WO2024057743A1 - Power storage device - Google Patents

Power storage device Download PDF

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Publication number
WO2024057743A1
WO2024057743A1 PCT/JP2023/027797 JP2023027797W WO2024057743A1 WO 2024057743 A1 WO2024057743 A1 WO 2024057743A1 JP 2023027797 W JP2023027797 W JP 2023027797W WO 2024057743 A1 WO2024057743 A1 WO 2024057743A1
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WO
WIPO (PCT)
Prior art keywords
power storage
flow path
storage element
forming member
gas
Prior art date
Application number
PCT/JP2023/027797
Other languages
French (fr)
Japanese (ja)
Inventor
久幸 山根
智弘 川内
Original Assignee
株式会社Ｇｓユアサ
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Publication of WO2024057743A1 publication Critical patent/WO2024057743A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/35—Gas exhaust passages comprising elongated, tortuous or labyrinth-shaped exhaust passages
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/35—Gas exhaust passages comprising elongated, tortuous or labyrinth-shaped exhaust passages
    • H01M50/358—External gas exhaust passages located on the battery cover or case

Definitions

  • the present invention relates to a power storage device including a power storage element.
  • Patent Document 1 includes a battery cell (power storage element) having a safety valve (gas discharge valve), and a smoke exhaust duct (flow path forming member) through which gas released from the battery cell (power storage element) flows.
  • a battery module power storage device
  • the present invention was achieved by the inventors of the present application newly paying attention to the above-mentioned problem, and an object of the present invention is to provide a power storage device that can suppress the influence on members around the power storage element.
  • a power storage device includes a power storage element having a gas exhaust valve, and a flow path forming member that forms a flow path for gas discharged from the gas exhaust valve, and wherein the gas flows through the flow path.
  • the flow direction is defined as the first direction
  • the length of the flow path forming member in the first direction is longer than the length of the electricity storage element in the first direction
  • the length of the flow path forming member is longer than the length of the electricity storage element in the first direction
  • a first value obtained by dividing the minimum flow path area, which is the minimum value of , by the area of the gas discharge valve in plan view, is smaller than 1.6.
  • the power storage device of the present invention it is possible to suppress the influence on members around the power storage element.
  • FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment.
  • FIG. 2 is an exploded perspective view showing each component when the power storage device according to the embodiment is disassembled.
  • FIG. 1 is a perspective view showing the configuration of a power storage element according to an embodiment.
  • FIG. 2 is a perspective view showing the configuration of an electrode body included in a power storage element according to an embodiment.
  • FIG. 2 is a perspective view showing the configuration of a flow path forming member according to an embodiment.
  • a power storage device includes a power storage element having a gas exhaust valve, and a flow path forming member that forms a flow path for gas discharged from the gas exhaust valve, and the power storage device includes
  • the flow direction in the flow path is a first direction
  • the length of the flow path forming member in the first direction is longer than the length of the electricity storage element in the first direction
  • the length in the first direction in the flow path is A first value obtained by dividing the minimum area of the flow path, which is the minimum value of orthogonal surfaces, by the area of the gas exhaust valve in plan view is smaller than 1.6.
  • the length of the power storage element in the first direction refers to the length of one power storage element among the plurality of power storage elements in the first direction.
  • the power storage element may include a positive electrode active material containing nickel.
  • a power storage element having a positive electrode active material containing nickel has a high capacity (high energy density), and the gas discharged from the gas exhaust valve tends to reach a relatively high temperature. Therefore, in the power storage device, the effect of adopting the configuration of the present application is high.
  • the second value obtained by dividing the total mass of the nickel included in the power storage element by the volume of the container of the power storage element is 100 g/L or more. good.
  • the content ratio of nickel in the energy storage element is high (the second value is 100 g/L or more), it has a higher capacity (higher energy density) and is discharged from the gas discharge valve. Gas tends to become hotter. Therefore, in the power storage device, the effect of adopting the configuration of the present application is high.
  • a third value obtained by dividing the total mass of the nickel included in the power storage element by the minimum area of the flow path is 0.15 g/mm2 or more. It may be said that there is.
  • the content ratio of nickel in the energy storage element is high (the third value is 0.15 g/mm2 or more), it has a higher capacity (higher energy density) and is discharged from the gas exhaust valve.
  • the gas that is used tends to become hotter. Therefore, in the power storage device, the effect of adopting the configuration of the present application is high.
  • the direction in which a pair of terminals (positive electrode and negative electrode) in one power storage element are lined up, the direction in which the short sides of the container of the power storage element face each other, or the short direction of the exterior body is referred to as the X-axis direction. It is defined as The X-axis direction is the same as the third direction.
  • the direction in which a plurality of power storage elements are lined up, the direction in which the long sides of the containers of power storage elements face each other, the longitudinal direction of the exterior body, or the direction in which the flow path forming member extends is defined as the Y-axis direction.
  • the Y-axis direction is the same as the first direction.
  • the direction in which the power storage element and the bus bar are lined up, the direction in which the main body and the lid of the container of the power storage element are lined up, and the vertical direction are defined as the Z-axis direction.
  • the Z-axis direction is the same as the second direction.
  • These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect with each other (orthogonal in this embodiment).
  • the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described as the vertical direction below.
  • the X-axis plus direction indicates the arrow direction of the X-axis
  • the X-axis minus direction indicates the opposite direction to the X-axis plus direction.
  • the X-axis direction refers to both or one of the X-axis plus direction and the X-axis minus direction.
  • the Y-axis direction and the Z-axis direction are expressed as “insulation”, it means "electrical insulation”.
  • FIG. 1 is a perspective view showing the appearance of a power storage device 1 according to the present embodiment.
  • FIG. 2 is an exploded perspective view showing each component when power storage device 1 according to the present embodiment is disassembled.
  • the power storage device 1 is a device that can charge electricity from the outside and discharge electricity to the outside.
  • power storage device 1 has a substantially rectangular parallelepiped shape.
  • the power storage device 1 is a battery module (battery assembly) used for power storage, power supply, or the like.
  • the power storage device 1 is used as a battery for driving or starting an engine of a mobile object such as an automobile, a motorcycle, a ship, a construction machine, an automatic guided vehicle, or a railway vehicle for an electric railway.
  • Examples of the above-mentioned vehicle include an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV).
  • the power storage device 1 is also used as a stationary battery for home or business use.
  • the power storage device 1 includes a power storage unit 10 and a board unit 20 attached to the power storage unit 10.
  • the board unit 20 is a device that monitors the state of the power storage element 100 included in the power storage unit 10 and controls the power storage element 100, and has a circuit board and the like inside.
  • the power storage unit 10 includes a plurality of power storage elements 100, a plurality of spacers 11, a busbar frame 12, a plurality of busbars 13, an exterior body 18 that accommodates these, and a flow path forming member. 200.
  • the power storage unit 10 may include a restraining member (end plate, side plate, etc.) that restrains the plurality of power storage elements 100.
  • the power storage element 100 is a secondary battery (single cell), and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery.
  • Power storage element 100 has a flat rectangular parallelepiped shape (prismatic shape). In this embodiment, a plurality (16) of power storage elements 100 are arranged in line in the Y-axis direction. The number of power storage elements 100 is not limited, and for example, only one power storage element 100 may be arranged.
  • the power storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or a capacitor. Power storage element 100 may be a primary battery.
  • Spacer 11 is arranged adjacent to power storage element 100 in the Y-axis direction.
  • Spacer 11 is a member (heat insulating plate or insulating plate) that heats or insulates power storage element 100 and other members.
  • spacers 11 are arranged between all of the power storage elements 100, but spacers 11 may not be arranged between any of the power storage elements 100.
  • the busbar frame 12 is a member that insulates the busbar 13 from other members and regulates the position of the busbar 13.
  • the bus bar frame 12 is made of an insulating member such as a resin material.
  • the bus bar frame 12 is arranged above the plurality of power storage elements 100 and positioned with respect to the plurality of power storage elements 100.
  • a plurality of bus bars 13 are arranged and positioned on the bus bar frame 12.
  • the busbar frame 12 is provided with a flow path forming member placement portion 12a in which the flow path forming member 200 is placed.
  • the flow path forming member placement portion 12a is a portion that is placed in the center of the busbar frame 12 in the X-axis direction and extends in the Y-axis direction (first direction).
  • Each bus bar 13 is a plate-like member that is arranged on the plurality of power storage elements 100 (on the busbar frame 12) and electrically connects the terminals 140 of the plurality of power storage elements 100.
  • Bus bar 13 is made of metal.
  • bus bar 13 connects 16 power storage elements 100 in series by connecting terminals 140 of adjacent power storage elements 100.
  • the connection mode of power storage element 100 is not limited to the above, and series connection and parallel connection may be combined in any manner.
  • a detection line 13a which is a cable for detecting the state (voltage, temperature, etc.) of each power storage element 100, is connected to the bus bar 13 or the terminal 140 of the power storage element 100.
  • the exterior body 18 is a rectangular (box-shaped) housing (module case) that constitutes the outer shell of the power storage unit 10.
  • the exterior body 18 is arranged outside the power storage element 100 and the like, and fixes the power storage element 100 and the like at a predetermined position.
  • the exterior body 18 includes an exterior body body 14 that constitutes the main body of the exterior body 18, an exterior body support body 15 that supports the exterior body body 14, and an exterior body lid body that constitutes a lid body (outer lid) of the exterior body 18. 17.
  • the exterior body 14 is a bottomed rectangular cylindrical housing with an opening formed therein.
  • the exterior main body 14 is formed of an insulating member or a metal coated with an insulating coating. As long as the insulation of the power storage element 100 and the like is maintained, the exterior body 14 may be formed of a conductive member such as metal.
  • a notch 14a through which the flow path forming member 200 passes is formed at the upper center of the end of the exterior body 14 on the Y-axis plus direction side.
  • the cutout portion 14a is a rectangular cutout that is open at the top.
  • the exterior support 15 and the exterior lid 17 are members that protect (reinforce) the exterior body 14.
  • the exterior body support 15 is a member that supports the exterior body body 14 from below (Z-axis negative direction), and has connection parts 15b and 15c.
  • the exterior lid 17 is a member disposed to close the opening on the upper surface of the exterior body 14, and includes connection parts 17b and 17c.
  • a rectangular opening (not shown) through which the flow path forming member 200 passes is formed at the center of the upper end (end on the Z-axis positive direction side) of the connecting portion 17c. In this way, the exterior support 15 and the exterior lid 17 are configured to be fixed while sandwiching the exterior body 14 from above and below.
  • the flow path forming member 200 is arranged above the plurality of power storage elements 100 (above the gas exhaust valve 131).
  • the flow path forming member 200 is a member that forms a flow path for gas discharged from the gas exhaust valve 131 of each power storage element 100.
  • the flow path forming member 200 is a long, cylindrical member that extends in the Y-axis direction across the plurality of power storage elements 100 .
  • the flow path forming member 200 forms an exhaust path through which the gas exhausted from the gas exhaust valve 131 flows in a predetermined direction (Y-axis positive direction).
  • the predetermined direction is the direction in which the plurality of power storage elements 100 are arranged, and also the direction in which the gas exhaust valves 131 included in each of the plurality of power storage elements 100 are arranged.
  • the power storage device 100 includes a plurality of power storage elements 100 arranged in the Y-axis direction (first direction), and the flow path forming member 200 is provided across the plurality of power storage elements 100.
  • the minimum area of the flow path in the flow path forming member 200 provided across the plurality of power storage elements 100 is divided by the area of the gas discharge valve 131 of any one of the plurality of power storage elements 100 in plan view. The value is less than 1.6.
  • the flow path forming member 200 is arranged in the flow path forming member placement portion 12a of the busbar frame 12.
  • the flow path forming member 200 is arranged to protrude from the end of the exterior body 18 in the Y-axis plus direction.
  • the gas discharged from the gas discharge valve 131 flows in the positive direction of the Y-axis and is discharged from an opening (exhaust port 250 to be described later) on the positive direction of the Y-axis.
  • FIG. 3 is a perspective view showing the configuration of power storage element 100 according to this embodiment.
  • FIG. 3 is a diagram showing an enlarged appearance of one power storage element 100 among the plurality of power storage elements 100 shown in FIG. 2.
  • FIG. 4 is a perspective view showing the configuration of electrode body 150 included in power storage element 100 according to the present embodiment. Specifically, FIG. 4(a) shows the configuration of the electrode body 150 in a partially unfolded state in which the electrode plate is wound, and FIG. 4(b) shows the configuration after the electrode plate is wound. The structure of the electrode body 150 is shown.
  • the power storage element 100 includes a container 110 and a pair of terminals 140 (a positive electrode and a negative electrode). Inside the container 110, an electrode body 150 and a pair (a positive electrode and a negative electrode) of current collectors 160 are housed. Although an electrolytic solution (non-aqueous electrolyte) is also sealed inside the container 110, illustration thereof is omitted.
  • the container 110 has a container main body 120 in which an opening is formed, and a container lid part 130 that closes the opening of the container main body 120.
  • the container 110 is a flat rectangular parallelepiped (square or box-shaped) case.
  • a gas exhaust valve 131 is provided in the container 110 (container lid 130).
  • the gas discharge valve 131 releases the pressure inside the container 110 when the pressure increases excessively.
  • the gas exhaust valve 131 is arranged between the pair of terminals 140 on the container lid 130, that is, near the center of the container lid 130 in the X-axis direction.
  • the gas exhaust valve 131 has a circular shape when viewed from the Z-axis direction (planar view direction), but the shape is not particularly limited.
  • the material of the container 110 is not particularly limited, and may be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate.
  • the terminals 140 are a positive terminal and a negative terminal arranged on the container lid 130 of the container 110.
  • the terminal 140 is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body 150 via the current collector 160.
  • the terminal 140 is made of aluminum, aluminum alloy, copper, copper alloy, or the like.
  • the current collector 160 is a conductive member (a positive electrode current collector and a negative electrode current collector) that is disposed between the electrode body 150 and the container 110 and electrically connects the terminal 140 and the electrode body 150.
  • the current collector 160 is joined to the electrode body 150 by welding or the like.
  • the electrode body 150 includes electrode plates (a positive electrode plate and a negative electrode plate) and a separator, and is a power storage element (power generation element) formed by winding these electrode plates and the separator.
  • the electrode body 150 has an electrode body body part 155 and end parts 156 and 157 that protrude from the electrode body body part 155 on both sides in the X-axis direction. Ends 156 and 157 are connected (joined) to a pair of current collectors 160.
  • the electrode body 150 includes a positive electrode plate 151, a negative electrode plate 152, and separators 153 and 154.
  • the positive electrode plate 151 is an electrode plate (electrode plate) in which a positive electrode active material layer 151b is formed on the surface of a positive electrode current collector foil 151a, which is a long strip-shaped metal foil.
  • the negative electrode plate 152 is an electrode plate (electrode plate) in which a negative electrode active material layer 152b is formed on the surface of a negative electrode current collector foil 152a, which is a long strip-shaped metal foil.
  • the positive electrode active material layer 151b includes a positive electrode active material, a binder, a conductive material, and the like.
  • the negative electrode active material layer 152b includes a negative electrode active material, a binder, a thickener, and the like.
  • any known material can be used as appropriate as long as it is a material capable of intercalating and deintercalating lithium ions.
  • polyanion compounds such as LiM1PO4 (M1 is one or more metal elements selected from Fe, Ni, Mn, Co, etc.), LiM22O4 (M2 is selected from Fe, Ni, Mn, Co, etc.) spinel type lithium transition metal oxides such as LiM3O2 (M3 is one or more metal elements selected from Fe, Ni, Mn, Co, etc.), etc.
  • LiM3O2 M3 is one or more metal elements selected from Fe, Ni, Mn, Co, etc.
  • a layered lithium transition metal oxide or the like can be used.
  • negative electrode active materials include lithium metal, lithium alloys, alloys capable of intercalating and deintercalating lithium, carbon materials (for example, graphite, non-graphitizable carbon, easily graphitizable carbon, amorphous carbon, etc.).
  • the separators 153 and 154 are microporous sheets made of resin.
  • any known material can be used as appropriate, as long as it does not impair the performance of power storage element 100.
  • a nonwoven fabric a synthetic resin microporous membrane made of polyolefin resin such as polyethylene, or the like can be used as the separators 153 and 154.
  • the electrode body 150 is formed by winding a laminate in which a positive electrode plate 151, a negative electrode plate 152, and separators 153 and 154 are alternately laminated.
  • the electrode body 150 of this embodiment is a flat electrode body formed by winding the positive electrode plate 151, the negative electrode plate 152, etc. around a winding axis L extending in the X-axis direction.
  • the winding axis L is a virtual axis that serves as a central axis when winding the positive electrode plate 151, the negative electrode plate 152, and the like.
  • the positive electrode active material layer 151b of this embodiment includes a positive electrode active material containing nickel.
  • the positive electrode active material of the positive electrode active material layer 151b is nickel-cobalt-manganese containing Ni, Co, and Mn in an element ratio of 5:2:3, 6:2:2, 8:1:1, etc.
  • These include lithium oxide (hereinafter also referred to as NCM), lithium nickel oxide, and lithium nickel/cobalt oxide in which a portion of the nickel in lithium nickel oxide is replaced with cobalt.
  • the value (hereinafter also referred to as the second value) obtained by dividing the total mass of nickel that the power storage element 100 has (hereinafter also referred to as mass C) by the volume of the container 110 of the power storage element 100 (hereinafter also referred to as volume D) is: It is preferable that it is 100 g/L or more.
  • Mass C is the total mass of nickel contained in the positive electrode active material. A certain area of the positive electrode active material layer 151b is cut out and dissolved in acid, and the amount of nickel per certain area is measured by ICP (inductively coupled plasma emission spectrometry).
  • the value of the mass C can be obtained by multiplying the ratio of the area of the positive electrode active material layer 151b to the above-mentioned constant area by the amount of nickel obtained in the measurement.
  • the volume D is calculated by measuring the dimensions of the container 110.
  • the second value is the value obtained by dividing the total mass of nickel in the positive electrode active material of the positive electrode active material layer 151b by the volume of the container 110. A detailed explanation of the second value will be given later.
  • FIG. 5 is a perspective view showing the configuration of the flow path forming member 200 according to the present embodiment.
  • FIG. 5 shows a state in which one power storage element 100 is disposed below the flow path forming member 200.
  • the flow path forming member 200 is a cylindrical member (in this embodiment, a rectangular cylindrical shape) that is long in the Y-axis direction.
  • the surface of the flow path forming member 200 in the negative direction of the Y axis is closed, and the surface of the flow path forming member 200 in the positive direction of the Y axis is open.
  • Flow path forming member 200 is arranged above gas exhaust valve 131 of each power storage element 100.
  • the flow path forming member 200 can be made of a metal member such as stainless steel or aluminum, or a member having heat insulating properties such as glass wool or mica. Alternatively, it can be formed from a member having insulation properties such as a resin material.
  • the flow path forming member 200 is preferably formed of a nonflammable member with high heat resistance. All walls of the flow path forming member 200 may be made of the same material, or any of the walls may be made of different materials.
  • the flow path forming member 200 has a bottom wall 210, a pair of side walls 220, a top wall 230, and a front wall 240. With this configuration, the flow path forming member 200 forms a flow path R for gas discharged from the gas exhaust valve 131.
  • the flow path R is a gas path extending in the Y-axis direction through which the gas flows. The gas flows in the Y-axis positive direction of the flow path R and is discharged from the exhaust port 250 at the end of the flow path forming member 200 in the Y-axis positive direction.
  • the flow path forming member 200 may be one member that integrally includes all the wall portions of the bottom wall portion 210, the pair of side wall portions 220, the top wall portion 230, and the front wall portion 240, or may include any one of the The wall portion may be separate and formed from a plurality of members.
  • the bottom wall portion 210 constitutes the bottom wall of the flow path forming member 200.
  • the bottom wall portion 210 is a flat and rectangular portion.
  • Bottom wall portion 210 is a wall portion that is disposed at a position facing container lid portion 130 of container 110 of power storage element 100 and extends in the Y-axis direction.
  • a plurality of openings 211 are formed in the bottom wall portion 210 and are arranged in the Y-axis direction.
  • the opening 211 is a through hole arranged at a position facing the gas exhaust valve 131 of the power storage element 100.
  • the opening 211 is a circular through hole that penetrates the bottom wall 210 in the Z-axis direction.
  • 16 openings 211 are arranged in line in the Y-axis direction, corresponding to 16 power storage elements 100.
  • the opening 211 has the same shape as the gas exhaust valve 131 when viewed from the Z-axis direction, but the shape of the opening 211 is not particularly limited. However, it is preferable that the opening 211 has the same shape as the gas exhaust valve 131 or a larger shape than the gas exhaust valve 131 when viewed from the Z-axis direction (planar view direction).
  • the side wall portion 220 constitutes a side wall of the flow path forming member 200.
  • the side wall portion 220 is a flat and rectangular portion, and is arranged along the gas flow path R.
  • the side wall portion 220 is a wall portion that is connected to the bottom wall portion 210 and the top wall portion 230 and extends in the Y-axis direction.
  • a pair of side walls 220 are arranged to connect both ends of the bottom wall 210 and the top wall 230 in the X-axis direction.
  • the upper wall portion 230 constitutes the upper wall of the flow path forming member 200.
  • the upper wall portion 230 is a flat and rectangular portion, and is arranged along the gas flow path R.
  • the top wall portion 230 is a wall portion that is disposed at a position facing the bottom wall portion 210 and extends parallel to the XY plane and in the Y-axis direction.
  • the flow path forming member 200 has an upper wall portion 230 that faces the gas exhaust valve 131 in the Z-axis direction (second direction) orthogonal to the Y-axis direction (first direction), and a top wall portion 230 that faces the gas exhaust valve 131 in the Y-axis direction and the Z-axis direction. It has a pair of side wall portions 220 in the X-axis direction (third direction) orthogonal to the axial direction. In this embodiment, no opening is formed in the upper wall portion 230 and the side wall portion 220 in the range where the power storage element 100 is arranged in the Y-axis direction.
  • the front wall portion 240 constitutes the front wall of the flow path forming member 200.
  • the front wall portion 240 is a flat and rectangular portion, and is arranged parallel to the XZ plane.
  • the front wall 240 is connected to the bottom wall 210, the side wall 220, and the top wall 230 to prevent gas from leaking from the flow path R.
  • the length of the flow path forming member 200 in the gas flow direction (Y-axis direction) is longer than the power storage element 100.
  • the length in the Y-axis direction is the same as that of the plurality of power storage elements 100 included in the power storage device 1 in the Y-axis direction. longer than the length of
  • the minimum flow path area (hereinafter also referred to as area B), which is the minimum value of the area of the surface perpendicular to the direction in which gas flows in the flow path R, is the area of the gas exhaust valve 131 in plan view (hereinafter also referred to as area A). ) (hereinafter referred to as the first value) is smaller than 1.6.
  • Area A is the area of gas exhaust valve 131 when viewed from the Z-axis direction. That is, the area A is an area in which the gas exhaust valve 131 can be opened when gas is exhausted from the gas exhaust valve 131.
  • Area B (flow path minimum area) is the minimum value of the area in a plane (XZ plane) perpendicular to the gas flow direction (Y-axis direction) in the flow path R. That is, the area B is the minimum value of the area of a cut surface obtained by cutting the flow path R along a plane parallel to the XZ plane.
  • the area of the cut surface is the same from one end to the other end in the Y-axis direction. Therefore, no matter where the flow path R is cut, the area of the cut surface is the area B.
  • the minimum value of the cross-sectional area of the flow path R in the Y-axis direction becomes the area B.
  • the cross-sectional area changes if the cross-sectional area at a position close to the gas exhaust valve 131 (position close to the opening 211) is made smaller, the gas flows immediately after flowing from the gas exhaust valve 131 into the opening 211.
  • the cross-sectional area at a position close to the gas exhaust valve 131 becomes area B.
  • the value obtained by dividing the area B calculated in this way by the area A becomes the first value.
  • the flow path forming member 200 of this embodiment has a relatively narrow flow path R, and the area B is relatively small. Specifically, as described above, the first value is smaller than 1.6. In order to further narrow the flow path R of the flow path forming member 200 and increase the gas flow rate in the flow path R, the first value is preferably smaller than 1.25. Furthermore, the value obtained by dividing the total mass (mass C) of nickel that the electricity storage element 100 has by the minimum area of the flow path (the minimum value (area B) of the surface perpendicular to the direction in which gas flows in the flow path R) (hereinafter, The third value) is preferably 0.15 g/mm2 or more. The first value, the third value, and the above-mentioned second value will be explained in detail below using the experimental results shown in Table 1.
  • test power storage elements and test power storage devices were manufactured as follows. Details will be explained with reference to Table 1 below.
  • a positive electrode paste was prepared by mixing a positive electrode active material, polyvinylidene fluoride (PVDF) as a binder, carbon black as a conductive material, and N-methylpyrrolidone (NMP) as a dispersion medium.
  • PVDF polyvinylidene fluoride
  • NMP N-methylpyrrolidone
  • the positive electrode active material was NCM (nickel/cobalt containing Ni, Co, and Mn in an element ratio of 5:2:3).
  • LFP lithium iron phosphate
  • the mass ratio of the positive electrode active material, PVDF, and carbon black was 90:5:5 (in terms of solid content).
  • a positive electrode mixture paste was applied to both sides of an aluminum foil (positive electrode current collector foil) and dried to form an unpressed positive electrode active material layer. Thereafter, hot roll pressing was performed on the unpressed positive electrode active material layer to obtain positive electrode plates of Examples 1 to 4 and Comparative Example 1.
  • the total mass of nickel contained in the positive electrode plate obtained by the above method is as shown in "Ni mass (C)" in Table 1, and 4 does not contain nickel.
  • a negative electrode paste was prepared by mixing natural graphite as a negative electrode active material, styrene-butadiene rubber (SBR) as a binder, carboxymethyl cellulose ammonium (CMC-NH4) as a thickener, and water as a dispersion medium.
  • SBR styrene-butadiene rubber
  • CMC-NH4 carboxymethyl cellulose ammonium
  • a negative electrode mixture paste was applied to both sides of the copper foil (positive electrode current collector foil) and dried to form an unpressed negative electrode active material layer. Thereafter, roll pressing was performed on the unpressed negative electrode active material layer to obtain negative electrode plates of Examples 1 to 4 and Comparative Example 1.
  • An electrode body was produced by winding up a separator, the above negative electrode plate, a separator, and the above positive electrode plate laminated in this order. At this time, a negative electrode plate was placed outside the positive electrode plate, and a separator was further placed outside the negative electrode plate. The above-mentioned electrode body was inserted into a container and the container was sealed to prepare a test power storage element.
  • the electrolytic solution used was a non-aqueous electrolytic solution in which LiPF6 was dissolved at a concentration of 1.0 mol/dm3 in a solvent in which ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate were mixed at a volume ratio of 30:35:35.
  • a separatorous polyolefin membrane coated with a mixture of alumina and PVDF was used so as to face the positive electrode.
  • the volume of the container (volume D) was as shown in “Container Volume (D)" ("Container Width”, “Container Thickness”, and “Container Height”) in Table 1.
  • the length (width) in the X-axis direction, the length (thickness) in the Y-axis direction, and the length (height) in the Z-axis direction of the container 110 in FIG. corresponds to "height”.
  • the container was provided with a gas exhaust valve, and the area (area A) of the gas exhaust valve was as shown in “Gas exhaust valve area (A)” in Table 1.
  • the volumetric energy density of the test electricity storage element was as shown in “Energy Density" in Table 1.
  • test power storage device A plurality of the test power storage elements described above were arranged in a resin box, and a flow path forming member was placed thereon.
  • the number of test power storage elements arranged in the test power storage device was as shown in “Number of power storage elements” in Table 1.
  • the length of the channel-forming member was as shown in “Channel-forming member length” in Table 1.
  • the minimum flow path area (area B) which is the minimum value of the surface perpendicular to the gas flow direction in the flow path R, was as shown in "Flow path minimum area (B)" in Table 1.
  • the above-mentioned first value (the value obtained by dividing the flow path minimum area (B) by the gas discharge valve area (A) (B/A)) is the “first value (B/A)” in Table 1. ” as shown.
  • the above-mentioned second value (the value obtained by dividing the Ni mass (C) by the container volume (D) (C/D)) was as shown in “Second Value (C/D)" in Table 1.
  • the above-mentioned third value (the value obtained by dividing the Ni mass (C) by the minimum area of the flow path (B) (C/B)) was as shown in “Third value (C/B)" in Table 1. .
  • the test power storage element (hereinafter referred to as a trigger power storage element) was heated with a heater without temperature control.
  • the temperature of the trigger power storage element was as shown in "Trigger power storage element temperature" in Table 1.
  • the temperature of the trigger storage element is measured by attaching a thermocouple to the long side of the container of the trigger storage element.
  • an adjacent power storage element another test power storage element adjacent to the trigger power storage element via a spacer was measured.
  • the adjacent power storage element is a test power storage element located upstream of the gas flow (in the negative Y-axis direction in FIG. 5) with respect to the trigger power storage element.
  • the remaining capacity of the adjacent power storage element was as shown in "Adjacent power storage element remaining capacity" in Table 1.
  • the test power storage elements were in a fully charged state, and a heat insulating plate made of glass fiber was used as a spacer between the test power storage elements.
  • Example 1 to 3 and Comparative Example 1 the positive electrode active material contains nickel, whereas in Example 4, the positive electrode active material does not contain nickel. Therefore, the energy density of Examples 1 to 3 and Comparative Example 1 is higher than that of Example 4.
  • the temperature of the trigger electricity storage element ("trigger electricity storage element temperature" in Table 1) is low, so Examples 1 to 3 are more preferable than Comparative Example 1.
  • Examples 1 to 3 are preferable to Comparative Example 1 because it is preferable that the remaining capacity of the adjacent electricity storage element (“adjacent electricity storage element remaining capacity" in Table 1) is large.
  • Examples 1 to 3 since the energy density of Examples 2 and 3 is higher than that of Example 1, Examples 2 and 3 are preferable to Example 1. In Examples 2 and 3, since the remaining capacity of the adjacent power storage element in Example 3 is larger than that in Example 2, Example 3 is preferable to Example 2.
  • Example 1 is preferred, Example 2 is more preferred, and Example 3 is even more preferred.
  • the first value of Example 1 is smaller than 1.6.
  • the first value is preferably smaller than 1.25, more preferably smaller than 1.0, and even more preferably smaller than 0.75. In this way, since it is better to have a smaller first value, it is further preferable that the first value is smaller than 0.5.
  • the first value is preferably 0.3 or more.
  • the second value (the value obtained by dividing the total mass (mass C) of nickel included in the power storage element 100 by the volume (volume D) of the container 110 of the power storage element 100) is 100 g/L or more. is preferable, and more preferably 180 g/L or more. According to Examples 2 and 3, the first value is more preferably 190 g/L or more. In manufacturing the electricity storage element 100, the second value is preferably 420 g/L or less.
  • the third value (the total mass (mass C) of nickel possessed by the power storage element 100 is the minimum value of the flow path minimum area (area B) of the surface perpendicular to the direction in which gas flows in the flow path R)
  • the value divided by is preferably 0.15 g/mm 2 or more.
  • the third value is more preferably 0.2 g/mm2 or more, and according to Example 3, it is even more preferably 0.4 g/mm2 or more.
  • the third value is preferably 0.55 g/mm2 or less.
  • the minimum area of the flow path (area B), which is the minimum value of the surface perpendicular to the direction in which gas flows in the flow path R, is used for gas discharge.
  • the first value divided by the area (area A) of the valve 131 in plan view is made smaller than 1.6.
  • the flow rate of the gas can be increased. Thereby, even when high-temperature gas is discharged from the gas discharge valve 131, it is difficult for the gas to remain in the flow path forming member 200.
  • the power storage element 100 the power storage element having a positive electrode active material containing nickel has a high capacity (high energy density), and the gas discharged from the gas exhaust valve 131 tends to reach a relatively high temperature. Therefore, the effect of adopting the configuration of this embodiment in power storage device 1 is high.
  • the third value is 0.15 g/mm2 or more
  • the gas discharged from the gas discharge valve 131 has a higher capacity (higher energy density). tends to become hotter. Therefore, the effect of adopting the configuration of this embodiment in power storage device 1 is high.
  • the flow path R in the flow path forming member 200 is The flow rate of the gas can be further increased.
  • the power storage element 100 has a rectangular parallelepiped shape that is flat in the Y-axis direction (long in the X-axis direction when viewed from the Z-axis direction), but the size and shape of the power storage element 100 are is not particularly limited.
  • the power storage element 100 may have an elongated cylindrical shape, an elliptical cylindrical shape, a polygonal cylindrical shape other than a rectangular parallelepiped, or the like.
  • the power storage element 100 may not have a flat shape, but may have a cylindrical shape (cylindrical shape, cylindrical shape) with a circular bottom surface, a rectangular parallelepiped shape with a square bottom surface, or the like.
  • the size, shape, and position of the flow path forming member 200 are not particularly limited.
  • the length of the flow path forming member 200 in the Y-axis direction may be shorter than the exterior body 18.
  • the flow path forming member 200 does not need to protrude from the exterior body 18 or may be arranged outside the exterior body 18.
  • the cross-sectional shape of the flow path R in the flow path forming member 200 may not be rectangular but may be circular, elliptical, oval, polygonal other than rectangular, or the like.
  • the cross-sectional shape of the flow path R in the flow path forming member 200 does not have to be the same shape in the direction in which the gas flows, and can be changed to any shape.
  • the flow path forming member 200 may extend in a direction different from the Y-axis direction, may have a curved shape, or may have a bent shape.
  • the direction in which gas flows in the channel R in the channel forming member 200 is the direction in which the channel forming member 200 extends, or the direction along the curved or bent shape of the channel forming member 200.
  • the flow path forming member 200 is a separate member from the busbar frame 12, the exterior body 18, etc., but it is formed integrally with the busbar frame 12 or the exterior body 18 (exterior body lid 17). (integrated).
  • a wall provided on the busbar frame 12 or the exterior body 18 (exterior body lid 17) may be used as a wall (wall of the flow path R) that serves as a gas guide in the flow path forming member 200.
  • the flow path forming member 200 is a member that extends in the Y-axis direction without being divided in the Y-axis direction, but a plurality of members divided in the Y-axis direction By being connected, a flow path forming member 200 that is long in the Y-axis direction may be configured.
  • the second value (the value obtained by dividing the total mass of nickel included in the power storage element 100 by the volume of the container 110) may be smaller than 100 g/L.
  • the third value (the value obtained by dividing the total mass of nickel included in the power storage element 100 by the minimum area of the flow path) may be smaller than 0.15 g/mm2.
  • the positive electrode active material of the positive electrode active material layer 151b formed on the positive electrode plate 151 of the electrode body 150 does not need to contain nickel. That is, the power storage element 100 may not have a positive electrode active material containing nickel, and may have the configuration as in Example 4 above. In Example 4, although the energy density is low, a large amount of remaining capacity of the adjacent power storage elements can be maintained.
  • the gas exhaust valve 131 is provided on the container lid 130 of the container 110 of the power storage element 100, but the gas exhaust valve 131 may be provided on the container body 120.
  • the electrode body 150 is a wound type electrode body in which the winding axis L is parallel to the container lid 130.
  • the electrode body 150 may be a wound type electrode body in which the winding axis L is perpendicular to the container lid 130.
  • the ends 156 and 157 are not limited to portions that protrude from the entire end of the electrode body body 155, but are tab portions (poles) that protrude from a part of the end of the electrode body body 155. It may also be a portion of a plate in which multiple tabs are stacked.
  • the electrode body 150 may be a laminated type (stack type) electrode body formed by laminating a plurality of flat plates, a bellows-type electrode body formed by folding the plates into a bellows shape, or other electrode bodies.
  • the electrode body may have the following form.
  • the present invention can be applied to a power storage device, etc. equipped with a power storage element such as a lithium ion secondary battery.
  • Power storage device 10
  • Power storage unit 11
  • Spacer 12
  • Busbar frame 12a
  • Flow path forming member arrangement portion 13
  • Busbar 14
  • Exterior main body 14a
  • Notch 15
  • Exterior support 17
  • Exterior cover 18
  • Exterior 20
  • Board unit 30
  • Cable 100
  • Energy storage element 110
  • Container 120
  • container lid 131
  • gas discharge valve 140
  • terminal 150
  • electrode body 151
  • positive electrode plate 151a positive electrode base material
  • 151b positive electrode active material layer 152
  • negative electrode base material 152a negative electrode base material
  • 152b negative electrode active material layer
  • 154 separator 160 current collector
  • flow Path forming member 210
  • Bottom wall 211 Opening 220
  • Side wall 230
  • Top wall 240
  • Outlet 250

Abstract

A power storage device 1 comprises: a power storage element 100 that includes a gas exhaust valve 131; and a flow channel forming member 200 that forms a flow channel R for gas exhausted from the gas exhaust valve 131. In a case where the direction in which the gas flows through the flow channel R is a first direction, the length of the flow channel forming member 200 in the first direction is greater than the length of the power storage element 100 in the first direction, and a first value, which is obtained by dividing a flow channel minimum area (area B), which is a minimum value of a surface orthogonal to the first direction in the flow channel R, by a plan-view area (area A) of the gas exhaust valve 131, is smaller than 1.6.

Description

蓄電装置Power storage device
　本発明は、蓄電素子を備える蓄電装置に関する。 The present invention relates to a power storage device including a power storage element.
　従来、ガス排出弁を有する蓄電素子と、ガス排出弁から排出されるガスの流路を形成する流路形成部材と、を備える蓄電装置が知られている。例えば、特許文献１には、安全弁（ガス排出弁）を有する電池セル（蓄電素子）と、電池セル（蓄電素子）から放出されたガスが流れる排煙ダクト（流路形成部材）と、を備える電池モジュール（蓄電装置）が開示されている。 Conventionally, power storage devices are known that include a power storage element having a gas exhaust valve and a flow path forming member that forms a flow path for gas discharged from the gas exhaust valve. For example, Patent Document 1 includes a battery cell (power storage element) having a safety valve (gas discharge valve), and a smoke exhaust duct (flow path forming member) through which gas released from the battery cell (power storage element) flows. A battery module (power storage device) is disclosed.
特開２０１８－６０６１号公報Unexamined Japanese Patent Publication No. 2018-6061
　上記従来の蓄電装置において、蓄電素子のガス排出弁からは高温のガスが排出されるため、当該ガスが流路形成部材内で滞留すると、蓄電素子の周囲の部材（他の蓄電素子等）に熱影響を及ぼすおそれがある。このため、蓄電装置において、蓄電素子のガス排出弁から排出されるガスが流路形成部材内で滞留するのを抑制し、蓄電素子の周囲の部材に影響を及ぼすのを抑制できる構成が望まれる。 In the above-mentioned conventional power storage device, high-temperature gas is discharged from the gas discharge valve of the power storage element, so if the gas stays in the flow path forming member, it may cause damage to the surrounding members of the power storage element (other power storage elements, etc.). There is a risk of thermal effects. Therefore, in a power storage device, it is desirable to have a configuration that can suppress the gas discharged from the gas discharge valve of the power storage element from staying in the flow path forming member and prevent it from affecting the surrounding members of the power storage element. .
　本発明は、本願発明者が上記課題に新たに着目することによってなされたものであり、蓄電素子の周囲の部材に影響を及ぼすのを抑制できる蓄電装置を提供することを目的とする。 The present invention was achieved by the inventors of the present application newly paying attention to the above-mentioned problem, and an object of the present invention is to provide a power storage device that can suppress the influence on members around the power storage element.
　本発明の一態様に係る蓄電装置は、ガス排出弁を有する蓄電素子と、前記ガス排出弁から排出されるガスの流路を形成する流路形成部材と、を備え、前記ガスが前記流路を流れる方向を第一方向とした場合、前記流路形成部材の第一方向の長さは、前記蓄電素子の第一方向の長さよりも長く、前記流路における前記第一方向と直交する面の最小値である流路最小面積を、前記ガス排出弁の平面視での面積で除した第一値は１．６よりも小さい。 A power storage device according to one aspect of the present invention includes a power storage element having a gas exhaust valve, and a flow path forming member that forms a flow path for gas discharged from the gas exhaust valve, and wherein the gas flows through the flow path. When the flow direction is defined as the first direction, the length of the flow path forming member in the first direction is longer than the length of the electricity storage element in the first direction, and the length of the flow path forming member is longer than the length of the electricity storage element in the first direction, A first value obtained by dividing the minimum flow path area, which is the minimum value of , by the area of the gas discharge valve in plan view, is smaller than 1.6.
　本発明における蓄電装置によれば、蓄電素子の周囲の部材に影響を及ぼすのを抑制できる。 According to the power storage device of the present invention, it is possible to suppress the influence on members around the power storage element.
実施の形態に係る蓄電装置の外観を示す斜視図である。FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. 実施の形態に係る蓄電装置を分解した場合の各構成要素を示す分解斜視図である。FIG. 2 is an exploded perspective view showing each component when the power storage device according to the embodiment is disassembled. 実施の形態に係る蓄電素子の構成を示す斜視図である。FIG. 1 is a perspective view showing the configuration of a power storage element according to an embodiment. 実施の形態に係る蓄電素子が有する電極体の構成を示す斜視図である。FIG. 2 is a perspective view showing the configuration of an electrode body included in a power storage element according to an embodiment. 実施の形態に係る流路形成部材の構成を示す斜視図である。FIG. 2 is a perspective view showing the configuration of a flow path forming member according to an embodiment.
　（１）本発明の一態様に係る蓄電装置は、ガス排出弁を有する蓄電素子と、前記ガス排出弁から排出されるガスの流路を形成する流路形成部材と、を備え、前記ガスが前記流路を流れる方向を第一方向とした場合、前記流路形成部材の第一方向の長さは、前記蓄電素子の第一方向の長さよりも長く、前記流路における前記第一方向と直交する面の最小値である流路最小面積を、前記ガス排出弁の平面視での面積で除した第一値は１．６よりも小さい。 (1) A power storage device according to one aspect of the present invention includes a power storage element having a gas exhaust valve, and a flow path forming member that forms a flow path for gas discharged from the gas exhaust valve, and the power storage device includes When the flow direction in the flow path is a first direction, the length of the flow path forming member in the first direction is longer than the length of the electricity storage element in the first direction, and the length in the first direction in the flow path is A first value obtained by dividing the minimum area of the flow path, which is the minimum value of orthogonal surfaces, by the area of the gas exhaust valve in plan view is smaller than 1.6.
　これによれば、蓄電素子のガス排出弁から排出されるガスの流路形成部材内での流路を狭く（第一値を１．６よりも小さく）することで、流路内での当該ガスの流速を速くできる。これにより、ガス排出弁から高温のガスが排出された場合でも、流路内でのガスの滞留が起きにくいため、蓄電素子の周囲の部材（他の蓄電素子等）に影響を及ぼすのを抑制できる。ここで、複数の蓄電素子を備える蓄電装置における「前記蓄電素子の第一方向の長さ」は、複数の蓄電素子のうちの一つの蓄電素子の第一方向の長さのことである。 According to this, by narrowing the flow path (the first value is smaller than 1.6) in the flow path forming member for the gas discharged from the gas discharge valve of the energy storage element, the The gas flow rate can be increased. As a result, even when high-temperature gas is discharged from the gas discharge valve, it is difficult for the gas to remain in the flow path, thereby suppressing the impact on components surrounding the energy storage element (other energy storage elements, etc.) can. Here, in a power storage device including a plurality of power storage elements, "the length of the power storage element in the first direction" refers to the length of one power storage element among the plurality of power storage elements in the first direction.
　（２）上記（１）に記載の蓄電装置において、前記蓄電素子は、ニッケルを含む正極活物質を有する、としてもよい。 (2) In the power storage device according to (1) above, the power storage element may include a positive electrode active material containing nickel.
　これによれば、蓄電素子において、ニッケルを含む正極活物質を有する蓄電素子は高容量（高エネルギー密度）を有しており、ガス排出弁から排出されるガスが比較的高温になり易い。このため、蓄電装置において、本願の構成を採用することによる効果が高い。 According to this, in a power storage element, a power storage element having a positive electrode active material containing nickel has a high capacity (high energy density), and the gas discharged from the gas exhaust valve tends to reach a relatively high temperature. Therefore, in the power storage device, the effect of adopting the configuration of the present application is high.
　（３）上記（２）に記載の蓄電装置において、前記蓄電素子が有する前記ニッケルの全質量を、前記蓄電素子の容器の体積で除した第二値は、１００ｇ／Ｌ以上である、としてもよい。 (3) In the power storage device according to (2) above, the second value obtained by dividing the total mass of the nickel included in the power storage element by the volume of the container of the power storage element is 100 g/L or more. good.
　これによれば、蓄電素子が有するニッケルの含有比率が高い場合（第二値が１００ｇ／Ｌ以上となる場合）に、より高容量（高エネルギー密度）となるため、ガス排出弁から排出されるガスがより高温になり易い。このため、蓄電装置において、本願の構成を採用することによる効果が高い。 According to this, when the content ratio of nickel in the energy storage element is high (the second value is 100 g/L or more), it has a higher capacity (higher energy density) and is discharged from the gas discharge valve. Gas tends to become hotter. Therefore, in the power storage device, the effect of adopting the configuration of the present application is high.
　（４）上記（２）または（３）に記載の蓄電装置において、前記蓄電素子が有する前記ニッケルの全質量を、前記流路最小面積で除した第三値は、０．１５ｇ／ｍｍ２以上である、としてもよい。 (4) In the power storage device according to (2) or (3) above, a third value obtained by dividing the total mass of the nickel included in the power storage element by the minimum area of the flow path is 0.15 g/mm2 or more. It may be said that there is.
　これによれば、蓄電素子が有するニッケルの含有比率が高い場合（第三値が０．１５ｇ／ｍｍ２以上となる場合）に、より高容量（高エネルギー密度）となるため、ガス排出弁から排出されるガスがより高温になり易い。このため、蓄電装置において、本願の構成を採用することによる効果が高い。 According to this, when the content ratio of nickel in the energy storage element is high (the third value is 0.15 g/mm2 or more), it has a higher capacity (higher energy density) and is discharged from the gas exhaust valve. The gas that is used tends to become hotter. Therefore, in the power storage device, the effect of adopting the configuration of the present application is high.
　以下、図面を参照しながら、本発明の実施の形態（その変形例も含む）に係る蓄電装置について説明する。なお、以下で説明する実施の形態は、いずれも包括的または具体的な例を示すものである。以下の実施の形態で示される数値、形状、材料、構成要素、構成要素の配置位置及び接続形態、製造工程、製造工程の順序等は、一例であり、本発明を限定する主旨ではない。各図において、寸法等は厳密に図示したものではない。各図において、同一または同様な構成要素については同じ符号を付している。 Hereinafter, a power storage device according to an embodiment of the present invention (including variations thereof) will be described with reference to the drawings. Note that the embodiments described below are all inclusive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing steps, order of manufacturing steps, etc. shown in the following embodiments are merely examples, and do not limit the present invention. In each figure, dimensions etc. are not strictly illustrated. In each figure, the same or similar components are designated by the same reference numerals.
　以下の説明及び図面中において、１つの蓄電素子における一対（正極及び負極）の端子が並ぶ方向、蓄電素子の容器の短側面が対向する方向、または、外装体の短手方向を、Ｘ軸方向と定義する。Ｘ軸方向は第三方向と同じである。複数の蓄電素子が並ぶ方向、蓄電素子の容器の長側面が対向する方向、外装体の長手方向、または、流路形成部材が延びる方向（流路形成部材内の流路におけるガスが流れる方向）を、Ｙ軸方向と定義する。Ｙ軸方向は第一方向と同じである。蓄電素子とバスバーとが並ぶ方向、蓄電素子の容器の本体と蓋部とが並ぶ方向、上下方向を、Ｚ軸方向と定義する。Ｚ軸方向は第二方向と同じである。これらＸ軸方向、Ｙ軸方向及びＺ軸方向は、互いに交差（本実施の形態では直交）する方向である。使用態様によってはＺ軸方向が上下方向にならない場合も考えられるが、以下では説明の便宜のため、Ｚ軸方向を上下方向として説明する。 In the following description and drawings, the direction in which a pair of terminals (positive electrode and negative electrode) in one power storage element are lined up, the direction in which the short sides of the container of the power storage element face each other, or the short direction of the exterior body is referred to as the X-axis direction. It is defined as The X-axis direction is the same as the third direction. The direction in which a plurality of power storage elements are lined up, the direction in which the long sides of the containers of power storage elements face each other, the longitudinal direction of the exterior body, or the direction in which the flow path forming member extends (the direction in which gas flows in the flow path in the flow path forming member) is defined as the Y-axis direction. The Y-axis direction is the same as the first direction. The direction in which the power storage element and the bus bar are lined up, the direction in which the main body and the lid of the container of the power storage element are lined up, and the vertical direction are defined as the Z-axis direction. The Z-axis direction is the same as the second direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect with each other (orthogonal in this embodiment). Depending on the usage mode, the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described as the vertical direction below.
　以下の説明において、Ｘ軸プラス方向とは、Ｘ軸の矢印方向を示し、Ｘ軸マイナス方向とは、Ｘ軸プラス方向とは反対方向を示す。単にＸ軸方向という場合は、Ｘ軸プラス方向及びＸ軸マイナス方向の双方向またはいずれか一方の方向を示す。Ｙ軸方向及びＺ軸方向についても同様である。平行及び直交などの、相対的な方向または姿勢を示す表現は、厳密には、その方向または姿勢ではない場合も含む。例えば、２つの方向が平行であるとは、当該２つの方向が完全に平行であることを意味するだけでなく、実質的に平行であること、すなわち、例えば数％程度の差異を含むことも意味する。さらに、以下の説明において、「絶縁」と表現する場合、「電気的な絶縁」を意味する。 In the following description, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the opposite direction to the X-axis plus direction. When simply referred to as the X-axis direction, it refers to both or one of the X-axis plus direction and the X-axis minus direction. The same applies to the Y-axis direction and the Z-axis direction. Expressions indicating relative directions or orientations, such as parallel and orthogonal, include cases where the directions or orientations are not strictly speaking. For example, when two directions are parallel, it does not only mean that the two directions are completely parallel, but also that they are substantially parallel, that is, they may differ by a few percent, for example. means. Furthermore, in the following description, when expressed as "insulation", it means "electrical insulation".
　（実施の形態）
　［１　蓄電装置１の全般的な説明］
　まず、本実施の形態における蓄電装置１の全般的な説明を行う。図１は、本実施の形態に係る蓄電装置１の外観を示す斜視図である。図２は、本実施の形態に係る蓄電装置１を分解した場合の各構成要素を示す分解斜視図である。 (Embodiment)
[1 General description of power storage device 1]
First, a general description of power storage device 1 in this embodiment will be given. FIG. 1 is a perspective view showing the appearance of a power storage device 1 according to the present embodiment. FIG. 2 is an exploded perspective view showing each component when power storage device 1 according to the present embodiment is disassembled.
　蓄電装置１は、外部からの電気を充電し、また外部へ電気を放電できる装置である。本実施の形態では、蓄電装置１は、略直方体形状を有している。例えば、蓄電装置１は、電力貯蔵用途または電源用途等に使用される電池モジュール（組電池）である。具体的には、蓄電装置１は、自動車、自動二輪車、船舶、建設機械、無人搬送車、または、電気鉄道用の鉄道車両等の移動体の駆動用またはエンジン始動用等のバッテリ等として用いられる。上記の自動車としては、電気自動車（ＥＶ）、ハイブリッド電気自動車（ＨＥＶ）、プラグインハイブリッド電気自動車（ＰＨＥＶ）が例示される。蓄電装置１は、家庭用または事業用等に使用される定置用のバッテリ等としても用いられる。 The power storage device 1 is a device that can charge electricity from the outside and discharge electricity to the outside. In this embodiment, power storage device 1 has a substantially rectangular parallelepiped shape. For example, the power storage device 1 is a battery module (battery assembly) used for power storage, power supply, or the like. Specifically, the power storage device 1 is used as a battery for driving or starting an engine of a mobile object such as an automobile, a motorcycle, a ship, a construction machine, an automatic guided vehicle, or a railway vehicle for an electric railway. . Examples of the above-mentioned vehicle include an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV). The power storage device 1 is also used as a stationary battery for home or business use.
　図１に示すように、蓄電装置１は、蓄電ユニット１０と、蓄電ユニット１０に取り付けられる基板ユニット２０と、を備える。基板ユニット２０は、蓄電ユニット１０が有する蓄電素子１００の状態の監視、及び、蓄電素子１００の制御を行う機器であり、内方に回路基板等を有する。さらに図２に示すように、蓄電ユニット１０は、複数の蓄電素子１００と、複数のスペーサ１１と、バスバーフレーム１２と、複数のバスバー１３と、これらを収容する外装体１８と、流路形成部材２００と、を有する。蓄電ユニット１０は、複数の蓄電素子１００を拘束する拘束部材（エンドプレート、サイドプレート等）等を有してもよい。 As shown in FIG. 1, the power storage device 1 includes a power storage unit 10 and a board unit 20 attached to the power storage unit 10. The board unit 20 is a device that monitors the state of the power storage element 100 included in the power storage unit 10 and controls the power storage element 100, and has a circuit board and the like inside. Furthermore, as shown in FIG. 2, the power storage unit 10 includes a plurality of power storage elements 100, a plurality of spacers 11, a busbar frame 12, a plurality of busbars 13, an exterior body 18 that accommodates these, and a flow path forming member. 200. The power storage unit 10 may include a restraining member (end plate, side plate, etc.) that restrains the plurality of power storage elements 100.
　蓄電素子１００は、二次電池（単電池）であり、より具体的には、リチウムイオン二次電池等の非水電解質二次電池である。蓄電素子１００は、扁平な直方体形状（角形）を有する。本実施の形態では、複数（１６個）の蓄電素子１００がＹ軸方向に並んで配列される。蓄電素子１００の個数等は限定されず、例えば１つの蓄電素子１００しか配置されなくてもよい。蓄電素子１００は、非水電解質二次電池には限定されず、非水電解質二次電池以外の二次電池であってもよいし、キャパシタであってもよい。蓄電素子１００は、一次電池であってもよい。 The power storage element 100 is a secondary battery (single cell), and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. Power storage element 100 has a flat rectangular parallelepiped shape (prismatic shape). In this embodiment, a plurality (16) of power storage elements 100 are arranged in line in the Y-axis direction. The number of power storage elements 100 is not limited, and for example, only one power storage element 100 may be arranged. The power storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or a capacitor. Power storage element 100 may be a primary battery.
　スペーサ１１は、Ｙ軸方向において蓄電素子１００と隣り合って配置される。スペーサ１１は、蓄電素子１００と他の部材とを断熱又は絶縁する部材（断熱板または絶縁板）である。本実施の形態では、スペーサ１１は、全ての蓄電素子１００同士の間に配置されるが、いずれかの蓄電素子１００同士の間にはスペーサ１１が配置されなくてもよい。 Spacer 11 is arranged adjacent to power storage element 100 in the Y-axis direction. Spacer 11 is a member (heat insulating plate or insulating plate) that heats or insulates power storage element 100 and other members. In this embodiment, spacers 11 are arranged between all of the power storage elements 100, but spacers 11 may not be arranged between any of the power storage elements 100.
　バスバーフレーム１２は、バスバー１３と他の部材との絶縁し、かつ、バスバー１３の位置を規制する部材である。バスバーフレーム１２は、樹脂材料等の絶縁性を有する部材等で形成される。バスバーフレーム１２は、複数の蓄電素子１００の上方に配置され、複数の蓄電素子１００に対して位置決めされる。バスバーフレーム１２上には、複数のバスバー１３が配置されて位置決めされる。バスバーフレーム１２には、流路形成部材２００が配置される流路形成部材配置部１２ａが設けられる。流路形成部材配置部１２ａは、バスバーフレーム１２のＸ軸方向中央部に配置され、かつ、Ｙ軸方向（第一方向）に延びる部分である。 The busbar frame 12 is a member that insulates the busbar 13 from other members and regulates the position of the busbar 13. The bus bar frame 12 is made of an insulating member such as a resin material. The bus bar frame 12 is arranged above the plurality of power storage elements 100 and positioned with respect to the plurality of power storage elements 100. A plurality of bus bars 13 are arranged and positioned on the bus bar frame 12. The busbar frame 12 is provided with a flow path forming member placement portion 12a in which the flow path forming member 200 is placed. The flow path forming member placement portion 12a is a portion that is placed in the center of the busbar frame 12 in the X-axis direction and extends in the Y-axis direction (first direction).
　各バスバー１３は、複数の蓄電素子１００上（バスバーフレーム１２上）に配置され、複数の蓄電素子１００の端子１４０同士を電気的に接続する板状部材である。バスバー１３は、金属で形成される。本実施の形態では、バスバー１３は、隣り合う蓄電素子１００の端子１４０同士を接続することで、１６個の蓄電素子１００を直列に接続する。蓄電素子１００の接続の態様は上記には限定されず、直列接続及び並列接続がどのように組み合わされていてもよい。バスバー１３、または、蓄電素子１００の端子１４０には、各蓄電素子１００の状態（電圧、温度等）を検出するためのケーブルである検出線１３ａが接続される。 Each bus bar 13 is a plate-like member that is arranged on the plurality of power storage elements 100 (on the busbar frame 12) and electrically connects the terminals 140 of the plurality of power storage elements 100. Bus bar 13 is made of metal. In this embodiment, bus bar 13 connects 16 power storage elements 100 in series by connecting terminals 140 of adjacent power storage elements 100. The connection mode of power storage element 100 is not limited to the above, and series connection and parallel connection may be combined in any manner. A detection line 13a, which is a cable for detecting the state (voltage, temperature, etc.) of each power storage element 100, is connected to the bus bar 13 or the terminal 140 of the power storage element 100.
　外装体１８は、蓄電ユニット１０の外殻を構成する矩形状（箱状）の筐体（モジュールケース）である。外装体１８は、蓄電素子１００等の外方に配置され、蓄電素子１００等を所定の位置で固定する。外装体１８は、外装体１８の本体を構成する外装体本体１４と、外装体本体１４を支持する外装体支持体１５と、外装体１８の蓋体（外蓋）を構成する外装体蓋体１７と、を有する。 The exterior body 18 is a rectangular (box-shaped) housing (module case) that constitutes the outer shell of the power storage unit 10. The exterior body 18 is arranged outside the power storage element 100 and the like, and fixes the power storage element 100 and the like at a predetermined position. The exterior body 18 includes an exterior body body 14 that constitutes the main body of the exterior body 18, an exterior body support body 15 that supports the exterior body body 14, and an exterior body lid body that constitutes a lid body (outer lid) of the exterior body 18. 17.
　外装体本体１４は、開口が形成された有底矩形筒状のハウジングである。外装体本体１４は、絶縁部材、または、絶縁塗装をした金属等により形成される。蓄電素子１００等の絶縁性が保たれる構成であれば、外装体本体１４は、金属等の導電部材で形成されてもよい。外装体本体１４のＹ軸プラス方向側の端部であって、その上部中央には流路形成部材２００が貫通する切欠部１４ａが形成されている。切欠部１４ａは、上方が開放された矩形状の切欠である。 The exterior body 14 is a bottomed rectangular cylindrical housing with an opening formed therein. The exterior main body 14 is formed of an insulating member or a metal coated with an insulating coating. As long as the insulation of the power storage element 100 and the like is maintained, the exterior body 14 may be formed of a conductive member such as metal. A notch 14a through which the flow path forming member 200 passes is formed at the upper center of the end of the exterior body 14 on the Y-axis plus direction side. The cutout portion 14a is a rectangular cutout that is open at the top.
　外装体支持体１５及び外装体蓋体１７は、外装体本体１４を保護（補強）する部材である。外装体支持体１５は、外装体本体１４を下方（Ｚ軸マイナス方向）から支持する部材であり、接続部１５ｂ及び１５ｃと、を有する。外装体蓋体１７は、外装体本体１４の上面の開口を塞ぐように配置される部材であり、接続部１７ｂ及び１７ｃと、を有する。接続部１７ｃの上端部（Ｚ軸プラス方向側の端部）の中央には、流路形成部材２００が貫通する矩形状の開口部（図示せず）が形成される。このように、外装体支持体１５及び外装体蓋体１７は、外装体本体１４を上下方向から挟み込んだ状態で固定される構成となっている。 The exterior support 15 and the exterior lid 17 are members that protect (reinforce) the exterior body 14. The exterior body support 15 is a member that supports the exterior body body 14 from below (Z-axis negative direction), and has connection parts 15b and 15c. The exterior lid 17 is a member disposed to close the opening on the upper surface of the exterior body 14, and includes connection parts 17b and 17c. A rectangular opening (not shown) through which the flow path forming member 200 passes is formed at the center of the upper end (end on the Z-axis positive direction side) of the connecting portion 17c. In this way, the exterior support 15 and the exterior lid 17 are configured to be fixed while sandwiching the exterior body 14 from above and below.
　流路形成部材２００は、複数の蓄電素子１００の上方（ガス排出弁１３１の上方）に配置される。流路形成部材２００は、各蓄電素子１００のガス排出弁１３１から排出されるガスの流路を形成する部材である。具体的には、流路形成部材２００は、複数の蓄電素子１００に跨ってＹ軸方向に延びる長尺で、かつ、筒状の部材である。流路形成部材２００は、ガス排出弁１３１から排出されるガスが所定方向（Ｙ軸プラス方向）に流れる排出経路を形成する。当該所定方向とは、複数の蓄電素子１００の配列方向であり、複数の蓄電素子１００のそれぞれが有するガス排出弁１３１の並び方向でもある。つまり、蓄電装置１００はＹ軸方向（第一方向）に並んだ複数の蓄電素１００子を備え、複数の蓄電素子１００に亘って流路形成部材２００が備えられている。本実施形態においては、複数の蓄電素子１００に亘って備えられた流路形成部材２００における流路最小面積を、複数の蓄電素子１００のいずれかのガス排出弁１３１の平面視の面積で除した値は１．６よりも小さい。 The flow path forming member 200 is arranged above the plurality of power storage elements 100 (above the gas exhaust valve 131). The flow path forming member 200 is a member that forms a flow path for gas discharged from the gas exhaust valve 131 of each power storage element 100. Specifically, the flow path forming member 200 is a long, cylindrical member that extends in the Y-axis direction across the plurality of power storage elements 100 . The flow path forming member 200 forms an exhaust path through which the gas exhausted from the gas exhaust valve 131 flows in a predetermined direction (Y-axis positive direction). The predetermined direction is the direction in which the plurality of power storage elements 100 are arranged, and also the direction in which the gas exhaust valves 131 included in each of the plurality of power storage elements 100 are arranged. That is, the power storage device 100 includes a plurality of power storage elements 100 arranged in the Y-axis direction (first direction), and the flow path forming member 200 is provided across the plurality of power storage elements 100. In the present embodiment, the minimum area of the flow path in the flow path forming member 200 provided across the plurality of power storage elements 100 is divided by the area of the gas discharge valve 131 of any one of the plurality of power storage elements 100 in plan view. The value is less than 1.6.
　本実施の形態では、流路形成部材２００は、バスバーフレーム１２の流路形成部材配置部１２ａに配置される。流路形成部材２００は、外装体１８のＹ軸プラス方向の端部から突出して配置される。ガス排出弁１３１から排出されるガスは、Ｙ軸プラス方向に流してＹ軸プラス方向側の開口部（後述の排出口２５０）から排出される。流路形成部材２００の構成の詳細な説明については、後述する。 In this embodiment, the flow path forming member 200 is arranged in the flow path forming member placement portion 12a of the busbar frame 12. The flow path forming member 200 is arranged to protrude from the end of the exterior body 18 in the Y-axis plus direction. The gas discharged from the gas discharge valve 131 flows in the positive direction of the Y-axis and is discharged from an opening (exhaust port 250 to be described later) on the positive direction of the Y-axis. A detailed description of the configuration of the flow path forming member 200 will be described later.
　［２　蓄電素子１００の説明］
　図３は、本実施の形態に係る蓄電素子１００の構成を示す斜視図である。図３は、図２に示した複数の蓄電素子１００のうちの１つの蓄電素子１００の外観を拡大して示す図である。本実施の形態における当該複数の蓄電素子１００は、全て同様の構成を有しているため、以下では、１つの蓄電素子１００の構成について詳細に説明する。図４は、本実施の形態に係る蓄電素子１００が有する電極体１５０の構成を示す斜視図である。具体的には、図４の（ａ）は、電極体１５０における極板の巻回状態を一部展開した状態での構成を示し、図４の（ｂ）は、極板を巻回した後の電極体１５０の構成を示している。 [2 Description of power storage element 100]
FIG. 3 is a perspective view showing the configuration of power storage element 100 according to this embodiment. FIG. 3 is a diagram showing an enlarged appearance of one power storage element 100 among the plurality of power storage elements 100 shown in FIG. 2. As shown in FIG. Since all of the plurality of power storage elements 100 in this embodiment have the same configuration, the configuration of one power storage element 100 will be described in detail below. FIG. 4 is a perspective view showing the configuration of electrode body 150 included in power storage element 100 according to the present embodiment. Specifically, FIG. 4(a) shows the configuration of the electrode body 150 in a partially unfolded state in which the electrode plate is wound, and FIG. 4(b) shows the configuration after the electrode plate is wound. The structure of the electrode body 150 is shown.
　図３に示すように、蓄電素子１００は、容器１１０と、一対（正極及び負極）の端子１４０とを備える。容器１１０の内方には、電極体１５０と、一対（正極及び負極）の集電体１６０とが収容されている。容器１１０の内方には電解液（非水電解質）も封入されているが、これらの図示は省略する。 As shown in FIG. 3, the power storage element 100 includes a container 110 and a pair of terminals 140 (a positive electrode and a negative electrode). Inside the container 110, an electrode body 150 and a pair (a positive electrode and a negative electrode) of current collectors 160 are housed. Although an electrolytic solution (non-aqueous electrolyte) is also sealed inside the container 110, illustration thereof is omitted.
　容器１１０は、開口が形成された容器本体１２０と、容器本体１２０の当該開口を閉塞する容器蓋部１３０と、を有する。容器１１０は、扁平な直方体形状（角形または箱形）のケースである。容器１１０（容器蓋部１３０）には、ガス排出弁１３１が設けられている。ガス排出弁１３１は、容器１１０内方の圧力が過度に上昇した場合に当該圧力を開放する。ガス排出弁１３１は、容器蓋部１３０における一対の端子１４０の間、つまり、容器蓋部１３０のＸ軸方向の中央付近に配置される。本実施の形態では、ガス排出弁１３１は、Ｚ軸方向（平面視方向）から見て円形状を有するが、その形状は特に限定されない。容器１１０（容器本体１２０及び容器蓋部１３０）の材質は、特に限定されず、例えばステンレス鋼、アルミニウム、アルミニウム合金、鉄、メッキ鋼板など溶接可能（接合可能）な金属とすることができる。電極体１５０等を容器本体１２０の内方に収容後、容器本体１２０と容器蓋部１３０とが溶接等によって接合されることにより、容器１１０の内部が密閉（密封）されている。 The container 110 has a container main body 120 in which an opening is formed, and a container lid part 130 that closes the opening of the container main body 120. The container 110 is a flat rectangular parallelepiped (square or box-shaped) case. A gas exhaust valve 131 is provided in the container 110 (container lid 130). The gas discharge valve 131 releases the pressure inside the container 110 when the pressure increases excessively. The gas exhaust valve 131 is arranged between the pair of terminals 140 on the container lid 130, that is, near the center of the container lid 130 in the X-axis direction. In this embodiment, the gas exhaust valve 131 has a circular shape when viewed from the Z-axis direction (planar view direction), but the shape is not particularly limited. The material of the container 110 (the container body 120 and the container lid 130) is not particularly limited, and may be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate. After the electrode body 150 and the like are housed inside the container body 120, the container body 120 and the container lid 130 are joined by welding or the like, so that the inside of the container 110 is hermetically sealed.
　端子１４０は、容器１１０の容器蓋部１３０に配置される正極端子及び負極端子である。端子１４０は、集電体１６０を介して、電極体１５０の正極板及び負極板に電気的に接続される。端子１４０は、アルミニウム、アルミニウム合金、銅、銅合金等で形成される。 The terminals 140 are a positive terminal and a negative terminal arranged on the container lid 130 of the container 110. The terminal 140 is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body 150 via the current collector 160. The terminal 140 is made of aluminum, aluminum alloy, copper, copper alloy, or the like.
　集電体１６０は、電極体１５０と容器１１０との間に配置され、端子１４０と電極体１５０とを電気的に接続する導電性の部材（正極集電体及び負極集電体）である。集電体１６０は、電極体１５０に溶接等によって接合されている。 The current collector 160 is a conductive member (a positive electrode current collector and a negative electrode current collector) that is disposed between the electrode body 150 and the container 110 and electrically connects the terminal 140 and the electrode body 150. The current collector 160 is joined to the electrode body 150 by welding or the like.
　電極体１５０は、極板（正極板及び負極板）とセパレータとを備え、これら極板及びセパレータが巻回されて形成された蓄電要素（発電要素）である。電極体１５０は、電極体本体部１５５と、電極体本体部１５５からＸ軸方向両側に突出する端部１５６及び１５７とを有する。端部１５６及び１５７が一対の集電体１６０に接続（接合）される。具体的には、図４の（ａ）に示すように、電極体１５０は、正極板１５１と、負極板１５２と、セパレータ１５３及び１５４と、を有している。 The electrode body 150 includes electrode plates (a positive electrode plate and a negative electrode plate) and a separator, and is a power storage element (power generation element) formed by winding these electrode plates and the separator. The electrode body 150 has an electrode body body part 155 and end parts 156 and 157 that protrude from the electrode body body part 155 on both sides in the X-axis direction. Ends 156 and 157 are connected (joined) to a pair of current collectors 160. Specifically, as shown in FIG. 4A, the electrode body 150 includes a positive electrode plate 151, a negative electrode plate 152, and separators 153 and 154.
　正極板１５１は、長尺帯状の金属箔である正極集電箔１５１ａの表面に、正極活物質層１５１ｂが形成された極板（電極板）である。負極板１５２は、長尺帯状の金属箔である負極集電箔１５２ａの表面に、負極活物質層１５２ｂが形成された極板（電極板）である。正極活物質層１５１ｂは、正極活物質、バインダ及び導電材等を含む。負極活物質層１５２ｂは、負極活物質、バインダ及び増粘剤等を含む。正極活物質、及び、負極活物質としては、リチウムイオンを吸蔵放出可能な物質であれば、適宜公知の材料を使用できる。 The positive electrode plate 151 is an electrode plate (electrode plate) in which a positive electrode active material layer 151b is formed on the surface of a positive electrode current collector foil 151a, which is a long strip-shaped metal foil. The negative electrode plate 152 is an electrode plate (electrode plate) in which a negative electrode active material layer 152b is formed on the surface of a negative electrode current collector foil 152a, which is a long strip-shaped metal foil. The positive electrode active material layer 151b includes a positive electrode active material, a binder, a conductive material, and the like. The negative electrode active material layer 152b includes a negative electrode active material, a binder, a thickener, and the like. As the positive electrode active material and the negative electrode active material, any known material can be used as appropriate as long as it is a material capable of intercalating and deintercalating lithium ions.
　正極活物質として、ＬｉＭ１ＰＯ４（Ｍ１はＦｅ、Ｎｉ、Ｍｎ、Ｃｏ等から選択される１種または２種以上の金属元素）等のポリアニオン化合物、ＬｉＭ２２Ｏ４（Ｍ２はＦｅ、Ｎｉ、Ｍｎ、Ｃｏ等から選択される１種または２種以上の金属元素）等のスピネル型リチウム遷移金属酸化物、ＬｉＭ３Ｏ２（Ｍ３はＦｅ、Ｎｉ、Ｍｎ、Ｃｏ等から選択される１種または２種以上の金属元素）等の層状リチウム遷移金属酸化物等を用いることができる。負極活物質としては、リチウム金属、リチウム合金の他、リチウムを吸蔵・放出可能な合金、炭素材料（例えば黒鉛、難黒鉛化炭素、易黒鉛化炭素、非晶質カーボン等）などが挙げられる。 As the positive electrode active material, polyanion compounds such as LiM1PO4 (M1 is one or more metal elements selected from Fe, Ni, Mn, Co, etc.), LiM22O4 (M2 is selected from Fe, Ni, Mn, Co, etc.) spinel type lithium transition metal oxides such as LiM3O2 (M3 is one or more metal elements selected from Fe, Ni, Mn, Co, etc.), etc. A layered lithium transition metal oxide or the like can be used. Examples of negative electrode active materials include lithium metal, lithium alloys, alloys capable of intercalating and deintercalating lithium, carbon materials (for example, graphite, non-graphitizable carbon, easily graphitizable carbon, amorphous carbon, etc.).
　セパレータ１５３及び１５４は、樹脂からなる微多孔性のシートである。セパレータ１５３及び１５４の素材としては、蓄電素子１００の性能を損なうものでなければ、適宜公知の材料を使用できる。例えば、セパレータ１５３及び１５４として、不織布、ポリエチレン等のポリオレフィン樹脂からなる合成樹脂微多孔膜等を用いることができる。 The separators 153 and 154 are microporous sheets made of resin. As the material for separators 153 and 154, any known material can be used as appropriate, as long as it does not impair the performance of power storage element 100. For example, as the separators 153 and 154, a nonwoven fabric, a synthetic resin microporous membrane made of polyolefin resin such as polyethylene, or the like can be used.
　電極体１５０は、正極板１５１及び負極板１５２と、セパレータ１５３及び１５４とが交互に積層された積層体が巻回されることで形成されている。本実施の形態の電極体１５０は、これら正極板１５１及び負極板１５２等が、容Ｘ軸方向に延びる巻回軸Ｌを中心に巻回されて形成された扁平な電極体である。巻回軸Ｌとは、正極板１５１及び負極板１５２等を巻回する際の中心軸となる仮想的な軸である。 The electrode body 150 is formed by winding a laminate in which a positive electrode plate 151, a negative electrode plate 152, and separators 153 and 154 are alternately laminated. The electrode body 150 of this embodiment is a flat electrode body formed by winding the positive electrode plate 151, the negative electrode plate 152, etc. around a winding axis L extending in the X-axis direction. The winding axis L is a virtual axis that serves as a central axis when winding the positive electrode plate 151, the negative electrode plate 152, and the like.
　本実施の形態の正極活物質層１５１ｂは、ニッケルを含む正極活物質を有している。具体的には、正極活物質層１５１ｂの正極活物質は、Ｎｉ、Ｃｏ、Ｍｎを５：２：３、６：２：２、８：１：１等の元素比率で含むニッケル・コバルト・マンガン酸リチウム（以下、ＮＣＭとも称す）、ニッケル酸リチウム、ニッケル酸リチウムのニッケルの一部をコバルトで置換したニッケル・コバルト酸リチウム等である。蓄電素子１００が有するニッケルの全質量（以下、質量Ｃとも称す）を、蓄電素子１００の容器１１０の体積（以下、体積Ｄとも称す）で除した値（以下、第二値とも称す）は、１００ｇ／Ｌ以上であるのが好ましい。質量Ｃは、正極活物質に含まれるニッケルの全質量である。正極活物質層１５１ｂの一定面積を削り出したものを酸に溶解し、ＩＣＰ（誘導結合プラズマ発光分析法）によって、上記一定面積あたりのニッケル量を測定する。上記一定面積に対する正極活物質層１５１ｂの面積の比率と、測定で得られたニッケル量とを乗ずることで質量Ｃの値が得られる。体積Ｄは、容器１１０の寸法を計測することにより算出する。このように、第二値は、正極活物質層１５１ｂの正極活物質内のニッケルの全質量を、容器１１０の体積で除した値である。第二値についての詳細な説明は、後述する。 The positive electrode active material layer 151b of this embodiment includes a positive electrode active material containing nickel. Specifically, the positive electrode active material of the positive electrode active material layer 151b is nickel-cobalt-manganese containing Ni, Co, and Mn in an element ratio of 5:2:3, 6:2:2, 8:1:1, etc. These include lithium oxide (hereinafter also referred to as NCM), lithium nickel oxide, and lithium nickel/cobalt oxide in which a portion of the nickel in lithium nickel oxide is replaced with cobalt. The value (hereinafter also referred to as the second value) obtained by dividing the total mass of nickel that the power storage element 100 has (hereinafter also referred to as mass C) by the volume of the container 110 of the power storage element 100 (hereinafter also referred to as volume D) is: It is preferable that it is 100 g/L or more. Mass C is the total mass of nickel contained in the positive electrode active material. A certain area of the positive electrode active material layer 151b is cut out and dissolved in acid, and the amount of nickel per certain area is measured by ICP (inductively coupled plasma emission spectrometry). The value of the mass C can be obtained by multiplying the ratio of the area of the positive electrode active material layer 151b to the above-mentioned constant area by the amount of nickel obtained in the measurement. The volume D is calculated by measuring the dimensions of the container 110. Thus, the second value is the value obtained by dividing the total mass of nickel in the positive electrode active material of the positive electrode active material layer 151b by the volume of the container 110. A detailed explanation of the second value will be given later.
　［３　流路形成部材２００の説明］
　次に、流路形成部材２００の構成について、詳細に説明する。図５は、本実施の形態に係る流路形成部材２００の構成を示す斜視図である。図５では、説明の便宜のため、流路形成部材２００の下方に、１つの蓄電素子１００を配置した状態を示している。 [3 Description of flow path forming member 200]
Next, the configuration of the flow path forming member 200 will be described in detail. FIG. 5 is a perspective view showing the configuration of the flow path forming member 200 according to the present embodiment. For convenience of explanation, FIG. 5 shows a state in which one power storage element 100 is disposed below the flow path forming member 200.
　図５に示すように、流路形成部材２００は、Ｙ軸方向に長い筒状（本実施の形態では、角筒状）の部材である。流路形成部材２００のＹ軸マイナス方向の面は閉塞しており、流路形成部材２００のＹ軸プラス方向の面は開口している。流路形成部材２００は、各蓄電素子１００のガス排出弁１３１の上に配置される。流路形成部材２００は、ステンレス鋼、アルミニウム等の金属製の部材、グラスウールまたはマイカ等の断熱性を有する部材で形成できる。または、樹脂材料等の絶縁性を有する部材等で形成できる。ガス排出弁１３１から排出される高温のガスが通過するため、流路形成部材２００は、耐熱性が高い不燃性の部材で形成されるのが好ましい。流路形成部材２００は、全ての壁が同じ材質で形成されてもよいし、いずれかの壁が異なる材質で形成されてもよい。 As shown in FIG. 5, the flow path forming member 200 is a cylindrical member (in this embodiment, a rectangular cylindrical shape) that is long in the Y-axis direction. The surface of the flow path forming member 200 in the negative direction of the Y axis is closed, and the surface of the flow path forming member 200 in the positive direction of the Y axis is open. Flow path forming member 200 is arranged above gas exhaust valve 131 of each power storage element 100. The flow path forming member 200 can be made of a metal member such as stainless steel or aluminum, or a member having heat insulating properties such as glass wool or mica. Alternatively, it can be formed from a member having insulation properties such as a resin material. Since the high-temperature gas discharged from the gas exhaust valve 131 passes therethrough, the flow path forming member 200 is preferably formed of a nonflammable member with high heat resistance. All walls of the flow path forming member 200 may be made of the same material, or any of the walls may be made of different materials.
　流路形成部材２００は、底壁部２１０と、一対の側壁部２２０と、上壁部２３０と、前壁部２４０と、を有する。この構成により、流路形成部材２００は、ガス排出弁１３１から排出されるガスの流路Ｒを形成する。流路Ｒは、ガスが流れるＹ軸方向に延びるガスの通り道である。当該ガスは、流路ＲのＹ軸プラス方向に流れ、流路形成部材２００のＹ軸プラス方向の端部の排出口２５０から排出される。流路形成部材２００は、底壁部２１０、一対の側壁部２２０、上壁部２３０及び前壁部２４０の全ての壁部を一体的に有する１つの部材であってもよいし、いずれかの壁部が別体であって複数の部材によって形成されていてもよい。 The flow path forming member 200 has a bottom wall 210, a pair of side walls 220, a top wall 230, and a front wall 240. With this configuration, the flow path forming member 200 forms a flow path R for gas discharged from the gas exhaust valve 131. The flow path R is a gas path extending in the Y-axis direction through which the gas flows. The gas flows in the Y-axis positive direction of the flow path R and is discharged from the exhaust port 250 at the end of the flow path forming member 200 in the Y-axis positive direction. The flow path forming member 200 may be one member that integrally includes all the wall portions of the bottom wall portion 210, the pair of side wall portions 220, the top wall portion 230, and the front wall portion 240, or may include any one of the The wall portion may be separate and formed from a plurality of members.
　底壁部２１０は、流路形成部材２００の底壁を構成する。底壁部２１０は、平板状かつ矩形状の部位である。底壁部２１０は、蓄電素子１００の容器１１０の容器蓋部１３０に対向する位置に配置され、Ｙ軸方向に延びる壁部である。底壁部２１０には、Ｙ軸方向に並ぶ複数の開口部２１１が形成されている。 The bottom wall portion 210 constitutes the bottom wall of the flow path forming member 200. The bottom wall portion 210 is a flat and rectangular portion. Bottom wall portion 210 is a wall portion that is disposed at a position facing container lid portion 130 of container 110 of power storage element 100 and extends in the Y-axis direction. A plurality of openings 211 are formed in the bottom wall portion 210 and are arranged in the Y-axis direction.
　開口部２１１は、蓄電素子１００のガス排出弁１３１と対向する位置に配置される貫通孔である。開口部２１１は、底壁部２１０をＺ軸方向に貫通する円形状の貫通孔である。本実施の形態では、１６個の蓄電素子１００に対応して、１６個の開口部２１１がＹ軸方向に並んで配置されている。開口部２１１は、Ｚ軸方向から見て、ガス排出弁１３１と同形状であるが、開口部２１１の形状は特に限定されない。ただし、開口部２１１は、Ｚ軸方向（平面視方向）から見て、ガス排出弁１３１と同形状またはガス排出弁１３１よりも大きい形状であるのが好ましい。 The opening 211 is a through hole arranged at a position facing the gas exhaust valve 131 of the power storage element 100. The opening 211 is a circular through hole that penetrates the bottom wall 210 in the Z-axis direction. In this embodiment, 16 openings 211 are arranged in line in the Y-axis direction, corresponding to 16 power storage elements 100. The opening 211 has the same shape as the gas exhaust valve 131 when viewed from the Z-axis direction, but the shape of the opening 211 is not particularly limited. However, it is preferable that the opening 211 has the same shape as the gas exhaust valve 131 or a larger shape than the gas exhaust valve 131 when viewed from the Z-axis direction (planar view direction).
　側壁部２２０は、流路形成部材２００の側壁を構成する。側壁部２２０は、平板状かつ矩形状の部位であり、ガスの流路Ｒに沿って配置される。側壁部２２０は、底壁部２１０と上壁部２３０とに接続され、Ｙ軸方向に延びる壁部である。本実施の形態では、一対の側壁部２２０が、底壁部２１０及び上壁部２３０のＸ軸方向両端部を繋ぐように配置される。 The side wall portion 220 constitutes a side wall of the flow path forming member 200. The side wall portion 220 is a flat and rectangular portion, and is arranged along the gas flow path R. The side wall portion 220 is a wall portion that is connected to the bottom wall portion 210 and the top wall portion 230 and extends in the Y-axis direction. In this embodiment, a pair of side walls 220 are arranged to connect both ends of the bottom wall 210 and the top wall 230 in the X-axis direction.
　上壁部２３０は、流路形成部材２００の上壁を構成する。上壁部２３０は、平板状かつ矩形状の部位であり、ガスの流路Ｒに沿って配置される。上壁部２３０は、底壁部２１０と対向する位置に配置され、ＸＹ平面に平行かつＹ軸方向に延びる壁部である。 The upper wall portion 230 constitutes the upper wall of the flow path forming member 200. The upper wall portion 230 is a flat and rectangular portion, and is arranged along the gas flow path R. The top wall portion 230 is a wall portion that is disposed at a position facing the bottom wall portion 210 and extends parallel to the XY plane and in the Y-axis direction.
 以上のように、流路形成部材２００は、Ｙ軸方向（第一方向）と直交するＺ軸方向（第二方向）でガス排出弁１３１と対向する上壁部２３０と、Ｙ軸方向およびＺ軸方向と直交するＸ軸方向（第三方向）の一対の側壁部２２０とを有する。本実施形態においては、Ｙ軸方向で蓄電素子１００が配置されている範囲において上壁部２３０および側壁部２２０には開口は形成されていない。 As described above, the flow path forming member 200 has an upper wall portion 230 that faces the gas exhaust valve 131 in the Z-axis direction (second direction) orthogonal to the Y-axis direction (first direction), and a top wall portion 230 that faces the gas exhaust valve 131 in the Y-axis direction and the Z-axis direction. It has a pair of side wall portions 220 in the X-axis direction (third direction) orthogonal to the axial direction. In this embodiment, no opening is formed in the upper wall portion 230 and the side wall portion 220 in the range where the power storage element 100 is arranged in the Y-axis direction.
　前壁部２４０は、流路形成部材２００の前壁を構成する。前壁部２４０は、平板状かつ矩形状の部位であり、ＸＺ平面に平行に配置される。前壁部２４０は、流路Ｒからガスが漏れ出すのを防止するために、底壁部２１０、側壁部２２０及び上壁部２３０に接続されて配置される。 The front wall portion 240 constitutes the front wall of the flow path forming member 200. The front wall portion 240 is a flat and rectangular portion, and is arranged parallel to the XZ plane. The front wall 240 is connected to the bottom wall 210, the side wall 220, and the top wall 230 to prevent gas from leaking from the flow path R.
　このような構成により、流路形成部材２００のガスが流れる方向（Ｙ軸方向）の長さは、蓄電素子１００よりも長い。本実施の形態では、流路形成部材２００のＹ軸プラス方向の端部が外装体１８から突出するため、Ｙ軸方向の長さが、蓄電装置１が備える複数の蓄電素子１００のＹ軸方向の長さよりも長い。　 With such a configuration, the length of the flow path forming member 200 in the gas flow direction (Y-axis direction) is longer than the power storage element 100. In this embodiment, since the end of the flow path forming member 200 in the Y-axis positive direction protrudes from the exterior body 18, the length in the Y-axis direction is the same as that of the plurality of power storage elements 100 included in the power storage device 1 in the Y-axis direction. longer than the length of　
　流路Ｒにおけるガスが流れる方向と直交する面の面積の最小値である流路最小面積（以下、面積Ｂとも称す）を、ガス排出弁１３１の平面視での面積（以下、面積Ａとも称す）で除した値（以下、第一値と称す）は、１．６よりも小さい。面積Ａは、Ｚ軸方向から見た場合のガス排出弁１３１の面積である。つまり、面積Ａは、ガス排出弁１３１からガスが排出される場合に、ガス排出弁１３１が開口可能な面積である。面積Ｂ（流路最小面積）は、流路Ｒにおけるガスが流れる方向（Ｙ軸方向）と直交する面（ＸＺ平面）で面積の最小値である。つまり、面積Ｂは、流路ＲをＸＺ平面に平行な面で切断した切断面の面積の最小値である。 The minimum flow path area (hereinafter also referred to as area B), which is the minimum value of the area of the surface perpendicular to the direction in which gas flows in the flow path R, is the area of the gas exhaust valve 131 in plan view (hereinafter also referred to as area A). ) (hereinafter referred to as the first value) is smaller than 1.6. Area A is the area of gas exhaust valve 131 when viewed from the Z-axis direction. That is, the area A is an area in which the gas exhaust valve 131 can be opened when gas is exhausted from the gas exhaust valve 131. Area B (flow path minimum area) is the minimum value of the area in a plane (XZ plane) perpendicular to the gas flow direction (Y-axis direction) in the flow path R. That is, the area B is the minimum value of the area of a cut surface obtained by cutting the flow path R along a plane parallel to the XZ plane.
　本実施の形態の流路Ｒは、Ｙ軸方向の一端から他端までに亘って当該切断面の面積が同じである。そのため、流路Ｒのいずれの位置で切断しても、その切断面の面積が面積Ｂとなる。Ｙ軸方向の一端から他端までに亘って流路Ｒの当該断面積が変化する場合には、流路ＲのＹ軸方向の当該断面積の最小値が面積Ｂとなる。流路Ｒにおいて、当該断面積が変化する場合、ガス排出弁１３１に近い位置（開口部２１１に近い位置）における当該断面積を小さくすると、ガス排出弁１３１から開口部２１１へ流入した直後にガスの流速を早くできるため、ガスの滞留を抑制できる。この場合、当該ガス排出弁１３１に近い位置（開口部２１１に近い位置）における当該断面積が面積Ｂとなる。このようにして算出される面積Ｂを面積Ａで除した値が、第一値となる。 In the flow path R of this embodiment, the area of the cut surface is the same from one end to the other end in the Y-axis direction. Therefore, no matter where the flow path R is cut, the area of the cut surface is the area B. When the cross-sectional area of the flow path R changes from one end to the other end in the Y-axis direction, the minimum value of the cross-sectional area of the flow path R in the Y-axis direction becomes the area B. In the flow path R, when the cross-sectional area changes, if the cross-sectional area at a position close to the gas exhaust valve 131 (position close to the opening 211) is made smaller, the gas flows immediately after flowing from the gas exhaust valve 131 into the opening 211. Since the flow rate of gas can be increased, gas retention can be suppressed. In this case, the cross-sectional area at a position close to the gas exhaust valve 131 (position close to the opening 211) becomes area B. The value obtained by dividing the area B calculated in this way by the area A becomes the first value.
　本実施の形態の流路形成部材２００は、比較的狭い流路Ｒを有しており、面積Ｂは比較的小さい。具体的には、上述の通り、第一値は、１．６よりも小さい。流路形成部材２００の流路Ｒをさらに狭くして、流路Ｒにおけるガスの流速を早くするために、第一値は、１．２５よりも小さいのが好ましい。さらに、蓄電素子１００が有するニッケルの全質量（質量Ｃ）を、上記流路最小面積（流路Ｒにおけるガスが流れる方向と直交する面の最小値（面積Ｂ））で除した値（以下、第三値と称す）は、０．１５ｇ／ｍｍ２以上であるのが好ましい。この第一値、第三値、及び、上述の第二値について、以下に、表１における実験結果を用いて詳細に説明する。 The flow path forming member 200 of this embodiment has a relatively narrow flow path R, and the area B is relatively small. Specifically, as described above, the first value is smaller than 1.6. In order to further narrow the flow path R of the flow path forming member 200 and increase the gas flow rate in the flow path R, the first value is preferably smaller than 1.25. Furthermore, the value obtained by dividing the total mass (mass C) of nickel that the electricity storage element 100 has by the minimum area of the flow path (the minimum value (area B) of the surface perpendicular to the direction in which gas flows in the flow path R) (hereinafter, The third value) is preferably 0.15 g/mm2 or more. The first value, the third value, and the above-mentioned second value will be explained in detail below using the experimental results shown in Table 1.
　［４　実験結果の説明］
　まず、実施例１～４及び比較例１において、以下の通り、試験用の蓄電素子及び試験用の蓄電装置の作製を行った。詳細については、以下の表１も参照しつつ、説明する。 [4 Explanation of experimental results]
First, in Examples 1 to 4 and Comparative Example 1, test power storage elements and test power storage devices were manufactured as follows. Details will be explained with reference to Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　（正極板の作製）
　正極活物質、バインダであるポリフッ化ビニリデン（ＰＶＤＦ）、導電材であるカーボンブラック、及び、分散媒であるＮメチルピロリドン（ＮＭＰ）を混合して正極ペーストを調製した。正極活物質としては、表１の「正極活物質」に示す通り、実施例１～３及び比較例１では、ＮＣＭ（Ｎｉ、Ｃｏ、Ｍｎを５：２：３の元素比率で含むニッケル・コバルト・マンガン酸リチウム）を用い、実施例４では、ＬＦＰ（リン酸鉄リチウム）を用いた。正極活物質、ＰＶＤＦ及びカーボンブラックの質量比率は９０：５：５（固形分換算）とした。アルミ箔（正極集電箔）の両面に正極合剤ペーストを塗布及び乾燥し、未プレスの正極活物質層を形成した。その後、未プレスの正極活物質層に対してホットロールプレスを行い、実施例１～４及び比較例１の正極板を得た。上記した方法で得られた正極板に含まれるニッケルの全質量（蓄電素子が有するニッケルの全質量（質量Ｃ））は、表１の「Ｎｉ質量（Ｃ）」に示す通りであり、実施例４はニッケルを含まない。 (Preparation of positive electrode plate)
A positive electrode paste was prepared by mixing a positive electrode active material, polyvinylidene fluoride (PVDF) as a binder, carbon black as a conductive material, and N-methylpyrrolidone (NMP) as a dispersion medium. As shown in "Positive electrode active material" in Table 1, in Examples 1 to 3 and Comparative Example 1, the positive electrode active material was NCM (nickel/cobalt containing Ni, Co, and Mn in an element ratio of 5:2:3). In Example 4, LFP (lithium iron phosphate) was used. The mass ratio of the positive electrode active material, PVDF, and carbon black was 90:5:5 (in terms of solid content). A positive electrode mixture paste was applied to both sides of an aluminum foil (positive electrode current collector foil) and dried to form an unpressed positive electrode active material layer. Thereafter, hot roll pressing was performed on the unpressed positive electrode active material layer to obtain positive electrode plates of Examples 1 to 4 and Comparative Example 1. The total mass of nickel contained in the positive electrode plate obtained by the above method (total mass of nickel in the electricity storage element (mass C)) is as shown in "Ni mass (C)" in Table 1, and 4 does not contain nickel.
　（負極板の作製）
　負極活物質である天然黒鉛、バインダであるスチレンーブタジエンゴム（ＳＢＲ）、増粘剤であるカルボキシメチルセルロースアンモニウム（ＣＭＣ－ＮＨ４）、及び、分散媒である水を混合して負極ペーストを調製した。天然黒鉛、ＳＢＲ及びＣＭＣ－ＮＨ４の質量比率は９８：１：１（固形分換算）とした。銅箔（正極集電箔）の両面に負極合剤ペーストを塗布及び乾燥し、未プレスの負極活物質層を形成した。その後、未プレスの負極活物質層に対してロールプレスを行い、実施例１～４及び比較例１の負極板を得た。 (Preparation of negative electrode plate)
A negative electrode paste was prepared by mixing natural graphite as a negative electrode active material, styrene-butadiene rubber (SBR) as a binder, carboxymethyl cellulose ammonium (CMC-NH4) as a thickener, and water as a dispersion medium. The mass ratio of natural graphite, SBR, and CMC-NH4 was 98:1:1 (in terms of solid content). A negative electrode mixture paste was applied to both sides of the copper foil (positive electrode current collector foil) and dried to form an unpressed negative electrode active material layer. Thereafter, roll pressing was performed on the unpressed negative electrode active material layer to obtain negative electrode plates of Examples 1 to 4 and Comparative Example 1.
　（試験用蓄電素子の作製）
　セパレータ、上記の負極板、セパレータ、上記の正極板の順に積層したものを巻き取ることによって電極体を作製した。この際、正極板の外側に負極板、さらに、その外側にセパレータが配置されるようにした。容器に上記電極体を挿入し、密封することによって試験用蓄電素子をそれぞれ作製した。電解液は、エチレンカーボネート、ジメチルカーボネート及びエチルメチルカーボネートを体積比率３０：３５：３５で混合した溶媒に、１．０ｍｏｌ／ｄｍ３の濃度でＬｉＰＦ６を溶解させた非水電解液を用いた。セパレータには、ポリオレフィン製微多孔膜にアルミナとＰＶＤＦとの混合体を塗工したもの正極に対向するようにして用いた。 (Production of electricity storage element for test)
An electrode body was produced by winding up a separator, the above negative electrode plate, a separator, and the above positive electrode plate laminated in this order. At this time, a negative electrode plate was placed outside the positive electrode plate, and a separator was further placed outside the negative electrode plate. The above-mentioned electrode body was inserted into a container and the container was sealed to prepare a test power storage element. The electrolytic solution used was a non-aqueous electrolytic solution in which LiPF6 was dissolved at a concentration of 1.0 mol/dm3 in a solvent in which ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate were mixed at a volume ratio of 30:35:35. As a separator, a microporous polyolefin membrane coated with a mixture of alumina and PVDF was used so as to face the positive electrode.
　容器の体積（体積Ｄ）は、表１の「容器体積（Ｄ）」（「容器幅」、「容器厚み」、及び、「容器高さ」）に示す通りであった。図５における容器１１０のＸ軸方向の長さ（幅）、Ｙ軸方向の長さ（厚み）、Ｚ軸方向の長さ（高さ）が、「容器幅」、「容器厚み」、「容器高さ」に相当する。容器には、ガス排出弁が設けられており、ガス排出弁の面積（面積Ａ）は、表１の「ガス排出弁面積（Ａ）」に示す通りであった。試験用蓄電素子の体積エネルギー密度は、表１の「エネルギー密度」に示す通りであった。 The volume of the container (volume D) was as shown in "Container Volume (D)" ("Container Width", "Container Thickness", and "Container Height") in Table 1. The length (width) in the X-axis direction, the length (thickness) in the Y-axis direction, and the length (height) in the Z-axis direction of the container 110 in FIG. corresponds to "height". The container was provided with a gas exhaust valve, and the area (area A) of the gas exhaust valve was as shown in "Gas exhaust valve area (A)" in Table 1. The volumetric energy density of the test electricity storage element was as shown in "Energy Density" in Table 1.
　（試験用蓄電装置の作製）
　上記の試験用蓄電素子を樹脂製ボックス内に複数配列し、その上に流路形成部材を設置した。試験用蓄電装置内に配列される試験用蓄電素子の個数は、表１の「蓄電素子個数」に示す通りであった。流路形成部材の長さは、表１の「流路形成部材長さ」に示す通りであった。流路Ｒにおけるガスが流れる方向と直交する面の最小値である流路最小面積（面積Ｂ）は、表１の「流路最小面積（Ｂ）」に示す通りであった。 (Production of test power storage device)
A plurality of the test power storage elements described above were arranged in a resin box, and a flow path forming member was placed thereon. The number of test power storage elements arranged in the test power storage device was as shown in "Number of power storage elements" in Table 1. The length of the channel-forming member was as shown in "Channel-forming member length" in Table 1. The minimum flow path area (area B), which is the minimum value of the surface perpendicular to the gas flow direction in the flow path R, was as shown in "Flow path minimum area (B)" in Table 1.
　以上の構成において、上述の第一値（流路最小面積（Ｂ）をガス排出弁面積（Ａ）で除した値（Ｂ／Ａ））は、表１の「第一値（Ｂ／Ａ）」に示す通りであった。上述の第二値（Ｎｉ質量（Ｃ）を容器体積（Ｄ）で除した値（Ｃ／Ｄ））は、表１の「第二値（Ｃ／Ｄ）」に示す通りであった。上述の第三値（Ｎｉ質量（Ｃ）を流路最小面積（Ｂ）で除した値（Ｃ／Ｂ））は、表１の「第三値（Ｃ／Ｂ）」に示す通りであった。 In the above configuration, the above-mentioned first value (the value obtained by dividing the flow path minimum area (B) by the gas discharge valve area (A) (B/A)) is the "first value (B/A)" in Table 1. ” as shown. The above-mentioned second value (the value obtained by dividing the Ni mass (C) by the container volume (D) (C/D)) was as shown in "Second Value (C/D)" in Table 1. The above-mentioned third value (the value obtained by dividing the Ni mass (C) by the minimum area of the flow path (B) (C/B)) was as shown in "Third value (C/B)" in Table 1. .
　試験用蓄電装置において、試験用蓄電素子（以下、トリガ蓄電素子と称す）を温度制御せずにヒータで加熱した。トリガ蓄電素子の温度は、表１の「トリガ蓄電素子温度」に示す通りであった。トリガ蓄電素子の温度は、トリガ蓄電素子の容器の長側面に熱電対を貼り付けることで測定する。その後、トリガ蓄電素子とスペーサを介して隣り合う他の試験用蓄電素子（以下、隣接蓄電素子と称す）の残存容量を測定した。隣接蓄電素子は、トリガ蓄電素子に対して、ガスの流れの上流（図５ではＹ軸マイナス方向）に位置する試験用蓄電素子である。隣接蓄電素子の残存容量は、表１の「隣接蓄電素子残存容量」に示す通りであった。上記試験において、試験用蓄電素子は満充電の状態であり、試験用蓄電素子間のスペーサとしてはグラスファイバー製の断熱板を用いた。 In the test power storage device, the test power storage element (hereinafter referred to as a trigger power storage element) was heated with a heater without temperature control. The temperature of the trigger power storage element was as shown in "Trigger power storage element temperature" in Table 1. The temperature of the trigger storage element is measured by attaching a thermocouple to the long side of the container of the trigger storage element. Thereafter, the remaining capacity of another test power storage element (hereinafter referred to as an adjacent power storage element) adjacent to the trigger power storage element via a spacer was measured. The adjacent power storage element is a test power storage element located upstream of the gas flow (in the negative Y-axis direction in FIG. 5) with respect to the trigger power storage element. The remaining capacity of the adjacent power storage element was as shown in "Adjacent power storage element remaining capacity" in Table 1. In the above test, the test power storage elements were in a fully charged state, and a heat insulating plate made of glass fiber was used as a spacer between the test power storage elements.
　実施例１～３及び比較例１では、正極活物質がニッケルを含むのに対し、実施例４では、正極活物質がニッケルを含まない。このため、実施例１～３及び比較例１のエネルギー密度は実施例４のそれよりも高い。実施例１～３及び比較例１において、トリガ蓄電素子の温度（表１の「トリガ蓄電素子温度」）が低いのが好ましいため、実施例１～３が比較例１よりも好ましい。隣接蓄電素子の残存容量（表１の「隣接蓄電素子残存容量」）が大きいのが好ましいため、実施例１～３が比較例１よりも好ましい。さらに、実施例１～３において、実施例１よりも実施例２、３のエネルギー密度が高いため、実施例２、３が実施例１よりも好ましい。実施例２、３において、実施例２よりも実施例３の隣接蓄電素子の残存容量が大きいため、実施例３の方が実施例２よりも好ましい。 In Examples 1 to 3 and Comparative Example 1, the positive electrode active material contains nickel, whereas in Example 4, the positive electrode active material does not contain nickel. Therefore, the energy density of Examples 1 to 3 and Comparative Example 1 is higher than that of Example 4. In Examples 1 to 3 and Comparative Example 1, it is preferable that the temperature of the trigger electricity storage element ("trigger electricity storage element temperature" in Table 1) is low, so Examples 1 to 3 are more preferable than Comparative Example 1. Examples 1 to 3 are preferable to Comparative Example 1 because it is preferable that the remaining capacity of the adjacent electricity storage element ("adjacent electricity storage element remaining capacity" in Table 1) is large. Furthermore, in Examples 1 to 3, since the energy density of Examples 2 and 3 is higher than that of Example 1, Examples 2 and 3 are preferable to Example 1. In Examples 2 and 3, since the remaining capacity of the adjacent power storage element in Example 3 is larger than that in Example 2, Example 3 is preferable to Example 2.
　以上により、実施例１が好ましく、実施例２がより好ましく、実施例３がさらに好ましい。実施例１の第一値（流路Ｒにおけるガスが流れる方向と直交する面の最小値である流路最小面積（面積Ｂ）を、ガス排出弁１３１の平面視での面積（面積Ａ）で除した値）は、１．６よりも小さい。実施例２、３により、第一値は、１．２５より小さいのが好ましく、１．０より小さいのがより好ましく、０．７５より小さいのがさらに好ましい。このように、第一値は、少ない方がよいため、さらに、０．５より小さいのが好ましい。流路形成部材２００からのガスの全量を短時間で排出するために、第一値は、０．３以上であるのが好ましい。 Based on the above, Example 1 is preferred, Example 2 is more preferred, and Example 3 is even more preferred. The first value of Example 1 (the minimum flow path area (area B) which is the minimum value of the surface perpendicular to the direction in which gas flows in the flow path R) is the area (area A) of the gas exhaust valve 131 in a plan view. ) is smaller than 1.6. According to Examples 2 and 3, the first value is preferably smaller than 1.25, more preferably smaller than 1.0, and even more preferably smaller than 0.75. In this way, since it is better to have a smaller first value, it is further preferable that the first value is smaller than 0.5. In order to discharge the entire amount of gas from the flow path forming member 200 in a short time, the first value is preferably 0.3 or more.
　実施例１により、第二値（蓄電素子１００が有するニッケルの全質量（質量Ｃ）を、蓄電素子１００の容器１１０の体積（体積Ｄ）で除した値）は、１００ｇ／Ｌ以上であるのが好ましく、１８０ｇ／Ｌ以上であるのがより好ましい。実施例２、３により、第一値は、１９０ｇ／Ｌ以上であるのがさらに好ましい。蓄電素子１００の作製上、第二値は、４２０ｇ／Ｌ以下であるのが好ましい。 According to Example 1, the second value (the value obtained by dividing the total mass (mass C) of nickel included in the power storage element 100 by the volume (volume D) of the container 110 of the power storage element 100) is 100 g/L or more. is preferable, and more preferably 180 g/L or more. According to Examples 2 and 3, the first value is more preferably 190 g/L or more. In manufacturing the electricity storage element 100, the second value is preferably 420 g/L or less.
　実施例１により、第三値（蓄電素子１００が有するニッケルの全質量（質量Ｃ）を、流路Ｒにおけるガスが流れる方向と直交する面の最小値である流路最小面積（面積Ｂ））で除した値）は、０．１５ｇ／ｍｍ２以上であるのが好ましい。実施例２により、第三値は、０．２ｇ／ｍｍ２以上であるのがより好ましく、実施例３により、０．４ｇ／ｍｍ２以上であるのがさらに好ましい。蓄電装置１の製造上、第三値は、０．５５ｇ／ｍｍ２以下であるのが好ましい。 According to Example 1, the third value (the total mass (mass C) of nickel possessed by the power storage element 100 is the minimum value of the flow path minimum area (area B) of the surface perpendicular to the direction in which gas flows in the flow path R) The value divided by ) is preferably 0.15 g/mm 2 or more. According to Example 2, the third value is more preferably 0.2 g/mm2 or more, and according to Example 3, it is even more preferably 0.4 g/mm2 or more. In terms of manufacturing the power storage device 1, the third value is preferably 0.55 g/mm2 or less.
　［５　効果の説明］
　以上のような構成により、本発明の実施の形態に係る蓄電装置１によれば、流路Ｒにおけるガスが流れる方向と直交する面の最小値である流路最小面積（面積Ｂ）をガス排出弁１３１の平面視での面積（面積Ａ）で除した第一値を、１．６よりも小さくする。このように、ガス排出弁１３１から排出されるガスの流路形成部材２００内での流路Ｒを狭く（第一値を１．６よりも小さく）することで、流路形成部材２００内での当該ガスの流速を速くできる。これにより、ガス排出弁１３１から高温のガスが排出された場合でも、流路形成部材２００内でのガスの滞留が起きにくい。その結果、蓄電素子１００の周囲の部材（他の蓄電素子１００等）に影響を及ぼすのを抑制できる。上記実験結果においては、ガスが排出された蓄電素子１００に隣接する他の蓄電素子１００の残存容量が低下するのを抑制できている。流路形成部材２００のガスが流れる方向の長さが蓄電素子１００よりも長いことで、蓄電素子１００からより離れた位置までガスを案内できるため、ガスが蓄電素子１００の周囲の部材（他の蓄電素子１００等）に影響を及ぼすのをさらに抑制できる。 [5 Explanation of effects]
With the configuration described above, according to the power storage device 1 according to the embodiment of the present invention, the minimum area of the flow path (area B), which is the minimum value of the surface perpendicular to the direction in which gas flows in the flow path R, is used for gas discharge. The first value divided by the area (area A) of the valve 131 in plan view is made smaller than 1.6. In this way, by narrowing the flow path R in the flow path forming member 200 for the gas discharged from the gas exhaust valve 131 (by making the first value smaller than 1.6), The flow rate of the gas can be increased. Thereby, even when high-temperature gas is discharged from the gas discharge valve 131, it is difficult for the gas to remain in the flow path forming member 200. As a result, it is possible to suppress influences on members around power storage element 100 (other power storage elements 100, etc.). In the above experimental results, it is possible to suppress a decrease in the remaining capacity of other power storage elements 100 adjacent to power storage element 100 from which gas has been discharged. Since the length of the flow path forming member 200 in the direction in which the gas flows is longer than that of the power storage element 100, the gas can be guided to a position further away from the power storage element 100. It is possible to further suppress the influence on the power storage element 100, etc.).
　蓄電素子１００において、ニッケルを含む正極活物質を有する蓄電素子は高容量（高エネルギー密度）を有しており、ガス排出弁１３１から排出されるガスが比較的高温になり易い。このため、蓄電装置１において、本実施の形態の構成を採用することによる効果が高い。 In the power storage element 100, the power storage element having a positive electrode active material containing nickel has a high capacity (high energy density), and the gas discharged from the gas exhaust valve 131 tends to reach a relatively high temperature. Therefore, the effect of adopting the configuration of this embodiment in power storage device 1 is high.
　蓄電素子１００が有するニッケルの含有比率が高い場合（第二値が１００ｇ／Ｌ以上となる場合）に、より高容量（高エネルギー密度）となるため、ガス排出弁１３１から排出されるガスがより高温になり易い。このため、蓄電装置１において、本実施の形態の構成を採用することによる効果が高い。 When the content ratio of nickel in the electricity storage element 100 is high (when the second value is 100 g/L or more), the capacity (high energy density) is higher, so the gas discharged from the gas discharge valve 131 is more Can easily reach high temperatures. Therefore, the effect of adopting the configuration of this embodiment in power storage device 1 is high.
　蓄電素子１００が有するニッケルの含有比率が高い場合（第三値が０．１５ｇ／ｍｍ２以上となる場合）に、より高容量（高エネルギー密度）となるため、ガス排出弁１３１から排出されるガスがより高温になり易い。このため、蓄電装置１において、本実施の形態の構成を採用することによる効果が高い。 When the content ratio of nickel in the electricity storage element 100 is high (the third value is 0.15 g/mm2 or more), the gas discharged from the gas discharge valve 131 has a higher capacity (higher energy density). tends to become hotter. Therefore, the effect of adopting the configuration of this embodiment in power storage device 1 is high.
　蓄電素子１００のガス排出弁１３１から排出されるガスの流路形成部材２００内での流路Ｒをさらに狭く（第一値を１．２５よりも小さく）することで、流路形成部材２００内での当該ガスの流速をさらに速くできる。 By further narrowing the flow path R in the flow path forming member 200 for the gas discharged from the gas discharge valve 131 of the power storage element 100 (by making the first value smaller than 1.25), the flow path R in the flow path forming member 200 is The flow rate of the gas can be further increased.
　［６　変形例の説明］
　以上、本実施の形態に係る蓄電装置１について説明したが、本発明は、上記実施の形態には限定されない。今回開示された実施の形態は、全ての点で例示であって制限的なものではなく、本発明の範囲には、特許請求の範囲と均等の意味及び範囲内での全ての変更が含まれる。 [6 Description of modification]
Although the power storage device 1 according to the present embodiment has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed this time are illustrative in all respects and are not restrictive, and the scope of the present invention includes all changes within the meaning and scope equivalent to the scope of the claims. .
　上記実施の形態では、蓄電素子１００は、Ｙ軸方向に扁平な（Ｚ軸方向から見てＸ軸方向に長い）直方体形状を有していることとしたが、蓄電素子１００の大きさ及び形状は特に限定されない。蓄電素子１００は、長円柱形状、楕円柱形状、または、直方体以外の多角柱形状等でもよい。蓄電素子１００は、扁平形状ではなく、底面が円形の円柱形状（円筒形、円筒型）でもよいし、底面が正方形の直方体形状等でもよい。 In the above embodiment, the power storage element 100 has a rectangular parallelepiped shape that is flat in the Y-axis direction (long in the X-axis direction when viewed from the Z-axis direction), but the size and shape of the power storage element 100 are is not particularly limited. The power storage element 100 may have an elongated cylindrical shape, an elliptical cylindrical shape, a polygonal cylindrical shape other than a rectangular parallelepiped, or the like. The power storage element 100 may not have a flat shape, but may have a cylindrical shape (cylindrical shape, cylindrical shape) with a circular bottom surface, a rectangular parallelepiped shape with a square bottom surface, or the like.
　上記実施の形態において、流路形成部材２００の大きさ、形状及び配置位置は特に限定されない。流路形成部材２００のＹ軸方向における長さが外装体１８よりも短くてもよい。流路形成部材２００が外装体１８から突出していなくてもよいし、外装体１８の外側に配置されてもよい。流路形成部材２００内の流路Ｒの断面形状は、長方形状ではなく、円形状、楕円形状、長円形状、長方形状以外の多角形状等でもよい。流路形成部材２００内の流路Ｒの断面形状は、ガスが流れる方向において同じ形状でなくてもよく、任意の形状に変化可能である。流路形成部材２００は、Ｙ軸方向とは異なる方向に延びていてもよいし、湾曲した形状でもよいし、折れ曲がった形状でもよい。この場合、流路形成部材２００内の流路Ｒにおけるガスが流れる方向は、流路形成部材２００が延びる方向、または、流路形成部材２００における湾曲形状または折れ曲がった形状に沿った方向となる。 In the embodiment described above, the size, shape, and position of the flow path forming member 200 are not particularly limited. The length of the flow path forming member 200 in the Y-axis direction may be shorter than the exterior body 18. The flow path forming member 200 does not need to protrude from the exterior body 18 or may be arranged outside the exterior body 18. The cross-sectional shape of the flow path R in the flow path forming member 200 may not be rectangular but may be circular, elliptical, oval, polygonal other than rectangular, or the like. The cross-sectional shape of the flow path R in the flow path forming member 200 does not have to be the same shape in the direction in which the gas flows, and can be changed to any shape. The flow path forming member 200 may extend in a direction different from the Y-axis direction, may have a curved shape, or may have a bent shape. In this case, the direction in which gas flows in the channel R in the channel forming member 200 is the direction in which the channel forming member 200 extends, or the direction along the curved or bent shape of the channel forming member 200.
　上記実施の形態では、流路形成部材２００は、バスバーフレーム１２及び外装体１８等と別体の部材であることとしたが、バスバーフレーム１２または外装体１８（外装体蓋体１７）と一体形成（一体化）されていてもよい。この場合、バスバーフレーム１２または外装体１８（外装体蓋体１７）に設けられた壁を、流路形成部材２００におけるガスのガイドとなる壁（流路Ｒの壁）として用いてもよい。 In the above embodiment, the flow path forming member 200 is a separate member from the busbar frame 12, the exterior body 18, etc., but it is formed integrally with the busbar frame 12 or the exterior body 18 (exterior body lid 17). (integrated). In this case, a wall provided on the busbar frame 12 or the exterior body 18 (exterior body lid 17) may be used as a wall (wall of the flow path R) that serves as a gas guide in the flow path forming member 200.
　上記実施の形態では、流路形成部材２００は、Ｙ軸方向に分割されることなくＹ軸方向に延びる部材であることとしたが、Ｙ軸方向に分割された複数の部材がＹ軸方向に繋がることでＹ軸方向に長い流路形成部材２００が構成されてもよい。 In the above embodiment, the flow path forming member 200 is a member that extends in the Y-axis direction without being divided in the Y-axis direction, but a plurality of members divided in the Y-axis direction By being connected, a flow path forming member 200 that is long in the Y-axis direction may be configured.
　上記実施の形態において、第二値（蓄電素子１００が有するニッケルの全質量を、容器１１０の体積で除した値）は、１００ｇ／Ｌよりも小さくてもよい。第三値（蓄電素子１００が有するニッケルの全質量を、流路最小面積で除した値）は、０．１５ｇ／ｍｍ２よりも小さくてもよい。電極体１５０の正極板１５１に形成された正極活物質層１５１ｂの正極活物質は、ニッケルを含んでいなくてもよい。つまり、蓄電素子１００は、ニッケルを含む正極活物質を有しておらず、上記実施例４のような構成を有していてもよい。上記実施例４においては、エネルギー密度が低いものの、隣接蓄電素子の残存容量を多く維持できている。 In the above embodiment, the second value (the value obtained by dividing the total mass of nickel included in the power storage element 100 by the volume of the container 110) may be smaller than 100 g/L. The third value (the value obtained by dividing the total mass of nickel included in the power storage element 100 by the minimum area of the flow path) may be smaller than 0.15 g/mm2. The positive electrode active material of the positive electrode active material layer 151b formed on the positive electrode plate 151 of the electrode body 150 does not need to contain nickel. That is, the power storage element 100 may not have a positive electrode active material containing nickel, and may have the configuration as in Example 4 above. In Example 4, although the energy density is low, a large amount of remaining capacity of the adjacent power storage elements can be maintained.
　上記実施の形態では、蓄電素子１００の容器１１０の容器蓋部１３０にガス排出弁１３１が設けられることとしたが、容器本体１２０にガス排出弁１３１が設けられてもよい。 In the above embodiment, the gas exhaust valve 131 is provided on the container lid 130 of the container 110 of the power storage element 100, but the gas exhaust valve 131 may be provided on the container body 120.
　上記実施の形態では、電極体１５０は、巻回軸Ｌが容器蓋部１３０に平行となる巻回型電極体であることとした。しかし、電極体１５０は、巻回軸Ｌが容器蓋部１３０に垂直となる巻回型電極体であってもよい。電極体１５０において、端部１５６及び１５７は、電極体本体部１５５の端部の全体から突出する部位には限定されず、電極体本体部１５５の端部の一部から突出するタブ部（極板の複数のタブが積層された部位）であってもよい。電極体１５０は、複数の平板状の極板が積層されて形成された積層型（スタック型）の電極体でもよいし、極板を蛇腹状に折り畳んだ蛇腹型の電極体でもよいし、その他の形態の電極体でもよい。 In the above embodiment, the electrode body 150 is a wound type electrode body in which the winding axis L is parallel to the container lid 130. However, the electrode body 150 may be a wound type electrode body in which the winding axis L is perpendicular to the container lid 130. In the electrode body 150, the ends 156 and 157 are not limited to portions that protrude from the entire end of the electrode body body 155, but are tab portions (poles) that protrude from a part of the end of the electrode body body 155. It may also be a portion of a plate in which multiple tabs are stacked. The electrode body 150 may be a laminated type (stack type) electrode body formed by laminating a plurality of flat plates, a bellows-type electrode body formed by folding the plates into a bellows shape, or other electrode bodies. The electrode body may have the following form.
　上記実施の形態及びその変形例に含まれる構成要素を任意に組み合わせて構築される形態も、本発明の範囲内に含まれる。 Embodiments constructed by arbitrarily combining the components included in the above embodiments and their modifications are also included within the scope of the present invention.
　本発明は、リチウムイオン二次電池等の蓄電素子を備えた蓄電装置等に適用できる。 The present invention can be applied to a power storage device, etc. equipped with a power storage element such as a lithium ion secondary battery.
　１　蓄電装置
　１０　蓄電ユニット
　１１　スペーサ
　１２　バスバーフレーム
　１２ａ　流路形成部材配置部
　１３　バスバー
　１４　外装体本体
　１４ａ　切欠部
　１５　外装体支持体
　１７　外装体蓋体
　１８　外装体
　２０　基板ユニット
　３０　ケーブル
　１００　蓄電素子
　１１０　容器
　１２０　容器本体
　１３０　容器蓋部
　１３１　ガス排出弁
　１４０　端子
　１５０　電極体
　１５１　正極板
　１５１ａ　正極基材
　１５１ｂ　正極活物質層
　１５２　負極板
　１５２ａ　負極基材
　１５２ｂ　負極活物質層
　１５３、１５４　セパレータ
　１６０　集電体
　２００　流路形成部材
　２１０　底壁部
　２１１　開口部
　２２０　側壁部
　２３０　上壁部
　２４０　前壁部
　２５０　排出口
  1 Power storage device 10 Power storage unit 11 Spacer 12 Busbar frame 12a Flow path forming member arrangement portion 13 Busbar 14 Exterior main body 14a Notch 15 Exterior support 17 Exterior cover 18 Exterior 20 Board unit 30 Cable 100 Energy storage element 110 Container 120 container body 130 container lid 131 gas discharge valve 140 terminal 150 electrode body 151 positive electrode plate 151a positive electrode base material 151b positive electrode active material layer 152 negative electrode plate 152a negative electrode base material 152b negative electrode active material layer 153, 154 separator 160 current collector 200 flow Path forming member 210 Bottom wall 211 Opening 220 Side wall 230 Top wall 240 Front wall 250 Outlet

Claims (4)

  1. 　ガス排出弁を有する蓄電素子と、
    　前記ガス排出弁から排出されるガスの流路を形成する流路形成部材と、を備え、
    　前記ガスが前記流路を流れる方向を第一方向とした場合、前記流路形成部材の第一方向の長さは、前記蓄電素子の第一方向の長さよりも長く、
    　前記流路における前記第一方向と直交する面の最小値である流路最小面積を、前記ガス排出弁の平面視での面積で除した第一値は１．６よりも小さい
    　蓄電装置。     a power storage element having a gas discharge valve;
    a flow path forming member that forms a flow path for gas discharged from the gas exhaust valve;
    When the direction in which the gas flows through the flow path is a first direction, the length of the flow path forming member in the first direction is longer than the length of the electricity storage element in the first direction,
    A first value obtained by dividing the minimum area of the flow path, which is the minimum value of a surface perpendicular to the first direction in the flow path, by the area of the gas exhaust valve in plan view, is smaller than 1.6.
  2. 　前記蓄電素子は、ニッケルを含む正極活物質を有する
    　請求項１に記載の蓄電装置。     The power storage device according to claim 1, wherein the power storage element has a positive electrode active material containing nickel.
  3. 　前記蓄電素子が有する前記ニッケルの全質量を、前記蓄電素子の容器の体積で除した第二値は、１００ｇ／Ｌ以上である
    　請求項２に記載の蓄電装置。     The power storage device according to claim 2, wherein a second value obtained by dividing the total mass of the nickel included in the power storage element by the volume of the container of the power storage element is 100 g/L or more.
  4. 　前記蓄電素子が有する前記ニッケルの全質量を、前記流路最小面積で除した第三値は、０．１５ｇ／ｍｍ２以上である
    　請求項２に記載の蓄電装置。
          The power storage device according to claim 2, wherein a third value obtained by dividing the total mass of the nickel in the power storage element by the minimum area of the flow path is 0.15 g/mm2 or more.
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