JP2018038133A - Charging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging system capable of shortening the charging time of a secondary battery. A power receiving device including a power receiving coil and a secondary battery, a power feeding device including a power feeding coil, and a determination unit configured to determine the presence or absence of a magnetic body in the secondary battery by communicating with the power receiving device, The power receiving device and the power feeding device are non-contact, and when the determining unit determines that the magnetic body exists in the secondary battery, the determining unit determines that the magnetic body does not exist in the secondary battery. A charging system in which a secondary battery is charged by flowing a current larger than a current value supplied to a power feeding coil to the power feeding coil. [Selection diagram] Figure 1

Description

  The present invention relates to a charging system for charging a secondary battery.

  The non-contact power feeding technology that transmits power from the power transmission side (power feeding side) to the power receiving side in a non-contact state can be expected to be highly convenient. Therefore, application to various product fields such as mobile phones and electric vehicles is being promoted.

As a technique related to charging / discharging of a secondary battery, for example, Patent Document 1 discloses a secondary battery, means for charging / discharging the secondary battery, means for controlling charging / discharging of the secondary battery, A charge / discharge system including means for detecting temperature, and when the temperature of the secondary battery is less than the appropriate charge / discharge temperature T ₀ , pulse charge / discharge conditions were performed until the temperature of the secondary battery reached T ₀ . Later, a charge / discharge system for starting charge / discharge is disclosed.
Further, in Patent Document 2, at least one metal selected from the group consisting of iron, nickel, copper, and silver is included in a metal state in at least one unfired body constituting the all solid state battery. A method for producing an all-solid battery is disclosed in which the unfired body is fired so that the metal maintains a metallic state, thereby promoting resin removal.
Patent Document 3 discloses that the negative electrode current collector of a sulfide solid state battery is a current collector containing Cu and / or Fe.

JP 2006-92901 A Japanese Patent Laying-Open No. 2015-65046 Japanese Patent Laying-Open No. 2015-5421

In the charge / discharge system disclosed in Patent Document 1, when the temperature is lower than T ₀ , the temperature of the secondary battery is raised by first performing pulse charge / discharge to raise the temperature to T ₀ or more, and then the circuit Since normal charging is performed by switching between the two, there is a problem that the time until charging is completed (charging time) tends to be long. This problem has been difficult to solve by simply combining the techniques disclosed in Patent Documents 1 to 3.

  Then, this invention makes it a subject to provide the charging system which can shorten the charging time of a secondary battery.

  A battery at a high temperature can accept a larger current than at a low temperature, and thus is easily charged quickly. Therefore, it is effective to increase the temperature of the battery in order to shorten the charging time. Here, if a dedicated device for heating the battery is separately prepared, the system becomes large. Therefore, it is preferable to heat the battery without using such a dedicated device. In order to shorten the charging time of the secondary battery, the present inventors have studied a system that rapidly charges the secondary battery while heating it. As a result, we found that it is possible to quickly charge a secondary battery using a magnetic material while simultaneously heating the secondary battery by induction heating by charging using an electromagnetic induction type non-contact power feeding technology. did. The present invention has been completed based on this finding.

In order to solve the above problems, the present invention takes the following means. That is,
The present invention includes a power receiving device including a power receiving coil and a secondary battery, a power feeding device including a power feeding coil, and a determination unit that determines the presence or absence of a magnetic substance in the secondary battery. If the judgment unit determines that there is a magnetic substance in the secondary battery, and the judgment unit determines that there is no magnetic substance in the secondary battery, the current value that flows to the power supply coil It is a charging system that charges a secondary battery by flowing a larger current to the feeding coil.

  ADVANTAGE OF THE INVENTION According to this invention, the charging system which can shorten the charging time of a secondary battery can be provided.

It is a figure explaining the example of a form of the charge system of this invention.

  The present invention will be described below with reference to the drawings. In addition, the form shown below is an illustration of this invention and this invention is not limited to the form shown below.

  FIG. 1 is a diagram for explaining an embodiment of the charging system of the present invention. The charging system 100 illustrated in FIG. 1 includes a power receiving device 10 having a power receiving coil 11 and a secondary battery 12, a power feeding device 20 having a power feeding coil 21, and a determination unit 30. The determination unit 30 determines whether or not a magnetic material is present in the secondary battery 12. Here, when the determination unit 30 determines that a magnetic material is present in the secondary battery 12, a current value (effective value of an alternating current) that flows from the power source (not shown; the same applies hereinafter) to the feeding coil 21. The same applies hereinafter) I1 [A], and the current value flowing from the power source to the feeding coil 21 when the determination unit 30 determines that no magnetic material is present in the secondary battery 12 is I2 [A]. In the charging system 100, a current is supplied from the power source to the feeding coil 21 so that 0 <I2 <I1. In this way, an alternating current magnetic field is generated by passing a current through the power feeding coil 21, and an induced current can be generated in the power receiving coil 11 using this as a medium. Since the power receiving coil 11 and the secondary battery 12 provided in the power receiving device 10 are connected, the secondary battery 12 can be charged by supplying a current to the power feeding coil 21.

  Further, the secondary battery 12 is arranged in a range covered by an alternating magnetic field generated by passing a current through the power supply coil 21. Therefore, the generated AC magnetic field also acts on the secondary battery 12. When a magnetic material is present in the secondary battery 12, an eddy current flows through the magnetic material and the magnetic material is induction-heated, so that the secondary battery 12 can be heated. As described above, when a magnetic material is present in the secondary battery 12, a larger current flows through the feeding coil 21 than when the magnetic material is not present in the secondary battery 12. Therefore, according to the charging system 100, the secondary battery 12 in which a magnetic body exists can be charged while heating. By heating and raising the temperature of the secondary battery 12, a larger current can be accepted than when the temperature is low, so that the secondary battery 12 can be rapidly charged according to the present invention. Furthermore, by performing heating and rapid charging at the same time, the charging time can be shortened as compared with the prior art in which charging is performed after heating. Therefore, according to the present invention, it is possible to provide the charging system 100 capable of shortening the charging time.

  In the present invention, the form of the power receiving coil 11 and the power feeding coil 21 is not particularly limited as long as it is a coil that can be used when charging a battery using an electromagnetic induction type non-contact power feeding technique. For example, a copper wire or a magnetic plating wire can be used as the power receiving coil 11, and a copper wire or a magnetic plating wire can be used as the feeding coil 21.

  As described above, the determination unit 30 determines whether or not a magnetic material is present in the secondary battery 12. In the present invention, the form of determination by the determination unit 30 is not particularly limited as long as it can be determined whether or not a magnetic material is present in the secondary battery 12. Specifically, for example, based on a signal transmitted from the magnetic impedance sensor, the determination unit 30 determines whether or not a magnetic material is present in the secondary battery 12, and from the power receiving device 10 side. For example, the determination unit 30 receives the transmitted magnetic body information to determine whether or not a magnetic body is present in the secondary battery 12.

  In the present invention, when a magnetic material is present in the secondary battery 12, the magnetic material is not particularly limited. Examples of magnetic materials that can be present in the secondary battery 12 include Fe, Co, Ni, and the like.

  Moreover, when a magnetic body exists in the secondary battery 12, the position of the magnetic body is not particularly limited. For example, the magnetic material can be present in at least one or more locations selected from the group consisting of a positive electrode layer, a negative electrode layer, and a current collector. When a magnetic substance is present in the positive electrode layer or the negative electrode layer, for example, a magnetic substance can be used as a conductive additive contained in these layers. By using a magnetic material as a conductive additive or a current collector, the magnetic material can have two functions as an electron movement path in the secondary battery 12 and a heat generating part during induction heating.

  In the present invention, the secondary battery 12 may be a secondary battery using a liquid electrolyte or a secondary battery (all-solid battery) using a solid electrolyte. When a liquid electrolyte is used, an electrolytic solution that can be used for a secondary battery can be appropriately used. Here, the all-solid-state battery is excellent in heat resistance as compared with the battery using the electrolytic solution. Since the charging system 100 is a system that performs rapid charging while heating the secondary battery 12, it is preferable to use an all-solid battery as the secondary battery 12.

When the secondary battery 12 is an all-solid battery, the positive electrode active material that can be used in the solid battery can be appropriately used as the positive electrode active material to be included in the positive electrode layer of the secondary battery 12. Examples of such a positive electrode active material include lithium cobaltate (LiCoO ₂ ), olivine type lithium iron phosphate (LiFePO ₄ ), spinel type lithium manganate (LiMn ₂ O ₄ ), and the like.

  In the secondary battery 12, the positive electrode layer and the negative electrode layer can contain a solid electrolyte that can be used for an all-solid battery, if necessary. Examples of such solid electrolytes include oxide-based amorphous solid electrolytes and sulfide-based amorphous solid electrolytes, as well as crystalline oxides and oxynitrides. However, it is preferable to use a sulfide solid electrolyte as the solid electrolyte from the viewpoint of easily improving the performance of the all-solid battery.

  Further, the positive electrode layer can contain a binder. Examples of such a binder include acrylonitrile butadiene rubber (ABR), butadiene rubber (BR), polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR), and the like.

  Furthermore, the positive electrode layer can contain a conductive additive that improves conductivity. Examples of the conductive additive that can be contained in the positive electrode layer include ferromagnetic materials typified by Fe, Co, Ni, etc., in addition to carbon materials such as ketjen black.

  Moreover, as a negative electrode active material contained in the negative electrode layer of the secondary battery 12, a carbon active material, an oxide active material, a metal active material, etc. can be mentioned, for example.

  Furthermore, the negative electrode layer may contain a binder that binds the negative electrode active material and the solid electrolyte, and a conductive additive that improves conductivity. Examples of the binder and conductive additive that can be contained in the negative electrode layer include the binder and conductive aid that can be contained in the positive electrode layer.

  Moreover, as a solid electrolyte contained in the solid electrolyte layer of the secondary battery 12, a solid electrolyte that can be used for an all-solid battery can be appropriately used. Examples of such a solid electrolyte include the solid electrolyte that can be contained in the positive electrode layer and the negative electrode layer. In addition, the solid electrolyte layer can contain a binder that binds the solid electrolytes from the viewpoint of developing plasticity. As such a binder, the said binder etc. which can be contained in a positive electrode layer can be illustrated.

  Moreover, the well-known metal which can be used as a collector of an all-solid-state battery can be used for the collector connected to a positive electrode layer or a negative electrode layer. As such a metal, a metal containing one or more elements selected from the group consisting of Cu, Ni, Al, V, Au, Pt, Mg, Fe, Ti, Co, Cr, Zn, Ge, and In. Materials can be exemplified. Among these, it is preferable to use an element (Fe, Co, Ni) exhibiting ferromagnetism as a current collector from the viewpoint of making the secondary battery 12 in a form that can be rapidly charged by the charging system 100.

  Moreover, in this invention, the receiving coil 11 and the secondary battery 12 should just be connected with the form which can supply with electricity. A rectifier circuit or a charging circuit may be provided between the power receiving coil 11 and the secondary battery 12.

  In the present invention, when the determination unit determines that there is no magnetic material in the secondary battery, the battery cannot be heated by induction heating. Charging is performed by limiting the current value.

DESCRIPTION OF SYMBOLS 10 ... Power receiving apparatus 11 ... Power receiving coil 12 ... Secondary battery 20 ... Power feeding apparatus 21 ... Power feeding coil 30 ... Judgment part 100 ... Charging system

Claims (1)

A power reception device including a power reception coil and a secondary battery, a power supply device including a power supply coil, and a determination unit that determines the presence or absence of a magnetic body in the secondary battery by communicating with the power reception device,
The power receiving device and the power feeding device are contactless,
When the determination unit determines that there is a magnetic substance in the secondary battery, the current that flows to the power supply coil when the determination unit determines that there is no magnetic substance in the secondary battery. A charging system for charging the secondary battery by flowing a current larger than the value to the feeding coil.

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