阅读说明：本技术 电源装置和具有该电源装置的电动车辆以及蓄电装置 (Power supply device, electric vehicle provided with same, and power storage device ) 是由 古上奈央 高桥宏行 于 2020-06-15 设计创作，主要内容包括：为了利用隔板吸收电池单体的膨胀并且抑制被电池单体加热的状态下的隔板的劣化,电源装置具有隔着隔板(2)沿厚度方向层叠多个电池单体(1)而成的电池块、配置于电池块的两端面的一对端板、以及与一对端板连结并借助端板将电池块固定为加压状态的束紧条。隔板(2)是由吸收电池单体(1)的膨胀的粘弹性的弹性片(6)、以及层叠于弹性片(6)的两面的绝热片(5)构成的三层构造,绝热片(5)设为无机粉末和纤维增强材料的复合材料(5A)。(In order to suppress deterioration of a separator in a state in which the separator absorbs expansion of a battery cell and is heated by the battery cell, a power supply device includes a battery block in which a plurality of battery cells (1) are stacked in a thickness direction with a separator (2) interposed therebetween, a pair of end plates disposed on both end surfaces of the battery block, and a tightening strip connected to the pair of end plates and fixing the battery block in a pressurized state via the end plates. The separator (2) has a three-layer structure comprising an elastic sheet (6) that absorbs the viscoelasticity of the battery cells (1) and heat insulating sheets (5) that are laminated on both sides of the elastic sheet (6), wherein the heat insulating sheets (5) are made of a composite material (5A) of inorganic powder and a fiber-reinforced material.)

1. A power supply device having a battery block in which a plurality of battery cells are stacked in a thickness direction with a separator interposed therebetween, a pair of end plates disposed on both end surfaces of the battery block, and a tightening strip connected to the pair of end plates and fixing the battery block in a pressurized state via the end plates,

the separator has a three-layer structure including an elastic sheet that absorbs the expansion of the battery cells and has viscoelasticity, and heat insulating sheets laminated on both surfaces of the elastic sheet,

the thermal insulation sheet is a composite of inorganic powder and fiber reinforcement.

2. The power supply device according to claim 1,

the insulation sheet is a composite of silica aerogel and a fibrous reinforcement.

3. The power supply device according to claim 1 or 2,

the elastic sheet is at least one selected from an elastomer sheet, a thermoplastic elastomer, and a foamed material.

4. The power supply device according to claim 3,

the elastic sheet is a synthetic rubber having a heat resistant limit temperature of 100 ℃ or higher.

5. The power supply device according to claim 3 or 4,

the elastic sheet is any one of fluororubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polyisobutylene rubber, ethylene propylene rubber, ethylene vinyl acetate copolymer rubber, chlorosulfonated polyethylene rubber, acrylate rubber, chlorohydrin rubber, urethane rubber, silicone rubber, thermoplastic olefin rubber, ethylene propylene diene rubber, butyl rubber, and polyether rubber.

6. The power supply device according to any one of claims 1 to 5,

the thickness of the elastic sheet is more than 0.2mm and less than 2.0 mm.

7. The power supply device according to any one of claims 1 to 6,

the thermal insulation sheet is thicker than the elastic sheet.

8. The power supply device according to any one of claims 1 to 7,

the thickness of the separator is 1mm to 3 mm.

9. The power supply device according to any one of claims 1 to 8,

the battery cell has a battery case having an upper end opening closed by a sealing plate,

the separator has the elastic piece disposed in a main body region other than a sealing portion region sandwiched between upper end portions of the battery cases between the adjacent battery cells.

10. An electric vehicle having the power supply apparatus of any one of claims 1 to 9,

the electric vehicle includes:

the power supply device;

a motor for traveling, to which electric power is supplied from the power supply device;

a vehicle body on which the power supply device and the motor are mounted; and

and wheels that are driven by the electric motor to run the vehicle body.

11. An electric storage device having the power supply device according to any one of claims 1 to 9,

the power storage device includes:

the power supply device; and

a power supply controller for controlling charging and discharging of the power supply device,

the secondary battery cell can be charged with electric power from the outside by the power supply controller, and is controlled by the power supply controller so as to be charged.

Technical Field

The present invention relates to a power supply device in which a plurality of battery cells are stacked, and an electrically powered vehicle and a power storage device having the power supply device.

Background

A power supply device in which a plurality of battery cells are stacked is suitable for a power supply for supplying electric power to a motor mounted on an electric vehicle and running the vehicle, a power supply for charging the vehicle by natural energy such as a solar battery or the like or midnight power, and a backup power supply for power failure. The power supply device of this structure sandwiches a separator between the stacked battery cells. In a power supply device in which a plurality of battery cells are stacked with separators interposed therebetween, the stacked battery cells are fixed in a pressurized state in order to prevent positional displacement due to swelling of the battery cells. In order to achieve the above object, in a power supply device, a pair of end plates are disposed on both end surfaces of a battery block in which a plurality of battery cells are stacked, and the pair of end plates are connected by a binding bar. (see patent document 1)

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-204708

Disclosure of Invention

Problems to be solved by the invention

In the power supply device, a plurality of battery cells are stacked to form a battery block, a pair of end plates are arranged on both end surfaces of the battery block, and the battery block is held in a pressurized state by a relatively strong pressure from both end surfaces and is connected by a binding bar. In a power supply device, a battery cell is fixed in a strongly pressurized state to prevent a failure due to relative movement and vibration of the battery cell. In the power supply device, for example, the area of the lamination surface is set to about 100cm²In the battery cell device according to (1), the end plate is pressed with a strong force of several tons and fixed by the tightening strip. In the power supply device having this structure, the partition is usedThe plate insulates the adjacently stacked battery cells, and a rigid plastic plate material is used for the separator. The hard plastic separator cannot absorb the expansion of the battery cell in a state where the internal pressure of the battery cell increases and expands, and in this state, the surface pressure of the battery cell and the separator rapidly increases, and a strong force acts on the end plate and the tie bar. Therefore, the end plate and the tightening strip are required to have extremely strong materials and shapes, and therefore, the power supply device becomes heavy and large, which disadvantageously increases the material cost.

In the power supply device, the elastic sheet compressed by the pressure of the battery cell is used for the separator, and the strong stress acting on the end plate and the tightening strip can be reduced in a state where the battery cell is expanded by the increase of the internal pressure. In particular, a rubber-like elastic sheet can be used as the separator of the elastic sheet, and the separator can be brought into close contact with the stacking surface of the battery cells in a surface contact state, thereby absorbing the swelling of the battery cells in a preferable state. However, the rubber-like elastic sheet has such a drawback that: degradation occurs when heated to an abnormally high temperature by the battery cell, resulting in a decrease in viscoelasticity, which is an important physical property.

The present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a technique capable of absorbing the expansion of a battery cell by a separator and also suppressing the deterioration of the separator in a state in which the battery cell is heated.

Means for solving the problems

A power supply device according to one embodiment of the present invention includes a battery block 10 in which a plurality of battery cells 1 are stacked in a thickness direction with a separator 2 interposed therebetween, a pair of end plates 3 disposed on both end surfaces of the battery block 10, and a tightening strip 4 connected to the pair of end plates 3 and fixing the battery block 10 in a pressurized state via the end plates 3. The separator 2 has a three-layer structure including an elastic sheet 6 that absorbs the expansion of the battery cell 1 and thermal insulation sheets 5 laminated on both sides of the elastic sheet, and the thermal insulation sheets 5 are a composite material 5A of inorganic powder and a fiber-reinforced material.

An electric vehicle according to an aspect of the present invention includes: the power supply device 100 described above; a traveling motor 93 to which electric power is supplied from the power supply device 100; a vehicle body 91 on which a power supply device 100 and a motor 93 are mounted; and a wheel 97 that is driven by the motor 93 to run the vehicle main body 91.

An electrical storage device according to an aspect of the present invention includes the power supply device 100 described above, and a power supply controller 88 that controls charging and discharging of the power supply device 100, and the secondary battery cell 1 can be charged by the power supply controller 88 using electric power from outside, and the secondary battery cell 1 can be charged by the control performed by the power supply controller 88.

ADVANTAGEOUS EFFECTS OF INVENTION

The above power supply device can absorb the expansion of the battery cell by the separator, and can also suppress the deterioration of the separator in a state of being heated by the battery cell.

Drawings

Fig. 1 is a perspective view of a power supply device according to an embodiment of the present invention.

Fig. 2 is a vertical sectional view of the power supply device shown in fig. 1.

Fig. 3 is a horizontal sectional view of the power supply device shown in fig. 1.

Fig. 4 is an enlarged cross-sectional view showing a stacked state of a separator and a battery cell.

Fig. 5 is an enlarged cross-sectional view showing another example of the separator.

Fig. 6 is a block diagram showing an example of a power supply device mounted on a hybrid vehicle that travels using an engine and a motor.

Fig. 7 is a block diagram showing an example of a power supply device mounted on an electric vehicle that travels only by a motor.

Fig. 8 is a block diagram showing an example of a power supply device applied to power storage.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings. In the following description, terms indicating specific directions and positions (for example, "up" and "down" and other terms including these terms) are used as necessary, but these terms are used for the purpose of facilitating understanding of the present invention with reference to the drawings, and the scope of protection of the present invention is not limited by the meanings of these terms. In addition, the same reference numerals shown in the plurality of drawings denote the same or equivalent parts or components.

The embodiments described below are specific examples of the technical idea of the present invention, and the present invention is not limited to the embodiments described below. The dimensions, materials, shapes, relative arrangements, and the like of the constituent members described below are not intended to limit the scope of the present invention to these, and are intended to be illustrative, unless otherwise specified. Note that the contents described in one embodiment and example can be applied to other embodiments and examples. In addition, the sizes, positional relationships, and the like of the members shown in the drawings may be exaggerated for the sake of clarity.

A power supply device according to embodiment 1 of the present invention includes a battery block in which a plurality of battery cells are stacked in a thickness direction with a separator interposed therebetween, a pair of end plates disposed on both end surfaces of the battery block, and a tightening bar connected to the pair of end plates and fixing the battery block in a pressurized state via the end plates, wherein the separator has a three-layer structure including an elastic sheet that absorbs the viscoelasticity of the battery cells due to expansion and heat insulating sheets stacked on both surfaces of the elastic sheet, and the heat insulating sheets are a composite material of inorganic powder and a fiber-reinforced material.

In the above power supply device, since the heat insulating sheet made of a composite material of inorganic powder and fiber reinforcement is laminated on the surface of the elastic sheet, the elastic sheet absorbs the expansion of the battery cells and the composite material prevents the elastic sheet from thermally failing. Therefore, in a state where the internal pressure of the battery cell rises and expands, the increase in the surface pressure of the battery cell and the separator can be suppressed. Further, the elastic sheet can be protected from the heat generated by the battery cell in a state where the battery cell expanded by the rise of the internal pressure generates heat at a high temperature. Therefore, the battery cell whose temperature rises to a high temperature can be prevented from heating the elastic sheet and deteriorating the elastic sheet. The battery cell heats up to a high temperature in a state where the internal pressure rises and expands. The composite material realizes heat insulation by using the inorganic powder, so that the composite material has high heat-resistant temperature, and can effectively cut off the heat energy of the battery monomer to protect the elastic sheet when the battery monomer generates heat at high temperature. Therefore, the separator can stably absorb the expansion of the battery cell without losing its elasticity in a state where the battery cell expands due to an increase in the internal pressure.

In the above power supply device, the elastic sheet of the separator suppresses an increase in the surface pressure due to the expansion of the battery cell, and therefore, it is possible to prevent the battery cell from expanding and applying an excessive stress to the end plate and the tightening strip. The end plate and the tightening strip, which can reduce the maximum stress, can be made thin to achieve light weight. In addition, in the power supply device in which the expansion of the battery cells is absorbed by the separators between the battery cells, the relative positional shift due to the expansion of the battery cells can be suppressed. This can also prevent the disadvantage of the electrical connection portion of the battery cell. This is because, in the stacked battery cells, the bus bars of the metal plates are fixed to the electrode terminals and electrically connected, but if the battery cells are displaced relative to each other, an unreasonable stress acts on the bus bars and the electrode terminals, which causes a failure.

In the power supply device according to embodiment 2 of the present invention, the heat insulating sheet is a composite material of silica aerogel and a fiber reinforcement.

In the above power supply device, the heat insulating sheet laminated on the surface of the elastic sheet is a composite material of silica aerogel and a fiber reinforcement, and therefore, the heat insulating sheet having excellent heat insulating properties can effectively insulate heat conduction between the battery cells, and can suppress occurrence of thermal runaway of the battery cells. The thermal runaway of the battery cell is caused by an internal short circuit, an erroneous process, or the like, which is caused by the internal short circuit of the positive electrode and the negative electrode. Since a large amount of heat is generated when the battery cell thermally runaway, the thermal runaway may be caused to an adjacent battery cell when the thermal insulation property of the separator is insufficient. If thermal runaway of the battery cell occurs, the entire power supply device releases extremely large thermal energy, and safety as a device is impaired. The composite material of silica aerogel and fiber reinforcement is a material obtained by filling the gaps of the fiber sheet with silica aerogel, and achieves excellent heat insulation characteristics with a thermal conductivity of 0.02W/m.K due to an extremely high porosity.

In addition, although the composite material of silica aerogel and fiber reinforcement exhibits extremely excellent heat insulation properties, there is a disadvantage that the heat insulation properties are lowered if the silica aerogel is broken by a strong compressive stress, but since the composite material is laminated on the elastic sheet, the expansion of the battery cell is absorbed by the elastic sheet, and the lowering of the heat insulation properties due to the breakage of the silica aerogel can also be suppressed. The composite material maintaining excellent heat insulating properties can protect the elastic sheet from heat generated by the battery cells and prevent thermal runaway of the battery cells, thereby ensuring the safety of the power supply device for a long period of time.

In the power supply device according to embodiment 3 of the present invention, the elastic sheet is at least one selected from an elastomer sheet, a thermoplastic elastomer, and a foam material. In the power supply device according to embodiment 4 of the present invention, the elastic sheet is made of an elastomer having a heat resistance limit temperature of 100 ℃.

In the power supply device according to embodiment 5 of the present invention, the elastic sheet is any one of fluororubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polyisobutylene rubber, ethylene-propylene rubber, ethylene-vinyl acetate copolymer rubber, chlorosulfonated polyethylene rubber, acrylate rubber, chlorohydrin rubber, urethane rubber, silicone rubber, thermoplastic olefin rubber, ethylene-propylene-diene rubber, butyl rubber, and polyether rubber.

In the power supply device according to embodiment 6 of the present invention, the thickness of the elastic sheet is set to 0.2mm to 2.0 mm.

In the power supply device according to embodiment 7 of the present invention, the heat insulating sheet is thicker than the elastic sheet.

In the power supply device according to embodiment 8 of the present invention, the thickness of the partition is set to be 1mm to 3 mm.

In the power supply device according to embodiment 9 of the present invention, the battery cell has a battery case whose upper end opening is closed by a sealing plate, and the separator has an elastic piece disposed in a main body region other than a sealing portion region sandwiched by the upper end portions of the battery cases between adjacent battery cells.

(embodiment mode 1)

Hereinafter, the specific power supply device and the electric vehicle will be described in detail.

The power supply device 100 shown in the perspective view of fig. 1, the vertical cross-sectional view of fig. 2, and the horizontal cross-sectional view of fig. 3 includes a battery block 10 in which a plurality of battery cells 1 are stacked in the thickness direction with a separator 2 interposed therebetween, a pair of end plates 3 disposed on both end surfaces of the battery block 10, and a tightening strip 4 that connects the pair of end plates 3 and fixes the battery block 10 in a pressurized state via the end plates 3.

(Battery block 10)

The battery cell 1 of the battery block 10 is a rectangular battery cell having a rectangular outer shape, and as shown in fig. 4, a sealing plate 12 is laser welded to an upper end opening of a battery case 11 having a closed bottom and hermetically fixed, thereby providing a sealed structure inside. As shown in fig. 1, the pair of positive and negative electrode terminals 13 are provided on both ends of the upper surface of the sealing plate 12 so as to protrude upward. An opening 15 of the safety valve 14 is provided between the electrode terminals 13. The safety valve 14 opens when the internal pressure of the battery cell 1 rises to a predetermined value or more to release the gas inside. The safety valve 14 can prevent the internal pressure of the battery cell 1 from rising.

(Battery cell 1)

The battery cell 1 is a lithium-ion secondary battery. The power supply device 100 in which the battery cell 1 is a lithium-ion secondary battery has an advantage that the charge capacity can be increased with respect to the capacity and weight. However, the battery cell 1 may be any chargeable battery such as a nonaqueous electrolyte secondary battery other than a lithium ion secondary battery.

(end plate 3, tightening strip 4)

The end plate 3 is a metal plate having an outer shape substantially equal to that of the battery cell 1 and is pressed by the battery block 10 without deformation, and the binding strips 4 are connected to both side edges thereof. The tightening strip 4 connects the battery cells 1 stacked on the end plate 3 in a pressurized state, and fixes the battery block 10 in the pressurized state at a predetermined pressure.

(partition board 2)

The separators 2 are interposed between the stacked battery cells 1, absorb expansion of the battery cells due to an increase in internal pressure, insulate the adjacent battery cells 1, and cut off heat conduction between the battery cells 1. In the battery block 10, a bus bar (not shown) of a metal plate is fixed to the electrode terminals 13 of the adjacent battery cells 1, and the battery cells 1 are connected in series or in parallel. In the battery cells 1 connected in series, a potential difference is generated in the battery case 11, and therefore, the battery cells can be stacked in an insulated manner by the separators 2. In the battery cells 1 connected in parallel, although no potential difference is generated in the battery case 11, the battery cells can be stacked adiabatically with the separators 2 in order to prevent the occurrence of thermal runaway.

As shown in the enlarged cross-sectional view of fig. 4, the separator 2 has a three-layer structure including an elastic sheet 6 having elasticity for absorbing expansion of the battery cell 1 due to an increase in internal pressure, and heat insulating sheets 5 laminated on both surfaces of the elastic sheet 6. The elastic sheet 6 is deformed by being pressed by the battery cell 1 that expands due to an increase in internal pressure, and is adjusted to have elasticity that absorbs the expansion of the battery cell 1. The amount of deformation of the elastic sheet 6 due to the expansion of the battery cell 1 is determined by the hardness of the material. Therefore, the hardness of the elastic sheet 6 is set to an optimum value in consideration of the amount of deformation of the battery cell 1 that expands due to an increase in internal pressure. The hardness of the elastic sheet 6 is set to an optimum value in consideration of the pressure of the battery cell 1, but at normal temperature, the hardness of the elastic sheet 6 is preferably 30 degrees or more and 85 degrees or less, and more preferably 40 degrees or more and 85 degrees or less. If the hardness of the elastic sheet 6 is too low, the elastic sheet 6 is compressed and thinned in a state where the battery cells 1 are stacked in a state where the battery cells 1 do not swell and fixed in a pressurized state by the end plates 3, and conversely, if the hardness of the elastic sheet 6 is too high, the amount of deformation caused by pressurization by the battery cells 1 whose internal pressure has increased is small, and expansion of the battery cells 1 cannot be absorbed. Therefore, the hardness of the elastic sheet 6 is set to an optimum value capable of absorbing the expansion of the battery cell 1 due to the increase in the internal pressure, in consideration of the pressure with which the battery cell 1 presses the separator 2.

The elastic sheet 6 is a sheet having viscoelasticity having both properties of tackiness and elasticity. Viscoelasticity is determined from relaxation time of stress relaxation after a certain strain is applied to a substance, and is considered to be viscous if the relaxation time is sufficiently short relative to the time scale of observation, to be elastic if long, and to be viscoelastic if the same time. The viscoelastic elastic sheet 6 is preferably composed of an elastomer, a foam, or a thermoplastic elastomer, and more preferably composed of an elastomer having a heat resistance limit temperature of 100 ℃.

Examples of the elastic sheet 6 include silicone rubber, fluorine rubber, urethane rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polyisobutylene rubber, ethylene-propylene rubber, ethylene-vinyl acetate copolymer rubber, chlorosulfonated polyethylene rubber, acrylate rubber, chlorohydrin rubber, thermoplastic olefin rubber, ethylene-propylene-diene rubber, butyl rubber, and polyether rubber.

In particular, fluororubbers and silicone rubbers have such characteristics: the thermal limit temperature is considerably high at 230 c, and it is possible to maintain elasticity in a state of being heated by the high-temperature battery cell, thereby stably absorbing the expansion of the battery cell generating heat at high temperature. Since the heat resistant limit temperature of the acrylate rubber is 160 ℃, the heat resistant limit temperature of the hydrogenated nitrile rubber, the ethylene propylene rubber, and the butyl rubber is 140 ℃ or more, the expansion can be stably absorbed even in a state where the battery cell generates heat at a high temperature.

The heat insulating sheet 5 is sandwiched between the lamination surface 1A of the battery cell 1 and the elastic sheet 6, and insulates heat transfer from the battery cell 1 that generates heat to the elastic sheet 6. The thermal insulation sheet 5 having a low thermal conductivity can lower the temperature of the elastic sheet 6 in a state heated by the high-temperature battery cell 1. The thermal insulation sheet 5 is a composite material 5A of inorganic powder and fiber reinforcement material having low thermal conductivity. The most preferable thermal insulation sheet 5 is a composite 5A of silica aerogel in which inorganic powder is silica aerogel and a fiber reinforcement. In the composite material 5A, silica aerogel is arranged in the gaps between the fiber sheets.

The composite 5A of silica aerogel and fiber reinforcement is filled with nano-sized silica aerogel having a porous structure in the fiber gaps of the fiber sheet. The composite 5A is manufactured by impregnating a gel raw material of silica aerogel into fibers. The silica aerogel is produced by impregnating a fiber sheet with silica aerogel, stacking the fibers, reacting the gel raw materials to form a wet gel, hydrophobizing the surface of the wet gel, and drying the wet gel with hot air. The fibers of the fibrous sheet are polyethylene terephthalate (PET). However, as the fibers of the fiber sheet, flame-retardant oxidized polyacrylonitrile fibers (japanese patent: acidified アクリル ), glass wool, or other inorganic fibers can be used.

The fiber diameter of the fiber sheet of the composite material 5A is preferably set to 0.1 μm to 30 μm. Making the fiber diameter of the fiber sheet smaller than 30 μm can reduce the thermal conductivity of the fibers, and can improve the heat insulating property of the heat insulating sheet 5. The silica aerogel is prepared from silicon dioxide (SiO)₂) The fine particles composed of the skeleton of (1) and 90 to 98% of air have a cluster structure in which 2 to 20nm spherical bodies are bonded together, and have fine pores of 100nm or less between the skeletons formed of the cluster, thereby forming a three-dimensional fine porous structure.

The composite material 5A of silica aerogel and fiber reinforcement as the thermal insulation sheet 5 has the following characteristics: the heat insulating property is lowered when the fragile silica aerogel is compressed and damaged by the pressure of the expanded battery cell 1. The laminated elastic sheet 6 can suppress the adverse effect of the silica aerogel being pressed and broken by the swollen battery cell 1. The elastic sheet 6 absorbs the expansion of the battery cell and reduces the compressive stress of the silica aerogel when the battery cell 1 expands, thereby preventing the breakage. Therefore, in the separator 2 having the laminated structure of the elastic sheet 6 and the composite material 5A, the excellent heat insulating property of the composite material 5A can exhibit the synergistic effect of preventing the elastic sheet 6 from failing at high temperature and the viscoelasticity of the elastic sheet 6 from breaking the silica aerogel, and the expansion of the battery cell 1 due to the increase in the internal pressure can be absorbed over a long period of time.

The thermal insulation sheet 5 of the composite material 5A of silica aerogel and fiber reinforcement is thin and exhibits excellent thermal insulation characteristics. The heat insulating sheet 5 is set to a thickness such that the temperature of the elastic sheet 6 is lower than the thermal limit temperature in a state where the battery cell 1 generates heat, in order to prevent a high-temperature failure of the elastic sheet 6. Therefore, the thickness of the heat insulating sheet 5 is set to an optimum value in consideration of the maximum temperature of the battery cell 1 and the heat resistance limit temperature of the elastic sheet 6, and is set to 0.4mm to 1.4mm, for example, and preferably 0.5mm to 1.2 mm. Further, the heat insulating sheet 5 of the composite material 5A laminated on both surfaces of the separator 2 can be made thick to suppress the occurrence of thermal runaway of the battery cell 1. The heat insulating sheet 5 is set to a thickness that can prevent the battery cell 1 from being thermally runaway, taking into account the energy of heat generation due to thermal runaway. When the charge capacity of the battery cell 1 is large, the battery cell 1 thermally runaway and the energy for generating heat is large. However, the thickness of the thermal insulation sheet 5 in the power supply device of the present embodiment is not limited to the above range, and the thickness of the thermal insulation sheet 5 is set to an optimum value by considering the thermal insulation characteristics of thermal runaway realized by the fibrous sheet and the silica aerogel and the thermal insulation characteristics required to prevent the occurrence of thermal runaway of the battery cell 1.

Since the separators 2 are stacked between the respective battery cells 1, the battery block 10 is large due to the thick separators 2. In order to miniaturize the battery block 10, the separator 2 is required to be as thin as possible. In the power supply device, the charge capacity with respect to the volume is an extremely important characteristic. In the power supply device 100, in order to miniaturize the battery block 10 and increase the charge capacity, the separator 2 is required to have characteristics such that the elastic sheet 6 and the heat insulating sheet 5 are thin and the occurrence of thermal runaway of the battery cell 1 can be prevented. The elastic sheet 6 is set to, for example, 0.2mm or more and 1.0mm or less, and more preferably 0.3mm or more and 0.8mm or less, and can suppress an increase in the compressive stress due to expansion of the battery cell 1. Further, it is preferable that the elastic sheet 6 is thinner than the heat insulating sheet 5 to reduce the compressive stress of the silica aerogel when the battery cell 1 expands.

In the separator 2 of fig. 4, the outer shape thereof is a quadrangular shape substantially equal to the outer shape of the lamination surface 1A of the battery cell 1. In the separator 2, the elastic sheet 6 and the heat insulating sheet 5 stacked in three layers have the same outer shape, and the elastic sheet 6 is sandwiched so as to face the entire surface of the heat insulating sheet 5. However, the separator 2 is not necessarily limited to a structure in which the elastic sheet 6 is sandwiched so as to face the entire surface of the heat insulating sheet 5. As shown in fig. 5, in the separator 2, the elastic sheet 6 may be disposed in the main body region 2b other than the sealing portion region 2a sandwiched between the upper end portions of the battery cases 11 of the adjacent cells 1. In the separator 2, the elastic sheet 6 is interposed in the main body region 2b other than the sealing region 2a, instead of the sealing region 2a, which is a region facing the sealing plate 12 that closes the upper end opening of the battery case 11. In the separator 2, in a state where the battery cell 1 is inflated, the elastic sheet 6 is disposed in a region where a large compressive stress is applied, so that the expansion of the battery cell 1 can be absorbed by the elastic sheet 6, and the elastic sheet 6 is not disposed in a region along the sealing plate 12 of the battery cell 1, so that deformation of the upper end portion of the battery cell 1 can be suppressed, and damage to the upper end portion can be prevented.

In the power supply device 100 described above, it is preferable that all the separators 2 have a structure in which the heat insulating sheets 5 are stacked on both sides of the elastic sheet 6, but it is not always necessary that all the separators 2 have a structure in which the heat insulating sheets 5 are stacked on both sides of the elastic sheet 6. In the power supply device, it is not necessary to provide all the separators with a stacked structure of the heat insulating sheet and the elastic sheet, and a separator having only a heat insulating sheet and a separator having a stacked structure of a heat insulating sheet and an elastic sheet may be provided in a mixed manner.

The elastic sheet 6 and the heat insulating sheet 5 are bonded together by an adhesive layer or an adhesive layer and laminated at a fixed position. The separator 2 and the battery cell 1 are also joined together by an adhesive layer or an adhesive layer and arranged at fixed positions. However, the separator 2 may be disposed at a fixed position of a battery holder (not shown) that disposes the battery cells 1 at a fixed position in a fitting structure.

In the above power supply device 100, the battery cells 1 are rectangular battery cells having a charge capacity of 6Ah to 80Ah, the heat insulating sheets 5 of the separators 2 are "NASBIS (registered trademark) made of fibrous sheets and silica aerogel and having a thickness of 1mm, and the elastic sheet 6 laminated between the two heat insulating sheets 5 is a urethane rubber sheet having a thickness of 0.5mm, so that the specific battery cells 1 are forcibly thermally runaway, and the occurrence of thermal runaway of the adjacent battery cells 1 can be prevented.

The above power supply device can be used as a power supply for a vehicle that supplies electric power to a motor that runs an electric vehicle. As an electric vehicle equipped with a power supply device, an electric vehicle such as a hybrid vehicle that runs using both an engine and a motor, a plug-in hybrid vehicle, or an electric vehicle that runs using only a motor can be used, and the above power supply device can be used as a power supply for the vehicle. An example in which a power supply device 100 having a large capacity and a high output is constructed in which a plurality of the above-described power supply devices are connected in series or in parallel to obtain electric power for driving a vehicle and a necessary control circuit is further added will be described.

(Power supply device for hybrid vehicle)

Fig. 6 shows an example of a hybrid vehicle equipped with a power supply device that travels using both an engine and a motor. The vehicle HV having the power supply device mounted thereon shown in the figure includes a vehicle main body 91, an engine 96 and a traveling motor 93 for causing the vehicle main body 91 to travel, wheels 97 driven by the engine 96 and the traveling motor 93, a power supply device 100 for supplying electric power to the motor 93, and a generator 94 for charging a battery of the power supply device 100. The power supply device 100 is connected to the motor 93 and the generator 94 via a DC/AC inverter 95. While the battery of the power supply device 100 is being charged and discharged, the vehicle HV travels using both the motor 93 and the engine 96. The motor 93 is driven to run the vehicle in a region where the engine efficiency is low, for example, at the time of acceleration or at the time of low-speed running. Electric power is supplied from the power supply device 100 to the motor 93 to drive the motor 93. The generator 94 is driven by the engine 96 or by regenerative braking when braking is applied to the vehicle, thereby charging the battery of the power supply device 100. As shown in fig. 6, the vehicle HV may also have a charging plug 98 for charging the power supply device 100. The power supply device 100 can be charged by connecting the charging plug 98 to an external power supply.

(Power supply device for electric vehicle)

Fig. 7 shows an example of a power supply device mounted on an electric vehicle that travels only by a motor. The vehicle EV shown in the figure, which is equipped with a power supply device, includes a vehicle main body 91, a traveling motor 93 for traveling the vehicle main body 91, wheels 97 driven by the motor 93, a power supply device 100 for supplying electric power to the motor 93, and a generator 94 for charging a battery of the power supply device 100. The power supply device 100 is connected to the motor 93 and the generator 94 via a DC/AC inverter 95. Electric power is supplied from the power supply device 100 to the motor 93 to drive the motor 93. The generator 94 is driven by energy generated when the vehicle EV is regeneratively braked, and charges the battery of the power supply device 100. Vehicle EV has a charging plug 98, and power supply device 100 can be charged by connecting charging plug 98 to an external power supply.

(Power supply device for electric storage device)

The present invention does not limit the use of the power supply device to the power supply of the motor for running the vehicle. The power supply device according to the embodiment can also be used as a power supply for a power storage device that charges and stores a battery with electric power generated by solar power generation, wind power generation, or the like. Fig. 8 shows an electricity storage device in which a battery of the power supply device 100 is charged by a solar battery 82 and stored.

The power storage device shown in fig. 8 charges the battery of the power supply device 100 with electric power generated by the solar battery 82 disposed on the roof, the roof platform, or the like of a building 81 such as a house or a factory. In this power storage device, after the battery of the power supply device 100 is charged by the charging circuit 83 using the solar battery 82 as a charging power supply, electric power is supplied to the load 86 through the DC/AC inverter 85. Therefore, the electrical storage device has a charge mode and a discharge mode. In the power storage device shown in the figure, a DC/AC inverter 85 and a charging circuit 83 are connected to a power supply device 100 via a discharging switch 87 and a charging switch 84, respectively. The on/off of the discharge switch 87 and the charge switch 84 is switched by a power supply controller 88 of the electrical storage device. In the charging mode, the power controller 88 switches the charging switch 84 on and the discharging switch 87 off, and allows the power supply device 100 to be charged from the charging circuit 83. When the charging is completed and the battery is in a full-charge state, or when the capacity is charged to a predetermined value or more, the power controller 88 turns off the charging switch 84 and turns on the discharging switch 87 to switch to the discharging mode, thereby allowing the discharging from the power supply device 100 to the load 86. Further, if necessary, the power supply to the load 86 and the charging to the power supply device 100 may be performed simultaneously with the charging switch 84 being turned on and the discharging switch 87 being turned on.

Further, although not shown, the power supply device may be used as a power supply for an electric storage device that charges and stores a battery with midnight electric power at night. The power supply device charged by the midnight power can be charged by the midnight power which is the surplus power of the power station, and output power during daytime when the power load is large, and limit peak power during daytime to be small. Further, the power supply device can also be used as a power supply for charging using both the output of the solar battery and the midnight power. The power supply device can effectively utilize both the electric power generated by the solar cell and the midnight electric power, and can efficiently store electricity while taking weather and power consumption into consideration.

The power storage device as described above can be suitably used for applications such as a backup power supply device that can be mounted on a rack of a computer server, a backup power supply device for a wireless base station such as a mobile phone, a power supply for power storage for home use or factory use, a power supply for street lamps, and the like, a power storage device combined with a solar cell, a signal device, a backup power supply for a traffic display for a road, and the like.

Industrial applicability

The power supply device of the present invention can be suitably used as a power supply for large current used for a power supply of a motor or the like for driving an electric vehicle such as a hybrid vehicle, a fuel cell vehicle, an electric vehicle, or an electric motorcycle. Examples of the power supply device include a plug-in hybrid electric vehicle, a hybrid electric vehicle, and an electric vehicle that can switch between an EV running mode and an HEV running mode. In addition, the present invention can be suitably used for applications such as a backup power supply device that can be mounted on a rack of a computer server, a backup power supply device for a wireless base station such as a mobile phone, a power supply for power storage for home use and factory use, a power supply for street lamps, a power storage device combined with a solar cell, a backup power supply for signal equipment, and the like.

Description of the reference numerals

100. A power supply device; 1. a battery cell; 1A, a lamination surface; 2. a partition plate; 2a, a sealing part area; 2b, a body region; 3. an end plate; 4. tightening the strip; 5. a heat insulating sheet; 5A, a composite material; 6. an elastic sheet; 10. a battery block; 11. a battery case; 12. a sealing plate; 13. an electrode terminal; 14. a safety valve; 15. an opening part; 81. a building; 82. a solar cell; 83. a charging circuit; 84. a charging switch; 85. a DC/AC inverter; 86. a load; 87. a discharge switch; 88. a power supply controller; 91. a vehicle main body; 93. an electric motor; 94. a generator; 95. a DC/AC inverter; 96. an engine; 97. a wheel; 98. a charging plug; HV, EV, vehicle.