this. For example, the tab film 50 may not be fastened by the fastening portion 123.

[0031] When the energy storage device 1 is repeatedly charged and discharged, particularly through rapid charging, the electrolyte contained in the storage section 11 becomes hot, which accelerates its decomposition and generates gas. Due to the generation of gas, the pressure inside the storage section 11 increases, and a force acts on the sealing band 12 that separates the first packaging material 141 and the second packaging material 142. The force that separates the first packaging material 141 and the second packaging material 142 is a force corresponding to the amount and speed of gas generation, or the force of expansion and contraction due to the charging and discharging of the battery itself. Due to the shape characteristics of the sealing band 12, the force that separates the first packaging material 141 and the second packaging material 142 tends to concentrate in the center of the X-direction of the portion adjacent to the long side of the storage section 11. Because the fastening portion 123 is formed along the entire length of the second sealing portion 122, the fastening force of the fastening portion 123 counteracts the force that would cause the first packaging material 141 and the second packaging material 142 to separate in the second sealing portion 122, making separation less likely to occur.

[0032] Furthermore, as shown in Figures 1, 2, and 3, the width of the sealing band portion 12 from the inside to the outside of the first sealing portion 121 is defined as width W1, and the width of the sealing portion 122 from the inside to the outside is defined as width W2. In this case, width W1 is greater than width W2. That is, the width W1 of the first sealing portion 121 is wider than the width W2 of the second sealing portion 122. As a result, the fastening strength of the first sealing portion 121 is higher than that of the second sealing portion 122. Therefore, even if a force that causes the first packaging material 141 and the second packaging material 142 to separate is applied to the first sealing portion 121, delamination is less likely to occur at the first sealing portion 121. Note that even if the width W1 is narrow and the fastening strength is weak, an auxiliary mechanism can be provided on the outside.

[0033] As described above, in the exterior member 10 of the energy storage device 1, the first sealing portion 121 increases the width W1 to expand the area to be heat-bonded, thereby increasing the fastening strength and suppressing delamination between the first packaging material 141 and the second packaging material 142. Furthermore, the second sealing portion 122 has a fastening portion 123 formed along its entire length, and the fastening force of the fastening portion 123 counteracts the force that would cause the first packaging material 141 and the second packaging material 142 to separate, thereby suppressing delamination between the first packaging material 141 and the second packaging material 142.

[0034] As described above, the force that separates the first packaging material 141 and the second packaging material 142 is concentrated in the central part in the X direction of the portion of the second sealing part 122 that connects to the long side of the housing part 11. However, it may also be concentrated in other locations. In this way, the spacing (pitch) of the stitches when sewing with the wire 124 of the fastening part 123 may be made narrower in the portion where the force that separates the first packaging material 141 and the second packaging material 142 is concentrated. In addition, multiple stages of the fastening part 123 may be provided in the portion where the force that separates the first packaging material 141 and the second packaging material 142 is concentrated.

[0035] With this configuration, the sealing performance can be maintained even if the internal pressure increases or the device expands and contracts due to discharge when rapid charging is repeatedly performed in the energy storage device 1, and even if thermal runaway occurs in the event of an internal short circuit, nail penetration, or other abnormality.

[0036] As described above, the exterior member 10 of the energy storage device 1 is a so-called single-cup type container in which a housing portion 11 is formed in a recess in the first packaging material 141, but it is not limited to this. For example, the exterior member 10 may be a double-cup type container in which recesses are formed in both the first packaging material 141 and the second packaging material 142 and the openings are butted together. Alternatively, it may be a four-sided sealed type container in which a lid portion 16 made of the second packaging material 142 is sealed to flange portions 15 that extend outward from the four sides of the opening 11a of the housing portion 11. Furthermore, the first packaging material 141 and the second packaging material 142 may each be formed from separate sheets.

[0037] Furthermore, in the energy storage device 1 of this embodiment, one of the long sides of the rectangular shape in a plan view is the folded portion between the first packaging material 141 and the second packaging material 142, with the positive terminal 31 located on one short side and the negative terminal 32 located on the other short side. However, the configuration is not limited to this, and for example, a configuration in which the positive terminal 31 and the negative terminal 32 are located on one short side may also be used.

[0038] Furthermore, at least one of the positive terminal 31 and the negative terminal 32 may be located on the long side opposite to the folded portion of the first packaging material 141 and the second packaging material 142, or both may be located there.

[0039] Furthermore, if the energy storage device is of the four-sided seal type, the positive terminal 31 may be located in the sealing band 12 provided on the short side or on the sealing band 12 provided on the long side. Similarly, the negative terminal 32 may be located in the sealing band 12 provided on the short side or on the sealing band 12 provided on the long side.

[0040] <Energy Storage Module 100> Details of the energy storage module 100 will be described below with reference to the drawings. Figure 6 is a perspective view of the energy storage module 100. The energy storage module 100 consists of multiple energy storage devices 1 housed in a case 200. Note that in the energy storage module 100 shown in Figure 6, a portion of the body 201 has been omitted from the illustration for ease of understanding.

[0041] As shown in FIG. 6, in the power storage module 100, ten power storage devices 1 are arranged inside the case 200, but the actual number of arranged devices is not limited to ten. The number and connection method of the power storage devices 1 arranged in the power storage module 100 may be changed according to the required capacitance, output voltage, etc. When the power storage devices 1 are connected in parallel, the positive electrode terminals 31 and the negative electrode terminals 32 of adjacent power storage devices 1 are arranged adjacent to each other. Also, when the power storage devices are connected in series, the positive electrode terminal 31 and the negative electrode terminal 32 of adjacent power storage devices 1 are arranged in the case 200 adjacent to each other.

[0042] The case 200 has a body portion 201 and a closing portion 202. The body portion 201 is formed in a cylindrical shape with both axial ends open. The closing portion 202 closes both axial ends of the body portion 201 respectively. By attaching the closing portion 202 to the body portion 201, the case 200 is sealed so that moisture from the outside does not penetrate.

[0043] The case 200 is formed of an insulator such as resin, for example. In some cases, a metal such as an aluminum alloy or stainless steel is used to increase the strength of the case 200. In this case, an insulating treatment is performed on the inner surface that contacts the power storage device 1 and the portions where the electrode terminals may contact.

[0044] Also, the positive electrode terminal 31 and the negative electrode terminal 32 of each power storage device 1 are connected to a bus bar (not shown). A lead-out terminal (not shown) is connected to the bus bar, and the lead-out terminal is led out to the outside of the case 200. The lead-out terminal is an external connection terminal connected to external devices such as a charging device and a load.

[0045] Note that the case 200 may be provided with an auxiliary mechanism (not shown) for increasing the fastening strength of the first sealing portion 121, or may be provided with a pressing member (not shown) for suppressing the movement of the power storage device 1 inside the case 200.

[0046] <Electric Vehicle 300> FIG. 7 is a side view of the electric vehicle 300. FIG. 8 is a plan view of the electric vehicle 300. The electric vehicle 300 includes a drive motor 302 as a power source for driving the wheels 301. A power storage pack 400 is installed under the floor of the vehicle body (mobile body main body) of the electric vehicle 300 as a drive source for supplying power to the drive motor 302.

[0047] The power storage pack 400 has a configuration in which a plurality of power storage modules 100 are arranged side by side on an exterior member such as a frame (not shown). The power storage pack 400 can obtain the required power storage capacity and output the required output voltage by connecting the power storage modules 100 arranged on the exterior member such as a frame in series and in parallel.

[0048] As shown in FIG. 8, in the power storage pack 400, the power storage modules 100 are arranged such that the Y direction is the height direction (gravity direction) of the electric vehicle 300, the Z direction is the front-rear direction of the electric vehicle 300, and the X direction is the left-right direction of the electric vehicle 300. That is, in the power storage pack 400, the power storage modules 100 with the Y direction as the height direction are arranged in the X direction and the Z direction.

[0049] When the electric vehicle 300 is a sedan type or a compact car type with a low overall height, a one-stage configuration of the power storage modules 100 in the height direction is used for the power storage pack 400. When the electric vehicle 300 is an SUV type or a one-box type with a high overall height, a multi-stage configuration of the power storage modules 100 in the height direction of the vehicle is used. By doing so, a power storage pack 400 with an output voltage and a power storage capacity corresponding to the weight and size of the vehicle can be provided.

[0050] Further, the electric vehicle 300 may be arranged such that the X direction intersecting the Z direction in which the power storage devices 1 in the power storage module 100 are arranged becomes the traveling direction. Even when the power storage module 100 is arranged on the electric vehicle 300 in this way, the same effects as described above can be obtained.

[0051] Alternatively, the energy storage devices 1 may be directly arranged in a row under the floor (chassis) of the electric vehicle 300 to form an energy storage unit with the same output voltage and storage capacity as the energy storage pack 400. By doing so, the exterior components such as the frame of the energy storage pack 400 can be omitted, thus enabling weight reduction. When the underfloor (chassis) of the electric vehicle 300 is configured in this way, the case 200 can also be omitted, further enabling weight reduction.

[0052] In addition to BEVs (Battery Electric Vehicles) and PHEVs (Plug-in Hybrid Electric Vehicles), other examples of mobile vehicles equipped with the aforementioned energy storage pack 400 include HEVs (Hybrid Electric Vehicles) and 48V power supply micro-hybrid vehicles.

[0053] Furthermore, the aforementioned energy storage module or energy storage pack may be mounted on other mobile devices. Examples of mobile devices that can be equipped with the energy storage module or energy storage pack include bipedal robots, trains, airplanes, helicopters, drones, flying cars, agricultural machinery, construction machinery, etc. Note that if the required output voltage and energy storage capacity are sufficient, the energy storage module may be used as a standalone unit.

[0054] Furthermore, the energy storage module or energy storage pack may be used for purposes other than as a power source for mobile devices. For example, it may be used as a fixed power source for an Energy Storage System, a Battery Energy Storage System, or an Uninterruptible Power Supply.

[0055] <First Modification> The first modification of the energy storage device 1A will be described with reference to the drawings. Figure 9 is a front view of the first modification of the energy storage device 1A. In the energy storage device 1A shown in Figure 9, the shape of the outer casing member 10A, the energy storage element 20A, and the positive terminal 31A and negative terminal 32A of the terminal portion 30A differ from those of the outer casing member 10, the energy storage element 20, and the positive terminal 31 and negative terminal 32 of the terminal portion 30. Other than these differences, the energy storage device 1A has the same configuration as the energy storage device 1. Therefore, parts of the energy storage device 1A that are substantially the same as those of the energy storage device 1 are given the same reference numerals, and detailed descriptions of these same parts are omitted.

[0056] As shown in Figure 9, in a front view, the housing portion 11 of the exterior member 10A of the energy storage device 1A is rectangular in shape with the Y direction as the longitudinal direction. Two first sealing portions 121 are formed at both ends in the X direction of the portion of the sealing band 12A that connects to one end of the housing portion 11 in the Y direction. A positive terminal 31A is placed on one of the two first sealing portions 121A, and a negative terminal 32A is placed on the other. The portion of the sealing band 12A other than the first sealing portions 121A is the second sealing portion 122A.

[0057] In the energy storage device 1A, the width of the first sealing portion 121A extending outward from the housing portion 11 is greater than the width of the other parts of the sealing band portion 12. Therefore, in the first sealing portion 121A, the adhesive strength between the positive terminal 31A or the negative terminal 32A and the first packaging material 141 and the second packaging material 142 is increased. In addition, a fastening portion 123 is formed along the entire length of the second sealing portion 122A of the sealing band portion 12A of the energy storage device 1A.

[0058] As a result, even if the storage device 1A repeatedly charges and discharges and the pressure inside the storage section 11 increases, the sealing performance of the storage section 11 can be maintained.

[0059] <Second Modification> Another example of the energy storage device will be described with reference to the drawings. Figure 10 is an enlarged front view of the energy storage device 1B of the second modification. Figure 11 is a cross-sectional view of the energy storage device 1B shown in Figure 10, taken along the line XI-XI. Figure 10 shows an enlarged view of the vicinity where the positive terminal 31B of the terminal portion 30B of the energy storage device 1B is located. In the energy storage device 1B, the shape of the positive terminal 31B of the outer casing member 10B is different from that of the positive terminal 31, and the configuration of the fastening portion 125 of the sealing band portion 12B is different from that of the fastening portion 123 of the sealing band portion 12. In all other respects, the energy storage device 1B has the same configuration as the energy storage device 1. The same reference numerals are used for the same parts of the energy storage device 1B as in the energy storage device 1, and detailed descriptions of the same parts are omitted. The negative terminal, which is not shown, has a similar configuration.

[0060] As shown in Figures 10 and 11, in the energy storage device 1B, the positive electrode terminal 31B has a plurality of through holes 311 that penetrate the first packaging material 141, the tab film 50, the positive electrode terminal 31B, and the second packaging material 142 in the Z direction. The through holes 311 are arranged in the Y direction. In the first sealing portion 121B of the energy storage device 1B, the wire 124 of the fastening portion 125 penetrates the first packaging material 141, the through holes 311, and the second packaging material 142. To explain further, the wire 124 is inserted through the through holes 311, and in the first sealing portion 121B, the first packaging material 141 and the second packaging material 142 are sewn to the positive electrode terminal 31B to form the fastening portion 125.

[0061] This configuration suppresses the peeling of the first packaging material 141 and the second packaging material 142 in the first sealing portion 121. In the energy storage device 1B, the fastening portion 125 is formed along the entire length of the sealing band portion 12B. This configuration allows the entire fastening portion 125 to be formed from a single wire, making it difficult to form weaker parts than other parts of the fastening portion 125. This increases the fastening force provided by the fastening portion 125. The fastening portion 125 may also be partially discontinuous. For example, the fastening portion 125 may be formed by dividing it into portions located at both ends in the X direction of the sealing band portion 12B and a portion located at one end in the Y direction.

[0062] As shown in Figure 12, the portion where the fastening portion 125 of the positive terminal 31B is formed may be the mesh portion 312. With this configuration, the fastening portion 125 can be formed on the first sealing portion 121B using a sewing machine or the like. This makes it easy to form the fastening portion 125 on the first sealing portion 121B. The ratio of the opening area of ​​the mesh portion 312 is preferably such that the positive terminal 31B has a certain level of rigidity while being easy to sew with the wire 124. The negative terminal may have a similar configuration.

[0063] <Third Modification> Further examples of the energy storage device will be described with reference to the drawings. Figure 13 is an enlarged cross-sectional view of the fastening portion 126 of the energy storage device 1C of the third modification. The configuration of the fastening portion 126 in the energy storage device 1C differs from that of the fastening portion 123 of the energy storage device 1. In all other respects, the energy storage device 1C has the same configuration as the energy storage device 1. The same reference numerals are used for the same parts of the energy storage device 1C as in the energy storage device 1, and detailed descriptions of the same parts are omitted.

[0064] As shown in Figure 13, the fastening portion 126 of the energy storage device 1C uses staples 127. The first packaging material 141 and the second packaging material 142 are fastened together along the entire length of the second sealing portion 122. Note that the staples 127 are just one example of fastening members. By constructing the fastening portion 126 using staples 127 in this way, it is easier to manufacture compared to a fastening portion constructed by sewing together wires. The material of the staples 127 can be metal or a material equivalent to that of the wire 124.

[0065] It should be noted that the present invention is not limited to the configuration described above, and various modifications are possible. Configurations obtained by appropriately combining the technical means disclosed for each different configuration are also included within the technical scope of the present invention.

[0066] <Summary> The energy storage module of the present invention has the following configuration.

[0067] (1) An energy storage device comprising: an electrode portion in which positive electrode plates and negative electrode plates are alternately stacked via an intermediate member; an outer casing member having a first packaging material and a second packaging material that cover the electrode portion from both outer sides in the stacking direction of the electrode portion; and terminal portions electrically connected to the positive electrode plate and the negative electrode plate, wherein the outer casing member has a housing portion for housing the electrode portion and a sealing band portion connected to at least a part of the outer edge of the housing portion so that the first packaging material and the second packaging material are directly or indirectly bonded together; and the sealing band portion has a fastening portion that applies a fastening force in the stacking direction to the first packaging material and the second packaging material by a fastening member that penetrates and fastens the first packaging material and the second packaging material.

[0068] (2) The sealing band portion comprises a first sealing portion to which the first packaging material and the second packaging material are adhered to the electrode portion, and a second sealing portion which is a portion different from the first sealing portion to which the first packaging material and the second packaging material are directly adhered, wherein the fastening portion is formed continuously over the entire length of at least the second sealing portion, as described in (1).

[0069] (3) The sealing band portion comprises a first sealing portion to which the first packaging material and the second packaging material are adhered to the electrode portion, and a second sealing portion which is a portion different from the first sealing portion to which the first packaging material and the second packaging material are directly adhered, wherein the fastening portion is formed in the first sealing portion, and the fastening member of the fastening portion formed in the first sealing portion which is adhered to the electrode portion of the positive electrode is conductive, as described in (1) or (2).

[0070] (4) The portion of the terminal portion to which the first sealing portion is bonded has a plurality of through holes that penetrate in the stacking direction, and the fastening portion is formed when the fastening member penetrates the through holes, as described in (2) or (3).

[0071] (5) The energy storage device according to any one of (1) to (4), wherein the width of the first sealing portion extending outward from the housing portion is wider than the width of the second sealing portion extending outward from the housing portion.

[0072] (6) The fastening portion is formed continuously along the entire length of the sealing band portion in a direction along the outer edge of the housing portion, as described in any of (1) to (5).

[0073] (7) The fastening portion is made of wire with a higher heat resistance temperature than the exterior member. The energy storage device according to any one of (1) to (6).

[0074] (8) The fastening member is a staple. The energy storage device according to any one of (1) to (7).

[0075] (9) A power storage module having a plurality of power storage devices according to any one of (1) to (8), and a case capable of housing the power storage devices arranged in the stacking direction.

[0076] (10) A mobile body having a plurality of energy storage modules as described in (9), a drive motor powered by the energy storage modules, and a main body on which the energy storage modules and the drive motor are arranged, and driven by the drive motor.

[0077] According to the present invention, it can be widely used in mobile bodies equipped with electric devices.

[0078] 100 Energy storage module 200 Case 201 Body 202 Enclosure 300 Electric vehicle 301 Wheel 302 Drive motor 311 Through hole 312 Mesh part 400 Energy storage pack 1, 1A, 1B, 1C Energy storage device 10, 10A, 10B Exterior member 11, 11a Opening 12, 12A, 12B Sealing band 121, 121A, 121B First sealing part 122, 122A Second sealing part 123 Fastening part 124 Wire 125 Fastening part 126 Fastening part 127 Staple pin 141 First packaging material 142 Second packaging material 15 Flange part 16 Lid part 20, 20A Energy storage element 21 Positive electrode plate 22 Negative electrode plate 23 Separator 30, 30A, 30B Terminal section 31, 31A, 31B Positive terminal 32, 32A Negative terminal 40 Resin sheet 41 Base layer 42 Barrier layer 43 Heat-adhesive resin layer 50 Tab film

Claims

1. An energy storage device comprising: an electrode portion in which positive electrode plates and negative electrode plates are alternately stacked via an intermediate member; an outer casing member having a first packaging material and a second packaging material that cover the electrode portion from both outer sides in the stacking direction of the electrode portion; and terminal portions electrically connected to the positive electrode plate and the negative electrode plate, wherein the outer casing member has a housing portion for housing the electrode portion and a sealing band portion connected to at least a part of the outer edge of the housing portion so that the first packaging material and the second packaging material are directly or indirectly bonded together; and the sealing band portion has a fastening portion that applies a fastening force in the stacking direction to the first packaging material and the second packaging material by a fastening member that penetrates and fastens the first packaging material and the second packaging material.

2. The sealing band portion comprises a first sealing portion to which the first packaging material and the second packaging material are adhered to the electrode portion, and a second sealing portion which is a portion different from the first sealing portion to which the first packaging material and the second packaging material are directly adhered, and the fastening portion is formed continuously over its entire length, at least the second sealing portion being continuous, according to claim 1.

3. The energy storage device according to claim 2, wherein the width of the first sealing portion extending outward from the housing portion is wider than the width of the second sealing portion extending outward from the housing portion.

4. The energy storage device according to any one of claims 1 to 3, wherein the fastening portion is formed continuously along the entire length in a direction along the outer edge of the housing portion of the sealing band portion.

5. The portion of the terminal portion to which the first sealing portion is bonded has a plurality of through holes that penetrate in the stacking direction, and the fastening portion is formed when the fastening member penetrates the through holes, as described in claim 2 or claim 3.

6. The sealing band portion comprises a first sealing portion to which the first packaging material and the second packaging material are adhered to the electrode portion, and a second sealing portion which is a portion different from the first sealing portion to which the first packaging material and the second packaging material are directly adhered, wherein the fastening portion is formed in the first sealing portion, and the fastening member of the fastening portion formed in the first sealing portion which is adhered to the electrode portion of the positive electrode is conductive, as described in claim 1.

7. The energy storage device according to any one of claims 1 to 6, wherein the fastening portion is made of a wire having a higher heat resistance temperature than the exterior member.

8. The energy storage device according to any one of claims 1 to 7, wherein the fastening member is a staple.

9. An energy storage module comprising a plurality of energy storage devices according to any one of claims 1 to 8, and a case capable of housing the energy storage devices arranged in the stacking direction.

10. A mobile body having a power storage module as described in claim 9, a drive motor powered by the power storage module, and a main body on which the power storage module and the drive motor are arranged, and driven by the drive motor.

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