Power supply device, electric vehicle equipped with the power supply device, and power storage device

Abstract

According to the present invention, for the purpose of having a separator absorb the expansion of a battery cell for a long period of time, end plates are arranged on both end faces of a battery block, which is obtained by stacking a plurality of battery cells (1) in the thickness direction, with separators (2) being interposed therebetween, and the pair of end plates are connected by means of a binding bar so as to fix the battery block in a pressurized state. Each separator (2) is provided with a thermal insulation layer (5), an elastic layer (6) that absorbs the expansion of a battery cell (1), and a stopper (7) that limits the compressive thickness of the elastic layer (6); and the stiffness of the stopper (7) is set to be higher than that of the elastic layer (6).

Description

[Technical field]

[0001] The present invention relates to a power supply device in which many battery cells are stacked, and an electric vehicle and a power storage device equipped with this power supply device. [Background technology]

[0002] Power supply devices with many stacked battery cells are suitable as power sources mounted on electric vehicles to supply power to the motor that runs the vehicle, as power sources charged with natural energy such as solar cells or overnight power, and as backup power sources in the event of a power outage. Power supply devices with this structure have separators sandwiched between the stacked battery cells. Power supply devices in which many battery cells are stacked with separators sandwiched between them fix the stacked battery cells in a pressurized state to prevent displacement due to expansion of the battery cells. To achieve this, the power supply device has a pair of end plates disposed on both end faces of a battery block in which many battery cells are stacked, and the pair of end plates are connected by a bind bar. (See Patent Document 1) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-220117 A Summary of the Invention [Problem to be solved by the invention]

[0004] The power supply unit is a battery block in which multiple battery cells are stacked, with a pair of end plates placed on both end faces of the battery block, which are held in a pressurized state with a fairly strong pressure from both ends and connected with a handlebar. The power supply unit applies strong pressure to the battery cells to fix them in place, preventing malfunctions due to relative movement or vibration of the battery cells. For example, this power supply unit can be used with a stacked surface area of ​​approximately 100 cm2. 2In a device that uses battery cells with the above structure, the end plates are pressed with a strong force of several tons or more and fixed with a bind bar. In a power supply device with this structure, adjacent stacked battery cells are insulated with separators, and hard plastic plates are used for the separators. When the internal pressure of the battery cells increases and they expand, the hard plastic separators cannot absorb the expansion of the battery cells, and in this state the surface pressure between the battery cells and the separators increases suddenly, and extremely strong forces are applied to the end plates and bind bars. For this reason, the end plates and handle bars are required to be made of extremely strong materials and shapes, which has the disadvantages of making the power supply device heavy and large, and increasing material costs.

[0005] The power supply device is provided with an elastic layer on the separator that is crushed by the pressure of the battery cells, thereby reducing the strong stress acting on the end plates and handlebars when the battery cells expand due to an increase in internal pressure. In particular, a rubber-like elastic material is used in the separator provided with the elastic layer, so that the expansion of the battery cells can be absorbed in a favorable manner. However, elastic layers such as rubber-like elastic materials have the disadvantage that when they are compressed with a strong pressure that exceeds their elastic limit, or when they are repeatedly compressed with a strong pressure, they deteriorate and their physical properties change, resulting in a decrease in their ability to absorb the expansion of the battery cells.

[0006] The present invention was developed with the aim of eliminating the above-mentioned drawbacks, and one of the objects of the present invention is to provide a technology that enables the separator to absorb the expansion of the battery cell for a long period of time. [Means for solving the problem]

[0007] A power supply device according to one embodiment of the present invention comprises a battery block 10 formed by stacking multiple battery cells 1 in the thickness direction with separators 2 sandwiched between them, a pair of end plates 3 arranged on both end faces of the battery block 10, and a bind bar 4 connected to the pair of end plates and fixing the battery block 10 in a pressurized state via the end plates 3. The separator 2 comprises a heat insulating layer 5, an elastic layer 6 that absorbs expansion of the battery cells 1, and a stopper 7 that limits the compression thickness of the elastic layer 6, with the rigidity of the stopper 7 being greater than that of the elastic layer 6.

[0008] An electric vehicle according to one embodiment of the present invention comprises the above-mentioned power supply unit 100, a motor 93 for driving which is supplied with power from the power supply unit 100, a vehicle body 91 equipped with the power supply unit 100 and the motor 93, and wheels 97 driven by the motor 93 to drive the vehicle body 91.

[0009] An energy storage device according to one embodiment of the present invention includes the above-mentioned power supply device 100 and a power supply controller 88 that controls charging and discharging of the power supply device 100. The power supply controller 88 enables charging of the secondary battery cell 1 using external power and controls charging of the secondary battery cell 1. Effect of the Invention

[0010] In the power supply device described above, the separator can absorb expansion of the battery cells for a long period of time. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view of a power supply device according to an embodiment of the present invention; [Diagram 2] 2 is a vertical sectional view of the power supply device shown in FIG. 1. [Diagram 3] 2 is a horizontal sectional view of the power supply device shown in FIG. 1. [Figure 4] FIG. 2 is a perspective view showing a separator and a battery cell. [Diagram 5] FIG. 4 is a perspective view showing another example of a separator. [Figure 6] FIG. 6 is a schematic side view of the separator shown in FIG. [Figure 7] FIG. 4 is a perspective view showing another example of a separator. [Figure 8] FIG. 8 is a schematic side view of the separator shown in FIG. [Figure 9] FIG. 4 is a perspective view showing another example of a separator. [Figure 10] FIG. 10 is a schematic side view of the separator shown in FIG. [Figure 11]FIG. 4 is a perspective view showing another example of a separator. [Figure 12] FIG. 12 is a schematic side view of the separator shown in FIG. [Figure 13] FIG. 4 is a perspective view showing another example of a separator. [Figure 14] FIG. 14 is a schematic side view of the separator shown in FIG. [Figure 15] FIG. 4 is a perspective view showing another example of a separator. [Figure 16] 16 is a cross-sectional view taken along line AA and line BB of the separator shown in FIG. 15. [Figure 17] 5 is an enlarged cross-sectional view of a main portion showing a state in which the stopper of the separator shown in FIG. 4 is pressed by an expanding battery cell. FIG. [Figure 18] 1 is a block diagram showing an example of a power supply device mounted on a hybrid vehicle that runs on an engine and a motor. [Figure 19] FIG. 1 is a block diagram showing an example in which a power supply device is mounted on an electric vehicle that runs only on a motor. [Figure 20] FIG. 11 is a block diagram showing an example of application to a power supply device for power storage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper", "lower", and other terms including these terms) are used as necessary, but the use of these terms is for the purpose of facilitating understanding of the invention with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present invention. In addition, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or members. Furthermore, the embodiments shown below are specific examples of the technical ideas of the present invention, and do not limit the present invention to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present invention. Furthermore, the contents described in one embodiment or example can be applied to other embodiments or examples. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

[0013] A power supply device according to a first embodiment of the present invention includes a battery block formed by stacking multiple battery cells in the thickness direction with separators sandwiched between them, a pair of end plates disposed on both end faces of the battery block, and bind bars connected to the pair of end plates and fixing the battery block in a pressurized state via the end plates. The separator includes a heat insulating layer, an elastic layer that absorbs expansion of the battery cells, and a stopper that limits the compression thickness of the elastic layer, with the rigidity of the stopper being greater than the rigidity of the elastic layer.

[0014] The above power supply device has a heat insulating layer on the separator to prevent heat generation from one battery cell from heating up adjacent battery cells, and an elastic layer to absorb expansion of the battery cells. In addition, a stopper is provided to restrict the elastic layer from being crushed too hard, preventing the elastic layer from deteriorating and losing its elasticity, allowing the separator to comfortably absorb expansion of the battery cells for a long period of time. Furthermore, because the stopper prevents deterioration of the elastic layer's physical properties, the elastic layer will not be crushed abnormally thin even when the internal pressure of the battery cells is high.

[0015] In addition to the above features, the separator's elastic layer can absorb the expansion of the battery cells over a long period of time, so the power supply device can also suppress deviations in the relative positions of the individual battery cells when the battery cells repeatedly expand and contract. Relative deviations in the positions of adjacent battery cells can cause damage to the metal bus bars that are fixed to the electrode terminals of the battery cells and the electrode terminals. A power supply device that can prevent relative deviations in the positions of battery cells caused by the separator expanding due to an increase in internal pressure can prevent failure of the connections between the electrode terminals and the bus bars due to the expansion of the battery cells.

[0016] In the power supply device according to the second embodiment of the present invention, an elastic layer is laminated onto a heat insulating layer.

[0017] In a power supply device according to a third embodiment of the present invention, the heat insulating layer is made of a hybrid material of inorganic powder and fiber reinforcement material.

[0018] The above power supply unit has an insulating layer made of a hybrid material of inorganic powder and fiber reinforcement, which has the advantage of ensuring the excellent heat resistance of the separator while preventing a deterioration in the physical properties of the insulating layer made of a hybrid material by using an elastic layer.

[0019] In a power supply device according to a fourth embodiment of the present invention, the inorganic powder is silica aerogel.

[0020] The power supply device described above has a feature that the insulating layer is made of a hybrid material of silica aerogel and fiber reinforcement, and an elastic layer is laminated on this insulating layer to prevent the elastic layer from being crushed abnormally thin by the stopper, thereby ensuring the extremely excellent insulating properties of the elastic layer for a long period of time and efficiently blocking heat conduction between battery cells. The insulating layer of the hybrid material of silica aerogel and fiber reinforcement exhibits extremely excellent insulating properties due to the low thermal conductivity of the fine inorganic powder silica aerogel. Silica aerogel is a fine particle composed of a silicon dioxide (SiO2) skeleton and 90% to 98% air, and this silica aerogel is filled into the gaps in the fiber sheet, achieving excellent insulating properties with a thermal conductivity of 0.02 W / m·K due to its extremely high porosity. The insulating properties of the insulating layer of this hybrid material decrease when the inorganic powder silica aerogel is destroyed by pressure. The insulating layer laminated on the insulating layer absorbs the expansion of the battery cell and prevents the battery cell from expanding and strongly pressurizing the silica aerogel. This prevents the expanding battery cells from pressurizing the silica aerogel and destroying it, ensuring excellent heat insulating properties for a long period of time. Furthermore, the stopper prevents the physical properties of the elastic layer from deteriorating, so the elastic layer elastically deforms for a long period of time. The elastically deforming elastic layer absorbs the expansion of the battery cells and prevents the silica aerogel from being destroyed by pressure. Since the stopper ensures that the physical properties of the elastic layer do not deteriorate for a long period of time, the expansion of the battery cells is absorbed by the elastic layer for a long period of time, and the silica aerogel is protected by the elastic layer, thereby preventing the deterioration of heat insulating properties due to pressure destruction.

[0021] Furthermore, in the above power supply device, when the battery cell expands, the elastic layer laminated on the insulating layer is deformed thinly to reduce the internal stress of the insulating layer, so the hybrid material of the insulating layer does not need to have the physical property of elastic deformation under pressure. Therefore, the hybrid material has the advantage that the insulating properties of the insulating layer can be improved by controlling the filling of silica aerogel so that the insulating properties are ideal.

[0022] In a power supply device according to a fifth embodiment of the present invention, the elastic layer is made of an elastic material. In a power supply device according to a sixth embodiment of the present invention, the elastic material is made of at least one material selected from the group consisting of synthetic rubber, thermoplastic elastomer, and foam material.

[0023] In a power supply device according to a seventh embodiment of the present invention, the stopper is made of a hybrid material of inorganic powder and fiber reinforcement.

[0024] In the power supply device described above, the stopper is made of a hybrid material of inorganic powder and fiber reinforcement, which gives the stopper excellent heat insulation properties. This structure gives the separator excellent heat insulation properties over a wide area, and can efficiently block heat conduction between adjacent battery cells. This effectively prevents the induction of thermal runaway in the battery cells, realizing the feature of highly guaranteeing the safety of the power supply device.

[0025] In the power supply device of the eighth embodiment of the present invention, the stopper penetrates the elastic layer. In the power supply device of the ninth embodiment of the present invention, the stopper penetrates the insulating layer and the elastic layer. Furthermore, in the power supply device of the tenth embodiment of the present invention, the stopper is made of a material having a higher Young's modulus than the insulating layer and the elastic layer.

[0026] In the power supply device according to the eleventh embodiment of the present invention, the separator is provided with a plurality of stoppers. In the power supply device described above, the arrangement of the stoppers can be adjusted so that multiple stoppers are used to suppress expansion of the battery cells to an ideal shape.

[0027] (Embodiment 1) A more specific power supply device and electric vehicle will be described in detail below. A power supply device 100 shown in the oblique view of Figure 1, the vertical cross-sectional view of Figure 2, and the horizontal cross-sectional view of Figure 3 comprises a battery block 10 in which multiple battery cells 1 are stacked in the thickness direction with separators 2 sandwiched between them, a pair of end plates 3 arranged on both end faces of the battery block 10, and a bind bar 4 that connects the pair of end plates 3 and fixes the battery block 10 in a pressurized state via the end plates 3.

[0028] (Battery block 10) As shown in Fig. 4, the battery cells 1 of the battery block 10 are rectangular battery cells with a square outer shape, and a sealing plate 12 is laser-welded to the opening of a battery case 11 that closes the bottom, creating an airtight structure inside. The sealing plate 12 has a pair of positive and negative electrode terminals 13 protruding from both ends. An opening 15 for a 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 above a predetermined value, releasing internal gas. The safety valve 14 prevents the internal pressure of the battery cell 1 from increasing.

[0029] (Battery cell 1) The battery cell 1 is a lithium ion secondary battery. The power supply device 100, which uses a lithium ion secondary battery as the battery cell 1, has the feature of being able to increase the charging capacity relative to the capacity and weight. However, the battery cell 1 can be any other rechargeable battery, such as a non-aqueous electrolyte secondary battery other than a lithium ion secondary battery.

[0030] (3 end plates, 4 bind bars) The end plates 3 are metal plates with an outline roughly equal to the outline of the battery cells 1 so that they do not deform when pressed by the battery block 10, and have bind bars 4 connected to their opposite edges. The bind bars 4 connect the stacked battery cells 1 with the end plates 3 in a pressurized state, and fix the battery block 10 in a pressurized state at a specified pressure.

[0031] (Separator 2) Separators 2 are sandwiched between stacked battery cells 1 to absorb expansion of the battery cells 1, insulate adjacent battery cells 1, and block heat conduction between the battery cells 1. A battery block 10 connects the battery cells 1 in series or parallel by fixing bus bars (not shown) to the electrode terminals 13 of adjacent battery cells 1. Battery cells 1 connected in series are stacked and insulated with separators 2 because a potential difference occurs in the battery case 11. Battery cells 1 connected in parallel do not generate a potential difference in the battery case 11, but are stacked and insulated with separators 2 to prevent the induction of thermal runaway.

[0032] The separator 2 in Figs. 4 to 14 has an elastic layer 6 laminated on the surface of the insulating layer 5. The separator 2 in Figs. 15 and 16 has a through hole 5a in the insulating layer 5, and the elastic layer 6 is inserted into the through hole 5a. Furthermore, the separator 2 has a stopper 7 that limits the compression thickness of the elastic layer 6. The stopper 7 has a higher Young's modulus than the elastic layer 6, and suppresses the expansion of the battery cell to prevent the elastic layer 6 from being crushed thinner than its elastic limit and losing its restorability. A hybrid material of inorganic powder and fiber reinforcement is suitable for the insulating layer 5. The inorganic powder of the hybrid material is preferably silica aerogel. In this insulating layer 5, inorganic powder such as silica aerogel, which has extremely low thermal conductivity, is filled into the gaps between the fibers.

[0033] The elastic layer 6 absorbs the expansion of the battery cell 1 and also presses against the surface of the battery cell 1 case, suppressing the surface pressure of the expanding battery cell 1 case surface pressing against the insulating layer 5. The insulating properties of a hybrid material of silica aerogel and fiber reinforcement material decrease when the silica aerogel is compressed and destroyed, but separator 2, which can reduce the surface pressure with elastic layer 6, prevents destruction of the silica aerogel and maintains excellent insulating properties.

[0034] The insulating layer 5, which is made of a hybrid material, is made of silica aerogel with a nano-sized porous structure and a fiber sheet. This insulating layer 5 is manufactured by impregnating fibers with the gel raw material of silica aerogel. After the fiber sheet is impregnated with the silica aerogel, the fibers are laminated and the gel raw material is reacted to form a wet gel, and the surface of the wet gel is further hydrophobized and dried with hot air. The fiber of the fiber sheet is polyethylene terephthalate (PET). However, the fiber of the fiber sheet can also be inorganic fiber such as oxidized acrylic fiber that has been treated with flame retardant or glass wool.

[0035] The fiber diameter of the fiber sheet of the heat insulating layer 5 is preferably 0.1 to 30 μm. By making the fiber diameter of the fiber sheet smaller than 30 μm, the thermal conduction through the fibers can be reduced, thereby improving the heat insulating properties of the heat insulating layer 5. Silica aerogel is an inorganic fine particle composed of 90% to 98% air, and has a three-dimensional microporous structure with micropores between the skeleton formed by clusters of nano-order spheres bonded together.

[0036] The insulating layer 5 made of the fiber sheet and silica aerogel is thin and has excellent insulating properties. The insulating layer 5 is set to a thickness that can prevent the induction of thermal runaway of the battery cell 1, taking into consideration the energy generated by the thermal runaway of the battery cell 1. The energy generated by the thermal runaway of the battery cell 1 increases as the charge capacity of the battery cell 1 increases. Therefore, the thickness of the insulating layer 5 is set to an optimal value taking into consideration the charge capacity of the battery cell 1. For example, in a power supply device in which the battery cell 1 is a lithium ion secondary battery with a charge capacity of 5 Ah to 20 Ah, the thickness of the insulating layer 5 is set to 0.5 mm to 2 mm, and optimally about 1 mm to 1.5 mm. However, the present invention does not specify the thickness of the elastic sheet to the above range, and the thickness of the insulating layer 5 is set to an optimal value taking into consideration the insulating properties of the fiber sheet and silica aerogel against thermal runaway and the insulating properties required to prevent the induction of thermal runaway of the battery cell 1.

[0037] The separator 2 shown in Figs. 4 to 14 has elastic layers 6 laminated on both sides of the insulating layer 5, and the separator 2 shown in Figs. 15 and 16 has elastic layers 6 disposed penetrating the insulating layer 5. The thick separator 2 is laminated between each battery cell 1 to make the battery block 10 larger. Since the battery block 10 is required to be small, the separator 2 is required to be as thin as possible to have insulating properties. This is because the power supply device 100 is required to have a large charging capacity relative to its volume. In order to make the battery block 10 small and increase the charging capacity of the power supply device 100, it is important that the separator 2 is thin overall to prevent the induction of thermal runaway of the battery cells 1. For this reason, the elastic layer 6 is, for example, 0.2 mm or more and 2 mm or less, more preferably 0.3 mm to 1 mm or less, to suppress an increase in compressive stress due to the expansion of the battery cells 1. Furthermore, the elastic layer 6 is preferably thinner than the insulating layer 5, while reducing the compressive stress when the battery cells 1 expand.

[0038] The elastic layer 6 is a non-foamed elastic body. However, in addition to the non-foamed elastic body, a thermoplastic elastomer or a foamed elastic body may be used. The elastic protrusion made of a non-foamed elastic body is compressed and the volume hardly changes due to its non-compressibility, so that the compressed and crushed elastic body is pushed out into the deformation space, and the elastic protrusion is deformed thinly. The elastic body of the elastic layer 6 is preferably a synthetic rubber, a thermoplastic elastomer, or a foamed material. The synthetic rubber is preferably a synthetic rubber having a heat resistance limit temperature of 100°C or higher. For example, the synthetic rubber may be silicone rubber, fluororubber, urethane rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprone rubber, nitrile rubber, hydrogenated nitrile rubber, polyisobutylene rubber, ethylene propylene rubber, ethylene vinyl acetate copolymer rubber, chlorosulfonated polyethylene rubber, acrylic rubber, epichlorohydrin rubber, thermoplastic olefin rubber, ethylene propylene diene rubber, butyl rubber, polyether rubber, etc.

[0039] In particular, fluororubber and silicone rubber have a fairly high heat resistance limit temperature of 230°C, and are characterized by their ability to maintain rubber-like elasticity when heated by high-temperature battery cells and stably absorb the expansion of battery cells that generate heat at high temperatures. Furthermore, the heat resistance limit temperature of acrylic rubber is 160°C, while that of hydrogenated nitrile rubber, ethylene propylene rubber, and butyl rubber is 140°C, both of which are above 100°C, so they can stably absorb expansion even when the battery cells generate heat at high temperatures.

[0040] The stopper 7 is disposed in the gap between adjacent battery cells 1. The stopper 7 is disposed so that both end faces face the battery cell surface. The stopper 7 comes into direct contact with the expanding battery cell surface at both end faces, or comes into contact with the battery cell surface via the elastic layer 6, thereby limiting the thickness to which the elastic layer 6 is crushed. The elastic layer 6 is elastically deformed to become thin when pressed by the expanding battery cell 1, but the thickness to which it is crushed is limited by the stopper 7. As shown in Figures 7 and 8, the stopper 7, which comes into contact with the battery cell surface via the elastic layer 6, presses the battery cell surface via the elastic layer 6, which is crushed thin, thereby limiting the expansion of the battery cell 1.

[0041] The stopper 7 limits the thickness by which the elastic layer 6 is crushed by the expanding battery cell 1, and therefore has higher rigidity than the elastic layer 6, and is preferably a rigid body with a high Young's modulus that is hardly compressed when pressed by the expanding battery cell 1. The stopper 7 does not necessarily have to be a rigid body that completely prevents the expansion of the battery cell 1. The stopper 7, which has a higher Young's modulus than the elastic layer 6, limits the expansion of the battery cell 1 more strongly than the elastic layer 6 when both end faces are in contact with the opposing surfaces of the battery cell 1, reducing the elastic layer 6 from being crushed thinly and protecting the elastic layer 6.

[0042] The stopper 7 is preferably a hybrid material of inorganic powder such as silica aerogel and a fiber reinforcement material, and is integral with the insulating layer 5. However, the stopper 7 can also be a hybrid material with a higher Young's modulus than the insulating layer 5. Furthermore, although not shown, the stopper 7 can be made of an insulating material such as hard plastic. The stopper 7 penetrates the separator 2, and both end faces are arranged in the gap between the opposing battery cells 1. The separator 2, in which the insulating layer 5 and the stopper 7 are made of a hybrid material, is entirely made of a hybrid material with excellent insulating properties, and can insulate the adjacent battery cells 1 in an ideal state. The hybrid material can increase the Young's modulus by increasing the packing density of the inorganic powder. The hybrid material, in which the insulating layer 5 and the stopper 7 are integrally formed, has a high packing density of the inorganic powder such as silica aerogel, and a high Young's modulus that limits the expansion of the battery cell 1. The stopper 7, which is integral with the insulating layer 5, is arranged between the elastic layers 6 arranged above and below, as shown in FIG. 4, or is arranged by guiding it to the recess 6b of the elastic layer 6 laminated on the surface, as shown in FIG. 8. However, as shown in FIG. 16, the separator 2 may have a through hole 5a formed in the heat insulating layer 5 used in combination with the stopper 7, and the elastic layer 6 may be disposed in this through hole.

[0043] The separators 2 in Figs. 4 to 14 have stoppers 7 extending in the width direction. The separators 2 in Figs. 4 and 8 have stoppers 7 arranged in the upper and lower central portions, the separators 2 in Figs. 5, 6, and 9 to 14 have stoppers 7 arranged along the upper and lower edges, and the separator in Fig. 15 uses the insulating layer 5 in addition to the stoppers 7 to guide the elastic layer 6 into the through holes 5a provided in the insulating layer 5. When the battery cell 1 is in an expanding state, the stoppers 7 come into contact with the surfaces of the adjacent battery cells 1 at both ends, as shown in the cross-sectional view of Fig. 17, to limit the expansion of the battery cell 1. The separators 2 with stoppers 7 arranged in the upper and lower central portions limit the expansion of the battery cell 1 at the upper and lower central portions, preventing the elastic layer 6 from being crushed thinly. In a power supply device without stoppers on the separator, when the internal pressure rises and the battery cell expands, the expansion at the center of the case becomes the largest, so the elastic layer is crushed thinnest at the center. As shown in Figures 4, 7 and 8, a separator 2 with a stopper 7 provided in the center limits the elastic layer 6 from being crushed thinly in the area where the expansion of the battery cell 1 is greatest, thereby protecting the area where the elastic layer 6 is particularly likely to lose its elasticity. A separator 2 with a stopper 7 provided along the upper edge limits the expansion of the upper part of the battery cell 1. Since the sealing plate 12 of the battery cell 1 is welded to the upper part of the battery case 11, deformation of the upper part causes damage to the connection between the battery case 11 and the sealing plate 12. A separator 2 with a stopper 7 provided in the upper edge can prevent the deformation of the upper edge of the battery cell 1 with the stopper 7, thereby preventing damage to the battery case 11. Furthermore, a separator 2 with stoppers 7 provided along the upper and lower edges has the characteristic of preventing deformation of the upper and lower edges of the battery cell 1, preventing damage to the upper and lower edges of the battery cell 1.

[0044] 5 and 6 has an integrated structure in which the insulating layer 5 and stopper 7 are made of a hybrid material, with the upper and lower edges of the insulating layer 5 thickened to serve as the stopper 7, and an elastic layer 6 laminated in the recess 5b provided between the upper and lower edges. This separator 2 is laminated between adjacent battery cells 1, and when the battery cells 1 are not in an expanded state, the surface of the elastic layer 6 is in close contact with the surface of the battery cell 1, and the stopper 7 is in a position that does not contact the battery cell surface. When the battery cell 1 expands and crushes the elastic layer 6, the battery cell surface comes into contact with the stopper 7, restricting the expansion.

[0045] The separator 2 in Figs. 7 and 8 also has an integrated structure of the insulating layer 5 and the stopper 7 made of a hybrid material, with the upper and lower central parts of the insulating layer 5 thickened to serve as the stopper 7. In this separator 2, the elastic layer 6 is laminated over the entire surface of the insulating layer 5, and a recess 6b for guiding the stopper 7 is provided on the inner surface of the elastic layer 6 to make the surface smooth. A thin elastic layer 6 is laminated on the surface of each end of the stopper 7, and the stopper 7 comes into contact with the battery cell surface via the elastic layer 6. This separator 2 is laminated between adjacent battery cells 1, and when the battery cell 1 is not expanded, the entire surface of the elastic layer 6 is in close contact with the surface of the battery cell 1, and when the battery cell 1 expands and thinly crushes the elastic layer 6, the stopper 7 presses against the battery cell surface via the thinly crushed elastic layer 6, limiting the expansion of the battery cell 1. In this separator 2, the stopper 7 presses against the battery cell surface via the elastic layer 6. The hybrid material stopper 7, which is pressed against the battery cell surface via the elastic layer 6, has the advantage that it can reduce the deterioration of insulating properties caused by damage to the silica aerogel in the elastic layer 6, compared to hybrid materials that press directly against the battery cell surface.

[0046] The separators 2 in Figs. 9 to 12 also have an integrated structure of the insulating layer 5 and stopper 7 made of a hybrid material, with the upper and lower edges of the insulating layer 5 thickened to serve as the stopper 7, and an elastic layer 6 consisting of multiple rows of ridges 6c extending in the width direction laminated in the recess 5b provided between the upper and lower edges. In the separator in Fig. 9, the ridges 6c of the elastic layer 6 arranged in the upper and lower central parts are low, and the ridges 6c of the elastic layer 6 arranged toward the upper and lower edges are high. In the separator 2 in Fig. 11, the elastic layer 6 consisting of multiple rows of ridges 6c has the same height and width. These separators 2 are laminated between adjacent battery cells 1, and when the battery cells 1 are not expanded, the surface of the elastic layer 6 is in close contact with the surface of the battery cell 1, and the stopper 7 does not come into contact with the surface of the battery cell 1. However, the separator 2 in Fig. 9 can also be in a state where, when the battery cell 1 is not expanding, the elastic layer 6 of the protruding strips 6c arranged at the upper and lower parts is in close contact with the surface of the battery cell 1, and the central protruding strip 6c is not in close contact with the surface of the battery cell 1. When the battery cell 1 expands and crushes the elastic layer 6, the battery cell surface hits the stopper 7 and the expansion is restricted, but while the separators 2 in Figs. 9 and 10 expand the battery cell surface so that the center protrudes, the separator 2 in Fig. 11 expands the battery cell surface to a state that approximates a flat surface. The elastic layer 6 of the protruding strips 6c is pressed against the expanding battery cell surface and crushed thin, but by being crushed so that its width becomes wider, it deforms more smoothly and absorbs the expansion of the battery cell 1.

[0047] The separator 2 in Figs. 13 and 14 also has an integrated structure of a heat insulating layer 5 and a stopper 7 made of a hybrid material, with the upper and lower edges of the heat insulating layer 5 thickened to serve as the stopper 7, and an elastic layer 6 that gradually becomes thicker toward the upper and lower edges is laminated in the recess 5b provided between the upper and lower edges. This separator 2 is laminated between adjacent battery cells 1, and when the battery cell 1 is not inflated, part of the surface of the elastic layer 6 is in close contact with the surface of the battery cell 1, and the stopper 7 does not come into contact with the battery cell surface. However, this separator 2 can also have the entire surface of the elastic layer 6 in close contact with the battery cell surface when the battery cell 1 is not inflated. When the battery cell 1 expands and crushes the elastic layer 6, the battery cell surface hits the stopper 7, restricting the expansion, but the battery cell expands into a shape that protrudes higher in the center.

[0048] Furthermore, in the separator 2 of Figs. 15 and 16, the insulating layer 5 and the stopper 7 are made of an integrated structure of a hybrid material, and the entire insulating layer 5 is also used as the stopper 7. The insulating layer 5 used in combination with the stopper 7 has a through hole 5a through which the elastic layer 6 is guided. The insulating layer 5 used in combination with the stopper 7 has a plurality of through holes 5a through which the elastic layer 6 is guided. This separator 2 has through holes 5a in a hybrid material having the same overall thickness, and can be used in combination with the insulating layer 5 and the stopper 7, so that the hybrid material can be easily manufactured. This separator 2 can efficiently absorb the expansion of the battery cell 1 by increasing the total area of ​​the through holes 5a and increasing the area of ​​the elastic layer 6, and conversely, can increase the total area of ​​the through holes 5a and increase the area of ​​the insulating layer 5 to improve the insulating properties. The elastic layer 6 guided through the through hole 5a is thicker than the insulating layer 5 used in combination with the stopper 7, and both sides of the elastic layer 6 are in close contact with the surface of the battery cell when the battery cell 1 is not expanded. When the battery cell 1 expands and crushes the elastic layer 6, the elastic layer 6 used in combination with the stopper 7 comes into contact with the surface of the battery cell, limiting the expansion of the battery cell 1.

[0049] The elastic layer 6, heat insulating layer 5, and stopper 7 are laminated in fixed positions by bonding via an adhesive or pressure-sensitive adhesive layer. The separator 2 and battery cell 1 are also bonded via an adhesive or pressure-sensitive adhesive layer and placed in fixed positions. However, the separator 2 can also be placed in a fixed position in a battery holder (not shown) that positions the battery cell 1 in a fixed position with a fitting structure.

[0050] In the above power supply device 100, the battery cells 1 are rectangular battery cells with a charging capacity of 6 Ah to 80 Ah, the insulating layer 5 of the separator 2 is "NASBIS (registered trademark) made by Panasonic" which is a fiber sheet filled with silica aerogel and has a thickness of 1 mm, the elastic layers 6 laminated on both sides of the insulating layer 5 are made of silicone rubber with a thickness of 0.5 mm, and the stoppers 7 are 1.5 mm high, thereby preventing deterioration of the elastic layer 6 due to an increase in the internal pressure of the battery cells 1.

[0051] The power supply device described above can be used as a vehicle power source that supplies power to a motor that runs an electric vehicle. Electric vehicles equipped with the power supply device include hybrid cars and plug-in hybrid cars that run on both an engine and a motor, and electric cars that run only on a motor, and the power supply device is used as a power source for these vehicles. Note that an example will be described in which a large capacity, high output power supply device 100 is constructed by connecting a large number of the above-mentioned power supply devices in series or in parallel to obtain power to drive a vehicle, and further adding necessary control circuits.

[0052] (Power supply unit for hybrid vehicles) FIG. 18 shows an example of a power supply device mounted on a hybrid vehicle that runs on both an engine and a motor. The vehicle HV equipped with the power supply device shown in this figure includes a vehicle body 91, an engine 96 and a motor 93 for running the vehicle body 91, wheels 97 driven by the engine 96 and the motor 93 for running, a power supply device 100 that supplies power to the motor 93, and a generator 94 that charges the 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. The vehicle HV runs on both the motor 93 and the engine 96 while charging and discharging the battery of the power supply device 100. The motor 93 is driven in an area where the engine efficiency is poor, such as during acceleration or low-speed running, to run the vehicle. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by the engine 96 or by regenerative braking when braking the vehicle, and charges the battery of the power supply device 100. 18, the vehicle HV may be provided with a charging plug 98 for charging the power supply device 100. The power supply device 100 can be charged by connecting this charging plug 98 to an external power source.

[0053] (Power supply unit for electric vehicles) FIG. 19 shows an example of a power supply device mounted on an electric vehicle that runs only by a motor. The vehicle EV equipped with the power supply device shown in this figure includes a vehicle body 91, a motor 93 for driving the vehicle body 91, wheels 97 driven by the motor 93, a power supply device 100 that supplies power to the motor 93, and a generator 94 that charges the 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. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by energy generated when the vehicle EV is subjected to regenerative braking, and charges the battery of the power supply device 100. The vehicle EV also includes a charging plug 98, which can be connected to an external power source to charge the power supply device 100.

[0054] (Power supply device for power storage device) Furthermore, the present invention does not limit the use of the power supply device to a power supply for a motor that runs a vehicle. The power supply device according to the embodiment can also be used as a power supply for a power storage device that charges a battery with power generated by solar power generation, wind power generation, or the like and stores the power. Fig. 20 shows a power storage device that charges a battery of the power supply device 100 with a solar cell 82 and stores the power.

[0055] The power storage device shown in FIG. 20 charges a battery of a power supply device 100 with power generated by a solar cell 82 arranged on the roof or rooftop of a building 81 such as a house or a factory. This power storage device charges the battery of the power supply device 100 with a charging circuit 83 using the solar cell 82 as a charging power source, and then supplies power to a load 86 via a DC / AC inverter 85. For this reason, this power storage device has a charging mode and a discharging mode. The power storage device shown in the figure connects the DC / AC inverter 85 and the charging circuit 83 to the power supply device 100 via a discharge switch 87 and a charge switch 84, respectively. The discharge switch 87 and the charge switch 84 are switched ON / OFF by a power storage device power supply controller 88. In the charge mode, the power supply controller 88 switches the charge switch 84 ON and the discharge switch 87 OFF to allow charging from the charging circuit 83 to the power supply device 100. Furthermore, when charging is completed and the battery is fully charged, or when a predetermined charged capacity or more has been reached, the power supply controller 88 switches the charging switch 84 OFF and the discharging switch 87 ON to switch to a discharging mode, permitting discharging from the power supply device 100 to the load 86. Furthermore, if necessary, the charging switch 84 can be turned ON and the discharging switch 87 can be turned ON to supply power to the load 86 and charge the power supply device 100 at the same time.

[0056] Furthermore, although not shown, the power supply device can also be used as a power source for a power storage device that uses late-night power at night to charge and store electricity in a battery. A power supply device that is charged with late-night power is charged with late-night power, which is surplus electricity from power plants, and outputs electricity during the day when the power load is high, making it possible to limit daytime peak power to a low level. Furthermore, the power supply device can also be used as a power source that charges with both the output of solar cells and late-night power. This power supply device effectively uses both the power generated by solar cells and the late-night power, and can efficiently store electricity while taking into account the weather and power consumption.

[0057] The above-described power storage device can be suitably used for applications such as a backup power supply device that can be mounted on a computer server rack, a backup power supply device for wireless base stations for mobile phones and the like, a power supply for home or factory storage, a power supply for street lights, a power storage device combined with a solar cell, and a backup power supply for traffic lights and road traffic indicators. [Industrial Applicability]

[0058] The power supply device according to the present invention can be suitably used as a large current power supply for the power supply of motors for driving electric vehicles such as hybrid cars, fuel cell cars, electric cars, and electric motorcycles. Examples of such power supply devices include plug-in hybrid electric cars, hybrid electric cars, electric cars, and the like that can switch between EV driving mode and HEV driving mode. The power supply device can also be suitably used for applications such as a backup power supply device that can be mounted on a rack for a computer server, a backup power supply device for wireless base stations for mobile phones, and the like, a power storage power supply for home and factory use, a power supply for street lights, and the like, a power storage device combined with a solar cell, and a backup power supply for traffic lights, and the like. [Explanation of symbols]

[0059] 100...power supply device, 1...battery cell, 2...separator, 3...end plate, 4...bind bar, 5...insulating layer, 5a...through hole, 5b...recess, 6...elastic layer, 6b...recess, 6c...convex strip, 7...stopper, 10...battery block, 11...battery case, 12...sealing plate, 13...electrode terminal, 14...safety valve, 15...opening, 81...building, 82...solar cell, 83...charging circuit, 84...charging switch, 85...DC / AC inverter, 86...load, 87...discharging switch, 88...power supply controller, 91...vehicle body, 93...motor, 94...generator, 95...DC / AC inverter, 96...engine, 97...wheel, 98...charging plug, HV, EV...vehicle

Claims

1. a battery block formed by stacking a plurality of battery cells in a thickness direction with separators sandwiched between the battery cells; a pair of end plates disposed on both end surfaces of the battery block; a bind bar connected to the pair of end plates and fixing the battery block in a pressurized state via the end plates, The separator is A thermal insulation layer; an elastic layer that absorbs the expansion of the battery cell; A stopper is provided to limit a compression thickness of the elastic layer, the stopper has a rigidity higher than that of the elastic layer; A power supply device, wherein the stopper is made of a hybrid material of inorganic powder and fiber reinforcement material.

2. 2. The power supply device according to claim 1, A power supply device, wherein the elastic layer penetrates the heat insulating layer.

3. 3. The power supply device according to claim 2, The power supply device, wherein the stopper is a part of the insulating layer.

4. 4. The power supply device according to claim 3, The power supply device according to claim 1, wherein the stopper is made of a material having a higher Young's modulus than the heat insulating layer and the elastic layer.

5. 5. A power supply device according to claim 1, A power supply device, characterized in that the elastic layer is laminated on the heat insulating layer.

6. 6. A power supply device according to claim 1, The heat insulating layer is A power supply device characterized by being made of a hybrid material of inorganic powder and fiber reinforcement material.

7. 7. The power supply device according to claim 6, The inorganic powder is A power supply device characterized by being made of silica aerogel.

8. 8. A power supply device according to claim 1, The elastic layer is A power supply device characterized by being made of an elastic body.

9. 9. The power supply device according to claim 8, The elastic body is A power supply device, characterized in that the material is at least one selected from the group consisting of synthetic rubber, thermoplastic elastomer, and foam material.

10. 10. A power supply device according to claim 1, A power supply device, wherein the separator comprises a plurality of the stoppers.

11. An electric vehicle comprising the power supply device according to any one of claims 1 to 10, The power supply device; a driving motor supplied with power from the power supply device; and a vehicle body having the power supply device and the motor mounted thereon; wheels that are driven by the motor to move the vehicle body; An electric vehicle comprising:

12. A power storage device comprising the power supply device according to any one of claims 1 to 10, The power supply device; a power supply controller for controlling charging and discharging of the power supply device; Equipped with The power storage device is characterized in that the power supply controller enables charging of the battery cells with external power and controls charging of the battery cells.

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