JP2013171732A - Power storage device and vehicle mounting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of interrupting a charging current during overcharge by reacting selectively on hydrogen.SOLUTION: The power storage device comprises: a layered electrode body 100 where a positive electrode sheet and a negative electrode sheet are sandwiching a separator; an electrolyte impregnating the electrode body and containing a material which generates hydrogen when an overvoltage is applied to the electrode body; a positive electrode external terminal 123 and a negative electrode external terminal 133 provided in a case 140 housing the electrode body; a collector terminal 120 for positive electrode connecting the positive electrode sheet and the positive electrode external terminal electrically; a collector terminal 130 for negative electrode connecting the negative electrode sheet and the negative electrode external terminal electrically; and a connection member having a substrate layer not absorbing hydrogen and a hydrogen storing alloy layer laminated on the substrate layer. When the hydrogen storing alloy layer is not storing hydrogen, only any one of the collector terminal for positive electrode or the collector terminal for negative electrode is connected electrically. When the hydrogen storing alloy layer is expanded by absorbing hydrogen, the connection member is deformed and connected electrically with both the collector terminal for positive electrode and the collector terminal for negative electrode.

Description

  The present invention relates to a power storage device and a vehicle equipped with the same.

  Patent Document 1 discloses a battery having a current interruption mechanism that interrupts a charging current when the battery is overcharged. This battery includes an explosion-proof valve that deforms in the internal pressure direction as the internal pressure increases, and a lead plate. The electrode terminal and the electrode material are electrically connected by the lead plate. When the internal pressure of the battery reaches a predetermined internal pressure and the explosion-proof valve is deformed, the lead plate is peeled off or broken to interrupt the charging current.

Japanese Patent Laid-Open No. 2-112151

  Various factors such as overcharge of the power storage device and aging deterioration can be cited as factors that cause gas generation in the power storage device, and the type of gas generated in the power storage device varies depending on the gas generation factor. Conventionally, in order to detect overcharge of a power storage device, an electrolyte containing a material that generates hydrogen when an overvoltage is applied to the electrode body has been used in the power storage device. In such a power storage device, hydrogen is hardly generated when aging deterioration of the power storage device is a factor, but hydrogen is generated when overcharge of the power storage device is a factor. For this reason, if the power storage device includes a current interrupting mechanism that operates selectively in response to hydrogen, the current is not interrupted when the power storage device is aged, and the current is interrupted when overcharged. be able to. In Patent Document 1, regardless of the type of gas generated in the power storage device, as long as the internal pressure of the power storage device increases, the lead plate is broken or peeled off to interrupt the current.

  In the first power storage device disclosed in this specification, a positive electrode sheet and a negative electrode sheet are impregnated into a layered electrode body with a sheet-like separator interposed therebetween, and an overvoltage is applied to the electrode body. In this case, an electrolyte containing a material that generates hydrogen, a case containing an electrode body, a positive electrode external terminal and a negative electrode external terminal provided in the case, and a positive electrode collector that electrically connects the positive electrode sheet and the positive electrode external terminal. A negative electrode current collector terminal that electrically connects the negative electrode sheet and the negative electrode external terminal; a connection member having a substrate layer that does not occlude hydrogen; and a hydrogen storage alloy layer laminated on the substrate layer. I have. When the hydrogen storage alloy layer does not store hydrogen, the connecting member is electrically connected to only one of the positive current collector terminal and the negative current collector terminal, and the hydrogen storage alloy layer absorbs hydrogen. When occluded and expanded, the substrate layer and the hydrogen storage alloy layer are deformed and electrically connected to both the positive current collector terminal and the negative current collector terminal.

  In the first power storage device described above, when the connection member expands by storing hydrogen, the substrate layer and the hydrogen storage alloy layer are deformed, and both the positive current collecting terminal and the negative current collecting terminal are used. Electrically connected to cut off current. According to the first power storage device, when an overvoltage is applied to the electrode body and hydrogen is generated when the power storage device is overcharged, the current can be cut off by selectively reacting with hydrogen. Charging current during charging can be selectively cut off.

  In the second power storage device disclosed in this specification, a positive electrode sheet and a negative electrode sheet are impregnated into a layered electrode body with a sheet-like separator interposed therebetween, and an overvoltage is applied to the electrode body. In this case, an electrolyte containing a material that generates hydrogen, a case containing an electrode body, a positive electrode external terminal and a negative electrode external terminal provided in the case, and a positive electrode collector that electrically connects the positive electrode sheet and the positive electrode external terminal. A connecting member having an electric terminal, a negative electrode current collecting terminal for electrically connecting the negative electrode sheet and the negative electrode external terminal, a substrate layer that does not occlude hydrogen, and a hydrogen storage alloy layer laminated on the substrate layer; ing. At least one of the positive electrode current collector terminal and the negative electrode current collector terminal has an external terminal side contact and an electrode sheet side contact spaced apart from each other. The connecting member is arranged between the external terminal side contact and the electrode sheet side contact, and when the hydrogen storage alloy layer does not store hydrogen, the external terminal side contact and the electrode sheet side contact are connected, When the hydrogen storage alloy layer stores hydrogen, the substrate layer and the hydrogen storage alloy layer are deformed, and the external terminal side contact and the electrode sheet side contact are blocked.

  In the second power storage device, when the hydrogen storage alloy layer stores hydrogen, the connection member is deformed by the substrate layer and the hydrogen storage alloy layer, so that the positive electrode current collector terminal and the negative electrode current collector terminal At least one of the external terminal side contact and the electrode sheet side contact is cut off to cut off the current. According to the second power storage device, the current can be cut off by selectively reacting with hydrogen, similarly to the first power storage device.

  In the third power storage device disclosed in this specification, a positive electrode sheet and a negative electrode sheet are impregnated into a layered electrode body with a sheet-like separator interposed therebetween, and an overvoltage is applied to the electrode body. In this case, an electrolyte containing a material that generates hydrogen, a case containing an electrode body, a positive electrode external terminal and a negative electrode external terminal provided in the case, and a positive electrode collector that electrically connects the positive electrode sheet and the positive electrode external terminal. An electric terminal, a negative electrode current collecting terminal that electrically connects the negative electrode sheet and the negative electrode external terminal, a conductive base material, and a hydrogen adsorbing material that adsorbs hydrogen are provided. The base material is electrically connected to only one of the positive electrode current collector terminal and the negative electrode current collector terminal when the hydrogen adsorbent material does not adsorb hydrogen, and the hydrogen adsorbent material adsorbs hydrogen. When the hydrogen adsorbent presses the base material, the base material moves, and the base material is electrically connected to both the positive electrode current collector terminal and the negative electrode current collector terminal.

  In the third power storage device, the base material is pressed by the hydrogen adsorbent material when the hydrogen adsorbent material expands by adsorbing hydrogen, and is electrically connected to both the positive electrode current collector terminal and the negative electrode current collector terminal. Connected to and cut off the current. According to the third power storage device, similarly to the first power storage device and the like, the current can be cut off by selectively reacting with hydrogen.

  In the fourth power storage device disclosed in this specification, a positive electrode sheet and a negative electrode sheet are impregnated into a layered electrode body with a sheet-like separator interposed therebetween, and an overvoltage is applied to the electrode body. In this case, an electrolyte containing a material that generates hydrogen, a case containing an electrode body, a positive electrode external terminal and a negative electrode external terminal provided in the case, and a positive electrode collector that electrically connects the positive electrode sheet and the positive electrode external terminal. An electrical terminal, a negative electrode current collector terminal that electrically connects the negative electrode sheet and the negative electrode external terminal, a conductive base material, and a hydrogen adsorbent that adsorbs hydrogen are provided. At least one of the positive electrode current collector terminal and the negative electrode current collector terminal has an external terminal side contact and an electrode sheet side contact spaced apart from each other. The substrate is electrically connected to both the external terminal side contact and the electrode sheet side contact when the hydrogen adsorbent is not adsorbing hydrogen, and when the hydrogen adsorbent expands by adsorbing hydrogen When the hydrogen adsorbent presses the base material, the base material moves, and the external terminal side contact and the electrode sheet side contact are interrupted.

  In the fourth power storage device, when the hydrogen adsorbing material absorbs hydrogen and expands, the base material is pressed by the hydrogen adsorbing material to cut off the external terminal side contact and the electrode sheet side contact, Shut off. According to the fourth power storage device, similarly to the first power storage device and the like, the current can be cut off by selectively reacting with hydrogen.

  The present specification also provides a vehicle equipped with the first to fourth power storage devices.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical storage apparatus which can selectively react with hydrogen and can interrupt | block an electric current, and the vehicle carrying this electrical storage apparatus can be provided.

1 is a cross-sectional view of a first power storage device according to Example 1. FIG. It is a figure which expands and shows the vicinity of the connection member of the electrical storage apparatus of FIG. It is a figure which expands and shows the vicinity of the connection member of the electrical storage apparatus of FIG. 1, and has shown the state which the connection member deform | transformed at the time of the overcharge of the electrical storage apparatus. 6 is a cross-sectional view of a second power storage device according to Embodiment 2. FIG. It is a figure which expands and shows the vicinity of the connection member of the electrical storage apparatus of FIG. It is a figure which expands and shows the vicinity of the connection member of the electrical storage apparatus of FIG. 4, and has shown the state which the connection member deform | transformed at the time of the overcharge of an electrical storage apparatus. FIG. 10 is a view showing the vicinity of a connection member according to a modification of Example 2. 6 is a cross-sectional view of a third power storage device according to Embodiment 3. FIG. It is a figure which shows the hydrogen adsorbent of the electrical storage apparatus of FIG. 8, and the insulating member which accommodates this. It is a figure which expands and shows the vicinity of the base material and hydrogen adsorption material of the electrical storage apparatus of FIG. It is a figure which expands and shows the vicinity of the base material and hydrogen adsorption material of the electrical storage apparatus of FIG. 8, and has shown the state which the connection member deform | transformed at the time of the overcharge of an electrical storage apparatus. 6 is a cross-sectional view of a fourth power storage device according to Embodiment 4. FIG. It is a figure which expands and shows the vicinity of the base material and hydrogen adsorption material of the electrical storage apparatus of FIG. It is a figure which expands and shows the vicinity of the base material and hydrogen adsorption material of the electrical storage apparatus of FIG. 11, and has shown the state which the connection member deform | transformed at the time of the overcharge of an electrical storage apparatus.

  The technologies related to the first to fourth power storage devices disclosed in this specification can be used for conventionally known power storage devices such as secondary batteries and capacitors. This power storage device includes a positive electrode sheet and a negative electrode sheet that are layered with a sheet-like separator interposed therebetween, an electrolyte, a case that accommodates the electrode body, a positive external terminal and a negative external terminal, a positive electrode A current collecting terminal and a negative current collecting terminal. The positive external terminal and the negative external terminal are provided on the case. The positive electrode current collector terminal electrically connects the positive electrode sheet and the positive electrode external terminal. The negative electrode current collector terminal electrically connects the negative electrode sheet and the negative electrode external terminal. The electrolyte includes a material that is impregnated in the electrode body and generates hydrogen when an overvoltage is applied to the electrode body. As a specific example, an aromatic monomer added for the purpose of generating hydrogen in an electrolyte solution used for a non-aqueous lithium ion secondary battery can be exemplified. The aromatic monomer generates a hydrogen by generating a polymerization reaction when the battery has a predetermined voltage or higher. Further, the power storage device disclosed in this specification may be mounted on a vehicle, an electric device, or the like.

  A first power storage device disclosed in this specification includes a connection member having a substrate layer that does not store hydrogen and a hydrogen storage alloy layer stacked on the substrate layer. The connection member is electrically connected to only one of the positive current collector terminal and the negative current collector terminal when the hydrogen storage alloy layer does not store hydrogen. When the hydrogen storage alloy layer expands by storing hydrogen, the substrate layer and the hydrogen storage alloy layer are deformed, and the connecting member is electrically connected to both the positive current collector terminal and the negative current collector terminal. The Thereby, the current collecting terminal for positive electrode and the current collecting terminal for negative electrode are short-circuited to interrupt the current. Since the hydrogen storage alloy layer is conductive, the hydrogen storage alloy layer can be short-circuited by contacting the positive electrode collector terminal and the negative electrode collector terminal. When a conductive material is used for the substrate layer, the substrate layer may be short-circuited by contacting the positive electrode current collector terminal and the negative electrode current collector terminal.

  The second power storage device includes a connection member having a substrate layer that does not store hydrogen and a hydrogen storage alloy layer stacked on the substrate layer. In the second power storage device, at least one of the positive electrode current collector terminal and the negative electrode current collector terminal has an external terminal side contact and an electrode sheet side contact that are separated from each other. The connecting member is disposed between the external terminal side contact and the electrode sheet side contact. When the hydrogen storage alloy layer does not store hydrogen, the connection member connects the external terminal side contact and the electrode sheet side contact. When the hydrogen storage alloy layer stores hydrogen, the substrate layer and the hydrogen storage alloy layer of the connecting member are deformed, and the external terminal side contact and the electrode sheet side contact are blocked. Since the hydrogen storage alloy layer is conductive, the hydrogen storage alloy layer can be used as a path for a current flowing between the external terminal side contact and the electrode sheet side contact. When a conductive material is used for the substrate layer, both the hydrogen storage alloy layer and the substrate layer can be used as a path for the current flowing between the external terminal side contact and the electrode sheet side contact. The resistance value can be reduced, which is preferable. Further, only the substrate layer may be connected to both the external terminal side contact and the electrode sheet side contact. Since the current flowing between the external terminal side contact and the electrode sheet side contact flows more on the substrate layer side and less on the hydrogen storage alloy layer, it suppresses the temperature increase of the hydrogen storage alloy layer due to heat generated by the current. Can do.

  As the hydrogen storage alloy layer, a conventionally known hydrogen storage alloy material that expands by hydrogen storage can be used. Specific examples include, but are not limited to, alloys containing palladium, titanium, manganese, zirconium, nickel, niobium, cobalt, aluminum, iron, magnesium, calcium, rare earth elements, and the like. Alloy), vanadium-based alloy (V-based alloy) and the like can be suitably used, and an alloy of palladium (Pd) and silver (Ag) (Pd-Ag alloy) can be particularly suitably used. The hydrogen storage alloy layer may be a single layer made of a single material or a laminate of a plurality of hydrogen storage alloy materials.

  As the substrate layer, a material that does not store hydrogen (that is, a material that is not a hydrogen storage alloy) can be used, and specific examples include, but are not limited to, metals or alloys (excluding hydrogen storage alloys), glass, ceramics, A plastic etc. can be mentioned. The substrate layer hardly expands even when hydrogen is generated in the power storage device. The substrate layer may be a single layer made of a single material, or may be a laminate of materials of a plurality of substrate layers.

  By adjusting the materials and shapes of the hydrogen storage alloy layer and the substrate layer, it is possible to adjust the amount of deformation of the connecting member during the storage of hydrogen. For example, in order to greatly deform the connection member during hydrogen storage, a material having a high volume expansion coefficient before and after hydrogen storage is used for the hydrogen storage alloy layer, the thickness of the hydrogen storage alloy layer is increased, and the rigidity of the substrate layer is increased. A method such as reducing the thickness of the substrate layer can be used. The amount of deformation of the connecting member relative to the amount of generated hydrogen can be confirmed by experiments, and based on this, the connecting member can be designed so that the current can be cut off for a predetermined amount of hydrogen.

  The connecting member may have a layer other than the hydrogen storage alloy layer and the substrate layer. For example, when the material of the hydrogen storage alloy layer is a Pd—Ag alloy, by further forming a thin Pt layer on the surface of the hydrogen storage alloy layer, the deformation sensitivity of the hydrogen storage alloy layer to hydrogen is improved, and the hydrogen storage alloy layer is formed. Deterioration of characteristics can be suppressed.

  Although a connection member is not limited, For example, it can manufacture by the method of forming and laminating | stacking a hydrogen storage alloy layer by vapor deposition etc. on the surface of a board | substrate layer. Further, a layer such as the above Pt layer may be laminated by vapor deposition or the like.

  A third power storage device disclosed in this specification includes a conductive base material and a hydrogen adsorbent that adsorbs hydrogen. The base material is electrically connected to only one of the positive electrode current collector terminal and the negative electrode current collector terminal when the hydrogen adsorbent does not adsorb hydrogen. When the hydrogen adsorbent expands by adsorbing hydrogen, the base material moves when the hydrogen adsorbent presses the base material, and the base material is electrically connected to both the positive current collector terminal and the negative current collector terminal. Connected. Thereby, the current collecting terminal for positive electrode and the current collecting terminal for negative electrode are short-circuited to interrupt the current.

  A fourth power storage device disclosed in this specification includes a conductive base material and a hydrogen adsorbent that adsorbs hydrogen. In the fourth power storage device, at least one of the positive electrode current collector terminal and the negative electrode current collector terminal has an external terminal side contact and an electrode sheet side contact that are separated from each other. When the hydrogen adsorbent does not adsorb hydrogen, the base material is electrically connected to only one of the external terminal side contact and the electrode sheet side contact. When the hydrogen adsorbent expands by adsorbing hydrogen, the base material moves when the hydrogen adsorbent presses the base material, and the base material is electrically connected to both the external terminal side contact and the electrode sheet side contact. Connected to.

  The material of the hydrogen adsorbent is not particularly limited as long as it is a material that adsorbs hydrogen and expands. For example, a conventionally known hydrogen storage alloy material described as the material of the hydrogen storage alloy layer may be used, or a carbon material that expands by adsorbing hydrogen such as activated carbon fibers and carbon nanotubes may be used. Good. Moreover, you may use combining the material which adsorb | sucks several hydrogen and expand | swells. Note that the third and fourth power storage devices may further include a member for facilitating expansion in the direction in which the hydrogen adsorbent presses the base material. For example, the hydrogen adsorbent is housed in a box-shaped member that is open only on the side on which the base material is installed, and the box-shaped member does not move when the hydrogen adsorbent expands. It may be fixed with. In this case, it is preferable that the box-shaped member is provided with a hydrogen passage for efficiently allowing hydrogen generated from the electrode body to reach the hydrogen adsorbent.

  The material of the base material is not particularly limited as long as it is a conductive material, but is preferably a material (for example, copper, aluminum, etc.) used as an electrode material of a power storage device. A plurality of conductive materials may be used in combination.

  In the first to fourth power storage devices, it is preferable that the connection member or the base material is installed so as not to be deformed or moved due to an internal pressure difference generated in the power storage device. For example, it is preferable that the first and second power storage devices are designed so that there is no pressure difference between the pressure on the hydrogen storage alloy layer side of the connection member and the pressure on the substrate layer side. In addition, it is preferable that the third and fourth power storage devices are designed so that a pressure difference does not occur in the direction in which the hydrogen adsorbent presses against the base material. The connecting member or the substrate can be connected to a part of the current collecting terminal, for example, by welding or by bonding with an adhesive. A marking portion may be provided in the connection portion between the current collecting terminal and the connection member or the base material or in the vicinity thereof so that the connection member or the base material is easily deformed.

  1 to 3 exemplify and explain the first power storage device 10 disclosed in this specification. FIG. 1 is a cross-sectional view of the power storage device 10. The power storage device 10 is a wound lithium ion secondary battery. The power storage device 10 includes an electrode body 100, a case 140, a positive current collecting terminal 120, a negative current collecting terminal 130, a positive external terminal 123, a negative external terminal 133, and a connection member 150. . The electrode body 100 is sandwiched between a positive electrode sheet including a positive electrode active material and a positive electrode current collector, a negative electrode sheet including a negative electrode active material and a negative electrode current collector, and the positive electrode sheet and the negative electrode sheet to separate each other. And a sheet-like separator. The positive electrode sheet, the separator, and the negative electrode sheet are laminated in this order and wound around the r-axis shown in FIG. The electrode body 100 is housed in a case and impregnated with a liquid electrolyte. The electrolyte contains an aromatic monomer additive. When an overvoltage is applied to the electrode body 100, the monomer additive contained in the electrolyte is polymerized to generate hydrogen.

  The case 140 includes a lid 141 that houses the electrode body 100 and a main body 142. The positive electrode current collecting terminal 120 includes a lower part 121 that is electrically connected to the positive electrode sheet of the electrode body 100, and an upper part 122 that connects the positive electrode external terminal 123 and the lower part 121. The upper part 122 extends in the positive direction of the x axis. The negative electrode current collector terminal 130 includes a lower part 131 that is electrically connected to the negative electrode sheet of the electrode body 100, and an upper part 132 that connects the negative electrode external terminal 133 and the lower part 131. The upper part 132 extends in the negative direction of the x axis shown in FIG. The positive external terminal 123 and the negative external terminal 133 pass through the lid 141 and are electrically connected to the positive current collecting terminal 120 and the negative current collecting terminal 130, respectively. The connecting member 150 is welded to the upper part 122 of the positive current collecting terminal 120 and is electrically connected to the positive current collecting terminal 120. The connection member 150 includes a hydrogen storage alloy layer 151 and a substrate layer 152. The material of the hydrogen storage alloy layer 151 is a Pd—Ag alloy. The material of the substrate layer 152 is the same metal material as that of the positive electrode current collector terminal 120 and does not occlude hydrogen. The inside of the case 140 is hermetically sealed by the lid 141.

  The upper part 122 of the positive electrode current collecting terminal 120 extends to the central part of the power storage device 10 in the x direction, and extends from the first part 122a to the negative electrode current collecting terminal 130 (positive direction of the x axis). The second portion 122b and the third portion 122c are provided, and the fourth portion 122d is electrically connected to the third portion 122c through the connection member 150. The third portion 122c, the fourth portion 122d, and the connection member 150 are separated from the second portion 122b in the z direction shown in FIG. The upper part 132 of the negative electrode current collector terminal 130 extends to the center of the power storage device 10 in the x direction, and extends from the first part 132a to the positive electrode current collector terminal 120 (the negative direction of the x axis). And a second portion 132b. The second portion 132b extends in a region between the second portion 122b, the third portion 122c, the fourth portion 122d, and the connection member 150. By the insulating member 160 provided between the second portion 122b and the fourth portion 122d and the second portion 132b, the second portion 132b becomes the second portion 122b, the third portion 122c, the fourth portion 122d and the connection member. It is being fixed so that it may not contact 150. In the state shown in FIG. 1, the positive electrode and the negative electrode of the power storage device 10 are insulated. Note that the upper side (region between the second portion 132b and the connection member 150) and the lower side (region between the connection member 150 and the electrode body 100) of the connection member 150 in a part in the y direction shown in FIG. The pressure acting on the upper side and the lower side of the connection member 150 is the same. Further, when hydrogen is generated in the power storage device 10, since the upper side and the lower side of the connection member 150 communicate with each other, the generated hydrogen diffuses to the upper side of the connection member 150 and is stored in the hydrogen storage alloy layer 151.

  2 and 3 are enlarged views of the connecting member 150 and the structure of the power storage device 10 in the vicinity thereof. FIG. 2 shows a case where the hydrogen storage alloy layer 151 does not store hydrogen, and FIG. 3 shows a case where the hydrogen storage alloy layer 151 stores hydrogen. During the normal operation of the power storage device 10, almost no hydrogen is generated in the power storage device 10. Therefore, as shown in FIG. 2, the hydrogen storage alloy layer 151 is in a flat plate state that does not store hydrogen, and the connecting member 150 is , Apart from the second portion 132b. When an overvoltage is applied to the electrode body 100 when the power storage device 10 is overcharged, hydrogen is generated from the electrolyte in the power storage device 10, and the hydrogen storage alloy layer 151 expands by storing hydrogen as shown in FIG. The substrate layer 152 hardly expands. Since the hydrogen storage alloy layer 151 and the substrate layer 152 are laminated, the connecting member 150 is curved so that the hydrogen storage alloy layer 151 protrudes. As a result, the connection member 150 comes into contact with the second portion 132b, and the positive electrode and the negative electrode are short-circuited by the connection member 150. Thereby, the charging current when the power storage device 10 is overcharged can be cut off.

  4 to 6 exemplify and explain the second power storage device 20 disclosed in this specification. FIG. 4 is a cross-sectional view of the power storage device 20. The power storage device 20 is a wound lithium ion secondary battery, similar to the power storage device 10 according to the first embodiment. The power storage device 20 is different from the power storage device 10 in the positive current collector terminal 220, the negative current collector terminal 230, and the connection member 250. Since the other configuration is the same as that of the power storage device 10, the description of the power storage device 10 is omitted by replacing the 100th reference number with the 200th level.

  The positive electrode current collector terminal 220 includes a lower part 221 that is electrically connected to the positive electrode sheet of the electrode body 200, and an upper part 222 that connects the positive electrode external terminal 223 and the lower part 221. The negative electrode current collecting terminal 230 is electrically connected to the negative electrode sheet of the electrode body 200. The connection member 250 is disposed between the lower part 221 and the upper part 222 of the positive electrode current collecting terminal 220 and is welded to the lower part 221 and the upper part 222. The lower part 221 and the upper part 222 are electrically connected via the connecting member 250.

  5 and 6 are enlarged views showing the connection member 250 and the structure of the power storage device 20 in the vicinity thereof. As shown in FIG. 5, the connection member 250 includes a hydrogen storage alloy layer 251 and a substrate layer 252. Both ends of the connection member 250 are welded to the external terminal side contact 222 a of the upper part 222 and the electrode sheet side contact 221 a of the lower part 221, respectively. A marking 260 is provided on the external terminal side contact 222 a to which the connection member 250 and the upper part 222 are connected. The material of the hydrogen storage alloy layer 251 is a Pd—Ag alloy, and the material of the substrate layer 252 is the same metal material as the positive electrode current collector terminal 220.

  FIG. 5 shows a case where the hydrogen storage alloy layer 251 does not store hydrogen, and FIG. 6 shows a case where the hydrogen storage alloy layer 251 stores hydrogen. During the normal operation of the power storage device 20, almost no hydrogen is generated in the power storage device 20. Therefore, as shown in FIG. 5, the hydrogen storage alloy layer 251 is in a flat plate state that does not store hydrogen. The external terminal side contact 222a and the electrode sheet side contact 221a are electrically connected. When an overvoltage is applied to the electrode body 200 when the power storage device 20 is overcharged, hydrogen is generated from the electrolyte in the power storage device 20, and the hydrogen storage alloy layer 251 expands by storing hydrogen as shown in FIG. The substrate layer 252 hardly expands. Since the hydrogen storage alloy layer 251 and the substrate layer 252 are laminated, the connection member 250 is curved so that the hydrogen storage alloy layer 251 protrudes, and the connection member 250 is broken at the engraved portion 260, so that the connection member 250 and the external terminal side contact 222a Is cut off. As a result, the current path of the positive electrode current collecting terminal 120 is interrupted, and the charging current when the power storage device 20 is overcharged can be interrupted.

(Modification)
In Example 2, both the hydrogen storage alloy layer 251 and the substrate layer 252 of the connection member 250 are connected to the external terminal side contact 222a and the electrode sheet side contact 221a. However, the present invention is not limited to this. For example, as shown in FIG. 7, the external terminal side contact 225a of the upper part 225 is in contact with only the substrate layer 252 and not in contact with the hydrogen storage alloy layer 251 by reducing the width of the upper part 225 in the y direction. You may do it. With this configuration, it is possible to cause more current to flow between the external terminal side contact 225a and the electrode sheet side contact 221a to flow to the substrate layer 252 side and to flow less to the hydrogen storage alloy layer 251. It can be suppressed that the hydrogen storage alloy layer 251 rises in temperature due to heat generated by current and changes in deformation.

  8 to 11 illustrate the third power storage device 30 and a part thereof disclosed in this specification. FIG. 8 is a cross-sectional view of the power storage device 30. The power storage device 30 is a wound lithium ion secondary battery, similar to the power storage device 10 according to the first embodiment. The power storage device 30 is different from the power storage device 10 in a positive current collecting terminal 320 and a negative current collecting terminal 330. The power storage device 30 is different from the power storage device 10 in that the power storage device 30 includes a base material 350, a hydrogen adsorbent 360, and an insulating member 380 instead of the connection member 150. Since the other configuration is the same as that of the power storage device 10, the description is omitted by replacing the 100th reference number of the power storage device 10 with the 300th number.

  FIG. 9 is a perspective view showing the insulating member 380 and the hydrogen adsorbent 360, and FIGS. 10 and 11 are enlarged views showing the base member 350 and the structure of the power storage device 30 in the vicinity thereof. The positive electrode current collecting terminal 320 includes a lower part 321 that is electrically connected to the positive electrode sheet of the electrode body 300, and an upper part 322 that connects the positive electrode external terminal 323 and the lower part 321. The negative electrode current collecting terminal 330 is electrically connected to the negative electrode sheet of the electrode body 300. The upper portion 322 has a first portion 322a and a second portion 322b extending to a position close to the negative electrode current collecting terminal 330 in the positive direction of the x-axis. The first portion 322a and the second portion 322b are separated from each other in the z direction. The base material 350 is bonded to the end surface 371 of the first portion 322a in the positive direction of the x axis and the end surface 372 of the second portion 322b in the positive direction of the x axis by a conductive adhesive at both ends in the z direction. Yes. The base material 350 and the end surface 371 are bonded more firmly than the base material 350 and the end surface 372. The first portion 322a and the second portion 322b are electrically connected via the base material 350. The hydrogen adsorbent 360 and the insulating member 380 are disposed between the first portion 322a and the second portion 322b. The base material 350 is located in the positive direction of the x axis with respect to the hydrogen adsorbent 360. In addition, in a part in the y direction shown in FIG. 8, the regions on both sides in the x direction of the insulating member 380 communicate with each other, and the region on the upper side (hydrogen adsorbent 360 side) and the lower side (electrode body) of the second portion 322b. The region on the 300 side is in communication. For this reason, the pressure which acts on the both sides of the x direction of the base material 350 is the same. When hydrogen is generated in the power storage device 30, the generated hydrogen diffuses from the region on the electrode body 300 side to the region on the hydrogen adsorbent 360 side.

  As shown in FIGS. 8 and 9, the insulating member 380 has a rectangular parallelepiped box shape in which only a surface facing the side surface 383 in the positive direction of the x axis is open. The upper surface 381 and the side surface 382 of the insulating member 380 are provided with holes 381a and 382a that penetrate the respective surfaces and reach the inner side of the insulating member 380. The upper surface 381 is bonded to the lower surface of the first portion 322a at the bonding portion 381b. Although not shown, a hole and an adhesive portion similar to those of the upper surface 381 are provided on the lower surface facing the upper surface 381, and the lower surface is bonded to the upper surface of the second portion 322b at the bonded portion. . Further, a hole similar to that of the side surface 382 is provided on the side surface that is not illustrated or faces the side surface 382. The insulating member 380 is fixed to the lower surface of the first portion 322a and the upper surface of the second portion 322b with an adhesive, and the hydrogen adsorbent 360 is accommodated inside the insulating member 380. The material of the hydrogen adsorbent 360 is a Pd—Ag alloy, and the material of the base material 350 is the same metal material as the positive electrode current collector terminal 320.

  During the normal operation of the power storage device 30, almost no hydrogen is generated in the power storage device 30. Therefore, as shown in FIG. 10, the hydrogen adsorbent 360 does not occlude hydrogen and is not in contact with the base material 350. . The base material 350 is bonded to the end surfaces 371 and 372, and the first portion 322 a and the second portion 322 b are electrically connected via the base material 350.

  If an overvoltage is applied to the electrode body 300 during overcharging of the power storage device 30, hydrogen is generated from the electrolyte in the power storage device 30, and the hydrogen adsorbent 360 expands by absorbing hydrogen as shown in FIG. Since the insulating member 380 is provided with holes 381a, 382a and the like, hydrogen is sufficiently supplied to the hydrogen adsorbent 360 even if it is accommodated in the insulating member 380. Since the hydrogen adsorbent 360 is accommodated in the insulating member 380 that is open only in the positive direction of the x axis, it mainly extends in the positive direction of the x axis toward the base material 350. The hydrogen adsorbent 360 extends from the positive end surfaces 371 and 372 of the x-axis of the first portion 322a and the second portion 322b to press the base member 350. Since the base material 350 and the end surface 371 are bonded more firmly than the base material 350 and the end surface 372, when pressed by the hydrogen adsorbent 360, the base material 350 and the end surface 372 are separated and separated. 350 and the end surface 371 are maintained in a bonded state. The hydrogen adsorbent 360 extends in the positive direction of the x axis until the base material 350 peeled at the end surface 372 contacts the negative electrode current collector terminal 330. As a result, the positive electrode current collector terminal 320 and the negative electrode current collector terminal 330 are short-circuited via the base material 350, and the charging current when the power storage device 30 is overcharged can be cut off.

  FIGS. 12 to 14 illustrate the fourth power storage device 40 and a part thereof disclosed in this specification. FIG. 12 is a cross-sectional view of the power storage device 40. The power storage device 40 is a wound lithium ion secondary battery, similar to the power storage device 30 according to the third embodiment. The power storage device 40 is different from the power storage device 30 in the positive electrode current collecting terminal 420, the base material 450, and the hydrogen adsorbent 460. Since the other configuration is the same as that of the power storage device 30, the description is omitted by replacing the 300th reference number of the power storage device 30 with the 300th number.

  FIGS. 13 and 14 are enlarged views of the base material 450 and the structure of the power storage device 40 in the vicinity thereof. The positive electrode current collecting terminal 420 includes a lower part 421 that is electrically connected to the positive electrode sheet of the electrode body 400, and an upper part 422 that connects the positive electrode external terminal 423 and the lower part 421. The negative electrode current collector terminal 430 is electrically connected to the negative electrode sheet of the electrode body 400. The upper portion 422 includes a first portion 422a and a second portion 422b extending in the x direction to a position close to the negative electrode current collecting terminal 430. The first portion 422a and the second portion 422b are separated in the z direction. When the base material 450 extends in the z direction and is positioned on the end surface in the positive direction of the x-axis of the second portion 422b and the external terminal side contact 425a positioned on the positive surface of the first portion 422a in the positive direction of the electrode sheet side Each of the contacts 425b is bonded with a conductive adhesive. The external terminal side contact 425a and the electrode sheet side contact 425b are electrically connected via the base material 450. The external terminal side contact 425a is provided with a marking portion 471 in which the thickness of the first portion 422a is reduced in the z direction, and the electrode sheet side contact 425b is stamped in which the thickness of the second portion 422b is reduced in the z direction. A portion 472 is provided. Similar to the power storage device 30, the hydrogen adsorbent 460 and the insulating member 480 are disposed between the first portion 422a and the second portion 422b. The insulating member 480 has the same shape as the insulating member 380, and is fixed to the lower surface of the first portion 422a and the upper surface of the second portion 422b with an adhesive. The hydrogen adsorbent 460 is formed of the same material as the hydrogen adsorbent 360 and is similarly housed inside the insulating member 480. The base material 450 is located in the positive direction of the x axis with respect to the hydrogen adsorbent 460.

  During the normal operation of the power storage device 40, almost no hydrogen is generated in the power storage device 40. Therefore, as shown in FIG. 13, the hydrogen adsorbent 460 does not occlude hydrogen and is not in contact with the base material 450. . The base material 450 is bonded to the external terminal side contact 425a and the electrode sheet side contact 425b, and the external terminal side contact 425a and the electrode sheet side contact 425b are electrically connected via the base material 450.

  When an overvoltage is applied to the electrode body 400 during overcharging of the power storage device 40, hydrogen is generated from the electrolyte in the power storage device 40, and the hydrogen adsorbent 460 expands by absorbing hydrogen as shown in FIG. Since the insulating member 480 is provided with a hole, even if the insulating member 480 is accommodated in the insulating member 480, hydrogen is sufficiently supplied to the hydrogen adsorbent 460. Since the hydrogen adsorbent 460 is accommodated in the insulating member 480 that is open only in the x direction, it mainly extends in the x direction toward the base material 450. The hydrogen adsorbent 460 extends until it protrudes from the end surfaces in the x direction of the first portion 422a and the second portion 422b and presses the base material 450. When pressed by the hydrogen adsorbent 460, the marking portions 471 and 472 are broken, and the base material 450 is separated from the external terminal side contact 425a and the electrode sheet side contact 425b. When the base material 450 is broken, the connection between the external terminal side contact 425a and the electrode sheet side contact 425b is cut off, and the charging current when the power storage device 40 is overcharged can be cut off.

  As mentioned above, although embodiment and the Example of this invention were described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

10, 20, 30, 40 Power storage device 100, 200, 300, 400 Electrode body 120, 220, 320, 420 Current collector terminal for positive electrode 121, 131, 221, 321, 421 Lower part 122, 132, 222, 322, 422 Upper part 122a, 132a, 322a, 422a First part 122b, 132b, 322b, 422b Second part 122c Third part 122d Fourth part 123, 223, 323, 423 Positive electrode external terminals 130, 230, 330, 430 Negative electrode current collecting terminals 133, 233, 333, 433 Negative electrode external terminal 140, 240, 340, 440 Case 141, 241, 341, 441 Cover 142, 242, 342, 442 Main body 150, 250 Connection member 151, 251 Hydrogen storage alloy layer 152, 252 Substrate Layer 160 Insulating member 221a Electrode sheet side Points 222a, 225a external terminal side contact 260,261,471,472 marking portion 350, 450 substrate 360,460 hydrogen adsorbent 380,480 insulation member 381a, 382a hole

Claims (5)

A positive electrode sheet and a negative electrode sheet layered in a state where a sheet-like separator is sandwiched therebetween,
An electrolyte containing a material that is impregnated in the electrode body and generates hydrogen when an overvoltage is applied to the electrode body;
A case for housing the electrode body;
A positive external terminal and a negative external terminal provided in the case;
A positive electrode current collecting terminal for electrically connecting the positive electrode sheet and the positive electrode external terminal;
A negative electrode current collecting terminal for electrically connecting the negative electrode sheet and the negative electrode external terminal;
A connection member having a substrate layer that does not store hydrogen and a hydrogen storage alloy layer laminated on the substrate layer,
When the hydrogen storage alloy layer does not store hydrogen, the connection member is electrically connected to only one of the positive current collector terminal and the negative current collector terminal,
When the hydrogen storage alloy layer expands by storing hydrogen, the substrate layer and the hydrogen storage alloy layer are deformed and electrically connected to both the positive current collector terminal and the negative current collector terminal. A power storage device. A positive electrode sheet and a negative electrode sheet layered in a state where a sheet-like separator is sandwiched therebetween,
An electrolyte containing a material that is impregnated in the electrode body and generates hydrogen when an overvoltage is applied to the electrode body;
A case for housing the electrode body;
A positive external terminal and a negative external terminal provided in the case;
A positive electrode current collecting terminal for electrically connecting the positive electrode sheet and the positive electrode external terminal;
A negative electrode current collecting terminal for electrically connecting the negative electrode sheet and the negative electrode external terminal;
A connection member having a substrate layer that does not store hydrogen and a hydrogen storage alloy layer laminated on the substrate layer; and
At least one of the positive electrode current collector terminal and the negative electrode current collector terminal has an external terminal side contact and an electrode sheet side contact spaced apart from each other,
The connecting member is disposed between the external terminal side contact and the electrode sheet side contact,
When the hydrogen storage alloy layer does not store hydrogen, connect the external terminal side contact and the electrode sheet side contact,
The power storage device, wherein when the hydrogen storage alloy layer stores hydrogen, the substrate layer and the hydrogen storage alloy layer are deformed to interrupt the external terminal side contact and the electrode sheet side contact. A positive electrode sheet and a negative electrode sheet layered in a state where a sheet-like separator is sandwiched therebetween,
An electrolyte containing a material that is impregnated in the electrode body and generates hydrogen when an overvoltage is applied to the electrode body;
A case for housing the electrode body;
A positive external terminal and a negative external terminal provided in the case;
A positive electrode current collecting terminal for electrically connecting the positive electrode sheet and the positive electrode external terminal;
A negative electrode current collecting terminal for electrically connecting the negative electrode sheet and the negative electrode external terminal;
A conductive substrate;
A hydrogen adsorbent that adsorbs hydrogen, and
The base material is electrically connected to only one of the positive electrode current collector terminal and the negative electrode current collector terminal when the hydrogen adsorbent does not adsorb hydrogen,
When the hydrogen adsorbent expands by adsorbing hydrogen, the base material moves when the hydrogen adsorbent presses the base material, and the base material moves between the positive electrode current collector terminal and the negative electrode current collector. A power storage device that is electrically connected to both electrical terminals. A positive electrode sheet and a negative electrode sheet layered in a state where a sheet-like separator is sandwiched therebetween,
An electrolyte containing a material that is impregnated in the electrode body and generates hydrogen when an overvoltage is applied to the electrode body;
A case for housing the electrode body;
A positive external terminal and a negative external terminal provided in the case;
A positive electrode current collecting terminal for electrically connecting the positive electrode sheet and the positive electrode external terminal;
A negative electrode current collecting terminal for electrically connecting the negative electrode sheet and the negative electrode external terminal;
A conductive substrate;
A hydrogen adsorbent that adsorbs hydrogen, and
At least one of the positive electrode current collector terminal and the negative electrode current collector terminal has an external terminal side contact and an electrode sheet side contact spaced apart from each other,
The base material is electrically connected to both the external terminal side contact and the electrode sheet side contact when the hydrogen adsorbent does not adsorb hydrogen,
When the hydrogen adsorbent expands by adsorbing hydrogen, the base material moves when the hydrogen adsorbent presses the base material, and the base material moves the external terminal side contact and the electrode sheet side contact. A power storage device that is electrically connected to only one of the two. A vehicle equipped with the power storage device according to any one of claims 1 to 4.

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