JP2007220372A - Battery, battery system, packed battery and vehicle using the same batteries - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery capable of lowering a parasitic inductance. <P>SOLUTION: In a power generator element 10 laminating many bipolar electrodes, positive electrodes are formed on one side of a current collector; negative electrodes are formed on the other side; and many electrolyte layers alternately has a positive electrode side terminal electrode connected with a positive electrode side current collector electrode 11, and a negative electrode side terminal electrode connected with a negative electrode side current collector electrode 12. The current flows in the opposite direction at the positive electrode side current collector electrode 11, and the negative electrode side current collector electrode 12. Such an opposite direction current flowing through the positive electrode side current collector electrode 11 and the negative electrode side current collector electrode 12 cancels magnetic fields, thereby making it possible to lower the inductance when a battery itself is seen as a current path through which a current is flowing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bipolar battery, a battery system, an assembled battery, and a vehicle equipped with these batteries.

In addition to batteries, electric vehicles and hybrid vehicles are equipped with inverters in order to adjust the necessary voltage and current amount (see, for example, Patent Document 1 below).
Japanese Patent Laying-Open No. 2005-057928

  By the way, in the case of a vehicle such as an electric vehicle or a hybrid vehicle, a battery with a large output is mounted, so that the battery itself becomes large, and the current path to a control circuit such as an inverter tends to be long due to the influence. For this reason, it has been found that the inductance of the entire current path including the battery is large and causes energy loss.

  Accordingly, an object of the present invention is to provide a battery that can reduce the energy loss by reducing the inductance in the current path of the battery to which the load is connected, and a battery system using such a battery, And providing a battery pack. Moreover, this invention is providing the electric vehicle which applied the battery, battery system, and assembled battery with few these energy losses.

  In order to achieve the above object, the present invention provides a power generation element in which a plurality of unit cells configured by interposing an electrolyte layer between a positive electrode and a negative electrode, and a current collector electrically connected to a termination electrode of the power generation element A battery comprising: a structure; and a reverse current path disposed so that a current flows in a direction opposite to a direction of a current flowing through the current collecting structure.

Moreover, this invention for achieving the said objective has the said battery and the alternating current load connected with the said battery, The length T of the total electric current path between the said battery and the said alternating current load, the said 1st The relationship between the distance D between the current collector structure and the second current collector structure, the frequency f of the AC load, the maximum AC current Imax of the AC load, and the maximum input voltage Vin of the load is as follows (1 ) Formula T × D × f × I × π × μ ₀ <Vin / 4 (1)
A battery system characterized by satisfying

Moreover, this invention for achieving the said objective has the said battery and the alternating current load connected with the said battery, and is the distance D between the said 1st current collection structure and the said 2nd current collection structure. The relationship between the frequency f of the AC load, the maximum AC current Imax of the AC load, and the maximum operating voltage V of the load is expressed by the following equation (2): D × f × Imax × π <V / (4 × 10 ⁻⁶ (2)
A battery system characterized by satisfying

  In order to achieve the above object, the present invention is an assembled battery in which a plurality of the batteries are electrically connected.

Moreover, this invention for achieving the said objective has the said assembled battery and the alternating current load connected with the said assembled battery, The length L of the total electric current path between the said assembled battery and the said alternating current load, Sum Ds of distances D between the first current collecting structure and the second current collecting structure of each battery constituting the assembled battery, frequency f of AC load, maximum AC current Imax of AC load And the maximum input voltage Vin of the load is expressed by the following equation (3): L × Ds × f × Imax × π × μ ₀ <Vin / 4 (3)
A battery system characterized by satisfying

Moreover, this invention for achieving the said objective has the said 1st current collection structure of each said battery which has the said assembled battery and the alternating current load connected with the said assembled battery, and comprises the said assembled battery, The relationship between the sum Ds of the distances D between the second current collecting structures, the frequency f of the AC load, the maximum AC current Imax of the AC load, and the maximum operating voltage V of the load is expressed by the following equation (4) Ds × f × Imax × π <V / (4 × 10 ⁻⁶ ) (4)
A battery system characterized by satisfying

  Furthermore, the present invention for achieving the above object is a vehicle on which any one of the battery, the assembled battery, and the battery system is mounted.

  According to the present invention, since the reverse current path for flowing the current in the direction opposite to the current flowing in the current collecting structure connected to the power generation element is provided, the electromagnetic induction caused by the current flowing in the current collecting structure is reversed. The magnetic field can be canceled by the reverse current flowing through the path, thereby reducing the parasitic inductance of the battery.

  Hereinafter, embodiments of a bipolar battery, an assembled battery, and a vehicle equipped with such a battery according to the present invention will be described in detail with reference to the drawings. In the drawings referred to in the following embodiments, the thickness and shape of each layer constituting a bipolar battery are exaggerated, but this is done to facilitate understanding of the contents of the invention. Yes, it is not consistent with the thickness and shape of each layer of an actual bipolar battery.

(Embodiment 1)
FIG. 1 is a schematic perspective view for explaining an internal configuration of a bipolar battery according to Embodiment 1 to which the present invention is applied. FIG. 2 is a cross-sectional view for explaining the overall configuration of the bipolar battery, and FIG. 3 is a side view seen from the direction of arrow a in FIG.

  First, referring to FIG. 1, the internal configuration of the bipolar battery 1 includes a positive current collecting electrode 11 (first current collecting electrode) and a negative current collecting electrode 12 (second current collecting electrode) for taking out electric power. Is connected to the terminal electrode of the power generation element 10. The positive electrode side collecting electrode 11 and the negative electrode side collecting electrode 12 are provided in parallel to each other. The positive current collecting electrode 11 and the negative current collecting electrode 12 serve as a current collecting structure or a reverse current path in the present invention. That is, if the positive current collecting electrode 11 is regarded as a current collecting structure, the negative current collecting electrode 12 becomes a reverse current path, and conversely if the positive current collecting electrode 11 is regarded as a reverse current path, the negative current collecting electrode 12 is It becomes a current collecting structure.

  The positive current collecting electrode 11 and the negative current collecting electrode 12 have the same size. The positive electrode side collecting electrode 11 and the negative electrode side collecting electrode 12 are preferably formed of a metal plate such as a stainless plate, a copper plate, or an aluminum plate.

  A positive electrode tab 110 and a negative electrode tab 120 are connected to the positive electrode side collecting electrode 11 and the negative electrode side collecting electrode 12. The positive electrode tab 110 and the negative electrode tab 120 are connected to bus bars, lead wires, and the like for electrically connecting an alternating current load (described later in detail) and the bipolar battery 1.

  Both the positive electrode tab 110 and the negative electrode tab 120 are provided so as to protrude from one side of the bipolar battery 1. As a result, when a load is connected to the bipolar battery 1, current flows through the positive current collecting electrode 11 and the negative current collecting electrode 12 in opposite directions.

  The positive electrode tab 110 and the negative electrode tab 120 may be formed from the same member as the positive electrode side collecting electrode 11 and the negative electrode side collecting electrode 12, or may be formed by integrating different members. When it is set as a separate member, for example, a metal plate such as a stainless steel plate, a copper plate, or an aluminum plate is connected to the positive current collecting electrode 11 and the negative current collecting electrode 12. For this connection, for example, ultrasonic bonding, welding, soldering, or the like is used.

  As shown in FIG. 2, the power generation element 10, the positive current collecting electrode 11, the negative current collecting electrode 12, and the like of the bipolar battery 1 are housed in a case 30.

  The case 30 is made of metal and is a separated type composed of an upper side 31 and a lower side 32. For example, the upper side 31 and the lower side 32 of the case 30 are joined together by screwing (not shown) at a position where they do not come into contact with the power generation element 10 and are entirely sealed. The screw to be used is preferably an insulating screw, but is not limited thereto. In addition, other than screwing, the upper side 31 and the lower side 32 may be bonded with an adhesive, or ultrasonic bonding, welding, soldering, caulking, or the like may be used.

  An insulating material 33 is provided inside the case 30. The insulating material 33 is in contact with the positive current collecting electrode 11 and the negative current collecting electrode 12.

  By this insulating material 33, the insulation between the case 30 (made of metal) and the positive current collecting electrode 11 and the negative current collecting electrode 12 is maintained. The withstand voltage of the insulating material 33 is preferably 1.5 times or more the operating voltage of the load (device) connected to the bipolar battery 1. Such a breakdown voltage is sufficient as a secondary battery for a vehicle, for example. Needless to say, the upper limit of the withstand voltage is not particularly limited because a higher withstand voltage may be used. Therefore, what is necessary is just to be able to obtain 1.5 times or more of operating voltage by the thickness of the insulating material 33, the structure of a raw material, etc. FIG. By arranging the collector electrode in close proximity to the metal case through such a withstand voltage insulating material, a current flows in the metal case in the direction of canceling out the magnetic field generated in the plane current path as the bipolar battery 1, The parasitic inductance of the part can be suppressed.

  An opening 34 is provided on one side of the case 30, and the positive electrode tab 110 and the negative electrode tab 120 are drawn out. The opening 34 is sealed with an insulating material 33 and a rubber gasket 35 in a state where the positive electrode tab 110 and the negative electrode tab 120 are pulled out. The opening 34 is sealed with the rubber gasket 35, thereby preventing moisture from entering the case. The gasket 35 may be made of other watertight elastic material such as silicone rubber instead of rubber. In addition, the gasket 35 and the surrounding insulating material 33 may be adhered by an adhesive, or water tightness may be maintained by an elastic force of a rubber material used as a gasket.

  FIG. 4 is a cross-sectional view of a main part for explaining the power generation element 10.

  The power generation element 10 in the bipolar battery 1 has a structure in which a plurality of bipolar electrodes 20 are stacked via an electrolyte layer 24.

  The bipolar electrode 20 has a positive electrode 22 formed on one surface of a current collector 21 and a negative electrode 23 formed on the other surface.

  Such a bipolar electrode 20 can be formed using, for example, various lamination methods such as a slurry coating method and a printing method.

  Here, as an example, a method for forming the bipolar electrode 20 using a slurry coating method will be described.

In the slurry application method, first, positive electrode slurry is applied to one side of the current collector 21 and dried to form the positive electrode 22. As the current collector 21, for example, a stainless steel foil (SUS foil), a copper foil, an aluminum foil, or the like can be used. As the positive electrode slurry, for example, a mixture of a positive electrode active material such as LiMn ₂ O _{4 and} a conductive auxiliary agent such as acetylene black, a binder such as PVDF, and a slurry viscosity adjusting solvent such as NMP is used.

  Next, a negative electrode slurry is applied to the opposite surface of the current collector 21 on which the positive electrode 22 is formed, and dried to form the negative electrode 23. As the negative electrode slurry, a mixture of a negative electrode active material such as hard carbon, a binder such as PCDF, and a slurry viscosity adjusting solvent such as NMP is used.

  In this manner, the bipolar electrode 20 is formed by forming the positive electrode 22 and the negative electrode 23 on both surfaces of the current collector 21.

  In order to assemble the bipolar electrode 20 formed in this way as the power generation element 10, the formed bipolar electrode 20 is cut to a predetermined size, and the positive electrode 22 and the negative electrode 23 in the peripheral part are further scraped off to form the seal layer 25. The surface of the current collector 21 is exposed for formation.

  Next, using a microporous film made of PP or the like, a separator made of nonwoven fabric, and the like, a seal layer 25 is formed by disposing silicone rubber or the like having a predetermined height on both surfaces of a predetermined portion from the outer side of the outer periphery of the separator. Form.

And the pregel solution used as the electrolyte layer 24 is immersed inside the sealing layer 25 of the said separator, and the gel electrolyte layer 24 is hold | maintained in the center part of a separator by making it heat-polymerize in inert atmosphere. For example, a polymer (copolymer of polyethylene oxide and polypropylene oxide), EC + DMC (1: 3), 1.0 MLi (C ₂ F ₅ SO ₂ ) ₂ N, and a polymerization initiator (BDK) were mixed in the pregel solution. Use things.

  The power generation element 10 is laminated so that the positive electrode 22 and the negative electrode 23 face each other with the electrolyte layer 24 interposed therebetween. As a result, the positive electrode 22 and the negative electrode 23 sandwiching one electrolyte layer 24 constitute a unit cell 28. A plurality of unit cells 28 are stacked to constitute the power generation element 10.

  The terminal electrode of the power generation element 10 uses the same current collector 21 as the bipolar electrode 20, but unlike the bipolar electrode 20, the positive electrode 22 or the negative electrode 23 is formed only on one surface. That is, the positive electrode side terminal is formed with the positive electrode 22 only on one side of the current collector 21, and the negative electrode side terminal is formed with the negative electrode 23 only on one side of the current collector 21. The positive electrode 22 and the negative electrode 23 are formed on the respective current collectors 21 in the same manner as the positive electrode 22 and the negative electrode 23 of the bipolar electrode.

  A positive electrode side collector electrode 11 is connected to the positive electrode side termination electrode of the power generation element 10, and a negative electrode side collector electrode 12 is connected to the negative electrode side termination electrode. This connection is performed by, for example, bonding by ultrasonic bonding, adhesion by a conductive adhesive, or the like. Further, the case 30 presses the entire power generation element 10, the positive current collecting electrode 11, and the negative current collecting electrode 12, so that the positive current collecting electrode 11 and the negative current collecting electrode 12 are attached to each terminal electrode. You may make it electrically connect.

  The electrolyte layer 24 is preferably formed of a gel solute. By using a gel electrolyte as the electrolyte layer 24, it is possible to prevent leakage, and to prevent a liquid junction, which is a problem peculiar to a dual electrode type secondary battery, to realize a highly reliable stacked battery. Can do.

  Here, the difference between the all solid polymer electrolyte and the polymer gel electrolyte will be described. A polymer gel electrolyte is an all-solid polymer electrolyte such as PEO (polyethylene oxide) containing an electrolyte solution usually used in a lithium ion battery. Moreover, what hold | maintained electrolyte solution in polymer frame | skeleton which does not have lithium ion conductivity like PVDF, PAN, and PMMA also corresponds to a polymer gel electrolyte. The ratio of the polymer and the electrolyte constituting the polymer gel electrolyte is wide. When 100% of the polymer is an all-solid polymer electrolyte and 100% of the electrolyte is a liquid electrolyte, all of the intermediates correspond to the polymer gel electrolyte. On the other hand, the all solid electrolytes include all electrolytes having Li ion conductivity such as polymers or inorganic solids. In the present invention, the solid electrolyte includes all of polymer gel electrolyte, all solid polymer electrolyte, and inorganic solid electrolyte.

  In addition, it is preferable to use a lithium-transition metal composite oxide for the positive electrode active material and a carbon or lithium-transition metal composite oxide for the negative electrode active material, so that a bipolar battery excellent in capacity and output characteristics can be obtained. Can be realized.

  The power generation element 10 formed in this way is obtained by connecting a plurality of single cells 28 in series. Therefore, a voltage that is several times as many as the number of stacked unit cells 28 appears between the positive electrode tab 110 and the negative electrode tab 120.

  In addition, in the case of illustration, although the cell of 7 layers was shown, naturally the number of layers of this cell is not limited to such a number.

  In the power generation element 10, the positive electrode side collecting electrode 11 and the negative electrode side collecting electrode 12 are joined as described above, and then the periphery thereof is covered with the insulating material 33, and the positive electrode tab 110 and the negative electrode tab 120 are disposed on one side of the case 30. It is housed in a metal case 30 in a state where it is pulled out outward in one direction.

  Hereinafter, the operation of the bipolar battery 1 configured as described above will be described.

  As shown in FIG. 1, the bipolar battery 1 of Embodiment 1 has a positive electrode side collecting electrode 11 and a negative electrode side collecting electrode 12 provided in parallel at the terminal electrode of the power generation element 10 with the same size. The positive electrode tab 110 and the negative electrode tab 120 connected to the positive electrode side collecting electrode 11 and the negative electrode side collecting electrode 12 are drawn from one side of the case.

  As a result, when a load is connected to the bipolar battery 1, the current flowing through the positive current collecting electrode 11 and the negative current collecting electrode 12 provided in parallel is caused to flow the same current in opposite directions. Current paths X and Y can be formed (see FIG. 1). For this reason, when the positive current collecting electrode 11 is the current path X and the negative current collecting electrode 12 is the reverse current path Y, currents of the same amount of current flow through the current paths in opposite directions. As a result, the electromagnetic induction caused by the respective currents is canceled by the magnetic field, and the parasitic inductance can be reduced.

  FIG. 5 is a drawing for explaining an example of a battery (referred to as a comparative example) in the case where there is no current path for passing currents in opposite directions, and FIG. The schematic perspective view which shows the internal structure of a battery, (B) is one tab side side view in the state which heat-welded the exterior | packing material of the battery of this comparative example. In addition, also in the battery of a comparative example, the same code | symbol is attached | subjected about the member similar to the bipolar battery 1 of this invention, and description is abbreviate | omitted.

  In the battery 100 of the comparative example shown in FIGS. 5A and 5B, the power generation element 10 is covered with an exterior material 150 such as a laminate film. The laminate film is a laminate of a plurality of metal foils and synthetic resin films, and has flexibility. The periphery of the exterior material 150 is heat-sealed.

  The power generation element 10 has a positive electrode side collector electrode 160 and a negative electrode side current collector electrode (positioned on the opposite side of the positive electrode side current collector electrode 160 across the power generator element 10 in FIG. 5A) connected to the terminal electrode. ing. A positive electrode tab 110 and a negative electrode tab 120 are integrally provided on the positive electrode side collecting electrode 160 and the negative electrode side collecting electrode, respectively, and the power generation element 10 and the like are sealed in a state of being pulled out from both sides of the exterior material 150. ing.

  For this reason, when the battery 100 of this comparative example is connected to a load, a current flows through a path from the positive electrode tab 110 to the negative electrode tab 120 through the positive electrode side collector electrode 160, the power generation element 10, and the negative electrode side collector electrode. It will be. Therefore, all of this current path has a parasitic inductance.

  In the bipolar battery 1 of the first embodiment, the parasitic inductance is reduced by the amount of magnetic field cancellation caused by the current paths X and Y running in parallel as compared with the battery 100 of the comparative example, and an AC load is connected accordingly. In this case, energy loss is reduced.

  In addition, although the bipolar battery 1 of this Embodiment 1 uses the metal case, it may replace with this and may be a battery sealed with a laminate film similarly to the battery of the comparative example. However, when sealing with a laminate film, care must be taken so that the positive electrode tab 110 and the negative electrode tab 120 drawn out from one side of the battery do not come into contact with each other. In particular, it is necessary to use a gasket, an insulating material, or the like that is not meltable by heat when the laminate film is heat-welded.

  Next, an operation when a load is connected to the bipolar battery 1 of Embodiment 1 will be described.

  FIG. 6 is a drawing showing an example of connection of an AC load, (A) is a schematic diagram showing an example of connection between a DC power source and a high-frequency load, and (B) is an example of connection between a secondary battery, an inverter and a load device. It is a schematic diagram which shows. FIG. 7 is an explanatory diagram showing changes in load current over time. FIG. 8 is a graph showing the relationship between the frequency and impedance of a bipolar battery, an electric field capacitor, a comparative battery, and a film capacitor according to the present invention. FIG. 9 is a schematic diagram showing the structure of an aluminum electric field capacitor.

  Here, the high frequency means a frequency of several tens of kHz or more, as is generally used. However, the present invention is not limited to those handling such high frequencies.

  As shown in FIG. 6A, generally, when the high frequency load 520 is operated by the DC power source 510, the DC power source 510 is connected to the high frequency power source 530. In the high frequency power supply 503, a capacitor or the like is inserted in order to reduce ripples in the high frequency component.

  When a secondary battery 540 is used as a DC power source, as shown in FIG. 6B, an inverter 500 is connected to the secondary battery 540 to create an AC. At that time, a capacitor 560 for suppressing ripples is provided in the circuit. Inserted. FIG. 6B shows an example in which a motor 550 is connected as a high frequency load.

  When such a high-frequency load is connected, the load current tends to gradually increase with time and gradually decrease as shown in FIG.

  For example, in the case of an inverter mounted on a hybrid vehicle or an electric vehicle, the switching frequency is about 50 kHz at the maximum. Therefore, it is necessary to handle an alternating current of high frequency components up to about 50 kHz as a high frequency power source.

  Specifically, for example, when a ripple voltage of about 20 V is allowed for an AC component of about 100 A, the impedance of the high-frequency power source at 50 kHz is required to be about 0.2Ω or less.

  From the relationship between the frequency and the impedance shown in FIG. 8, it can be seen that an electrolytic capacitor can ensure an impedance of about 0.2Ω or less near 50 kHz. Therefore, many electrolytic capacitors are conventionally used as capacitors used to absorb ripples. In FIG. 8, the secondary battery of the comparative example is the same as the secondary battery of the comparative example described above.

  Here, the self-inductance per unit length in parallel conductors in which current flows in opposite directions is expressed by the following equation (1).

In the formula (1), a is the radius of the conducting wire, d is the interval between the parallel conducting wires, μ ₀ is the vacuum permeability (1.256 × 10 ⁻⁶ N / A ² ), and π is the circumference.

  As can be seen from the equation (1), the inductance per unit length of the current path increases as the distance d between the parallel conductors increases. Further, the longer the length of the conducting wire, the larger the inductance of the current path.

  On the other hand, as shown in FIG. 9, the aluminum electric field capacitor 600 is functionally composed of an element 610 which is a capacitor and a lead wire 602 extending in parallel therewith. The element 610 is a parallel plate.

The inductance component of the aluminum electric field capacitor 600 is an inductance of a large parallel plate in the element unit 610, and is very low in a frequency band (about 1 to several tens kHz) that is usually used as an AC power source. On the other hand, assuming that the lead wire 620 is, for example, a parallel conducting wire having an interval of 3 cm, a length of 1 cm, and a radius of 1 mm, the inductance is about 10 ⁻⁸ H. Therefore, the inductance component of the aluminum electric field capacitor 600 is mainly the inductance component of the lead wire 620, and the impedance of the electric field capacitor 600 at a high frequency is defined by the inductance of the lead wire 620.

  In addition, although the impedance with respect to the frequency of a film capacitor is also shown in FIG. 8 for reference, as can be seen from the figure, the film capacitor has an impedance in an AC frequency band (about 1 to several tens kHz) that is normally used. Is an order of magnitude higher than electrolytic capacitors.

  Next, the inductance of the flat conductor will be described.

  FIG. 10 is an explanatory diagram for explaining the inductance of the flat conductor.

  First, referring to FIG. 10A, the magnetic field generated by the current flowing through the flat conductor can be expressed by the following equation (2).

In the equation, B represents magnetic flux density, μ ₀ represents vacuum permeability, H represents magnetic field, Φ represents magnetic flux, and j represents surface current density.

  Referring to FIG. 10 (B), the inductance per unit length from the magnetic field generated by the current flowing in the opposite direction through the two opposing flat conductors and the magnetic flux penetrating between the flat conductors is the following (3) to ( 5) It is expressed by the formula.

  In the formula, w represents the current in the plane of the parallel conductor and the length in the vertical direction.

From these formulas, in order to realize 10 ⁻⁸ H, which is equivalent to the aluminum electric field capacitor, with respect to the inductance generated at the output terminal (between the positive electrode tab and the negative electrode tab) of the bipolar battery 1, length (m) × The thickness (m) <2 × 10 ⁻² may be satisfied. The ripple voltage generated by the parasitic inductance is 2πf · μ ₀ · d · T · I, and the normally allowed ripple voltage is less than or equal to 1/2 the operating voltage of the load device, so 2πf · μ ₀ · d · d and T may be set appropriately so as to satisfy l · I <V / 2. Here, T is the length of the current path.

  Here, the voltage of the battery is proportional to the cross-sectional area as shown in FIG. Further, the internal resistance of the battery is inversely proportional to the area, and increases as the thickness increases. Therefore, it is desirable that the length is a ratio of 5 times or more than the thickness.

Since the parasitic inductance of the energizing path flowing inside the bipolar battery is about 1 μH per 1 m, for example, as an optimum example for HEV, if the thickness is 10 mm and the length is 300 mm, the inductance becomes 4 × 10 ⁻⁹ H. .

That is, when a high-frequency load is connected to the bipolar battery 1 of the first embodiment, the length T in the current path direction of the positive current collecting electrode 11 and the negative current collecting electrode 12, and the positive current collecting electrode 11 and the negative current side The product of the distance D between the collecting electrodes 12, the vacuum permeability, the maximum frequency f of the high frequency load, the maximum alternating current Imax, and the circumference is ¼ or less of the maximum input voltage Vin of the high frequency load. It is preferable that That is, it is preferable that T × D × f × I × π × μ ₀ <Vin / 4.

  This is to reduce the parasitic inductance of the current path due to the size of the positive current collecting electrode 11 and the negative current collecting electrode 12, and by appropriately designing the length and thickness of the battery used for high frequency, It is possible to compensate for a ripple voltage that does not hinder the operation of the load device.

In addition, the product of the distance D between the positive current collecting electrode 11 and the negative current collecting electrode 12, the maximum alternating current Imax, the maximum frequency f, and the circumferential ratio is 1 / of the maximum operating voltage V of the load device. It is preferably (4 × 10 ⁻⁶ ) or less. That is, it is preferable that D × f × Imax × π <V / (4 × 10 ⁻⁶ ). Thereby, the ripple voltage due to the parasitic inductance caused by the current flowing in the thickness direction of the high-frequency battery can be suppressed to a level that does not hinder the operation of the load device such as the motor.

  FIG. 12 is a block diagram for explaining the layout of the battery system using the bipolar battery according to the present embodiment described above.

  The battery system as shown can be used for an electric vehicle, a hybrid vehicle, and the like, for example.

  In this battery system, a bipolar battery 1 serving as a DC power source is connected to an inverter 500. In the figure, one battery (bipolar battery 1) is shown. However, when actually used in an electric vehicle or a hybrid vehicle, it is used as an assembled battery (detailed later) in which a plurality of bipolar batteries 1 are connected. Often done.

  In a battery system used for an electric vehicle, a hybrid vehicle, and the like, the current path of the battery itself has also increased inductance due to the size of the battery.

For example, in the battery system shown in FIG. 12, when a conventional secondary battery is used, the inductance in the length direction of one conventional secondary battery is about 5 × 10 ⁻⁸ H. When 50 conventional secondary batteries are connected in series, the inductance of the entire current path is about 10 ⁻⁵ H when the wiring length of the battery system is 4 m, the interval is 5 cm, and the wire radius is 1 mm.

On the other hand, when the bipolar battery 1 in the present embodiment is used, if the inductance is 4 × 10 ⁻⁹ H per piece, and 50 pieces are connected in series, the entire battery system shown in FIG. The inductance of all current paths is about 1 × 10 ⁻⁸ H.

  From Fig. 8, 0.1Ω at 1MHz and ωL is impedance (resistance). ω = 2πf. Therefore, the inductance as the current path of the battery used in the battery system can be suppressed sufficiently low.

  As described above, according to the first embodiment, by providing the negative current collecting electrode 12 in which the current flows in the opposite direction to the current flowing in the positive current collecting electrode 11, the currents flowing in the opposite directions to each other are provided. The magnetic field is canceled by this, and the parasitic inductance can be reduced. Therefore, the length of the current path that has been required based on the size of the battery can be significantly reduced. Further, since the battery shape is a flat type (thin) and the current collecting structure facing each other is a flat plate, the parasitic inductance generated in the current path can be canceled and the high frequency impedance can be reduced.

  As a result, in the case of a battery system in which a high-frequency load such as an inverter or a laser oscillator is connected to the bipolar battery 1, it is possible to achieve an inductance equivalent to that of a conventional electric field capacitor. Ripple current can be suppressed only by installing the battery 1. For this reason, it is possible to reduce the installation space and weight by eliminating the need to install an electric field capacitor. Moreover, since the parasitic inductance is reduced by the bipolar battery 1 alone, it is possible to supply a low-cost, small and light high-frequency bipolar battery.

(Embodiment 2)
FIG. 13 is a cross-sectional view for explaining the configuration of the bipolar battery according to the second embodiment. In the figure, members having the same functional configuration as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  This bipolar battery 2 is a rectangular flat battery, like the bipolar battery 1 of the first embodiment.

  In the configuration, the positive electrode side collector electrode 11 is provided on one of the terminal electrodes of the power generation element 10 (here, the positive electrode side terminal). The negative electrode side collector electrode 12 is connected to the other end electrode (the negative electrode side end) of the power generation element 10, and is further connected to the negative electrode side current collector electrode 12, so that a current flows in a direction opposite to the negative electrode side current collector electrode 12. 15 is connected. The negative electrode side collecting electrode 12 and the conductive member 15 may be integrated with the same member, or may be integrated by connecting different members.

Similar to the first embodiment, an opening 34 is provided on one side of the case 30, and the positive electrode tab 110 connected to the positive current collecting electrode 11 and the negative electrode tab 120 connected to the conductive member 15. Has been pulled out. The positive electrode tab 110 and the negative electrode tab 120 are instructed to seal the opening 34 by the gasket 35. The case 30 is insulated from the positive current collecting electrode 11, the negative current collecting electrode 12, and the conductive member 15 by an insulating material 33. Further, the parallel portion of the negative electrode side collecting electrode 12 and the conductive member 15 is also insulated by the insulating material 33. Thus, the same current as that of the negative electrode side collecting electrode 12 is obtained. By providing the conductive member 15 that flows in the reverse direction, electromagnetic induction in the current path of the negative current collecting electrode 12 is canceled by the reverse current path by the conductive member 15. For this reason, the parasitic inductance on the negative electrode side collecting electrode 12 side can be reduced.

  FIG. 14 is a diagram illustrating an arrangement example of a battery system in which the bipolar battery 2 and the inverter 500 according to the second embodiment are combined.

  As shown in the figure, among the current paths connecting the bipolar battery 2 and the inverter 500, the current path connecting Y1 and Y2 is canceled next time by the current path Z of the conductive member 15 provided in parallel to the negative current collecting electrode 12. Will be. Therefore, the parasitic inductance in this battery system is approximately only the portion of the current path X connecting the bipolar battery 2 and the inverter 500.

(Embodiment 3)
Embodiment 3 is an assembled battery in which a plurality of bipolar batteries according to Embodiment 1 or Embodiment 2 are combined.

  FIG. 15 is a diagram illustrating the configuration of the assembled battery 300 according to the third embodiment and is a side view on the electrode tab side.

  In this assembled battery 300, as shown in the figure, a plurality of bipolar batteries 1 or 10 according to the first or second embodiment are stacked, and electrode tabs 110 and 120 are connected to each other by a bus bar 310. A plurality of bipolar batteries 1 or 10 are connected in series.

  Thus, the assembled battery 300 in which the plurality of bipolar batteries 1 or 10 are connected in series can obtain a high capacity and a high output.

  FIG. 16 is a diagram showing an example in which the assembled battery 300 is mounted on a vehicle such as an electric vehicle.

  In order to mount the assembled battery 300 on the electric vehicle 400, for example, it is preferable to mount it under the seat in the center of the vehicle body of the electric vehicle 400. This is because if it is installed under the seat, the interior space and the trunk room can be widened. In particular, the assembled battery 300 to which the present invention is applied eliminates the need for a large electrolytic capacitor, so that more space in the vehicle can be used. Of course, the place where the assembled battery 300 is mounted is not limited to under the seat, but may be a lower part of the rear trunk room or an engine room in front of the vehicle.

  The electric vehicle 400 using the assembled battery 300 as described above has high durability and can provide sufficient output even when used for a long period of time. Furthermore, it is possible to provide electric vehicles and hybrid vehicles that are excellent in fuel efficiency and driving performance.

  The present invention is suitable not only for a bipolar battery but also for a secondary battery to which an AC load (particularly a high frequency load) is connected.

It is a schematic perspective view for demonstrating the internal structure of the bipolar battery of Embodiment 1 to which this invention is applied. It is sectional drawing for demonstrating the whole structure of a bipolar battery. It is the side view seen from the arrow a direction in FIG. It is principal part sectional drawing for demonstrating an electric power generation element. It is drawing for demonstrating the example of a battery in case it does not have the current pathway for flowing an electric current in a mutually reverse direction. It is drawing which shows the example of a connection of alternating current load. It is explanatory drawing which shows the change in the time of load current. It is a graph which shows the relationship between the frequency and impedance of the bipolar battery by this invention, an electric field capacitor, the battery of a comparative example, and a film capacitor. It is a schematic diagram which shows the structure of an aluminum electric field capacitor. It is explanatory drawing explaining the inductance of a flat conductor. It is explanatory drawing which shows the relationship between the cross-sectional area of a battery, and a voltage. It is a block diagram explaining the layout of the battery system using the bipolar battery by this embodiment. It is sectional drawing for demonstrating the structure of the bipolar battery of Embodiment 2 to which this invention is applied. It is drawing which shows the example of arrangement | positioning of the battery system which combined the bipolar battery and inverter of Embodiment 2. FIG. It is drawing explaining the structure of the assembled battery of Embodiment 3 to which this invention is applied. It is drawing which shows the state by which the assembled battery was mounted in the vehicle.

Explanation of symbols

1, 2, ... bipolar battery,
10 ... Power generation element,
20: Bipolar electrode,
21 ... current collector,
22 ... positive electrode layer,
23 ... negative electrode layer,
24 ... electrolyte layer,
30 ... case,
33. Insulating material,
300 ... assembled battery,
400 ... Electric car,
500 ... Inverter,
520: High frequency load.

Claims (13)

A power generation element in which a plurality of unit cells configured by interposing an electrolyte layer between a positive electrode and a negative electrode are laminated;
A current collecting structure electrically connected to a terminal electrode of the power generating element;
A reverse current path arranged so that a current flows in a direction opposite to the direction of the current flowing through the current collecting structure;
A battery comprising: The current collecting structure is a first current collecting electrode connected to one terminal electrode of the power generation element;
The battery according to claim 1, wherein the reverse current path is a second current collecting electrode connected to the other terminal electrode of the power generating element.   The battery according to claim 2, wherein the first current collecting electrode and the second current collecting electrode are flat and have the same size. The power generation element, the first current collecting electrode, and the second current collecting electrode are housed in a case that blocks moisture,
4. The battery according to claim 2, wherein an electrode tab electrically connected to the first current collecting electrode and the second current collecting electrode is drawn out from one side of the case.   The battery according to claim 4, wherein the case has conductivity, and the first current collecting electrode and the second current collecting electrode are disposed via the case and an insulating material.   The battery according to claim 5, wherein the withstand voltage of the insulating material is 1.5 times or more of an operating voltage of a connected load. The power generation element is:
A bipolar electrode in which the positive electrode is formed on a first surface of a current collector and the negative electrode is formed on a second surface opposite to the first surface;
The battery according to claim 1, wherein a plurality of the bipolar electrodes are arranged and laminated so that the positive electrode and the negative electrode face each other with the electrolyte layer interposed therebetween. The battery according to any one of claims 1 to 7,
An AC load connected to the battery,
Total current path length T between the battery and the AC load, a distance D between the first current collecting structure and the second current collecting structure, a frequency f of the AC load, the AC load The maximum alternating current Imax and the maximum input voltage Vin of the load satisfy the following expression (1).
T × D × f × I × π × μ ₀ <Vin / 4 (1) The battery according to any one of claims 1 to 7,
An AC load connected to the battery,
The relationship among the distance D between the first current collecting structure and the second current collecting structure, the frequency f of the AC load, the maximum AC current Imax of the AC load, and the maximum operating voltage V of the load is The battery system characterized by satisfying the following formula (2).
D × f × Imax × π <V / (4 × 10 ⁻⁶ ) (2)   A battery pack according to any one of claims 1 to 7, wherein a plurality of batteries are electrically connected. The assembled battery according to claim 10;
An AC load connected to the assembled battery,
Length L of the total current path between the assembled battery and the AC load, and a distance D between the first current collecting structure and the second current collecting structure of each battery constituting the assembled battery Of the alternating load, the maximum alternating current Imax of the alternating load, and the maximum input voltage Vin of the load satisfy the following expression (3).
L × Ds × f × Imax × π × μ ₀ <Vin / 4 (3) The assembled battery according to claim 10;
An AC load connected to the assembled battery,
Sum Ds of distances D between the first current collecting structure and the second current collecting structure of each battery constituting the assembled battery, frequency f of AC load, maximum AC current Imax of AC load , And the maximum operating voltage V of the load satisfies the following formula (4).
Ds × f × Imax × π <V / (4 × 10 ⁻⁶ ) (4)   Any one of the battery according to any one of claims 1 to 7, the assembled battery according to claim 10, and the battery system according to any one of claims 8, 9, 11, and 12. A vehicle characterized by being mounted.

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