JP2016085849A - Battery and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excessive heat generation by interrupting the current reliably at the time of temperature rise due to occurrence of an abnormality.SOLUTION: A battery 1 has a battery element 10, a first chamber 13a for sealing the battery element 10, one or two second chambers 13b having interior isolated from that of the first chamber 13a, a pair of first terminals 11 connected with the battery element 10, and a second terminal 12 having a tip located in the two second chambers 13b. At least one of the first terminals 11 is arranged while the tip is located in the second chamber 13b. The second terminal 12 is arranged across the interior and exterior of the second chamber 13b, so that the tip is in contact with the first terminal 11 located in the second chamber 13b, in the second chamber 13b. In the second chamber 13b, a blend 14 generating gas when the potential difference between the pair of first terminals 11 goes above a predetermined value is encapsulated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery having a function of interrupting current when an abnormality occurs, thereby preventing excessive heat generation.

  Non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries have already been put to practical use as batteries for notebook computers and mobile phones due to their advantages such as high energy density, low self-discharge, and excellent long-term reliability. Yes. However, in recent years, electronic devices have been enhanced in functionality and used in electric vehicles, and development of lithium ion secondary batteries with higher energy density has been demanded.

  On the other hand, as the energy capacity or energy density of the battery increases, the temperature of the battery increases when a short circuit occurs due to an external impact or a circuit failure or when an overcharge state occurs. At this time, the oxygen release reaction of the active material and the thermal decomposition reaction of the electrolytic solution occur, and the battery further generates heat. If the battery generates excessive heat, in some cases, it may lead to thermal runaway that makes temperature control impossible.

  Conventionally, various blocking mechanisms have been disclosed as solutions for battery heat generation. For example, Patent Document 1 discloses that a compound that is oxidized at a predetermined voltage or higher is added to an electrolytic solution. This compound induces decomposition or vaporization of the electrolyte components due to heat generation during oxidation, raises the internal pressure of the battery, and effectively functions as a safety means (CID; Current Interrupt Device) that operates by the pressure rise. Patent Document 2 discloses a breaking mechanism in which a thermal fuse is incorporated in a current output conductor. In Patent Document 3, a battery case that accommodates an electrode assembly has a structure that can be extended in the direction in which the electrode lead is drawn, and the battery case expands when the internal pressure of the battery rises. A shut-off mechanism is disclosed which is adapted to separate.

  In Patent Document 4, in a battery in which a battery case that houses an electrode assembly is formed of a bag made of a heat-fusible film, the inside of the bag is adjacent to a main chamber that houses the electrode assembly, and the main chamber. A battery having a structure divided into a subchamber through which electrode leads pass is disclosed. The partition seal portion that partitions the main chamber and the sub chamber has a weak seal portion. Further, in the sub chamber, the electrode lead is provided with a blocking mechanism for disconnecting the connection due to an increase in internal pressure. According to the battery having such a configuration, when the internal pressure of the main chamber rises due to an abnormality or the like, the weak seal portion is opened and the sub chamber expands, thereby disconnecting the electrode lead.

Special table 2010-527134 gazette Special table 2011-519124 gazette Special table 2013-535791 gazette JP 2000-067846 A

  Batteries can be broadly classified into two types. One is called a cylindrical battery or a square battery in which an internal electrode is wound, and the other is a stacked battery in which electrodes are stacked. In a large battery, a stacked type tends to be used with emphasis on heat dissipation performance. Moreover, the exterior tends to be manufactured from a metal casing and a laminated film obtained by coating a metal foil with a resin film from the viewpoint of weight reduction, heat dissipation performance, and cost.

  Looking at the above-described prior art based on this tendency, the invention described in Patent Document 1 operates the safety means by utilizing the increase in the internal pressure of the battery due to the generation of gas. Therefore, although it functions effectively in the case of a battery having an exterior body that does not deform, such as a metal housing, a battery having a film as an exterior cannot fully exhibit the effect.

  The structure described in Patent Document 2 relates to a battery having a laminated electrode with high heat dissipation and a laminate film as an exterior, but in a large battery through which a large current flows, a thermal fuse is a fuse part. Since the resistance value becomes high, there is a risk of energy loss.

  The structure described in Patent Document 3 is superior in that there is no energy loss as described above because it can detect a gas generated in an abnormal condition in the laminate exterior and shut off the electric circuit. However, since the outer laminate is folded, the electrodes may be displaced by vibration, and there is a possibility of ignition due to contact between the electrodes. In addition, even when the battery is normal, the internal electrolyte solution slightly volatilizes due to the environmental temperature, or when the battery is used for a long time, volatile components are generated due to electrolysis of the electrolyte solution. In this case, there is a possibility that the electrode is also displaced by vibration. When such a phenomenon occurs when the battery is transported or used for an automobile, not only the battery performance is deteriorated, but also there is a risk of causing a thermal runaway due to a short circuit of the electrode.

  The structure described in Patent Document 4 requires that the gas generated in the main chamber breaks the weak seal portion, passes through it, enters the sub chamber, and further expands the sub chamber. The time lag from ascent to current interruption increases. For this reason, it is difficult to reliably prevent thermal runaway, and particularly in a high-energy battery, it is difficult to obtain a sufficient effect because the thermal runaway speed of the active material is increased.

  An object of the present invention is to reliably cut off a current at the time of temperature rise due to occurrence of abnormality and prevent excessive heat generation.

According to one aspect of the invention, a battery element;
A first chamber for sealing the battery element;
One or two second chambers having an interior isolated from the interior of the first chamber;
A pair of first terminals connected to the battery element, wherein at least one of the pair of first terminals is disposed with a tip portion positioned in the second chamber;
A second terminal having a distal end portion located in the second chamber, the first terminal located in the second chamber and the second terminal disposed in contact with the second chamber and extending between the inside and the outside of the second chamber; ,
A mixture that is sealed in the second chamber and generates a gas when a potential difference between the pair of first terminals is equal to or greater than a predetermined value;
A battery is provided.

  In the present invention, the mixture includes a redox shuttle agent that generates heat when a potential difference between the pair of first terminals is equal to or higher than the predetermined value, and a gas generating material that generates gas at a predetermined temperature or higher. Is preferred. Further, the second chamber is expanded by the generated gas, whereby the first terminal and the second terminal can be separated from each other.

Moreover, according to the other aspect of this invention, it has the battery element to which a pair of 1st terminal was connected, the 1st chamber which seals the said battery element, and the inside isolated from the inside of the said 1st chamber. A method of manufacturing a battery having one or two second chambers,
Arranging at least one first terminal of the pair of first terminals such that the second terminal can be brought into contact with the tip;
A portion where the first terminal and the second terminal are arranged so as to be in contact with each other, and a mixture that generates gas when a potential difference between the pair of first terminals is equal to or greater than a predetermined value. And in a state of contacting the second terminal with the second terminal,
A method of manufacturing a battery having

  According to the present invention, gas can be generated in the second chamber by the reaction of the redox shuttle agent, and overcharge can be prevented by utilizing the expansion of the second chamber due to the generation of this gas.

It is a top view which shows typically the structure of the battery by one Embodiment of this invention. In the battery shown in FIG. 1, it is a top view which shows the state which the 2nd chamber extended in the terminal direction. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is a figure explaining the other form of the electric current interruption mechanism used by this invention. It is the top view which showed typically the other form of the electric current interruption mechanism used by this invention. It is the schematic diagram seen from the side surface side of the electric current interruption mechanism shown to FIG. 10A. FIG. 10B is a diagram showing a state in which the second chamber starts to expand in the current interrupt mechanism shown in FIG. 10B. FIG. 10C is a diagram showing a state where the second chamber is further expanded and the snap male connector and the female connector are disengaged in the current interrupt mechanism shown in FIG. 10C. It is a figure explaining the package which a 2nd chamber can extend | expand in a terminal direction. It is a figure explaining the electric current interruption operation | movement of the battery using the package shown in FIG. It is a figure explaining the electric current interruption operation | movement at the time of bending the 2nd chamber toward the 1st chamber in the battery shown in FIG. It is a top view which shows typically the structure of the battery by the other embodiment of this invention provided with the element for voltage adjustment. It is typical sectional drawing which shows the structure of the battery element which a laminated type secondary battery has. It is a schematic diagram which shows an example of the electric vehicle provided with the battery of this invention. It is a schematic diagram which shows an example of the electrical storage equipment provided with the battery of this invention.

  Referring to FIG. 1, there is shown a schematic diagram of a battery 1 according to an embodiment of the present invention, which includes a battery element 10, an exterior body 13 that seals the battery element 10, and a current interruption mechanism 15. The battery element 10 includes a positive electrode, a negative electrode, a separator, and an electrolytic solution. The exterior body 13 is formed of a laminate film that is an exterior material that can be welded, and is a first chamber that seals the battery element 10 by a seal portion 13c formed by joining by thermal welding or ultrasonic welding. 13a and a second chamber 13b having an interior isolated from the interior of the first chamber 13a. The first chamber 13a and the second chamber 13b may be adjacent to each other as illustrated, or may be separated from each other. The bonding method of the exterior material is not limited to welding, and bonding using an adhesive may be used. Bonding with an adhesive, or jointly bonding with an adhesive and bonding by welding, the selection range of the material of the exterior material is widened.

  A pair of first terminals 11 connected to the positive electrode and the negative electrode respectively extend from the battery element 10. At least one of the pair of first terminals 11 extends so that a part thereof is positioned in the second chamber 13b, and is arranged so as to be electrically connectable to external wiring via the second chamber 13b. If it is, it may be arranged arbitrarily. In the illustrated example, one first terminal 11 extends into the second chamber 13b, and the other is arranged on one side of the battery element 10 so as to be drawn out of the exterior body 13 without passing through the second chamber 13b. Yes.

  The current interrupting mechanism 15 is configured to operate when the potential difference between the positive electrode and the negative electrode exceeds a predetermined value, and interrupts the current between the battery element 10 and the external wiring. Of the pair of first terminals 11, the first terminal 11 extending into the second chamber 13 b constitutes a part of the current interrupt mechanism 15. In addition, the current interruption mechanism 15 includes a second terminal 12 that cooperates with the first terminal 11 so as to be electrically disconnected from the first terminal 11 in the second chamber 13b, and a second chamber. It has the mixture 14 enclosed in 13b, and the auxiliary terminal 16 electrically connected with the other 1st terminal 11 and arrange | positioned in the 2nd chamber 13b.

  The mixture 14 is configured to generate gas when the potential difference between the positive electrode and the negative electrode is greater than or equal to a predetermined value. As such a mixture 14, a redox shuttle agent that generates an oxidation-reduction reaction when the potential difference between the positive electrode and the negative electrode is equal to or higher than a predetermined value and generates heat, and a gas generating material that generates gas at a predetermined temperature or higher; Can be included.

  Here, the “predetermined value” means a reaction potential specific to the redox shuttle agent that causes the redox shuttle agent to undergo an oxidation-reduction reaction. In addition, the gas generating material is a material that generates a gas at a temperature higher than the normal temperature and higher than a predetermined temperature that does not cause thermal runaway of the battery, although it exists as a solid or liquid at normal temperature. The second chamber 13b can be expanded. Here, “normal temperature” refers to a temperature range of 20 ± 15 ° C. (that is, 5 ° C. to 35 ° C.) specified in JIS Z 8703. In this embodiment, the second chamber 13b is configured to expand in the direction (arrow A direction) in which the second terminal 12 is pulled out by expanding. In the present invention, the “terminal direction” means a direction in which the second terminal 12 is pulled out.

  The 2nd terminal 12 is a terminal which connects the 1st terminal 11 in which the front-end | tip part is located in the 2nd chamber 13b, and the external electrical wiring of the battery 1, and a 1st terminal is a 1st terminal in the 2nd chamber 13b. 11 and is arranged across the inside and the outside of the second chamber 13b. Furthermore, before the second chamber 13b extends, the second terminal 12 is in contact with the first terminal 11 at one end, but the second terminal 12 moves as the second chamber 13b extends, It is fixed to the exterior body 13 so as to be away from the first terminal 11. Therefore, when the first terminal 11 and the second terminal 12 are separated from each other, the electrical connection between the battery element and the external electric wiring is interrupted. In order to make the contact between the first terminal 11 and the second terminal 12 before the second chamber 13b expands more reliably, before the mixture 14 generates gas, the exterior material is opposed in the second chamber 13b. It is preferable that the inside of the second chamber 13b is in a vacuum state so that the inner surfaces to be in close contact with each other. Such a vacuum state can be realized by carrying out bonding of the exterior material for forming the second chamber 13b under reduced pressure.

  As long as the auxiliary terminal 16 has a configuration capable of generating a potential difference equal to the potential difference between the pair of first electrodes 11 in the second chamber 13b, the arrangement, structure, and the like may be arbitrary. For example, as shown in FIG. 1, the entire auxiliary terminal 16 is disposed in the second chamber 13 b and is electrically connected to the first terminal 11 that is drawn out without passing through the second chamber 13 b through appropriate wiring. Can be connected. Alternatively, the auxiliary terminal 16 is arranged so that a part of the auxiliary terminal 16 is drawn out of the second chamber 13 b and the portion of the auxiliary terminal 16 drawn out of the second chamber 13 b is electrically connected to the first terminal 11. It can also be.

  According to the battery 1 configured as described above, when the battery 1 is overcharged during charging and the potential difference between the pair of first terminals 11 becomes equal to or higher than the reaction potential of the redox shuttle agent, the second chamber 13b has a second potential. The oxidation-reduction reaction is repeated between the 1 terminal 11 and the auxiliary terminal 16. The redox shuttle agent generates heat by repeating this oxidation-reduction reaction. When the temperature in the second chamber 13b becomes equal to or higher than a predetermined temperature due to heat generation, gas is generated from the gas generating material, and the second chamber 13b expands. When the second chamber 13b expands, the second chamber 13b expands in the direction of arrow A. As a result, as shown in FIG. 2, the first terminal 11 and the second terminal 12 are separated from each other. Current is interrupted between the second terminal 12. As a result, overcharging of the battery 1 can be prevented.

  As long as the current interruption mechanism 15 is configured so that the first terminal 11 and the second terminal 12 are separated from each other by the expansion of the second chamber 13b, the current interruption mechanism 15 is not limited to the structure shown in the above-described embodiment and adopts an arbitrary structure. be able to. Hereinafter, various forms of the current interrupting mechanism 15 that can be used in the present invention will be described. In addition, although the form shown below demonstrates centering around the structure of the inside of a 2nd chamber or the periphery of a 2nd chamber, another part can be comprised similarly to the form mentioned above. Moreover, the form shown below is shown as an example of a current interruption | blocking mechanism, and this invention is not limited to the following forms.

  As shown in FIG. 3, the second chamber 13b can also be configured to expand in the thickness direction of the second chamber 13b, which is the facing direction of the exterior material. In this case, the first terminal 11 and the second terminal 12 Can be separated in the thickness direction of the second chamber 13b. To that end, in the second chamber 13b, the first terminal 11 can be joined to one inner surface of the facing exterior material, and the second terminal 12 can be joined to the other inner surface. Before the expansion of the second chamber 13b due to gas generation, the first terminal 11 and the second terminal 12 are in contact with each other in an overlapping state and are electrically connected (A). When gas is generated in the second chamber 13b and the second chamber 13b expands, the exterior material is separated in the facing direction in the second chamber 13b. As a result, the first terminal 11 and the second terminal 12 are separated from each other, and the current is interrupted therebetween.

  A general adhesive can be used for joining the first terminal 11 and the second terminal 12 to the exterior material. The type of the adhesive may be arbitrary and can be appropriately selected according to the purpose. For example, a flexible adhesive mainly composed of an acrylic resin, a styrene resin, or a butadiene resin is preferable because it is excellent in followability to the exterior material and is excellent in flexibility. In addition, an isocyanate-based urethane resin is preferable because the processing time is shortened. In addition, it is preferable to use an epoxy resin or an amide resin because of excellent heat resistance. Further, it is preferable to heat-weld with polyethylene resin or polypropylene resin because it can be joined in a very short time. In this case, it is preferable to use an exterior material whose inner surface is coated with these resins because joining by heat welding can be easily performed.

  The material of the first terminal 11 is preferably a material that does not corrode in the battery 1. Specifically, as long as the first terminal 11 is connected to the negative electrode, gold, platinum, copper, carbon, stainless steel, nickel, or the like can be used. If it is the 1st terminal 11 connected with a positive electrode, aluminum etc. can be used. The second terminal 12 is not particularly limited as long as it is a conductive material, but copper, aluminum, and the like are preferable because they are highly conductive and inexpensive. In addition, it is preferable to use nickel, iron, stainless steel, or the like because a battery tab having high strength can be obtained.

  As another form of the current interruption mechanism 15, the first terminal 11 and the second terminal 12 that are electrically connected by being temporarily fixed in contact with each other may be used. The strength of the temporary fixing is set to such an extent that the temporary fixing between the first terminal 11 and the second terminal 12 is released by the expansion of the second chamber 13b. The frictional force between the first terminal 11 and the second terminal 12 can be used for temporary fixing.

  When the current interrupting mechanism has a structure in which the first terminal 11 and the second terminal 12 are electrically connected by temporary fixing, for example, as illustrated in FIG. 4, the first terminal 11 may be a bundle of a plurality of conductive wires. And the 2nd terminal 12 can be comprised. As for the 1st terminal 11 and the 2nd terminal 12, the bundle | flux of the conducting wire is unwound in each edge part, and the conducting wire of the 1st terminal 11 and the conducting wire of the 2nd terminal 12 are entangled in the part of this dissolved conducting wire Thus, it is possible to temporarily fix the two in an electrically connected state. The second chamber is configured to be able to expand in the connecting direction between the first terminal 11 and the second terminal 12, and when the second chamber expands, the second terminal 12 moves away from the first terminal 11. Be pulled. By pulling the second terminal 12, the entanglement of the conducting wire is released, and the current is interrupted between the first terminal 11 and the second terminal 12.

  Moreover, as shown in FIG. 5, even if it is a case where the 1st terminal 11 and the 2nd terminal 12 are comprised with a plate-shaped conductor, the mutually opposing surface (contact surface) of the 1st terminal 11 and the 2nd terminal 12 Can be formed on a rough surface having a large number of irregularities, such as a “file”, and both can be temporarily fixed. Since the first terminal 11 and the second terminal 12 have a large number of concavities and convexities on the opposing surfaces, the first terminal 11 and the second terminal 12 are caused by the frictional force between the opposing surfaces when they are in contact with each other. And will not slide sideways. As a result, until the second chamber expands and the first terminal 11 and the second terminal 12 are separated from each other, the contact state between them can be satisfactorily maintained. As described above, when the first terminal 11 and the second terminal 12 are configured to maintain the contact state with each other by using frictional forces due to a large number of projections and depressions, before the second chamber expands, the second chamber Is in a reduced pressure state (vacuum state), the first terminal 11 and the second terminal 12 can be more reliably brought into contact with each other.

  Moreover, when the 1st terminal 11 and the 2nd terminal 12 are plate-shaped, it is preferable to form the unevenness | corrugation which meshes with or fits into the 1st terminal 11 and the 2nd terminal 12. As a result, the frictional force between the first terminal 11 and the second terminal 12 increases, and the first terminal 11 and the second terminal 12 can be more effectively prevented from separating in normal times. As an example of the unevenness, as shown in FIG. 6, a part of the first terminal 11 and the second terminal 12 are bent into a meshing waveform, or a recess 111 that fits into each other as shown in FIG. The convex part 121 etc. are mentioned.

  When the first terminal 11 and the second terminal 12 are bent into a waveform, the number of bends of the first terminal 11 and the second terminal 12, the waveform period, the difference in height of the waveform, and the like may be arbitrary. When the concave portions 111 and the convex portions 121 are formed in the first terminal 11 and the second terminal 12, the number of the concave portions 111 / the convex portions 121, the depth of the concave portions 11, the height of the convex portions 121, the concave portions 111 / the convex portions 121 The shape and the like may be arbitrary. The concave portion 111 and the convex portion 121 may be formed on either side of the first terminal 11 and the second terminal 12 or may be mixed. Moreover, the recessed part 111 may be formed by the hole as shown in FIG. 7, and may be formed by the hollow. When the recess 111 is formed by a hole, the first terminal 11 and the second terminal 12 can be more strongly coupled. When the recess 111 is formed by a recess, processing is easy.

  As another form of temporarily fixing the first terminal 11 and the second terminal 12 in contact with each other, as shown in FIG. 8, the tip of the first terminal 11 and the tip of the second terminal 12 are folded back, It can also be set as the structure where the folded-back parts were engaged like a hook (A). When the second chamber expands, the first terminal 11 and the second terminal 12 are pulled away from each other, thereby disengaging them from each other and interrupting the current between them (B). Also in the case shown in FIG. 8, it is preferable to seal the second chamber in a reduced pressure state so that the first terminal 11 and the second terminal 12 are in close contact with each other by the atmospheric pressure received by the exterior material. Thereby, position shift with the 1st terminal 11 and the 2nd terminal 12 can be prevented.

  As shown in FIG. 9, the current interruption mechanism may have a clip 20 that temporarily fixes the first terminal 11 and the second terminal 12. The clip 20 assists the first terminal 11 and the second terminal 12 that are in contact with each other so as not to be displaced. Therefore, the clip 20 may be any clip as long as the overlapping portions of the first terminal 11 and the second terminal 12 are sandwiched so that both can be brought into contact with each other. When the clip 20 is used, it works effectively when the second chamber is configured to expand in the direction in which the terminal is pulled out. The clip 20 can also be applied when the first terminal 11 and the second terminal 12 are uneven.

  Or the electric current interruption mechanism may have the snap 30 which temporarily fixes the 1st terminal 11 and the 2nd terminal 12, as shown to FIG. 10A and 10B. The snap 30 has a male connector 31 and a female connector 32 that are fitted to each other, one of which is electrically connected to the first terminal 11 and fixed, and the other is electrically connected to the second terminal 12 and fixed. ing. From the viewpoint of electrical connection, the connector electrically connected to the first terminal 11 constitutes a part of the first terminal 11, and the connector electrically connected to the second terminal 12 is the second terminal. It can also be said that part of 12 is constituted. Therefore, even in the configuration in which the first terminal 11 and the second terminal 12 are temporarily fixed by the snap 30, the first terminal 11 and the second terminal 12 are in contact with each other in the second chamber 13b before the second chamber 13b is expanded. ing.

  The male connector 31 and the female connector 32 are fitted to each other before the second chamber 13b is expanded, and the first terminal 11 and the second terminal 12 are electrically connected. On the other hand, when the second chamber expands in the battery thickness direction, the male connector 31 and the female connector 32 are disengaged, and the current between the first terminal 11 and the second terminal 12 is interrupted.

  The snap 30 can have any structure as long as the two members can be releasably fitted. The snap 30 is also called a hook, and there are a magnet type and a spring type as a fixing method for the male connector 31 and the female connector 32. Any fixing method can be used in the present invention. The attachment structure of the snap 30 may be arbitrary, and in the form shown in FIGS. 10A and 10B, the male connector 31 and the female connector 32 are respectively provided in the exterior of the exterior body 13 at positions facing each other. The body 13 penetrates and is fixed to the exterior body 13. Further, since the electrical connection between the first terminal 11 and the second terminal 12 is made by fitting the male connector 31 and the female connector 32, the first terminal 11 and the second terminal 12 are in direct contact with each other. There is no need to be. Therefore, in the present embodiment, the second terminals 12 are arranged outside the exterior body 13 to reduce the number of parts interposed between the exterior bodies 13 in the seal portion of the exterior body 13. Thereby, the airtightness of the second chamber 13b can be maintained satisfactorily. However, the 2nd terminal 12 can also be arrange | positioned in the 2nd chamber 13b similarly to the form mentioned above.

  Further, in this embodiment, the second chamber 13b has a first portion and a portion where the snap 30 is disposed in order to easily release the fitting between the male connector 31 and the female connector 32 when the second chamber 13b expands. A buffer portion 13d is provided between the chamber 13a. The buffer chamber 13d is a portion formed by folding the exterior body 13 into a mountain fold, and is substantially flat before the second chamber 13b expands. Due to the expansion of the second chamber 13b, the buffer portion 13d starts to expand as shown in FIG. 10C, and finally, as shown in FIG. 10D, the side having the buffer portion 13d in the second chamber 13b greatly expands, and the male connector 31 And the female connector 32 are disengaged. Thus, since the second chamber 13b has the buffer portion 13d, the second chamber 13b can be expanded to a greater extent, and as a result, the current can be interrupted more reliably due to the expansion of the second chamber 13b. Can do.

  In the temporary fixing using the snap 30, the coupling force in the direction perpendicular to the fitting direction of the male connector 31 and the female connector 32 is relatively high. Therefore, the temporary fixing using the snap 30 has high resistance to vibration in the in-plane direction perpendicular to the thickness direction of the battery. In other words, it is possible to obtain a structure in which the first terminal 11 and the second terminal 12 are not easily displaced even when strong vibrations act in this direction. Note that the bonding force of the snap 30 can be assisted by the atmospheric pressure by forming the second chamber by bonding the exterior material under reduced pressure. Therefore, in this case, the fitting direction between the male connector 31 and the female connector 32, that is, the thickness direction of the battery can be highly resistant to vibration.

  A state in which the first terminal 11 and the second terminal 12 are in contact with each other by coating with a thermoplastic resin from the outside so as to cover the overlapping and contacting portions of the first terminal 11 and the second terminal 12 Can be temporarily fixed. In this case, the thermoplastic resin coated for temporary fixing, that is, the temporary fixing resin, has a melting point higher than the temperature of the battery element 10 when the battery is operating normally and is sealed in the second chamber. The temperature is preferably below the temperature at which the mixture being worked. Thereby, while the battery is operating normally, the electrical connection state between the first terminal 11 and the second terminal 12 is maintained. On the other hand, when the temperature of the battery rises to a temperature at which the mixture generates gas due to the occurrence of an abnormality, the temporary fixing resin melts and the second chamber expands, whereby the current between the first terminal 11 and the second terminal 12 is increased. Can be cut off.

  It is preferable to operate the current interruption mechanism at an early stage of safety, that is, when the temperature of the battery is sufficiently lower than the thermal runaway temperature of the active material. For this purpose, the temporary fixing resin has a melting point of less than 200 ° C. It is preferable. In order to fill the second chamber with a gas, the melting point of the temporary fixing resin is preferably equal to or lower than the melting point of the resin used as the sealing layer of the exterior material. For example, when a polypropylene resin is used as the sealing layer of the exterior material, the melting point of the temporary fixing resin is 160 ° C. or lower, preferably 150 ° C. or lower, more preferably 140 ° C. or lower, which is the melting point of the polypropylene resin. When ethylene resin is used as the sealing layer of the exterior material, the melting point of the temporary fixing resin is 120 ° C. or lower, preferably 110 ° C. or lower, more preferably 100 ° C. or lower, which is the melting point of the ethylene resin.

  On the other hand, when the stability of the battery is taken into consideration, it is not preferable that the temporary fixing resin melts at a stage where no abnormality has occurred. Accordingly, the melting point of the temporary fixing resin is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, and further preferably 80 ° C. or higher.

  As described above, the temporary fixing resin can be selected from resins having an appropriate melting point depending on the type of resin used as the sealing layer of the exterior material, the temperature at which the current interrupting mechanism is operated, and the like.

  FIG. 11 shows a specific example of the exterior body 13 configured such that the second chamber extends in the terminal direction. Hereinafter, the exterior body 13 that extends in the direction in which the first terminal and the second terminal are pulled out will be described with reference to FIG. 11 and the like. In the following description, when referring to the direction of the exterior material, the direction perpendicular to the “terminal direction” is referred to as the “width direction”.

  In the example illustrated in FIG. 11, the exterior body 13 includes a pair of main sheets 131 that are opposed to each other with a battery element (not illustrated in FIG. 11) sandwiched from above and below as a sheath material, and a pair of positions at which the second chamber is located. And a pair of side sheets 132 disposed between the main sheets 131. The pair of main sheets 131 and the pair of side sheets 132 are formed as surfaces that can be welded only on one side, and the pair of main sheets 131 are arranged with the surfaces that can be welded facing each other. The pair of side sheets 132 are folded in half with the weldable surface facing outside, and are arranged between the main sheets 131 at both ends in the width direction of the main sheet 131 at positions that become the second chambers with the folds facing each other. Is done.

  The main sheet 131 and the side sheet 132 arranged as described above are welded at a site that extends over the entire outer periphery of the main sheet 131 and a site that is a boundary between the first chamber and the second chamber. By arranging the side sheet 132, the side sheet 132 forms a side wall of the second chamber. Then, the main sheet 131 is folded in the second chamber along the width direction of the main sheet 131 so that the mountain portions 133 are formed on the front surface side and the back surface side of the exterior body 13. Thereby, the length of the second chamber in the terminal direction is shortened. By generating gas in the second chamber in this state, the second chamber can be extended in the terminal direction.

  FIG. 12 shows an example of a battery to which the exterior body shown in FIG. 11 is applied. When the exterior body shown in FIG. 11 is applied as the exterior body of the battery, the second terminal 12 is in contact with the first terminal 11 before the second chamber extends, but the second chamber 12 extends as the second chamber extends. The positional relationship with the first terminal 11 is determined so as to be away from the first terminal 11 and is fixed to the exterior body 13. Moreover, the mixture mentioned above is enclosed in the second chamber.

  As in this embodiment, by folding the exterior material so that the second chamber can extend in the terminal direction, the first terminal 11 and the second terminal 12 can be reliably blocked by the expansion of the second chamber, and after the blocking The possibility that the two come into contact again is extremely low. As a result, the safety of the battery can be further improved. Moreover, it becomes possible to arbitrarily change the extending direction of the second chamber by bending the second chamber with respect to the first chamber. For example, as shown in FIG. 13, if the second chamber is bent toward the first chamber, the increase in the occupied space of the battery due to the extension of the second chamber can be reduced. In particular, if the bending angle is 90 degrees, the second chamber can be extended in the thickness direction of the first chamber. In an actual battery, the number of stacked electrodes is large and the thickness of the battery element is thick, so that the thickness of the first chamber is extremely thick compared to the second chamber. Therefore, if the second chamber is configured to extend in the thickness direction of the first chamber, there is almost no increase in the space occupied by the battery even when the second chamber is extended, and the minimum installation space is required. A safe battery system (battery pack) that can be installed can be provided.

  11-13, the example which formed the one peak part 133 in the 2nd chamber was shown. However, a bellows structure in which a plurality of peak portions 133 are arranged in the terminal direction can also be used. Further, by forming the plurality of peak portions 133 in the second chamber, it is possible to obtain a large extension amount while reducing the height of the peak portion 133. It is preferable that the height of the mountain portion 133 can be reduced because the thickness of the second chamber in the folded state can be reduced. Further, the method of folding the exterior body 13 for extending the second chamber in the terminal direction is not limited to the method shown in FIGS. 11 to 13, for example, applying the method disclosed in Patent Document 4 described above, It can also be set as the structure which folded the exterior material in the terminal direction in the part of the 2nd chamber. Also in this case, the number of folding points may be one or more than one.

  As mentioned above, although several forms of the electric current interruption mechanism were demonstrated, it is the material which the 2nd chamber 13b by which an electric current interruption mechanism is arrange | positioned, and the mixture 14 can contain below in relation to an electric current interruption mechanism. A supplementary explanation of the redox shuttle agent and the gas generating material will be given.

(Second room)
In each form mentioned above, although the form which has the 2nd chamber 13b only in the one 1st terminal 11 side was shown, you may have another 2nd chamber 13b also in the other 1st terminal 11 side. . In this case, it is more preferable that both of the second chambers 13b include the current interrupting mechanism 15 because the safety devices are provided on both the positive electrode side and the negative electrode side.

  In the case where the pair of first terminals 11 are drawn from the same side of the battery element 10, a current interruption mechanism can be provided to both the positive electrode side and the negative electrode side in one second chamber. This is preferable in terms of improving safety. Further, since the pair of first terminals 11 are arranged in the same second chamber, the auxiliary terminal 16 is not necessary. Furthermore, since the number of the second chambers may be one, when the second chamber structure that extends in the terminal direction at the time of expansion is adopted, the increase in the occupied space of the battery after the second chamber is expanded is two second chambers. Less than a room. Therefore, a safe battery system (battery pack) that can be installed in a smaller installation space can be provided.

(Redox shuttle agent)
As the redox shuttle agent, a compound that can be uniformly dissolved or dispersed in the non-aqueous electrolyte and has an oxidation potential higher than the maximum (SOC 100%) potential normally used for the positive electrode active material is used. it can.
However, the redox shuttle agent is preferably selected as appropriate according to the maximum potential used by the positive electrode active material. The oxidation potential of the redox shuttle agent is preferably 0.1 to 2 V higher than the maximum potential of the positive electrode, and more preferably 0.2 to 1 V higher. When the oxidation potential of the redox shuttle agent is within the above range, the reaction of the redox shuttle agent can be suppressed when the secondary battery is operated at a normal voltage, and the redox shuttle agent can be quickly reduced in the event of an abnormality such as overcharge. The shuttle agent reacts to stop the operation of the secondary battery.

  Examples of the compound that can be used as the redox shuttle agent include aromatic compounds, heterocyclic complexes, metallocene complexes such as ferrocene, Ce compounds, and radical compounds. Moreover, a redox shuttle agent can be used individually by 1 type, or can also be used in combination of 2 or more type.

  Specific examples of the compound include 3,4-difluoroanisole, 2,4-difluoroanisole, 1-methoxy-2,3,4,5,6-pentafluorobenzene, 2,3,5,6-tetra Fluoroanisole, 4- (trifluoromethoxy) anisole, 3,4-dimethoxybenzonitrile, 1,2,3,4-tetrachloro-5,6-dimethoxybenzene, 1,2,4,5-tetrachloro-3 , 6-Dimethoxybenzene 4-fluoro-1,2-dimethoxybenzene, 4-bromo-1,2-dimethoxybenzene, 2-bromo-1,4-dimethylbenzene, 1-bromo-3-fluoro-4-methoxybenzene 2-bromo-1,3-difluoro-5-methoxybenzene, 4,5-difluoro-1,2-dimethoxybenzene, 2,5-difluoro -1,4-dimethoxybenzene, 1,2,3,4-tetrachloro-5,5-dimethoxycyclopentadiene, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, 2,5 -Di-tert-butyl-1,4-dimethoxybenzene, 4-tert-butyl-1,2-dimethoxybenzene, 1,4-ditetrabutyl-2,5-trifluoromethoxybenzene, 1,2-ditetrabutyl-4, A monocyclic compound having one or more electron-withdrawing or electron-donating substituents such as 5-trifluoromethoxybenzene; 4-chloro-1,2-methylenedioxybenzene, 4-bromo-1, 2-methylenedioxybenzene, 3,4-methylenedioxybenzonitrile, 4-nitro-1,2-methylenedioxybenzene, 2-chloro-5 A heterocyclic compound such as methoxypyrazine; a radical compound such as a nitroxyl radical compound; a cerium compound such as cerium nitrate; a metallocene complex such as ferrocene complex; .

  The redox shuttle agent is a compound that can be uniformly dissolved or dispersed in the nonaqueous electrolyte, and can be appropriately selected according to the required maximum potential of the positive electrode. Each of these compounds has a reaction potential corresponding to the compound, and the oxidation reaction rate greatly increases when the potential becomes higher than that potential. For example, 2,5-di-tert-butyl-1,4-dimethoxybenzene has a reaction potential of about 3.9V, and 4-bromo-1,2-dimethoxybenzene has a reaction potential of about 4.3V.

  When charging at a constant current, the voltage between the positive and negative electrodes of the battery 1 becomes high voltage, and the redox shuttle agent reacts when the redox shuttle agent in the second chamber 13b is exposed to a potential higher than the reaction potential. Then, a redox reaction is repeated with the negative electrode. Heat is generated according to the reaction amount, and the temperature in the second chamber 13b is raised.

  In addition, aromatic compounds having one or more alkoxy groups (methoxybenzenes and dimethoxybenzenes) have excellent chemical stability of the oxidant produced by the oxidation reaction, resulting in a decrease in battery performance due to side reactions and the like. It can be suppressed. A compound having a halogen atom has a high redox reaction potential and can be applied to a positive electrode having a higher redox potential, that is, a secondary battery having a higher energy density.

(Gas generating material)
A volatile material can be used as the gas generating material enclosed in the second chamber. As the temperature in the second chamber rises due to the action of the redox shuttle agent, the volatile material previously placed in the second chamber expands in the second chamber. Volatile materials remain in the second chamber until abnormal heat generation occurs in the battery. For this reason, even if it is a material which affects the battery characteristic of the battery in a 1st chamber, it can be used without worrying about the bad influence on a battery characteristic.

  An example of the solid volatile material is an adsorbent that has adsorbed a gas. For example, if silica gel or zeolite adsorbed with moisture is used, the adsorbent releases gas such as moisture with heat, and the second chamber can be expanded. Metal hydrates can also be used as the gas generating material. For example, when aluminum hydroxide is heated, moisture is released. These materials cannot be put in the first chamber because moisture moves to the electrolyte even in the operating temperature range of the battery, resulting in destruction of the lithium ion battery such as electrolysis. However, by providing the second chamber separately from the first chamber, these materials can be placed in the second chamber. Therefore, by putting these materials in the second chamber, it is possible to cut off the current while maintaining the temperature rise due to the occurrence of abnormality without affecting the characteristics of the battery.

  It is also possible to use a liquid as the gas generating material. If at least one solvent constituting the liquid is volatilized, gas can be generated. It is preferable to operate the current interruption mechanism at an early stage of safety, that is, when the temperature of the battery is sufficiently lower than the thermal runaway temperature of the active material, and for this purpose, the volatilization temperature of the solvent should be less than 200 ° C. preferable. In order to fill the second chamber with gas, the volatilization temperature of the solvent is preferably not higher than the melting point of the resin used as the sealing layer of the exterior material. For example, when a polypropylene resin is used as the sealing layer of the exterior material, the volatilization temperature of the solvent is 160 ° C. or lower, preferably 150 ° C. or lower, more preferably 140 ° C. or lower, which is the melting point of the polypropylene resin. When ethylene resin is used as the sealing layer of the exterior material, the volatilization temperature of the solvent is 120 ° C. or lower, preferably 110 ° C. or lower, more preferably 100 ° C. or lower, which is the melting point of the ethylene resin.

  On the other hand, when considering the stability of the battery, it is not preferable that the solvent volatilizes at a stage where no abnormality has occurred. Accordingly, the volatilization temperature of the solvent is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, and further preferably 80 ° C. or higher.

  Specifically, water can be used as the solvent. Of the water, pure water is particularly preferable. The pure water does not generate gas due to electrolysis even when the first terminal on the positive electrode side and the negative electrode side exists in the second chamber.

  Moreover, it is also possible to use a non-aqueous solvent, for example, the electrolyte component mentioned later as a solvent. By using the electrolyte component, even if the seal section separating the first chamber and the second chamber is damaged and liquid leaks from the second chamber to the first chamber, the first chamber should be kept in a non-aqueous state. Can do. Moreover, if the liquid in the second chamber has the same configuration as the electrolyte in the first chamber, the function of the battery can be maintained even if the liquid in the second chamber leaks into the first chamber.

  Examples of such non-aqueous solvents include diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, and the like. Moreover, since the gas for operating the current interruption mechanism is preferably a nonflammable or flame retardant gas, a gas containing fluorine or phosphorus atoms is preferable. For example, fluorinated esters such as methylfluoroethyl carbonate, fluorinated ethers such as fluorinated carbonates, tetrafluoroethyl tetrafluoropropyl ether, decafluoropropyl ether, and octafluorobenzyl tetrafluoroethyl ether, and phosphate esters Can be mentioned.

[Additional battery configuration]
Next, the structure which can be added in order to improve the safety | security of a battery in the battery of this invention is demonstrated.

  As shown in FIG. 14, when there is only one first terminal 11 disposed in the second chamber 13b and the auxiliary terminal 16 is disposed in the second chamber 13b, It is preferable to further include an element 40 having a non-linear current-voltage characteristic (IV characteristic) connected in series between the other first terminal 11 and the auxiliary terminal 16 that are not arranged.

  As such an element 40, for example, an arbitrary element having a non-linear IV characteristic such as a diode, a Zener diode, or a varistor can be used. Further, the number of elements 40 may be arbitrary, may be one, or may be plural as necessary.

  Thus, by providing the element 40 having the non-linear IV characteristic, the redox shuttle agent redox reaction can be generated at a voltage different from the reaction potential of the redox shuttle agent. For example, even when a redox shuttle agent having a reaction potential of 3.8 V is used, the redox shuttle agent can be made to function at a relatively high voltage, for example, 4.3 V or higher. Means. Thereby, it becomes possible to deal with batteries having various driving voltages, and the degree of freedom in selecting a material for the redox shuttle agent is increased. Furthermore, since a redox shuttle agent having a high oxidation-reduction potential tends to deteriorate, the ability to use a redox shuttle agent having a low oxidation-reduction potential is advantageous in terms of extending the life of the current interrupt mechanism 15.

  The characteristics of the element 40 to be used can be determined according to the target operating voltage and the magnitude of the current flowing through the circuit. For example, one of the important characteristics of the element 40 is that it can operate at an assumed charging current. The element 40 preferably has high non-linearity, that is, the current is sufficiently small below a certain voltage (threshold voltage) at which IV characteristics change, and the current is sufficiently high above the threshold voltage. When a single element 40 cannot obtain a sufficient current above the threshold voltage at which IV characteristics change, a circuit in which a plurality of elements 40 are connected in parallel can be configured to increase the maximum current. Considering that the element 40 is connected between the positive and negative electrodes, it is preferable to select an element that operates at an appropriate threshold voltage (usually about 1.5 V or less) according to the design. If necessary, a plurality of elements 21 can be connected in series to increase the threshold voltage. In order to reduce the leakage current during normal operation, the element 40 is required to have a small leakage current below the threshold voltage.

  The present invention has been described with reference to typical embodiments. Although this invention is not limited to the form mentioned above, Preferably it can apply to a lithium ion secondary battery.

  There are various types of secondary batteries such as a cylindrical type, a flat wound rectangular type, a laminated rectangular type, a coin type, a flat wound laminated type, and a laminated laminated type, depending on the structure and shape of the electrode. The present invention is applicable to any of these types. Among these, the shape of the secondary battery to which the present invention is applied is preferably a laminated laminate type from the viewpoint that the separator is not easily broken. Hereinafter, a laminated laminate type secondary battery will be described.

  A laminated laminate type secondary battery includes a battery element and an outer package in which the battery element is sealed. As shown in FIG. 15, the battery element can have a configuration in which a plurality of negative electrodes a and a plurality of positive electrodes c are alternately stacked with separators b interposed therebetween. The electrolytic solution is sealed in the exterior body together with the negative electrode a, the positive electrode c, and the separator b. The negative electrode a has an extension (also called a tab) protruding from the separator b. The extension portion is an end portion of the negative electrode current collector d included in the negative electrode a that is not covered with the positive electrode active material. Similarly, in the positive electrode c, an extension portion (tab) that is an end portion of the positive electrode current collector e of the positive electrode c that is not covered with the positive electrode active material protrudes from the separator b. The extension part of the positive electrode c and the extension part of the negative electrode a are formed at positions that do not interfere with each other when the positive electrode c and the negative electrode a are laminated. The extensions of all negative electrodes a are collected together and connected to the negative terminal g by welding. The negative terminal g may be the other of the first terminals 11 described above, or the other of the first terminals 11 may be connected to the negative terminal g. Similarly, all the positive electrode c extensions are gathered together and connected to the positive electrode terminal f by welding. The positive terminal f may be one of the first terminals 11 described above, or one of the first terminals 11 may be electrically connected to the positive terminal f.

  Hereinafter, each of these elements will be described in detail by taking a lithium ion secondary battery as an example.

<Separator>
As separators, webs and sheets made of organic materials, for example, woven fabrics such as cellulose, non-woven fabrics, polyolefins such as polyethylene and polypropylene, polyimides, porous polymer membranes such as porous polyvinylidene fluoride membranes, or ion conductive polymers An electrolyte membrane or the like can be used. These can be used alone or in combination.

Moreover, the separator which consists of inorganic materials, such as a ceramic and glass, can also be used as a separator. As an inorganic separator, a nonwoven fabric separator made of ceramic short fibers such as alumina, alumina-silica, potassium titanate, or a base material made of a woven fabric, a nonwoven fabric, paper, or a porous film, a heat-resistant nitrogen-containing aromatic polymer, and A separator comprising a layer containing ceramic powder, or a heat resistant layer is provided on a part of the surface, and this heat resistant layer is a porous thin film layer containing ceramic powder, a porous thin film layer of a heat resistant resin, or Porous thin film layer separator made of a composite of ceramic powder and heat-resistant resin, or porous made by binding secondary particles formed by sintering or dissolving and recrystallizing a part of primary particles of a ceramic material by a binder A separator provided with a membrane layer or a base material layer made of a polyolefin porous membrane, and formed on one or both sides of the base material layer The heat-resistant insulating layer includes a separator containing oxidation-resistant ceramic particles and a heat-resistant resin, or a porous film formed by combining a ceramic substance and a binder, Silica (SiO ₂ ), alumina (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), nitride of silicon (Si), hydroxide of aluminum (Al), zirconium (Zr ) Alkoxide, a separator using a titanium (Ti) ketone compound, or a polymer substrate, and Al ₂ O ₃ , MgO, TiO ₂ , Al (OH) ₃ , Mg ( Examples thereof include a separator including a ceramic-containing coating layer of OH) ₂ and Ti (OH) ₄ .

<Negative electrode>
The negative electrode has a negative electrode current collector formed of a metal foil, and a negative electrode active material coated on both surfaces of the negative electrode current collector. The negative electrode active material is bound so as to cover the negative electrode current collector with a negative electrode binder. The negative electrode current collector is formed to have an extension connected to the negative electrode terminal, and the negative electrode active material is not applied to the extension.

  The negative electrode active material in the present embodiment is not particularly limited. For example, a carbon material that can occlude and release lithium ions, a metal that can be alloyed with lithium, a metal oxide that can occlude and release lithium ions, and the like. Is mentioned.

  Examples of the carbon material include carbon, amorphous carbon, diamond-like carbon, carbon nanotube, or a composite thereof. Here, carbon with high crystallinity has high electrical conductivity, and is excellent in adhesiveness and voltage flatness with a negative electrode current collector made of a metal such as copper. On the other hand, since amorphous carbon having low crystallinity has a relatively small volume expansion, it has a high effect of relaxing the volume expansion of the entire negative electrode, and deterioration due to non-uniformity such as crystal grain boundaries and defects hardly occurs.

  Examples of the metal include Al, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, Zn, La, or alloys of two or more thereof. Moreover, you may use these metals or alloys in mixture of 2 or more types. These metals or alloys may contain one or more non-metallic elements.

  Examples of the metal oxide include silicon oxide, aluminum oxide, tin oxide, indium oxide, zinc oxide, lithium oxide, and composites thereof. The negative electrode active material preferably contains tin oxide or silicon oxide, and more preferably contains silicon oxide. This is because silicon oxide is relatively stable and hardly causes a reaction with other compounds. Moreover, it is preferable that the whole or one part has an amorphous structure. An amorphous structure is considered to have relatively few elements due to non-uniformity such as grain boundaries and defects. It can be confirmed by X-ray diffraction measurement (general XRD measurement) that all or part of the metal oxide has an amorphous structure. Specifically, when the metal oxide does not have an amorphous structure, a peak specific to the metal oxide is observed. However, the metal oxide may have a case where all or part of the metal oxide has an amorphous structure. Inherent peaks are broad and observed.

  In addition, a carbon material, a metal, and a metal oxide can be mixed and used independently. For example, the same kind of materials such as graphite and amorphous carbon may be mixed, or different kinds of materials such as graphite and silicon may be mixed.

  As the binder for the negative electrode, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene-butadiene copolymer rubber, polytetrafluoroethylene, polypropylene, polyethylene, Polyimide, polyamideimide, or the like can be used. The amount of the binder for the negative electrode used is 0.5 to 25 parts by mass with respect to 100 parts by mass of the negative electrode active material from the viewpoints of “sufficient binding force” and “higher energy” which are in a trade-off relationship. Is preferred.

  As the negative electrode current collector, aluminum, nickel, stainless steel, chromium, copper, silver, and alloys thereof are preferable from the viewpoint of electrochemical stability. Examples of the shape include foil, flat plate, and mesh.

<Positive electrode>
The positive electrode has a positive electrode current collector formed of a metal foil, and a positive electrode active material coated on both surfaces of the positive electrode current collector. The positive electrode active material is bound so as to cover the positive electrode current collector with a positive electrode binder. The positive electrode current collector is formed to have an extension connected to the positive electrode terminal, and the positive electrode active material is not applied to the extension.

The positive electrode active material has a layered structure such as LiMnO ₂ , LixMn ₂ O ₄ (0 <x <2), Li ₂ MnO ₃ , Li _x Mn _1.5 Ni _0.5 O ₄ (0 <x <2). Lithium manganate or lithium manganate having a spinel structure, LiCoO ₂ , LiNiO ₂ or a part of these transition metals replaced with other metals, LiNi _1/3 Co _1/3 Mn _1/3 O _2, etc. Lithium transition metal oxides whose specific transition metals are less than half, those in which these lithium transition metal oxides have an excess of Li over the stoichiometric composition, those having an olivine structure such as LiFePO ₄ , etc. It is done. Further, these metal oxides were partially substituted with Al, Fe, P, Ti, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, Zn, La, etc. Materials can also be used. In _{particular, Li α Ni β Co γ Al} δ O 2 (1 ≦ α ≦ 2, β + γ + δ = 1, β ≧ 0.7, γ ≦ 0.2) or _{Li α Ni β Co γ Mn δ} O 2 (1 ≦ α ≦ 1.2, β + γ + δ = 1, β ≧ 0.6, γ ≦ 0.2). A positive electrode active material can be used individually by 1 type or in combination of 2 or more types.

  A radical material or the like can also be used as the positive electrode active material.

  As the positive electrode binder, the same binder as the negative electrode binder can be used. The amount of the binder for the positive electrode to be used is preferably 2 to 15 parts by mass with respect to 100 parts by mass of the positive electrode active material from the viewpoints of “sufficient binding force” and “high energy” in a trade-off relationship. .

  As the positive electrode current collector 24, the same one as the negative electrode current collector can be used.

  A conductive auxiliary material may be added to the coating layer of the positive electrode active material for the purpose of reducing impedance. Examples of the conductive auxiliary material include carbonaceous fine particles such as graphite, carbon black, and acetylene black.

  As the positive electrode current collector, for example, aluminum, nickel, silver, or an alloy thereof can be used. Examples of the shape of the positive electrode current collector include a foil, a flat plate, and a mesh. As the positive electrode current collector, an aluminum foil can be suitably used.

<Electrolyte>
As the electrolytic solution used in the present embodiment, a nonaqueous electrolytic solution containing a lithium salt (supporting salt) and a nonaqueous solvent that dissolves the supporting salt can be used.

  As the non-aqueous solvent, an aprotic organic solvent such as a carbonic acid ester (chain or cyclic carbonate), a carboxylic acid ester (chain or cyclic carboxylic acid ester), or a phosphoric acid ester can be used.

  Examples of carbonate solvents include cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), and vinylene carbonate (VC); dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate. (EMC), chain carbonates such as dipropyl carbonate (DPC); and propylene carbonate derivatives.

  Examples of the carboxylic acid ester solvent include aliphatic carboxylic acid esters such as methyl formate, methyl acetate, and ethyl propionate; and lactones such as γ-butyrolactone.

  Among these, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (MEC), dipropyl carbonate Carbonic acid esters (cyclic or chain carbonates) such as (DPC) are preferred.

  Examples of the phosphate ester include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, trioctyl phosphate, and triphenyl phosphate.

  Other solvents that can be contained in the non-aqueous electrolyte include, for example, ethylene sulfite (ES), propane sultone (PS), butane sultone (BS), dioxathilane-2,2-dioxide (DD), and sulfolene. 3-methylsulfolene, sulfolane (SL), succinic anhydride (SUCAH), propionic anhydride, acetic anhydride, maleic anhydride, diallyl carbonate (DAC), dimethyl 2,5-dioxahexanoate, 2,5 -Dioxahexaneniate dimethyl, furan, 2,5-dimethylfuran, diphenyl disulfide (DPS), dimethoxyethane (DME), dimethoxymethane (DMM), diethoxyethane (DEE), ethoxymethoxyethane, chloroethylene carbonate , Dimethyl ether, methyl ether Ether, methyl propyl ether, ethyl propyl ether, dipropyl ether, methyl butyl ether, diethyl ether, phenyl methyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), tetrahydropyran (THP), 1,4-dioxane (DIOX), 1,3-dioxolane (DOL), methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl difluoroacetate, methyl propionate, ethyl propionate, propyl propionate, methyl formate , Ethyl formate, ethyl butyrate, isopropyl butyrate, methyl isobutyrate, methyl cyanoacetate, vinyl acetate, diphenyl Disulfide, dimethyl sulfide, diethyl sulfide, adiponitrile, valeronitrile, glutaronitrile, malononitrile, succinonitrile, pimonitrile, suberonitrile, isobutyronitrile, biphenyl, thiophene, methyl ethyl ketone, fluorobenzene, hexafluorobenzene, carbonate electrolyte, glyme , Ether, acetonitrile, propiononitrile, γ-butyrolactone, γ-valerolactone, dimethyl sulfoxide (DMSO) ionic liquid, phosphazene, methyl formate, methyl acetate, ethyl propionate and other aliphatic carboxylic acid esters, or these compounds In which a part of the hydrogen atoms are substituted with fluorine atoms.

As the supporting salt in the present embodiment, LiPF ₆ , LiAsF ₆ , LiAlCl ₄ , LiClO ₄ , LiBF ₄ , LiSbF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiN ( CF ₃ SO _{2) 2} normal lithium salt which can be used in lithium ion batteries or the like can be used. The supporting salt can be used alone or in combination of two or more.

  A non-aqueous solvent can be used individually by 1 type or in combination of 2 or more types.

<Exterior body>
The exterior body can be appropriately selected as long as it is stable to the electrolytic solution and has a sufficient water vapor barrier property. For example, in the case of a laminated laminate type secondary battery, it is preferable to use a laminate film of aluminum and resin as the outer package. An exterior body may be comprised with a single member and may be comprised combining several members.

  The battery element of the present invention is not limited to the battery element of the above lithium ion secondary battery, and the present invention can be applied to any battery. However, since the problem of heat dissipation often becomes a problem in a battery with an increased capacity, the present invention is preferably applied to a battery with an increased capacity, particularly a lithium ion secondary battery.

As described above, the battery 1 according to the embodiment of the present invention is
A battery element 10;
A first chamber 13a for sealing the battery element 10;
One or two second chambers 13b having an interior isolated from the interior of the first chamber 13a;
A pair of first terminals 11 connected to the battery element 10, wherein at least one of the pair of first terminals 11 is disposed with the tip portion positioned in the second chamber 13b;
A second terminal 12 having a distal end located in the second chamber 13b and in contact with the first terminal 11 in the second chamber 13b and disposed across the inside and the outside of the second chamber 13b;
A mixture 14 sealed in the second chamber 13b and generating a gas when the potential difference between the pair of first terminals 11 is a predetermined value or more;
Have

  In the battery 1, the mixture 14 includes a redox shuttle agent that generates heat when the potential difference between the pair of first terminals 11 is equal to or higher than the predetermined value, and a gas generating material that generates gas at a predetermined temperature or higher. be able to. Further, the battery 1 is preferably configured such that the second chamber 13b is expanded by the generated gas, whereby the first terminal 11 and the second terminal 12 are separated from each other.

  Below, one form of the manufacturing method of the battery of this invention is demonstrated.

One form of battery manufacturing method is:
A battery element 10 to which a pair of first terminals 11 are connected, a first chamber 13a for sealing the battery element 10, and one or two second chambers 13b having an interior isolated from the interior of the first chamber 13a. A method for producing a battery having
A step of disposing the second terminal 12 so as to be in contact with the tip of at least one of the pair of first terminals 11;
The first terminal 11 includes a portion where the first terminal 11 and the second terminal 12 are arranged so as to be in contact with each other, and a mixture that generates gas when the potential difference between the pair of first terminals 11 exceeds a predetermined value. And in a state where the second terminal 12 is in contact with the second terminal 13,
Have

  In the above manufacturing method, it is preferable that the step of enclosing the portion where the first terminal 11 and the second terminal 12 are in contact with each other and the mixture 14 in the second chamber 13b is performed in a reduced-pressure atmosphere. Moreover, it is preferable that the process of arrange | positioning the 2nd terminal 12 temporarily fixes the 1st terminal 11 and the 2nd terminal 12 in the state which mutually contacted.

  The battery according to the invention can be used, for example, in all industrial fields that require a power source, as well as in industrial fields related to the transport, storage and supply of electrical energy. Specifically, power supplies for mobile devices such as mobile phones and notebook computers; power supplies for transportation and transportation media such as trains, satellites, and submarines, including electric vehicles such as electric cars, hybrid cars, electric bikes, and electric assist bicycles A backup power source such as a UPS; a power storage facility for storing power generated by solar power generation, wind power generation, etc .;

  As an example of the various devices and the power storage facility, FIGS. 16 and 17 show an electric vehicle 200 and a power storage facility 300, respectively. Electric vehicle 200 and power storage facility 300 have assembled batteries 210 and 310, respectively. The assembled batteries 210 and 310 are configured such that a plurality of the above-described batteries 1 are connected in series and in parallel to satisfy required capacity and voltage.

DESCRIPTION OF SYMBOLS 1 Battery 10 Battery element 11 1st terminal 12 2nd terminal 13 Exterior body 13a 1st chamber 13b 2nd chamber 14 Mixture 15 Current interruption mechanism 16 Auxiliary terminal 20 Clip 30 Snap 31 Male connector 32 Female connector 40 (Non-linear current voltage characteristic 111) Concave part 121 Convex part 131 Main sheet 132 Side sheet 133 Mountain part 200 Electric vehicle 210, 310 Battery pack 300 Power storage equipment

Claims (15)

A battery element;
A first chamber for sealing the battery element;
One or two second chambers having an interior isolated from the interior of the first chamber;
A pair of first terminals connected to the battery element, wherein at least one of the pair of first terminals is disposed with a tip portion positioned in the second chamber;
A second terminal having a distal end portion located in the second chamber, the first terminal located in the second chamber and the second terminal disposed in contact with the second chamber and extending between the inside and the outside of the second chamber; ,
A mixture that is sealed in the second chamber and generates a gas when a potential difference between the pair of first terminals is equal to or greater than a predetermined value;
Having a battery.   2. The mixture according to claim 1, wherein the mixture includes a redox shuttle agent that generates heat when a potential difference between the pair of first terminals is equal to or higher than the predetermined value, and a gas generating material that generates gas at a predetermined temperature or higher. battery.   3. The battery according to claim 1, wherein the second chamber is expanded by the generated gas, whereby the first terminal and the second terminal are separated from each other.   Only one of the pair of first terminals is disposed in the second chamber, and an auxiliary terminal connected to the other first terminal is further disposed in the second chamber. The battery according to any one of 1 to 3.   The battery according to claim 4, wherein elements having non-linear current-voltage characteristics are connected in series between the auxiliary terminal and the other first terminal.   The battery according to claim 5, wherein the element is a diode.   The battery according to claim 1, wherein the first terminal and the second terminal are temporarily fixed in contact with each other.   The battery according to any one of claims 1 to 7, wherein the gas generating material includes a volatile material.   The battery according to claim 8, wherein the volatile material is a solvent.   The battery according to claim 9, wherein the solvent is a non-aqueous solvent.   The electric vehicle which has a battery as described in any one of Claims 1-10.   The electrical storage equipment which has a battery as described in any one of Claim 1 to 10. A battery element having a battery element to which a pair of first terminals are connected, a first chamber for sealing the battery element, and one or two second chambers having an interior isolated from the interior of the first chamber. A manufacturing method comprising:
Arranging at least one first terminal of the pair of first terminals such that the second terminal can be brought into contact with the tip;
A portion where the first terminal and the second terminal are arranged so as to be in contact with each other, and a mixture that generates gas when a potential difference between the pair of first terminals is equal to or greater than a predetermined value. And in a state of contacting the second terminal with the second terminal,
The manufacturing method of the battery which has this.   The method of manufacturing a battery according to claim 13, wherein the step of enclosing the portion where the first terminal and the second terminal are in contact with each other and the mixture in the second chamber is performed in a reduced pressure atmosphere.   The method of manufacturing a battery according to claim 13 or 14, wherein the step of arranging the second terminal includes temporarily fixing the first terminal and the second terminal in contact with each other.

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