JP2017084988A - Power storage unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage unit which can show a desired characteristic by making a power storage device insusceptible to an ambient air temperature.SOLUTION: A power storage unit (1) comprises: a power storage element (21); a power storage housing (25) for housing the power storage element (21) therein; at least one power storage device (20) having electrode terminals (22, 23) exposed outside the power storage housing (25); a storing case (10) for storing the power storage device (20); heat insulation means (11a) for intercepting the heat exchange between the outside and inside of the storing case (10); and a non-contact power receiver-supplier (30) disposed in the storing case (10), performing power reception from and power supply to an outside device (50, 60) provided outside the storing case (10) in a non-contact manner, and connected with the power storage device (20).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power storage unit.

  In recent years, power storage devices that take into account environmental problems that can be repeatedly charged and discharged have been widely used in various fields. For example, in the field of automobiles, use in electric vehicles, hybrid vehicles, and vehicle devices using various electric motors as driving sources is promoted and attracting attention. These vehicles are equipped with a power storage device such as a secondary battery or an electric double layer capacitor in order to supply electric power to the motor or store electric energy during deceleration.

  The characteristics of the electricity storage device vary depending on the use temperature. Therefore, there is a power storage unit in which the power storage device is covered with a heat insulating member so that the power storage device exhibits desired characteristics (see, for example, Patent Document 1).

JP 2001-31487 A

  However, in the power storage unit disclosed in Patent Document 1, since the electrode terminal of the power storage device is exposed from the heat insulating member (see FIG. 5), the electrode terminal is affected by the outside air temperature. Therefore, the power storage unit is desired to further improve the heat insulation effect in order to reduce the change in characteristics of the power storage device.

  An object of this invention is to provide the electrical storage unit which can exhibit a desired characteristic by making an electrical storage device less susceptible to the influence of outside temperature.

  The power storage unit of the present invention includes a power storage element, a power storage housing that houses the power storage element, one or more power storage devices having electrode terminals exposed to the outside of the power storage housing, and the power storage device inside Receipt between a storage case to be stored, heat insulating means for blocking heat flow between the outside and the inside of the storage case, and an external device disposed inside the storage case and provided outside the storage case A non-contact power supply / reception device that performs electricity contactlessly and is connected to the power storage device.

  According to the above power storage unit, heat is insulated between the outside and the inside of the storage case, so that the heat input and output between the outside of the storage case and the power storage housing of the power storage device is blocked. In addition, since power is supplied to and received from an external device provided outside the storage case, the heat conduction between the outside of the storage case and the storage element via the electrode terminals is also blocked. Therefore, the temperature of the power storage element can be maintained without being affected by the outside temperature of the storage case, and the performance of the power storage device can be appropriately maintained while avoiding the deterioration of the output characteristics at the low temperature and the deterioration of the electrode material at the high temperature.

It is a schematic diagram which shows the outline | summary of the electrical storage unit of this embodiment. Similarly, it is a schematic diagram which shows the outline | summary of the electrical storage device of FIG. Similarly, it is a block diagram which shows the electrical structure outline | summary of the control apparatus of FIG. Similarly, it is the figure which showed typically the temperature characteristic of the internal resistance of various electrical storage devices.

(1. Configuration of power storage unit)
Hereinafter, specific embodiments of the power storage unit of the present invention will be described with reference to the drawings. In FIG. 1, the power storage unit 1 includes a storage case 10, a power storage device 20, and a contactless power supply / reception device 30. The power storage unit 1 receives power from the external device 50 to charge the power storage device 20, feeds the power output from each power storage device 20 to the external device 60, and operates the motor M via the external device 60. It is an apparatus for driving.

  The storage case 10 includes a container body 11 and a lid body 12. The storage case 10 stores the power storage device 20 and the controller 30 a of the non-contact power feeding / receiving device 30 in the storage portion 111 of the container body 11. The lid 12 covers the opening 114 of the container body 11 and seals it so that the internal space of the storage case 10 is a vacuum space 11b that is maintained in a vacuum state.

  The container body 11 has an overall shape of a rounded substantially rectangular parallelepiped box shape, and has a substantially rectangular opening 114 that opens upward in FIG. 1 at the center, and a housing portion 111 that is recessed in a substantially rectangular parallelepiped shape is formed. The At the periphery of the opening 114, a joint portion 11c is formed having a diameter that is enlarged in a similar size toward the outer side in the radial direction (horizontal direction). The upper end surface of the joint portion 11 c forms a flat joint end surface 115, and the end surface of the lid body 12 is overlapped on the container body 11 to cover the opening 114. Reference numerals 116 and 117 in FIG. 1 are pedestals for disposing the power storage device 20 and the controller 30a in the vacuum space 11b so as to be separated from the bottom surface of the housing portion 111.

  All the wall portions forming the container body 11 are formed by forming a metal plate-like first container body wall 112 and a second container body wall 113 obtained by molding a nonmagnetic metal material into the outer shape of the container body 11 into the vacuum layer 11a. It is formed as a double layer that is arranged on the outside and the inside via a joint. The container body 11 having the vacuum layer 11a is formed by a known method. For example, a manufacturing method is known in which a joint between a first container body wall 112 and a second container body wall 113 is sealed while being welded with a predetermined joining material in a high-temperature vacuum furnace. As the nonmagnetic metal material forming the container body 11, for example, austenitic stainless steel such as SUS304 or SUS316, aluminum, or the like can be used.

  The lid 12 has the same outer peripheral shape corresponding to the outer peripheral shape of the joint portion 11c of the container main body 11, and has an overall shape of a rounded substantially square plate. As with the container body 11, all the wall portions forming the lid body 12 are a metal plate-like first lid wall 122 and second lid wall obtained by molding a nonmagnetic metal material into the outer shape of the lid body 12. 123 is formed as a double layer in which the outer layer and the outer layer are bonded to each other via the vacuum layer 12a. A pair of resonance coils 31 and 32 that are linked to the controller 30a are attached to the second lid wall 123 inside the lid 12. The pair of resonance coils 31 and 32 are attached so as to be separated from the second lid wall 123 and disposed in the vacuum space 11b.

  The outer peripheral edge of the lid 12 forms a joint 12 c with the container body 11. The lower end surface of the joining portion 12c on the second lid wall 123 side forms a joining end surface 125, forms an overlapping surface with the joining end surface 115 of the container body 11, and covers the opening 114. The container body 11 and the lid body 12 are joined by welding the entire circumference along the boundary line between the joint portions 11 c and 12 c exposed on the outer peripheral surface of the storage case 10. The bonding strength between the container body 11 and the lid 12 and the degree of adhesion that can maintain the internal space as the vacuum space 11b can be maintained. For example, the storage device 20, the controller 30 a, etc. are accommodated in the container body 11, the controller 30 a is connected to the resonance coils 31, 32, and assembly work such as covering the opening 114 with the lid 12 is performed under vacuum. If so, it can be welded by irradiating an electron beam along the boundary line. In this case, the internal space of the storage case 10 can be maintained in the vacuum space 11b. If the assembly work is performed in the atmosphere, laser welding can be performed. In this case, air remains in the internal space. Reference numeral 13 in FIG. 1 indicates a portion welded by an appropriate method.

  The container body 11 and the lid body 12 may be joined by a method using an appropriate sealing material other than welding the entire circumference along the boundary line between the joint portions 11c and 12c described above. For example, an O-ring can be attached between the joining end faces 115 and 125. In this case, a pair of large and small O-rings on the inner diameter side and the outer diameter side can also be used. When the atmosphere remains in the internal space of the storage case 10, a vacuum space can be formed between the two O-rings for heat insulation.

  A predetermined plurality of power storage devices 20 are held in a frame (not shown). The electricity storage device 20 has a flat, rectangular parallelepiped box shape, and is connected in series or in parallel in consideration of the entire battery capacity while being held in a frame. FIG. 2 shows a state where unconnected power storage devices 20 are stacked. Each power storage device 20 is placed and stored in the storage case 10 while being separated from the bottom surface (second container body wall 113) of the storage unit 111. The electricity storage device 20 is electrically connected to the controller 30a through appropriate connection means so that the positive electrode terminal 22 and the negative electrode terminal 23 of each electricity storage device 20 are connected to a predetermined port.

  The power storage device 20 can be repeatedly charged and discharged. For example, an electric double layer capacitor, a lithium ion capacitor, a lithium ion secondary battery, or the like can be used. The power storage device 20 includes a power storage element 21, a positive electrode terminal 22, a negative electrode terminal 23, and a power storage casing 25, and stores the power storage element 21 inside a laminated power storage casing 25. Inside the electricity storage housing 25, a positive electrode terminal 22 and a negative electrode terminal 23 that are connected to the electricity storage element 21 and partially protrude outside the electricity storage housing 25 are accommodated.

  The electricity storage element 21 includes a positive electrode plate 212, a negative electrode plate 213, and an electrolytic solution. FIG. 2 shows a configuration example of the electricity storage element 21 including the flat plate-like positive electrode plates 212 and the negative electrode plates 213 alternately stacked via the separators 214 and a non-aqueous electrolyte solution (not shown). The positive electrode plate 212 and the negative electrode plate 213 are integrally connected to each other between the positive electrode current collectors or the negative electrode current collectors.

The positive electrode plate 212 is a slurry obtained by suspending and mixing a positive electrode mixture in which various additives, for example, a conductive additive, a binder, a thickener and the like are appropriately added to a positive electrode material, and mixing them in an appropriate solvent. Can be applied to one or both sides of the positive electrode current collector, pressed and dried. The positive electrode material is not particularly limited, and a known material can be used. In the case of an electric double layer capacitor or a lithium ion capacitor, activated carbon, polyacene, or the like can be used. For lithium ion secondary batteries, lithium transition metal composite oxides such as LiMnO ₂ , LiCoO ₂ , and LiNiO ₂ that can reversibly insert and desorb lithium ions can be used.

  As the positive electrode current collector, foil, mesh, or the like made of aluminum, stainless steel, copper, nickel, or the like can be used. Ketjen black, acetylene black, etc. as conductive aids, polyvinylidene fluoride, SBR rubber, polyacrylic acid, etc. as binders, carboxymethyl cellulose, etc. as thickeners, N-methyl as solvent. An organic solvent such as pyrrolidone or water can be used.

  Similarly to the positive electrode plate 212, the negative electrode plate 213 can be manufactured by applying a negative electrode mixture obtained by adding an appropriate additive to the negative electrode material to the negative electrode current collector, pressing, and drying. If it is an electric double layer capacitor, the negative electrode material similar to a positive electrode material can be used. In the case of a lithium ion capacitor or a lithium ion secondary battery, a carbon-based material such as graphite that can reversibly insert and desorb lithium ions can be used. As the negative electrode current collector, foil, mesh, or the like made of copper, stainless steel, nickel, or the like can be used. If it is a lithium ion capacitor, the lithium electrode for lithium ion pre dope can be manufactured. For example, a lithium metal foil is crimped to a lithium electrode current collector such as copper or stainless steel.

As the electrolytic solution, a non-aqueous electrolytic solution containing a known supporting salt as an electrolyte can be used. In the case of an electric double layer capacitor, typically, γ-butyrolactone, propylene carbonate or the like is used as a main solvent, carbonates such as ethylene carbonate is used as a secondary solvent, and a metal cation or quaternary ammonium is used as an electrolyte. The concentration is adjusted to a predetermined concentration using a salt of a cation such as a cation and an anion such as BF ⁴⁻ and PF ⁶⁻ . If a lithium ion capacitor or a lithium ion secondary battery, an electric double layer similar non-aqueous solvent and a capacitor, it is possible to use LiPF _6, LiBF ₄ or the like as a lithium salt.

  The positive electrode body integrated with the positive electrode plates 212 and the negative electrode body integrated with the negative electrode plates 213 are connected to a tab-shaped positive electrode terminal 22 and a negative electrode terminal 23 for taking out electric power made of a conductor. The positive electrode terminal 22 and the negative electrode terminal 23 are electrically connected to the positive electrode body or the negative electrode body, respectively. The positive electrode terminal 22 and the negative electrode terminal 23 are fixed in a state where the positive electrode terminal 22 and the negative electrode terminal 23 are inserted into the welding surface of the laminate resin film, and the non-contact power feeding / receiving device 30 outside the power storage case 25 is connected to the power storage element 21 inside the power storage case 25. .

  The non-contact power supply / reception device 30 is a device for performing power contact / reception with an external device in a non-contact manner, and any known device can be used as long as so-called wireless power supply and power reception can be performed. Not. The non-contact power feeding / receiving device 30 can employ a magnetic resonance method, an electromagnetic induction method, a radio wave reception method, or the like. For example, a non-contact power supply / reception device 30 using a magnetic resonance method will be briefly described with reference to FIGS. 1 and 3. The non-contact power supply / reception device 30 includes a controller 30 a and a pair of resonance coils 31 and 32. Resonant coils 31 and 32 housed in the coil case are fixed to the back surface of the lid 12 of the housing case 10.

  The resonance coil 31 resonates with the resonance coil 51 of the external device 50 via an electromagnetic field. As a result, the power storage unit 1 receives power supplied from the external device 50 and enables the power storage device 20 to be charged. The number of turns of the resonance coil 31 is appropriately set so that the resonance intensity and the degree of coupling thereof are increased based on the distance from the resonance coil 51 of the external device 50, the resonance frequency of the resonance coil 31 and the resonance coil 51, and the like. . The resonance coil 31 outputs the power received from the external device 50 via the resonance coil 51 to the controller 30a (rectifier 33). Reference numeral 53 denotes a device for converting a predetermined alternating voltage into a resonable high frequency.

  The controller 30 a includes a rectifier 33, a DC / DC converter 34, a DC / AC inverter 35, a high frequency driver 36, an ECU 37, and a power source DC / DC converter 38. The rectifier 33 rectifies the AC voltage of the power received via the resonance coil 31 and converts it into a DC voltage. The DC / DC converter for power supply 38 receives the DC voltage rectified by the rectifier 33 and converts it to a predetermined DC voltage, and supplies the DC / DC converter 34, the DC / AC inverter 35, the high frequency driver 36, and the ECU 37 with the power supply voltage ( Drive voltage).

  ECU37 monitors the output signal which shows the present device state obtained from the electrical storage device 20, and controls the voltage output to the electrical storage device 20 from the DC / DC converter 34 according to a charge condition (what is called SOC), for example. The non-contact power supply / reception device 30 includes control signal exchanging means (not shown) that exchanges various electric signals (control signals and the like) such as start and end of power supply and reception in a non-contact manner. A control signal input to the non-contact power supply / reception device 30 via the control signal exchanging means is input to the ECU 37, which controls the outputs of the DC / DC converter 34, the DC / AC inverter 35, and the high frequency driver 36.

  The DC / DC converter 34 converts the DC voltage rectified by the rectifier 33 into an appropriate voltage level based on a control signal from the ECU 37 and outputs the converted voltage to the power storage device 20. In this way, charging of the electricity storage device 20 can be performed without contact with the external device 50.

  The DC / AC inverter 35 receives electric power discharged from the power storage device 20, converts it into a predetermined AC voltage based on a control signal from the ECU 37, and outputs it to the high frequency driver 36. The high frequency driver 36 converts the AC power input from the DC / AC inverter 35 into a high frequency AC voltage that can resonate with the resonance coil 62 based on a control signal from the ECU 37, and converts the high frequency power to the resonance coil 32. Output. The resonance coil 32 to which the high frequency power is input resonates with the resonance coil 62 of the external device 60 through an electromagnetic field. When the resonance coil 62 resonates with the resonance coil 32, the external device 60 receives power supplied from the power storage unit 1. In this way, the electric power discharged from the electricity storage device 20 is supplied to the PCU (power control unit) 63 of the external device 60 in a non-contact manner, and the PCU 63 can supply electric power to the motor M.

  FIG. 4 exaggeratedly shows the difference in the degree of change in internal resistance with respect to temperature change for the above-mentioned electric double layer capacitor (EDLC), lithium ion capacitor (LIC), and lithium ion secondary battery (LIB). A graph is shown. It is well known that the internal resistance varies depending on the temperature of the electricity storage device, the electrochemical reaction rate, and the like. As illustrated, the degree of change in internal resistance with respect to temperature change increases in the order of lithium ion secondary battery> lithium ion capacitor> electric double layer capacitor. The heat insulation effect obtained by contactless power supply / reception between the external devices 50 and 60 and the power storage unit 1 is particularly advantageous in a lithium ion secondary battery or a lithium ion capacitor having a large degree of change in internal resistance at low temperatures. This is preferable in that it can compensate for the decrease in output characteristics.

(2. Effect of power storage unit)
According to the embodiment, the power storage unit 1 includes the power storage element 21, the power storage casing 25 that houses the power storage element 21, and the positive terminal 22 and the negative terminal 23 that are exposed to the outside of the power storage casing 25. The power storage device 20, the storage case 10 for storing the power storage device 20 therein, the heat insulating means (vacuum layer 11a, vacuum space 11b) for blocking heat flow between the outside and the inside of the storage case 10, and the storage case 10, and a non-contact power supply / reception device 30 connected to the power storage device 20 for receiving and supplying power between the external devices 50 and 60 provided outside the storage case 10 in a non-contact manner. .

  Therefore, since heat insulation is performed between the outside and the inside of the storage case 10, heat input / output between the outside of the storage case 10 and the power storage case 25 of the power storage device 20 is blocked. In addition, since power is supplied and received between the external devices 50 and 60 in a non-contact manner, heat conduction between the outside of the storage case 10 and the storage element 21 via the positive terminal 22 and the negative terminal 23 is also cut off. The Therefore, the temperature of the electricity storage element 21 can be maintained without being affected by the outside air temperature of the storage case 10, and the electricity storage device can be avoided by avoiding lowering of output characteristics (increase in internal resistance) at low temperatures and thermal deterioration of electrode materials at high temperatures. 20 performances can be maintained appropriately.

  Moreover, according to the said embodiment, the storage case 10 is provided with the container main body 11 and the cover body 12, and the heat insulation means is the vacuum layer 11a provided in at least one of the container main body 11 and the cover body 12. Therefore, the heat conduction between the inside and the outside of the storage case 10 via the gas molecules can be suppressed without impairing the ease of assembling the power storage unit 1, and heat insulation can be performed effectively.

  In addition, a heat insulation means is not necessarily limited to the means through the vacuum described in the said embodiment, A well-known heat insulating material etc. can be used. Specifically, the container body and lid are formed of suitable foaming insulation (urethane foam, etc.), and the interior space of the container body and lid is filled with a material such as fiber insulation (glass wool, etc.). Can be.

  Moreover, according to the said embodiment, the heat insulation means is the vacuum space 11b formed in the inside of the storage case 10. FIG. Therefore, the heat conduction between the inside and the outside of the storage case 10 is more effectively interrupted, and the heat insulation between the power storage device 20 or the non-contact power supply / reception device 30 and the storage case 10 is achieved. The temperature of the electrical storage element 21 can be maintained better.

  Moreover, according to the said embodiment, the storage case 10 is formed with a non-magnetic material, and the non-contact power feeding / receiving device 30 can be a device that performs non-contact power feeding / receiving by an electromagnetic induction method or a magnetic resonance method. Therefore, it is possible to reduce the loss of electromagnetic waves that are to be induced by electromagnetic induction or magnetic resonance and should be electromagnetically resonated, thereby increasing the efficiency of power supply and reception.

  Moreover, according to the said embodiment, the electrical storage device 20 can be used as a lithium ion capacitor or a lithium ion secondary battery. Therefore, the power storage device 20 is accompanied by an oxidation-reduction electrode reaction with at least one of the electrodes (the positive electrode plate 212 and the negative electrode plate 213). Due to the temperature dependence of the electrode reaction rate, the output of the power storage device 20 particularly at low temperatures due to the outside temperature. However, there is a disadvantage that the increase / decrease width with respect to the output at high temperature is large and the control of the electric load is complicated. Maintaining the temperature of the power storage element 21 in a predetermined range can make use of an advantageous potential having a high energy density while compensating for the drawbacks.

  Moreover, according to the said embodiment, the electrical storage device 20 can be used as an electrical double layer capacitor. Therefore, it is possible to use an easily available electrode material, and it is possible to stabilize the electricity storage element 21 material particularly when the outside air temperature is high.

  In addition, for example, the power storage unit 1 of the above-described embodiment can be used as a driving assist power source for a motor that is rotationally driven to assist the steering force of the steering device. In order to meet the demand for higher output, it can be suitably used for applications in which large power is supplied by a high voltage of a capacitor provided separately from the battery, if necessary.

1: storage unit, 10: storage case, 11a, 12a: vacuum layer, 11b: vacuum space, 21: storage element, 20: storage device, 22: positive terminal (electrode terminal), 23: negative terminal (electrode terminal), 25: Storage case, 30: Non-contact power supply / reception device, 50, 60: External device

Claims (6)

A power storage element, a power storage housing for storing the power storage element therein, and one or more power storage devices having electrode terminals exposed to the outside of the power storage housing;
A storage case for storing the electricity storage device therein;
Heat insulating means for blocking heat flow between the outside and the inside of the storage case;
A non-contact power supply / reception device that is disposed inside the storage case, performs power supply / reception with an external device provided outside the storage case, and is connected to the power storage device;
A power storage unit comprising: The storage case includes a container body and a lid;
The power storage unit according to claim 1, wherein the heat insulating means is a vacuum layer provided on at least one of the container main body and the lid.   The power storage unit according to claim 1 or 2, wherein the heat insulating means is a vacuum space formed inside the storage case.   The electrical storage according to any one of claims 1 to 3, wherein the storage case is formed of a nonmagnetic material, and the contactless power supply / reception device is a device that performs contactless power supply / reception by an electromagnetic induction method or a magnetic resonance method. unit.   The electrical storage unit as described in any one of Claims 1-4 whose said electrical storage device is a lithium ion capacitor or a lithium ion secondary battery.   The electrical storage unit as described in any one of Claims 1-4 whose said electrical storage device is an electrical double layer capacitor.

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