KR20180137560A - Storage systems, vehicles, and machinery - Google Patents

Abstract

A power storage system comprising a secondary battery and a rapid charge / discharge battery device, characterized in that the power density of the secondary battery is less than 7000 W / kg and the power density of the rapid charge / discharge battery device is 7000 W / kg or more. It is also preferable that the power density of the rapid charge / discharge battery device is 9000 W / kg or more. Further, the energy density of the secondary battery is preferably 30 Wh / kg or more.

Description

Storage systems, vehicles, and machinery

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power storage system and a vehicle, an electronic apparatus, and a mechanical equipment using the same.

From the viewpoint of reducing CO ₂ and saving energy, automobiles with a hybrid system that combines an engine (gasoline engine, diesel engine, etc.) and a motor are being developed. In addition, the development of electric vehicles and fuel vehicles that are driven by motors is also underway.

The motor is powered by electricity. These motor-driven automobiles require a method of effectively utilizing electricity. Motor-driven vehicles are equipped with a power storage system that collects electricity. When the vehicle is accelerated, the motor is driven by electricity supplied from the power storage system. Further, regenerative energy generated by functioning the motor as a generator at the time of braking (deceleration) of the vehicle is charged in the power storage system.

International Publication No. WO2008 / 007626 (Patent Document 1) discloses the use of a power storage system in which a battery (secondary battery) and a capacitor are combined. The capacitor is capable of rapid discharging and rapid charging as compared with a secondary battery. By using a capacitor, deterioration of the secondary battery is prevented. On the other hand, the capacity of the capacitor was about 4000 W / kg. For example, in International Publication No. WO2001 / 093289 (Patent Document 2), an electrode material combining a carbon material and copper is used.

International Publication No. 2008/007626 International Publication No. 2001/093289 International Publication No. 2016/039157

Regenerative energy refers to recovery and accumulation of energy at the time of braking and reuse. At the time of braking, in other words, the energy at the time of deceleration is converted into electricity and stored. Conventional capacitors have a power density of about 4000 W / kg. The power storage system needs to be provided with a momentary high output when the vehicle decelerates. However, in the conventional capacitor performance, it is not always possible to cope with a momentary high output. The object of the present invention is to provide a power storage system capable of coping with such a problem and capable of coping with a momentary high output at the time of deceleration.

A power storage system according to an embodiment includes a secondary battery and a quick charge / discharge battery device. In the power storage system, the power density of the secondary battery is less than 7000 W / kg and the power density of the rapid charge / discharge battery device is 7000 W / kg or more. A power storage system capable of coping with a momentary high output power can be obtained by combining a rapid charge / discharge battery device with high power density and a secondary battery with low power density.

1 is a view showing an example of a power storage system according to the embodiment.
2 is a diagram showing another example of the power storage system according to the embodiment.
3 is a diagram showing an example of a rapid charge / discharge electric storage device.
4 is a schematic view showing an embodiment of an automobile which is an example of a power storage system according to the embodiment.
Fig. 5 is a schematic view showing an embodiment of an electric vehicle as an example of a power storage system according to the embodiment. Fig.
6 is a circuit diagram showing an embodiment of a medical device which is an example of a power storage system according to the embodiment.
7 is a schematic diagram showing an embodiment of an elevator which is an example of a power storage system according to the embodiment.
8 is a schematic diagram showing an embodiment of a robot which is an example of a power storage system according to the embodiment.

The power storage system according to the embodiment is characterized in that the power density of the secondary battery is less than 7000 W / kg and the power density of the rapid charge / discharge battery device is not less than 7000 W / kg in the power storage system including the secondary battery and the rapid charge / .

1 shows an example of a power storage system. In the figure, reference numeral 1 denotes a power storage system, 2 denotes a secondary battery, and 3 denotes a rapid charge / discharge storage device.

In the power storage system 1, the secondary battery 2 and the rapid charge / discharge battery device 3 are connected in parallel. The secondary battery 2 may be a battery capable of charging and discharging. Examples of such a battery include a Li ion secondary battery, a nickel hydrogen battery, a lead acid battery, and a fuel cell. The secondary battery 2 has a power density of less than 7000 W / kg. Also, the power density of the rapid charge / discharge battery device is 7000 W / kg or more. The power density of the rapid charge / discharge battery device is preferably 9000 W / kg or more.

The power density shows how much output is obtained per kg (kilogram). It is a value indicating the instantaneous power supply amount of the power storage device. The larger the power density, the larger the instantaneous power supply.

Also, the power density can be expressed not only as output per weight, but also as output per unit volume. For example, the power density can be expressed as an output per liter (l) instead of the output per kilogram. The power density per volume, in which the unit of volume is expressed as 1 L, indicates how much power per 1 L is obtained.

It is desirable that the power density of the rapid charge / discharge battery device is 7000 W / kg or more and 10000 W / L or more. In this case, it is possible to cope with both of the rapid charging / discharging storage device, and further, the weight saving and miniaturization of the power storage system.

The power density for the rapid charge / discharge battery device can be obtained, for example, as follows.

The power density represented by the weight of the single cell of the rapid charge / discharge battery device, that is, the weight power density P (W / kg), can be obtained by the following equation (1).

P (W / kg) = (V ₁ ² -V ₂ ² ) / 4RM (1)

Here, V ₁ is the discharge start voltage (V), V ₂ is the discharge end voltage (V), R is the internal resistance (?), And M is the cell weight (kg).

The power density, that is, the volume power density P (W / L) represented by the volume of the single cell of the rapid charge / discharge battery device can be obtained by the following equation (2).

P (W / L) = (V ₁ ² -V ₂ ² ) / 4RV (2)

Here, V ₁ is the discharge start voltage (V), V ₂ is the discharge end voltage (V), R is the internal resistance (?), And V is the cell volume (L).

When the power storage device is a rapid charge / discharge storage device including, for example, tungsten oxide as described later in the electrode layer, the discharge start voltage V ₁ and the discharge end voltage V ₂ may be set to the following values. The discharge start voltage V ₁ is set to 2.5V. And the discharge end voltage V ₂ is set to 1.5V. Referred to here discharge start voltage V ₁ and the end of discharge voltage V ₂ is, for example, the power storage device will to correspond to excessive charging or excessive discharging upper and lower limits of the voltage range that can be safely charged and discharged is not, the power storage device The cell voltage when the state of charge (SOC) of the laminate cell is 100%, and the cell voltage when the state of charge is 0%, respectively.

The internal resistance R can be measured in the following manner. First, the SOC of a storage device, for example, a laminate cell, to be measured is adjusted to 50%. The laminate cell is subjected to series resistance measurement at 1 kHz (amplitude 10 mV) by an alternating current impedance method, and the obtained value is referred to as an internal resistance R. [

The cell weight M is obtained by measuring the weight (including external containers) of the laminate cell to be measured. The cell volume V is calculated from the length in the longitudinal direction, the width in the lateral direction and the thickness (V = length × width × thickness (thickness)) by measuring the dimensions of the laminated electrode portion ).

For example, a plurality of power storage devices may be electrically connected in series in order to supplement the performance of each power storage device when a power storage device with insufficient performance is used. In this case, even if sufficient performance as a whole is obtained, the number of power storage devices increases, and the overall weight or volume increases. That is, even if a plurality of power storage devices are used in combination to increase the overall output (power), the output per unit weight or volume (power density) is still low.

The rapid charge / discharge battery device in the power storage system according to the embodiment has a high power density and can exhibit sufficient output even in a single cell state, for example. Further, even when a plurality of cells of the rapid charge / discharge battery device are electrically connected in series, for example, a high output can be obtained while suppressing an overall increase in weight or volume to a relatively low level. That is, the weight power density of the rapid charge / discharge battery device is, for example, 7000 W / kg or more per cell. Further, even when a plurality of cells are connected in series, the overall weight power density may be 7000 W / kg or more. Similarly, the volume power density of the rapid charge / discharge battery device is, for example, 10000 W / L or more per cell, and the total volume power density may be 10000 W / L or more even when a plurality of cells are connected in series.

As a specific example, when twelve rapid charging / discharging electric devices having one cell with a power density of 13000 W / kg and one cell with a weight of 0.09 kg are connected in series, the total power (W) is 14040 W, . Power (W) = power density (W / kg) × weight (kg) × number of series. Alternatively, power (W) = power density (W / L) x volume (L) x number of series can also be obtained.

The power storage system of the embodiment is a combination of a secondary battery having a power density of less than 7000 W / kg and a rapid charge / discharge storage device of 7000 W / kg or more. Since the rapid charge / discharge battery device having high power density is used, charge / discharge can be performed by the rapid charge / discharge battery device before the secondary battery. Therefore, momentary power supply becomes possible.

The secondary battery preferably has an energy density of 30 Wh / kg or more. The energy density is a value indicating the capacity of the secondary battery. A secondary battery having a large capacity, and a power storage device having a high instantaneous power. Such a power storage system can perform rapid charge and discharge by the rapid charge / discharge storage device. Therefore, the number of charging and discharging of the secondary battery can be reduced. Thus, deterioration of the secondary battery can be prevented.

Although the values of the power density and the energy density are different depending on the type of the secondary battery, a typical example is given below.

The power density of a typical lithium ion secondary battery may be, for example, about 2400 W / kg (about 3730 W / L). The energy density of a typical lithium ion secondary battery may be, for example, about 120 Wh / kg (about 190 Wh / L).

The power density of a typical lead battery may be, for example, about 100 W / kg. The energy density of a typical lead battery may be, for example, about 30 Wh / kg.

The power density of a typical nickel hydrogen battery may be, for example, about 300 W / kg. The energy density of a typical nickel hydrogen battery may be, for example, about 40 Wh / kg.

Also, the power density of a typical capacitor such as an Electric Double Layer Capacitor (EDLC) may be, for example, about 6700 W / kg. The energy density of a typical capacitor may be, for example, about 4 Wh / kg.

The ratio of the energy density (Wh / kg) of the storage system / the cell weight (kg) of the storage system to the cell weight of the storage system when the total weight of the cells of the secondary battery cell and the rapid charge- Or more. The fact that the energy density is higher than the cell weight of the storage system indicates that it is lighter than the capacity.

In other words, when the energy density of the power storage system is represented by E _S , and the total weight of the cells of the secondary battery and the cells of the rapid charge-discharge device in the power storage system is represented by W _S , the energy density E _S it Wh / kg) and greater than the non-E _S / W _S, i.e., the total energy density on the total weight of the cell according to the power storage system of the cell weight W _s (kg) of the power storage system 1 is preferred. Such a preferable power storage system satisfies the relationship E _S / W _S? 1.

Also, by using a rapid charge / discharge battery device having high power density, it is possible to reduce the size and weight of the power storage system. The reduction in size and weight of the power storage system is also effective in improving the fuel economy of the vehicle when mounted on a vehicle to be described later. Further, as described later, when the regenerative energy of the vehicle is charged, it is possible to store even at a speed of 25 km / h or more.

Further, as shown in Fig. 2, a plurality or a plurality of types of secondary batteries or quick charge / discharge devices may be connected. 2, the first secondary battery 2-1, the second secondary battery 2-2, the first rapid charge / discharge battery device 3-1, and the second rapid charge / discharge battery device 3-2 . The first secondary battery 2-1 and the second secondary battery 2-2 are connected in series. Further, the first rapid charge / discharge battery device 3-1 and the second quick charge / discharge battery device 3-2 are connected in series. The secondary batteries are connected in series and the rapid charging / discharging storage devices are connected in series. The secondary battery group and the fast charge / discharge storage device group are connected in parallel. Thus, the capacity of the power storage system can be increased.

2 shows an example in which two secondary batteries 2-1 and 2-2 are electrically connected in series in the secondary battery group. However, in the secondary battery group, three or more secondary batteries may be connected in series. Alternatively, in the secondary battery group, three or more secondary batteries may be electrically connected by a combination of series connection and parallel connection.

On the other hand, in the fast charge / discharge storage device group in Fig. 2, the two rapid charge / discharge devices 3-1 and 3-2 are electrically connected in series. However, in the rapid charge / discharge storage device group, three or more rapid charge / discharge storage devices may be connected in series. Alternatively, in the rapid charge / discharge storage device group, three or more rapid chargeable / dischargeable devices may be electrically connected by a combination of series connection and parallel connection.

Further, the form of electrical connection between the secondary battery 2 and the quick charge / discharge battery device 3 is not limited to the parallel connection. For example, when the power storage system 1 is provided in a vehicle such as an automobile, the secondary battery 2 and the rapid charge / discharge storage device 3 (the secondary battery group and the rapid charge / discharge storage device group) And can be connected in series.

In automobiles, alternators are used. Electricity (regenerative energy) generated by the alternator is first accumulated in the rapid charge / discharge battery device, as will be described later in detail. Thereafter, electricity from the rapid charge-discharge device is charged into the secondary battery electrically connected in series with the rapid charge-discharge device through a control circuit such as a DC-DC converter. The electricity charged in the secondary battery can be supplied to a load including an electronic device such as an air conditioner built in a vehicle, for example.

The battery device connected to the alternator of the vehicle may be electrically connected in parallel with the secondary battery group and the group of rapid charging and discharging storage devices.

In addition, the secondary battery and the rapid charge / discharge battery device may be integrated unit structures or may be disposed at distant positions.

The secondary battery and the rapid charge / discharge battery device may be electrically connected directly, or may be connected through a control circuit such as a DC-DC converter, for example, as in the above example.

In addition to the DC-DC converter, the control circuit may include a switching element, an average cell voltage control, a current sensor, and the like. In addition, a CPU, a temperature sensor, and the like may be provided as necessary.

It is also preferable that the rapid charge / discharge battery device is provided with tungsten oxide powder in the electrode layer. 3 shows an example of the cell structure of the rapid charge / discharge battery device. In the figure, reference numeral 4 denotes a negative electrode, 5 denotes a positive electrode, 6 denotes a negative electrode layer, 7 denotes a positive electrode layer, 8 denotes a separator, and 9 denotes an electrolyte solution.

A negative electrode layer 6 is provided on the negative electrode side electrode 4. A positive electrode layer 7 is provided on the positive electrode 5. The negative electrode layer 6 and the positive electrode layer 7 are opposed to each other with the separator 8 interposed therebetween. An electrolyte 9 is filled between the negative electrode layer 6 and the positive electrode layer 7.

It is preferable to provide tungsten oxide powder in either the negative electrode layer 6 or the positive electrode layer 7. [ The tungsten oxide powder preferably has an activation energy E _alpha of 0.05 eV or less. Further, it is preferable that the powder has a hopping conduction characteristic at room temperature (25 캜). Further, it is preferable that the oxygen deficiency amount of the powder is 1 x 10 ¹⁸ cm ^-3 or more. It is also preferable that the carrier density of the powder is not less than 1 x 10 ¹⁸ cm ^-3 . The average particle diameter of the powder is preferably 50 占 퐉 or less, more preferably 10 占 퐉 or less. It is also preferable that the nanoparticles have an average particle diameter of less than 1 mu m. Such tungsten oxide powder is disclosed in International Publication No. WO2016 / 039157 (Patent Document 3).

The tungsten oxide powder of the present invention can increase the storage capacity and improve the charging / discharging efficiency by providing oxygen deficiency. Further, by increasing the amount of oxygen deficiency, it is preferable to set the range of WO _{2.68 to 2.75} .

By introducing oxygen deficiency into the crystal structure of tungsten oxide, the diffusion path of Li ions in the crystal structure becomes large. For example, the crystal structure of tungsten oxide having a composition represented by WO _2.72 has a hexagonal tunnel and diffusion of Li ions in the crystal is fast. Because of this, Li ion conductivity is high, so that the charging and discharging efficiency is enhanced. Further, as will be described later, by introducing oxygen deficiency, the internal resistance of the electrode layer including tungsten oxide can be reduced. Further, the internal resistance of the rapid charge / discharge battery device can be reduced.

The introduction of oxygen deficiency into the crystal structure of tungsten oxide can be performed, for example, by treating the tungsten oxide powder in a hydrogen-mixed nitrogen atmosphere.

The positive electrode 5 and the negative electrode 4 are made of a conductive material. Examples of the conductive material include copper, aluminum, titanium, carbon-coated aluminum, carbon-coated copper, and alloys thereof.

When the tungsten oxide powder is used for the negative electrode layer 6, the positive electrode layer 7 is preferably a lithium composite oxide. Examples of the lithium composite oxide include lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganese oxide (LiMn ₂ O ₄ ), ternary materials (for example, LiNi _1/3 Mn _1/3 Co _{1 / 3} O ₂ ) and the like are preferable. When the tungsten oxide powder is used for the positive electrode layer 7, the negative electrode layer 6 is preferably a graphite-based material or a metal layer pre-doped with Li. Examples of the graphite-based material include graphite, hard carbon, carbon nanotubes, graphene, and fullerene. Examples of the metal layer include lithium, silicon, and a silicon alloy. It is preferable that the electrode layer disposed opposite to the electrode layer made of the tungsten oxide powder is a Li single layer or a Li composite oxide. The combination of these can efficiently transfer Li ions. Therefore, the power density and the energy density can be increased.

In addition, it is preferable that the internal resistance of the electrode layer including tungsten oxide powder is lowered so that the cell of the rapid charge-discharge battery device is reduced in weight and in size. Specifically, by reducing the internal resistance of the electrode layer, it is preferable to set the internal resistance of the rapid charge-discharge battery device to 10 Ω · cm ² or less.

In addition, by reducing the internal resistance, it is possible to reduce the heat generation amount of the cell during power storage. Thereby, even if the moving speed of the vehicle is 25 km / h or more, electric energy such as regenerative energy can be safely stored.

When the moving speed of the vehicle is high, the regenerative energy becomes a large current. If a large current is to be stored, the cell generates heat and a safety problem arises. For this reason, conventionally, the regenerative energy is stored only in a low speed region of 15 km / h or less, for example. Since the rapid charge / discharge battery device according to the embodiment reduces the internal resistance, the amount of heat generated by the cell can be suppressed. Thus, even when the moving speed of the vehicle is 25 km / h or more, safety at the time of storage is high.

The internal resistance in the electrical storage device can be reduced, for example, as follows. For example, by introducing oxygen deficiency into the crystal structure of tungsten oxide, the internal resistance of the electrode layer can be lowered.

A method of mixing a conductive material with a tungsten oxide powder may also be mentioned. It is also effective to provide a conductive material between the electrode layer made of tungsten oxide powder and the negative electrode or the positive electrode. As the conductive material, carbon powder can be mentioned. The internal resistance of the electrode layer can be reduced by using the tungsten oxide powder and the conductive material together. The reduction of the internal resistance is connected to the improvement of the power density. B / A? 0.3 when the weight of the tungsten oxide powder is A (g) and the weight of the conductive material (carbon powder) is B (g). If it is less than 0.01, the effect of addition of the conductive material is small. On the other hand, if it is more than 0.3, the content of the tungsten oxide powder is reduced and the capacity is lowered. It is preferable that C> D when the average particle diameter of the tungsten oxide powder is C (mu m) and the average particle diameter of the conductive material is D (mu m). By reducing the particle diameter of the conductive material, the tungsten oxide powder enters the gap between the tungsten oxide powders, so that the internal resistance can be easily reduced.

More specifically, for example, a conductive auxiliary agent such as acetylene black, ketjen black or graphite may be used as the conductive material to be mixed with tungsten oxide or the conductive material to be provided between the electrode layer and the negative electrode or the positive electrode. For example, by mixing the particulate conductive auxiliary agent and the tungsten oxide powder, the contact resistance between the particles in the electrode layer can be reduced, and as a result, the internal resistance can be suppressed.

When a conductive material is provided between the electrode layer and the negative electrode or between the positive electrode and the negative electrode, a conductive layer such as a carbon layer is formed on the metal foil or the alloy foil as the negative electrode or the positive electrode, The adhesion between the electrode layer and the foil can be improved.

The method of forming the conductive layer is not limited to the following, but a conductive layer can be formed, for example, as follows. The coating material containing the conductive material is applied to the surface of the foil. By drying the applied coating material, a conductive layer is obtained. Further, in the case where a carbon layer is formed on the aluminum foil by using a coating material containing a carbon material as the conductive material, carbon coated aluminum can be produced.

As another method for lowering the internal resistance, there is a method of increasing the electrode density by performing a pressing treatment. As an example, the case where tungsten oxide powder is contained in the negative electrode layer will be described below.

First, a negative electrode layer (tungsten oxide layer) is formed on the negative electrode. The negative electrode layer may contain a conductive material (a conductive auxiliary agent) in addition to the tungsten oxide powder. In addition, the negative electrode may include a conductive layer.

The formed negative electrode layer is subjected to a pressing treatment. At this time, the density of the negative electrode layer, which was 1.8 g / cm ³ , for example, could be increased to about 3.6 g / cm ³ as a result of the press. Preferably after pressing the electrode density not less than 2.2g / cm ^3, more preferably not less than 3.0g / cm ^3. It is also preferable that the positive electrode (not including tungsten oxide), which is a counter electrode, is also subjected to a pressing treatment.

In the above example, a negative electrode layer containing tungsten oxide is used. However, in the case of a power storage system having a positive electrode layer containing tungsten oxide, the density of the positive electrode layer can also be increased by pressing.

The press pressure in the press treatment is preferably 300 kg / cm or more for both the negative electrode side and the positive electrode side. Thereby, the electrode density of either the negative electrode layer or the positive electrode layer can be set to 2.2 g / cm ³ or more.

These means for reducing the internal resistance may be combined. For example, tungsten oxide with oxygen deficiency and metal foil coated with a carbon layer can be combined.

The thickness of the positive electrode layer 7 and the negative electrode layer 6 is preferably in the range of 1 占 퐉 to 100 占 퐉. The positive electrode layer 7 or the negative electrode layer 6 made of tungsten oxide powder preferably has a porosity of 20% or more and 80% or less. If the film thickness is less than 1 mu m, the amount of tungsten oxide powder is small and the capacity is reduced. On the other hand, if it is thicker than 100 mu m, the electrolyte may be hardly penetrated into the inside. If the porosity is higher than 80%, the amount of tungsten oxide powder is reduced, and the capacity is lowered. If the porosity is less than 20%, the electrolytic solution may hardly enter the inside.

The contact area between the tungsten oxide powder and the other electrode material and the electrolyte decreases if the electrolyte does not reach the inside of any of the positive electrode layer 7 and the negative electrode layer 6. [ As a result, the efficiency of the exchange of Li ions between the positive electrode and the negative electrode is lowered, so that the power density of the electrical storage device may be lowered.

As described above, when the electrode density is increased by the pressing treatment, it is preferable to increase the electrode density in a range where the porosity stays 20% or more and 80% or less.

It is preferable that the separator is made of porous polyethylene or polypropylene and has a thickness of 5 占 퐉 or more and 50 占 퐉 or less so as to prevent a short circuit by the negative electrode and the positive electrode. The electrolytic solution contains LiPF ₆ , LiBF ₄ , LiClO ₄ , and LiCF ₃ SO ₃ as a Li salt as an electrolyte, and contains ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), gamma butyrolactone (γ-BL), valerolactone (VL) It is preferably a mixed solvent.

It is preferable to increase the area where the positive electrode and the negative electrode face each other to improve the power density because the number of regions in which Li ions can be efficiently received between these electrodes increases. The opposed areas of the positive electrode and the negative electrode can be enlarged by, for example, enlarging the area of each electrode and arranging a lot of overlapping portions therebetween. Further, by using a plurality of positive electrodes and a plurality of negative electrodes, for example, by constructing a multi-layer laminate type laminated cell, the opposing areas of the positive electrode and the negative electrode can be collectively increased.

By appropriately combining the above design, the power density of the rapid charge / discharge battery device can be made 7000 W / kg or more. Specifically, tungsten oxide powder is used for the electrode layer, the internal resistance is reduced by the above means, the thickness and the porosity of the electrode layer are set within the above-mentioned range, and the area where the positive electrode and the negative electrode face each other is increased, A rapid charge / discharge storage device can be obtained.

In the above-described power storage system, rapid charging and discharging becomes possible. In addition, since the rapid charge / discharge battery device having high power density can be preferentially used, the number of times of use of the secondary battery can be reduced. As a result, the service life of the secondary battery can be extended. Further, by using a rapid charge / discharge battery device having a power density of 7000 W / kg or more, it is possible to achieve miniaturization and weight saving as a power storage system.

Such a power storage system is preferably used in vehicles, electronic equipment, and mechanical equipment.

The vehicle includes a car, a train, and the like. A car is a motor-driven automobile such as a hybrid car or an electric car. Further, the automobile is not particularly limited such as a private car, a bus, a crane car, and a truck.

The motor-driven vehicle recovers and accumulates energy when decelerating. The energy at deceleration is called the regenerative energy. This regenerative energy is stored in the rapid charge / discharge storage device. The regenerative energy is generated when decelerating, in short, during braking. The brakes will be stepped on each time. Since the rapid charge-discharge device with a power density of 7000 W / kg or more is used, the instantaneous regenerative energy can be efficiently recovered. In addition, electricity necessary for acceleration of the motor can be instantaneously supplied. Also, the regenerative energy is generated at the time of deceleration. Until now, only a deceleration down to 15 km / h or less has been saved. By using a rapid charge / discharge battery device having a power density of 7000 W / kg or more, the regenerative energy can be stored even when the moving speed of the vehicle is 25 km / h or more. Also from this point, the efficiency of the storage increases. In addition, it is also possible to reduce the weight, which leads to an improvement in fuel economy.

Further, the electronic apparatus represents an apparatus that is electrically driven. For example, medical devices such as CT set the contract power to the maximum power. On the other hand, it is used at about 50% to 80% of the maximum power under normal use conditions. By using the power storage system according to the embodiment, power can be supplied from the power storage system only when maximum power is required. As a result, the contracted power can be lowered. Since a rapid charge / discharge system with high power density is used, even if the maximum power is instantaneously required, it can be supplied sufficiently. The electronic device includes, for example, using a method of supplementing power that is insufficient for maximum power by a power storage system.

In addition, the machinery is equipped with running equipment. As the mechanical equipment, there is one kind selected from an elevator, a crane, a robot, and a machine tool. These machines are equipped with motors. For example, the elevator has a motor (a traction machine) for raising and lowering the car up and down. When the motor is attached, it repeats rising and falling. The regenerative energy can be stored at the time of ascending and descending. By using a rapid charge / discharge device with a power density of 7000 W / kg or more, even slight acceleration / deceleration can be stored.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power storage system according to an embodiment will be described below with reference to drawings, with reference to the drawings.

Fig. 4 is a schematic diagram showing the recovery of regenerative energy of a motor vehicle as an example of an embodiment of a vehicle related to the power storage system according to the embodiment, more specifically, an automobile. In the figure, reference numeral 2 denotes a secondary battery, 3 denotes a rapid charge / discharge battery device, 10 denotes an alternator, 11 denotes a DC-DC converter, 12 denotes a load, 41 denotes an engine and 42 denotes a wheel.

The alternator 10 is an alternating current generator for converting kinetic energy of rotation of the engine 41 into electric energy and is responsible for energy recovery. For example, even when the vehicle is decelerated, the rotation of the wheel 42 that rolls the road surface is transmitted to the engine 41 via the power transmission mechanism such as an axle or a differential gear, so that the engine 41 rotates. The alternator 10 performs power generation using this rotation energy.

The electric energy generated by the alternator 10 is once stored in the rapid charge / discharge storage device 3. [ Thereafter, electricity can be collected from the rapid charge / discharge battery device 3 through the DC-DC converter 11 to the secondary battery 2. Further, electricity can be supplied from the secondary battery 2 to the load 12 and used. The load 12 includes, for example, an electronic device built in a vehicle, such as a car navigation system, an air conditioner, and an audio device.

By using the electricity collected in the secondary battery 2 as the power for the load 12, for example, it is possible to supply power sufficiently even if the power generation in the engine consuming the fuel in the hybrid car is reduced. As a result, fuel consumption can be reduced.

Generating by the alternator 10 and charging the power storage system is referred to as energy recovery. That is, the kinetic energy at the time of deceleration of the automobile is converted into electric energy, and is recovered as regenerative energy.

Deceleration energy recovery is greatly affected by the water solubility. That is, when the charging (charging) speed and capacity of the battery or the power storage system are not sufficient when the alternator is charged (regenerated) with the regenerative energy into the battery or the power storage system, the recovery rate of the regenerative energy may be lowered. For example, the charge acceptance of the lead battery is limited, and the generated power of the alternator can not be efficiently recovered. Therefore, the utilization of the capacitor is under review. However, for a lead battery whose terminal voltage is almost constant, the voltage of the capacitor varies depending on the charged state. Therefore, the alternator needs to cope with a wide voltage. In consideration of this, a variable voltage type alternator corresponding to a voltage of 12V-25V is also being developed. By employing this alternator, it is possible to increase the capacitor voltage up to 25 V at the time of deceleration regeneration, and it is possible to improve the energy regeneration amount.

The amount of current varies depending on the output and voltage of the alternator. For example, assuming that the terminal voltage of the power storage system is 24V, if the output from the alternator is 3kW, then the power storage system is charged (3kW = 24V x 125A) with a current of 125A and if the output is 5kW, 24V × 208A), and if the output is 10kW, the power storage system is stored at a current of 416A (10kW = 24V × 416A).

If the amount of current from the alternator to the power storage system is too large, there is a fear that the cell is heated and the temperature rises and safety is impaired. In order to ensure safety, for example, a control circuit having a safety mechanism for putting a switch of the cooling mechanism in a case where the temperature has risen or a stop mechanism for stopping the current flow may be adopted. Since it consumes electric power to operate the cooling mechanism, it is preferable that the amount of current is not excessively increased. For example, it is desirable that the design is such that the charge water solubility of the power storage system can correspond to the output of the alternator.

The secondary battery 2 has a large capacity as compared with the rapid charge / discharge battery device 3. It is possible to provide a margin for the capacity of the rapid charging and discharging device 3 by charging the regenerated secondary battery 2 with electricity from the rapid charging and discharging device 3 through the DC-DC converter 11. [ By doing so, the rapid charge / discharge electric storage device 3 can recover the regenerated energy generated when the vehicle decelerates next time, without leaving out. If there is not enough margin in the capacity of the rapid charge / discharge battery device 3, the amount of recovering the regenerative energy can be reduced. Otherwise, the rapid charge / discharge electric storage device 3 may be overcharged and the safety may be impaired.

Fig. 5 is a schematic diagram showing the recovery of the regenerative energy of the electric motor as one example of the embodiment relating to the power storage system according to the embodiment, more specifically, the electric vehicle, that is, the railway vehicle. In the drawings, reference numeral 50 denotes a train, 51 denotes a pentagonal, 52 denotes a wheel, 1 denotes a power storage system, 21 denotes a voltage converter, 22 denotes an inverter, 23 denotes a line, and 31 denotes a line.

A drive motor (not shown) for driving the pentagraph 51, the voltage converter 21, the power storage system 1, the inverter 22, and the wheel 52 is electrically connected to the electric motor vehicle 50 . Further, the pentagraph 51 comes into contact with the cantilever 23 disposed on the route of the electric motor vehicle 50. In order to ensure contact between the pentagraph 51 and the guard 23, the pentagonal 51 may be of a height changeable by, for example, a spring-like structure.

DC power is supplied from the guard wire 23 to the electric motor vehicle 50 via the pentagonal line 51. The voltage converter 21 appropriately converts the DC voltage, for example, converts a direct current of 1500 V into a direct current of 600 V, and supplies the direct current to the inverter 22 and the power storage system 1. [ The voltage converter 21 may be, for example, a DC-DC converter. The inverter 22 converts the direct current power into alternating current and supplies it to the drive motor. As the wheel 52 is driven by the operation of the drive motor, the electric motor vehicle 50 can be driven.

The DC power supplied to the power storage system 1 is stored in, for example, a secondary battery or a secondary battery group included in the power storage system 1. In addition, the direct current can be supplied to both of the rapid charge / discharge storage device or the rapid charge / discharge storage device group or the rapid charge / discharge storage device (group) and the secondary battery (group) included in the power storage system 1 instead of the secondary battery .

When the electric motor vehicle 50 is decelerated, for example, power supply to the drive motor is interrupted and brake is applied. When the wheel 52 rolls on the line 31, the driving motor rotates, and regenerative electric power is generated. The inverter 22 converts the regenerative electric power generated in the drive motor into a direct current and supplies it to the power storage system 1. The regenerative power supplied to the power storage system 1 after being DC-converted is stored in the rapid charge / discharge battery device. The power storage system 1 can regenerate kinetic energy at the time of deceleration by storing the regenerative electric power.

Since the power density of the rapid charge / discharge battery device is high, the charge storage property of the power storage system 1 is high. For example, even if the instantaneous regenerative power is large, the temperature rise of the rapid charge / discharge accumulation system is small. Therefore, the regenerative electric power at the time of deceleration can be large current in the electric vehicle 50 that repeats the acceleration from the inter-station to the high traveling speed and the deceleration therefrom, but the power storage system 1 can cope with the input of the large current.

The regenerative electric power stored in the rapid charge-discharge device by energy recovery can be subsequently charged into the secondary battery. As in the case of the automobile described above, the regenerative energy is transferred to the secondary battery having a larger capacity to provide a capacity margin to the rapid charging / discharging storage device, whereby the regenerative electric power when the electric vehicle 50 is decelerated next is recovered more . It is preferable that the power supplied through the pentagraph 51 is charged in the secondary battery of the power storage system 1 in order to secure a capacity margin in the rapid charge /

The electric power stored in the power storage system 1 (the rapid charge / discharge accumulation device and / or the secondary battery) can be used, for example, to drive the electric vehicle 50 in the section without the cusp 23. Further, electric power stored in the power storage system 1 can be used as electric power of an electronic apparatus in which the electric vehicle 50 such as a light load, an air conditioner, an electronic display panel, etc., is incorporated.

Embodiments of a power storage system in a mechanical equipment will be described with reference to the drawings. The mechanical equipment using the power storage system according to the embodiment includes an electronic equipment requiring a power source for driving and a mechanical equipment including a facility requiring a power source when operating.

Fig. 6 is a circuit diagram showing an X-ray generating apparatus as an example of an embodiment of a mechanical apparatus related to a power storage system according to an embodiment, more specifically, a medical instrument. In the figure, reference numeral 60 denotes an X-ray generator, 61 denotes a generator (X-ray generator), 62 denotes a central processing unit (CPU), 1 denotes a power storage system, 24 denotes an switchboard, and R1 denotes a photographing room.

The X-ray generator 60 may be, for example, an X-ray irradiator included in an X-ray CT (Computed Tomography) apparatus. The X-ray CT apparatus may include, for example, an X-ray detector capable of exchanging a signal with a wire or wireless with the X-ray generator 60.

The CPU 62 controls the operation of the X-ray generator 60. For example, the CPU 62 can control and manage the supply of electric power to the respective parts of the X-ray generator 60. [ Further, the CPU 62 can control and manage the operation of the entire X-ray CT apparatus including the exchange of signals between the X-ray generator 60 and the X-ray detector.

The commercial power is supplied from the distribution board 24 to the power storage system 1. [ The commercial power is stored in both the rapid charge / discharge storage device of the power storage system 1, the secondary battery, or the rapid charge / discharge storage device and the secondary battery. A part of the commercial power is also supplied to the CPU 62 and used to operate the CPU 62. [ The switchboard 24 may be, for example, a switchboard provided in a medical facility provided with the X-ray generator 60. [

The electric power stored in the power storage system 1 is supplied to the generator 61. The supply amount of electric power to the generator 61 is controlled by the CPU 62 because the amount of electric power required by the generator 61 differs depending on the use situation. For example, the power consumed by the generator 61 when generating an X-ray for capturing an X-ray image may be 5.5 kWs (using an X-ray generator with an output of 80 kW and consuming 110 kVA for 50 msec . On the other hand, for example, the power consumed by the generator 61 is low during the waiting time after waiting for the next photographing after the photographing of the X-ray image.

Power can be supplied from the rapid charge / discharge battery device to the generator 61 when a large amount of electric power is required in a short period of time, for example, when an X-ray requiring a high output is instantaneously required. Since the energy density of the rapid charge-discharge device is high, it is possible to cope with a momentary high output. Power can be supplied to the generator 61 from the secondary battery, for example, during the waiting time when the power consumption is small. It is preferable to use the electric power stored in the rapid charge / discharge electric storage device only when a high output is required in order to secure a power margin against high output such as at the time of photographing of an X-ray image.

The X-ray generator 60 requires a lot of power (for example, 5.5 kWs) when generating X-rays in the generator 61, for example, but does not require much power in the air, for example. That is, a high power supply amount may be required only when the generator 61 is operated. For example, when the commercial power supplied from the switchboard in the air is stored in the rapid charge / discharge storage device of the power storage system 1 and the generator 61 is operated, the power stored in the rapid charge / discharge storage device is momentarily taken Can be used. As a concrete example, it is assumed that the amount of power for operating the generator 61 is 5.5 kWs, and the operation is performed once every 5 seconds. When the 1.1 kW of power is supplied to the rapid charge / discharge battery device during the waiting time of 5 seconds and accumulated, the operation of the generator 61 can be procured at the moment of shooting.

Thus, by using the power storage system 1, sufficient power can be supplied to the generator 61 even when the power supplied from the power distribution board 24 is always suppressed to a low level. Therefore, even when the contracted power does not satisfy the maximum power required for operation of the X-ray generator 60, the operation of the X-ray generator 60 is not hindered.

The generator 61 of the X-ray generator 60, the CPU 62 and the power storage system 1 can be installed in the photographing room R1 in the medical facility as shown in the figure. Alternatively, at least one of the CPU 62 and the power storage system 1 may be installed outside the photographing room R1. For example, the CPU 62 and / or the power storage system 1 may be installed in a front chamber (not shown) adjacent to the photographing room R1. The distribution board 24 may be provided outside the photographing room R1 as shown in Fig. 6, or may be installed in the photographing room R1.

The medical facility may have a plurality of photographing rooms R1 in which the generators 61 are installed. The CPU 62 may be provided in each of the plurality of photographing rooms R1, or a single CPU may manage the operations in all the photographing rooms collectively. Alternatively, for example, one power storage system 1 may be provided in each of the generators 61 in the plurality of photographing rooms Rl. Alternatively, the power storage system 1 may be provided in each of the plurality of photographing rooms R1, The power supply to the power source can be provided.

As an embodiment of an elevator relating to a power storage system according to an embodiment, Fig. 7 shows a schematic diagram showing the operation of the elevator. In the drawings, reference numeral 70 denotes an elevator, 71 denotes a car, 72 denotes a balance weight, 73 denotes a traction machine, 1 denotes a power storage system, 25 denotes a commercial power supply, and 26 denotes a control panel.

The car 71 and the balance weight 72 are connected to each other by a cable or the like through a hoisting machine 73 and a pulley. For example, when the traction machine 73 pulls the cable in one direction, the counterweight 72 descends with the car 71 rising. When the hoisting machine 73 pulls the cable in the opposite direction, the counterbalance 72 rises with the car 71 descending.

The control panel 26 supplies electric power from the commercial power supply 25 to the traction machine 73 in accordance with the situation. The hoisting machine 73 is operated using the supplied electric power, so that the car 71 can be raised and lowered. When the electric power is accumulated in the secondary battery or the rapid charging / discharging storage device of the power storage system 1, that is, when the charging is left, the control panel 26 receives the power from the secondary battery or the rapid charging / discharging storage device The electric power can be supplied to the traction machine 73. The control panel 26 may simultaneously supply electric power to the traction machine 73 from both the commercial power supply 25 and the power storage system 1. [

The balance weight 72 is designed such that the balance weight 72 is balanced with the car 71 when the number of passengers of the car 71 is about half of the capacity. The hoisting machine 73 is operated by the electric power supplied from the commercial power supply 25 or the power storage system 1 in the state in which the weight of the counterbalance 72 is substantially equal to the weight of the car 71 including the occupant, 71).

When the number of people riding on the car 71 is large, the weight of the car 71 including the occupant may be higher than the weight of the weight 72. In this case, gravity can be used when lowering the crawler 71, and the cable is pulled toward the crawler 71 as the crawler 71 descends. As the cable passes through the hoisting machine 73, the hoisting machine 73 rotates and generates electricity. That is, when the car 71 descends due to gravity, regenerative electric power is generated.

On the other hand, when the number of people riding on the car 71 is small, the weight of the car 71 including the occupant can be lower than the weight of the weight 72. [ In this case, the action of gravity on the balance weight 72 can be utilized when raising the car 71, and the cable is attracted toward the balance weight 72 as the car 71 rises. As the cable passes through the hoisting machine 73, the hoisting machine 73 rotates and generates electricity. That is, when the balance weight 72 is lowered by gravity, regenerative electric power is generated.

In any case, the regenerative electric power generated by the traction machine 73 is supplied to the rapid charge / discharge electric storage device of the power storage system 1 through the control panel 26. The regenerative power can be supplied to the secondary battery once it is stored in the rapid charge / discharge battery device. Alternatively, the regenerative electric power accumulated in the rapid charge-discharge battery device can be supplied to the traction machine 73 as electric power for raising and lowering the car 71. It is preferable to secure a margin of the capacity of the rapid charge-discharge battery device in order to maintain a large amount of regenerative power that can be recovered, as in the case of the vehicle described above. By moving the regenerative electric power stored in the rapid charge / discharge electric storage device to the secondary battery or the traction device 73, the spare capacity of the rapid charge / discharge electric storage device can be ensured.

The regenerative electric power accumulated in the secondary battery is also supplied to the traction machine 73 as necessary. The amount of the commercial power from the commercial power supply 25 can be reduced by providing a part of the electric power for operating the traction machine 73 as the regenerative electric power accumulated in the rapid charge / discharge electric storage device or the secondary battery. Also, by using a secondary battery of a large capacity as a secondary battery included in the power storage system 1, it is possible to operate the elevator 70 even in a situation where power supply from the commercial power supply 25 can not be received due to a power failure or the like have.

As an embodiment of the robot relating to the power storage system according to the embodiment, Fig. 8 shows a schematic diagram of the automatic guided vehicle. In the figure, reference numeral 80 denotes an unmanned conveyance vehicle, 81 a charge / discharge monitor device, 82 a charger, 1 a power storage system, and 25 a commercial power supply.

When the automatic guided vehicle 80 is charged, commercial power is supplied from the commercial power supply 25 to the power storage system 1 via the charger 82. [ The charger 82 and the power storage system 1 can be electrically connected through an external terminal (not shown) provided in the automatic guided vehicle 80, for example.

Charge / discharge monitor device 81 monitors the state of charge (SOC) of power storage system 1. The charge / discharge monitor device 81 can monitor the state of charge of the entire power storage system 1 as a whole. Alternatively, the charging / discharging monitoring device 81 may determine the charging state of each cell of the rapid charge / discharge battery device included in the power storage system 1 and the charging state of each cell of the secondary battery included in the power storage system 1 You can monitor. Further, the charging state of all of the plurality of electrically charged rapid charging / discharging electric storage devices, that is, the charging state of the rapid charging / discharging storage device group, and the charging state of the entire electrically connected plurality of secondary batteries, Can be monitored.

The charge / discharge monitoring device 81 monitors the presence or absence of an abnormal state in the power storage system 1. [ The abnormal state may include, for example, overcharge, overdischarge, excessive temperature rise, etc. of the rapid charge / discharge battery device or the secondary battery.

The charge / discharge monitoring device 81, for example, detects that the charging state of the secondary battery in the power storage system 1 is lower than the predetermined value, and transmits a signal to a control system not shown. The control system may be provided on the automatic guided vehicle 80 or on the outside of the automatic guided vehicle 80. [ The signal may be transmitted to the control system by wire or wireless.

The control system, which receives the signal indicating that the state of charge of the secondary battery is lower than the predetermined value, can transmit the charging instruction to the automatic guided vehicle. The indication may be transmitted by wire or wireless. The unmanned return vehicle that has received the instruction moves to a predetermined position, for example, to electrically connect the charger 82 and the power storage system 1, if necessary, and starts charging.

At the time of charging, commercial power can be simultaneously input to both the secondary battery, the rapid charge / discharge battery device included in the power storage system 1, or both the secondary battery and the rapid charge / discharge battery device. For the following reason, it is preferable to charge the secondary battery to charge the rapid charge / discharge battery device.

The amount of current supplied from the commercial power supply 25 is unstable, a surge current is generated, and a large current is supplied to the power storage system 1 in some cases. When the control circuit (not shown) including the charge / discharge monitor device 81 or the charger 82 detects the occurrence of the surge current, the control is performed so that the current is input to the rapid charge / discharge battery device I do. The rapid charge / discharge device has high energy density and high water-solubility, so it can safely cope with the surge current. For example, even when a large surge current is input, the temperature rise of the rapid charge / discharge storage device is suppressed, so that damage to the member of the automatic guided vehicle 80 due to heating is less likely to occur. After the current is stabilized, by charging the secondary battery with the power once accumulated in the rapid charge-discharge device, and by opening the capacity of the rapid charge-discharge device, it is possible to cope with the generation of the surge current again.

The charge / discharge monitoring device 81, for example, detects that the power storage system 1 is in the full charge state, and transmits a signal to the control system. The full charge state of the electrical storage system 1 may be a state in which the secondary battery is fully charged, or both the secondary battery and the rapid charge / discharge storage device are fully charged. The control system can issue an instruction to start the operation to the unmanned return vehicle, depending on the situation.

By using a large-capacity secondary battery in the power storage system 1, it is possible to reduce the number of times that charging is required. By reducing the number of times of charging, it is possible to reduce the number of times that the automatic guided vehicle 80 comes and goes to a position where electrical connection between the charger 82 and the power storage system 1 can be made, and work efficiency can be improved.

As described above, vehicles, electronic equipment, and machinery equipped with the power storage system according to the embodiments can efficiently store the regenerative energy. In addition, since the instantaneous discharge can be coped with, the contract power can be lower than the maximum power.

(Example)

(Examples 1 to 5 and Comparative Example 1)

A rapid charge / discharge battery device was manufactured as follows.

Negative electrode layer material: tungsten oxide powder WO _2.72 (particle diameter 2 μm), a conductive auxiliary agent (acetylene black having a particle diameter of 0.03 μm), a PVDF binder

Positive electrode layer material: LiCoO ₂ powder (particle diameter: 5 μm) Conductive additive (acetylene black having a particle diameter of 0.03 μm), PVDF binder

Aluminum foil (thickness: 15 占 퐉) or carbon-coated aluminum foil (thickness: 15 占 퐉)

Separator: Polypropylene (thickness: 25 占 퐉)

Electrolyte: EC / DEC (1 / 1vol%) 1M LiPF ₆

Using these, rapid charge-discharge electric storage devices relating to Samples 1 to 3 and 5 to 6 shown in Table 1 and Table 2 were produced.

Sample 4 was a conventional Li-ion capacitor.

When fabricating a laminate cell as a rapid charge / discharge battery device, a separator was disposed between a plurality of negative electrodes and a plurality of positive electrodes to alternately laminate. The total area of the counter electrode shown in Table 1 is the sum of the areas of the portions where the negative electrode and the positive electrode face each other. The other electrode designs shown in Table 1, namely, the thicknesses, the density and the porosity of the electrode layers, the weight ratio B / A between the weight A of the electrode base material and the tungsten oxide powder and the weight B of the conductive auxiliary agent were matched at the positive electrode and the negative electrode for each sample. For example, with respect to the sample 1, both the thickness of the negative electrode layer and the thickness of the positive electrode layer were set to 16 mu m.

When the electrodes (negative electrode and positive electrode) of Samples 1, 2 and 4 were produced, no pressing was performed. When the electrodes (negative electrode and positive electrode) of Samples 3, 5, and 6 were fabricated, they were pressed to increase the electrode density.

The electrode density was measured in the following manner. First, arbitrary three layers out of a plurality of stacked electrodes were taken out to obtain an electrode to be measured. The weight of the electrode including the substrate (aluminum foil and the like) was measured. Further, the dimensions (area and thickness) of the electrode including the substrate were measured, and the volume was determined. From the obtained values, the weight and volume of the substrate were subtracted, respectively, and the weight and volume of the electrode layer alone were calculated. The weight of the electrode layer was divided by volume to obtain the electrode density (not including the substrate).

The porosity of the electrode layers (negative electrode layer and positive electrode layer) was measured as follows. The area of the pore (void) was measured by observing (20,000 times) a cross section of 20 mu m in thickness in the electrode layer in a transverse direction using a scanning electron microscope (SEM). In addition, the pores can be discriminated by the contrast difference. In addition, when it is not possible to measure in a visual field, it is measured by dividing into a plurality of circuits.

The power density (unit of weight and volume), energy density, cell weight, cell volume, and internal resistance shown in Table 2 were measured by the method described previously. The one-cell average voltage is an average voltage measured when discharging at 1 C in a predetermined voltage range. For example, in the case of the rapid charge / discharge battery device sample 1, it represents an average voltage measured when the cell is discharged at 1 C in a voltage range of 1.5 V or more and 2.5 V or less.

Subsequently, a lead battery was prepared as a secondary battery. The secondary battery had an average voltage of 12 V, a power density of 100 W / kg, an energy density of 30 Wh / kg, a weight of 10 kg, and a capacity of 5.7 L.

The power storage systems according to Examples 1 to 5 and Comparative Example 1 were fabricated by combining the rapid charge / discharge battery device samples 1 to 6 and the secondary battery in parallel. The combination conditions are as shown in Table 3. The cell weight of the power storage system is a sum of the cell weight of the rapid charge / discharge battery device and the cell weight of the secondary battery.

The capacity of the power storage system is a sum of the cell capacity of the rapid charge / discharge battery device and the cell capacity of the secondary battery.

The weight power density and the energy density as the whole power storage system were calculated as follows. Weight power density of power storage system P _S = (weight power density of rapid charging / discharging device × total cell weight according to number of series + weight power density of secondary cell × total cell weight according to number of series) / Gross weight + cell gross weight of secondary cell). The weight energy density E _{S of the} power storage system (weight energy density of the rapid charge / discharge device × total cell weight according to the number of series + weight energy density of the secondary battery × total cell weight according to the number of series) / (rapid charge / Gross cell weight of the cell + total cell weight of the secondary cell).

As a specific example, the first embodiment will be described. In Example 1, six test pieces 1 (power density 7000 W / kg, energy density 22.6 Wh / kg) were connected in series. The weight of the cell at that time is 0.54 kg. Lead batteries (power density 100W / kg, energy density 30Wh / kg) weigh 10kg. For this reason, the weight W _S of the power storage system is 0.54 + 10 = 10.54 kg. The power density of the power storage system is (7000 W / kg x 0.54 kg + 100 W / kg x 10 kg) /10.54 kg = 454 W / kg.

In addition, the energy density ratio E _S / W _S of the storage system with respect to the cell weight of the storage system was calculated.

As can be seen from Table 3, the power storage system according to the embodiment had high power density and high energy density. In addition, compared to Comparative Example 1, the weight of the cell can also be reduced.

In addition, the power storage system according to the embodiment is also downsized as compared with the comparative example 1.

Subsequently, the temperature rise was measured when a power of 3 kW (= 24 V × 125 A), 5 kW (= 24 V × 208 A) and 10 kW (= 24 V × 416 A) was applied for 10 seconds. As shown in Fig. 4, the measurement was performed by connecting the battery from the alternator to the rapid charge / discharge battery device, the DC-DC converter, and the secondary battery.

The applied power of 3 kW, 5 kW, and 10 kW is based on the output of the alternator. The application time of 10 seconds assumes the deceleration time of the electric vehicle.

The measurement results of the temperature rise are shown in Table 4. Specifically, the temperature was raised from the normal temperature of the power storage system.

As can be seen from Table 4, in the power storage system according to the embodiment, temperature rise is suppressed. When the output of the alternator was 5 kW or more, the difference in temperature rise between the examples and the comparative example was remarkable. The output of the alternator can be 5 kW or more when the vehicle speed is 25 km / h or more. That is, in the power storage system according to the embodiment, the regenerative energy can be stored even at a speed of 25 km / h or more. As a result, it can be seen that the storage efficiency is improved.

Further, in the power storage system according to the embodiment, since the temperature rise when the output of the alternator is 5 kW or more is suppressed, the frequency of operating the cooling mechanism can be reduced as compared with the comparative example. Therefore, the power efficiency in the vehicle can be increased.

(Examples 1A to 5A, Comparative Example 1A)

In addition, a Li ion secondary battery was prepared as a secondary battery. Li-ion secondary batteries were three-tiered with an average voltage of 3.6 V, a power density of 3400 W / kg (about 6500 W / L), an energy density of 75 Wh / kg (about 140 Wh / L), a weight of 0.25 kg and a volume of 0.13 L. (0.75 kg, 0.39 L)

A power storage system according to Examples 1A to 5A and Comparative Example 1A was produced under the combination conditions shown in Table 5 using a Li ion secondary battery instead of a lead battery.

By changing to a Li ion secondary battery, the secondary battery from the lead battery, the increased power density P _S, the energy density E _S of the power storage system. This is because the secondary battery is replaced with a lightweight one.

Measurement was carried out under the same conditions as in Example 1, and the temperature rise of the rapid charge-discharge battery devices in Examples 1A to 5A and Comparative Example 1A was measured. The results are shown in Table 6.

Similar results were obtained even when the type of the secondary battery of the power storage system was changed. Thus, it has been found that various secondary batteries and rapid charge / discharge storage devices can be unitized in the power storage system.

According to at least one embodiment and the embodiments described above, a power storage system including a secondary battery having a power density of less than 7000 W / kg and a rapid charge / discharge battery device having a power density of 7000 W / kg or more is provided. This power storage system can cope with a momentary high output.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. These new embodiments can be implemented in various other forms, and various omissions, substitutions, alterations, and the like can be made without departing from the gist of the invention. These embodiments and modifications are included in the scope and spirit of the invention and are included in the scope of equivalents to the invention described in the claims. The above-described embodiments can be combined with each other.

Claims (13)

A power storage system comprising a secondary battery and a rapid charge / discharge battery device, wherein a power density of the secondary battery is less than 7000 W / kg and a power density of the rapid charge / discharge battery device is 7000 W / kg or more. A secondary battery having a power density of less than 7000 W / kg,
A rapid charge-discharge battery device having a power density of 7000 W / kg or more
. 3. The method according to claim 1 or 2,
Wherein the power density of the rapid charge / discharge battery device is 9000 W / kg or more. 4. The method according to any one of claims 1 to 3,
Wherein the power density of the rapid charge / discharge battery device is 10000 W / L or more. 5. The method according to any one of claims 1 to 4,
Wherein the secondary battery has an energy density of 30 Wh / kg or more. 6. The method according to any one of claims 1 to 5,
When the total weight of the cells of the secondary battery and the rapid charge and discharge storage device is the cell weight W _S of the storage system, the energy density E _S of the storage system and the cell weight W _S of the storage system A power storage system having a ratio E _S / W _S of 1 or greater. 7. The method according to any one of claims 1 to 6,
Wherein the rapid charge / discharge battery device comprises an electrode layer containing tungsten oxide powder. 8. The method according to any one of claims 1 to 7,
Wherein the internal resistance of said rapid charge-discharge battery device is 10? Cm ² or less. A vehicle comprising the power storage system according to any one of claims 1 to 8. 10. The method of claim 9,
And the regenerative energy is stored in the power storage system. 11. The method of claim 10,
Wherein the regenerative energy can be stored in the power storage system even when the moving speed of the vehicle is 25 km / h or more. A mechanical equipment comprising the power storage system according to any one of claims 1 to 8. 13. The method of claim 12,
Wherein the machine is any one selected from an elevator, a crane, a robot, a medical device, and a machine tool.

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