JP6135351B2 - SECONDARY BATTERY PACK, MOBILE HAVING THE SAME, AND SECONDARY BATTERY FIXING METHOD - Google Patents

Description

  The present invention relates to a secondary battery pack including a plurality of single cells in an outer case, a moving body including the same, and a method for fixing a secondary battery.

  A relatively large-capacity secondary battery pack for supplying electric power to the motor is mounted on a vehicle such as an electric vehicle that runs using the motor as a drive source. This secondary battery pack is configured by housing a positive electrode, a negative electrode, and an electrolyte solution (electrolyte), which are power generation elements, in an outer case in a state in which a plurality of single cells are stored in a battery container (for example, , See Patent Document 1). In addition, such a secondary battery pack is required to be fixed so that the single cell does not move in the outer case due to vibration accompanying traveling of the vehicle. Therefore, in the secondary battery pack described in Patent Document 1, a plurality of single cells and an exterior case are fixed together by bolts that penetrate in the arrangement direction of the single cells.

JP 2009-205986 A

  As in the secondary battery pack described in Patent Document 1, when a plurality of single cells and an outer case are fixed with bolts, a space for forming holes through which the bolts are inserted is secured in the single cells and the outer case. Accordingly, the single cell and the outer case, and thus the secondary battery pack, are increased in size accordingly. In addition, since the unit cell itself is provided with a space for opening a hole or a hole is formed, the structure of the unit cell may be specialized and diversion to another type of secondary battery pack may be difficult.

  In view of the above circumstances, the present invention does not cause an increase in the size of a secondary battery pack, and does not require processing for fixing the single cell to the exterior case. It is an object of the present invention to provide a moving body provided with this and a method for fixing a secondary battery.

The secondary battery pack of the present invention comprises an outer case having a lid that can be opened and closed, and a plurality of single cells accommodated in the outer case,
The lid is provided with a fixture that protrudes to the inside of the exterior case and fixes the single cell by pressing the outer surface of the single cell.

  The moving body of the present invention is mounted with the above secondary battery pack as a power source.

The secondary battery fixing method of the present invention is a method of accommodating and fixing a single cell of a secondary battery in an exterior case having a lid that can be opened and closed,
The single cell is fixed to the exterior case by pressing the outer surface of the single cell with a fixture protruding from the lid to the inside of the exterior case.

  According to the present invention, the secondary battery pack is not increased in size, and processing of the single cell itself can be made unnecessary for fixing to the outer case.

1 is a schematic diagram showing in principle the basic structure of a power generation element in a molten salt battery. It is a perspective view which shows simply the lamination structure of a molten salt battery main body (main-body part as a battery). It is a cross-sectional view about the structure similar to FIG. It is a perspective view which shows the outline of the external appearance of the molten salt battery (single cell) of the state accommodated in the battery container. 1 is a longitudinal sectional view along one direction showing a secondary battery pack according to a first embodiment of the present invention. It is a longitudinal cross-sectional view along the other direction of the secondary battery pack. It is a perspective view which decomposes | disassembles and shows the cover body and fixing tool of the secondary battery pack which concern on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which expands and shows the cover body and fixing tool in the secondary battery pack. It is a longitudinal cross-sectional view which shows the secondary battery pack which concerns on the 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the secondary battery pack which concerns on the 4th Embodiment of this invention. It is a perspective view which turns over and shows the cover body in the secondary battery pack. It is a longitudinal cross-sectional view which shows the secondary battery pack which concerns on the 5th Embodiment of this invention. It is a longitudinal cross-sectional view which expands and shows a part of FIG. It is a longitudinal cross-sectional view along one direction of the secondary battery pack which concerns on the 6th Embodiment of this invention. It is a longitudinal cross-sectional view along the other direction of the secondary battery pack. It is a schematic perspective view which decomposes | disassembles and shows a part of the secondary battery pack. It is the schematic which shows the electric vehicle carrying a secondary battery pack.

[Summary of Embodiment of the Present Invention]
First, the gist of the embodiment of the present invention will be listed and described. In addition, each embodiment described below can also combine the part arbitrarily.
(1) The secondary battery pack of the present invention includes an exterior case having a lid that can be opened and closed, and a plurality of single cells accommodated in the exterior case,
The lid is provided with a fixture that protrudes to the inside of the exterior case and fixes the single cell to the exterior case by pressing the outer surface of the single cell.

  With such a configuration, it is not necessary to secure a space for forming a hole through which the fixing bolt is inserted in the exterior case or the single cell as in the conventional case, and the single cell and the exterior case, and thus the secondary battery pack. Increase in size can be prevented. Moreover, since it is not necessary to process the single cell itself to fix it to the outer case, the single cell structure is not special, and the versatility of the single cell can be enhanced.

(2) In the secondary battery pack according to (1), it is preferable that the fixture is provided on the lid so that the position thereof can be adjusted.
According to this configuration, it is possible to appropriately adjust the position of the fixture according to the state on the unit cell side, for example, the position of the electrode terminal or the electric wiring.

(3) In the secondary battery pack according to the above (1) or (2), it is preferable that one of the fixtures is configured to be provided in a range extending over a plurality of single cells.
With such a configuration, a plurality of single cells can be fixed by one fixing tool, and the number of fixing tools can be reduced to simplify the structure and reduce the manufacturing cost.

(4) In the secondary battery pack according to any one of (1) to (3), an electrode terminal protrudes from an outer surface of the single cell, and the fixture has a protruding amount of the terminal. It is preferable that the protrusion protrudes from the inner surface of the lid body with a larger protrusion amount.
With such a configuration, the outer surface of the unit cell from which the terminal of the electrode protrudes can be pressed with a fixture.

(5) In the secondary battery pack according to any one of (1) to (4), the single cells disposed between the adjacent single cells and at an end portion in the arrangement direction of the single cells. A spacer that is inserted into at least one of the cell and the side plate of the exterior case adjacent to the cell and that forms a gap for absorbing the bulging deformation of the side surface of the single cell. Is preferred.
With such a configuration, even when the outer surface of the single cell swells during charging or the like, it can be absorbed by the gap between the single cells, and deformation of the outer case that houses these single cells is prevented. be able to.

(6) In the secondary battery pack according to (5), it is preferable that the fixture has an insertion portion that constitutes the spacer.
With such a configuration, the fixture can also function as a spacer, and an increase in the number of parts due to the provision of the spacer can be suppressed.

(7) A mobile body according to an embodiment of the present invention is mounted with the secondary battery pack according to any one of (1) to (6) as a power source.
With such a configuration, it is possible to suppress the single cell from moving in the outer case due to vibration accompanying the movement of the moving body.

(8) A method for fixing a secondary battery according to an embodiment of the present invention is a method for accommodating and fixing a single cell of a secondary battery in an outer case having an openable / closable lid,
The single cell is fixed to the exterior case by pressing the outer surface of the single cell with a fixture protruding from the lid to the inside of the exterior case.

  With such a configuration, it is not necessary to secure a space for forming a hole through which the fixing bolt is inserted in the exterior case or the single cell as in the conventional case, and the single cell and the exterior case, and thus the secondary battery pack. Increase in size can be prevented. Moreover, since it is not necessary to process the single cell itself to fix it to the outer case, the single cell structure is not special, and the versatility of the single cell can be enhanced.

[Details of the embodiment of the present invention]
Next, the molten salt battery used for the secondary battery pack according to the embodiment of the present invention will be described.
[Basic structure of molten salt battery]
FIG. 1 is a schematic diagram showing in principle the basic structure of a power generation element in a molten salt battery. In the figure, the power generation element includes a positive electrode 1, a negative electrode 2, and a separator 3 interposed therebetween. The positive electrode 1 is composed of a positive electrode current collector 1a and a positive electrode material 1b. The negative electrode 2 includes a negative electrode current collector 2a and a negative electrode material 2b.

The material of the positive electrode current collector 1a is, for example, an aluminum nonwoven fabric (wire diameter: 100 μm, porosity: 80%). The positive electrode material 1b is a mixture of, for example, NaCrO ₂ as a positive electrode active material, acetylene black, PVDF (polyvinylidene fluoride), and N-methyl-2-pyrrolidone at a mass ratio of 85: 10: 5: 100. It is a thing. And what was kneaded in this way is filled in the positive electrode collector 1a of an aluminum nonwoven fabric, and after drying, it presses at 100 Mpa, and it forms so that the thickness of the positive electrode 1 may be set to about 1 mm.
On the other hand, in the negative electrode 2, an Sn—Na alloy containing, for example, tin as a negative electrode active material is formed on the aluminum negative electrode current collector 2a by plating.

  The separator 3 interposed between the positive electrode 1 and the negative electrode 2 is obtained by impregnating a glass non-woven fabric (thickness 200 μm) or a polyolefin sheet (thickness 50 μm) with a molten salt as an electrolyte. This molten salt is, for example, a mixture of 56 mol% NaFSA (sodium bisfluorosulfonylamide) and 44 mol% KFSA (potassium bisfluorosulfonylamide), and has a melting point of 57 ° C. At a temperature equal to or higher than the melting point, the molten salt melts and becomes an electrolytic solution in which high-concentration ions are dissolved and touches the positive electrode 1 and the negative electrode 2. Moreover, this molten salt is nonflammable. The operating temperature range of this molten salt battery is 57 ° C to 190 ° C.

In addition, although the material, component, and numerical value of each part mentioned above are suitable examples, it is not limited to these.
For example, in addition to the above, a mixture of NaFSA and LiFSA, KFSA, RbFSA or CsFSA is also suitable as the molten salt. In addition, other salts composed of organic cations and the like may be mixed. Generally, the molten salt includes (a) a mixture containing NaFSA, (b) a mixture containing NaTFSA (sodium bistrifluoromethylsulfonylamide), ( c) Mixtures containing NaFTA (sodium fluorosulfonyl-trifluoromethylsulfonylamide) are suitable. It is also possible to mix two or more of (a) to (c). In these cases, since the molten salt of each mixture has a relatively low melting point, a state in which high-concentration ions are dissolved with a small amount of heating can be realized and the molten salt battery can be operated.

[Specific structure of molten salt battery]
Next, a more specific configuration of the power generation element of the molten salt battery will be described. FIG. 2 is a perspective view schematically showing a laminated structure of a molten salt battery main body (main body portion as a battery) 10, and FIG. 3 is a cross-sectional view of the same structure.
2 and 3, a plurality (six are shown) of rectangular flat plate-like negative electrodes 2 and a plurality (five are shown) of rectangles accommodated in a bag-like separator 3 respectively. The flat positive electrodes 1 are opposed to each other and are stacked in the vertical direction in FIG. 3, that is, in the stacking direction, to form a stacked structure.

  The separator 3 is interposed between the positive electrode 1 and the negative electrode 2 adjacent to each other. In other words, the positive electrode 1 and the negative electrode 2 are alternately stacked via the separator 3. For example, 20 positive electrodes 1 and 21 negative electrodes 2 and 20 separators 3 as “bags”, but 40 intervening between positive electrodes 1 and 2 are actually stacked. is there. The separator 3 is not limited to a bag shape, and may be 40 separated.

  In FIG. 3, the separator 3 and the negative electrode 2 are drawn so as to be separated from each other, but they are in close contact with each other when the molten salt battery is completed. Naturally, the positive electrode 1 is also in close contact with the separator 3. In addition, the vertical and horizontal dimensions of the positive electrode 1 are smaller than the vertical and horizontal dimensions of the negative electrode 2 in order to prevent the generation of dendrites, and the outer edge of the positive electrode 1 passes through the separator 3. Thus, it faces the peripheral edge of the negative electrode 2.

[Practical single cell]
The molten salt battery main body 10 configured as described above is a “single cell” (single cell) forming a physical individual as a molten salt battery, for example, by being accommodated in a rectangular parallelepiped battery container made of an aluminum alloy. / Unit cell).
FIG. 4 is a perspective view showing an outline of the appearance of the molten salt battery main body in the state accommodated in the battery container 11, that is, the single cell B of the molten salt battery. 2 and 3, the terminals 1t and 2t are drawn out from the battery case 11 while maintaining insulation from the battery case 11 from the positive electrode 1 and the negative electrode 2, respectively. The inner surface of the battery container 11 is insulated, and the battery container 11 is electrically insulated from the molten salt battery body 10 inside. In FIG. 4, the long side direction of the upper surface of the single cell B is indicated by X, the short side direction is indicated by Y, and the vertical direction is indicated by Z. The terminals 1t and 2t are provided on the upper surface of the single cell B and closer to the end in the X direction.

[First Embodiment of Secondary Battery Pack]
FIG. 5 is a longitudinal sectional view along one direction (Y direction) showing the secondary battery pack 100 according to the first embodiment of the present invention, and FIG. It is a longitudinal cross-sectional view along the X direction. 5 and 6, the direction of XYZ corresponds to FIG. 4.
5 and 6, the secondary battery pack 100 includes an outer case 101, an assembled battery 103, and a heater 104. The exterior case 101 includes a case main body 105 and a lid body 106, and is formed in a hexahedral box shape.

  The lid 106 is constituted by an upper plate of the exterior case 101. The case main body 105 includes a bottom plate 105a of the outer case 101 and four side plates 105b to 105e. Therefore, the case main body 105 has an opening 105 f at its upper end, and the opening 105 f is closed by the lid 106. The lid body 106 is detachably attached to the exterior case 101 (openable and closable) with a fixing screw (not shown) or the like. The outer case 101 preferably has rigidity (hardness) and heat conductivity capable of maintaining the entire shape, and is formed of a metal material such as iron or aluminum alloy, for example.

The assembled battery 103 is configured by arranging a plurality of (eight in the example shown in FIG. 5) unit cells B in the Y direction, and is disposed in the outer case 101. The number of single cells B can be appropriately changed according to the required voltage or current.
The heater 104 is, for example, a sheet heater (for example, about 3 mm thick) in which a heating wire is embedded using silicon rubber as a base material. The heater 104 is in contact with the outer case 101 and heats it. The heater 104 of the present embodiment is provided so as to be in contact with the bottom surface of the outer case 101 and both end surfaces in the X direction. However, the arrangement of the heater 104 is not particularly limited. For example, the heater 104 may be provided so as to be in contact with both end surfaces of the outer case 101 in the Y direction, and each single cell is provided inside the outer case 101. A heater 104 may be provided so as to be in contact with B or the outer surface of each single cell B.

The lid 106 of the outer case 101 is provided with a plurality of fixtures 110 for fixing the single cell B to the outer case 101. The fixture 110 protrudes downward from the lower surface of the lid 106 above each unit cell B, and a lower end surface thereof is pressed against the upper surface of the unit cell B.
More specifically, the fixture 110 is formed in a columnar shape, a prism shape, a cylindrical shape, a rectangular tube shape, a block shape or the like that is long in the vertical direction. Further, the height of the fixture 110 in the vertical direction (the amount of protrusion from the lid 106) is larger than the height of the terminals 1t and 2t of the single cell B. The fixture 110 is in contact with a position on the upper surface of the single cell B away from the electrode terminals 1t and 2t, for example, the center in the X direction. Moreover, although components such as an electric wiring and a pressure relief valve (not shown) are arranged in the vicinity of the terminals 1t and 2t, the fixture 110 is arranged at a position avoiding these electric wiring and components.

The fixture 110 is pressed between the lid 106 and the single cell B by being pressed against the upper surface of the single cell B. Therefore, each single cell B is sandwiched between the lid body 106 (fixing tool 110) of the outer case 101 and the bottom plate 105a, and the movement in the vertical direction is restricted.
Therefore, for example, when the secondary battery pack 100 is mounted on a vehicle, the vertical movement of the single cell B is suppressed by the fixture 110 even if vibration is transmitted to the secondary battery pack 100 as the vehicle travels. Further, it is possible to prevent the single cell B from being lifted upward in the outer case 101 and scratching the single cell B or applying a force to the electric wiring. Note that the assembled battery 103 in the outer case 101 is also restricted in movement in the Y direction with respect to the outer case 101 by having both end surfaces in the Y direction in contact with the side plates 105b and 105c of the case body 105, and both end surfaces in the X direction are By contacting the side plates 105d and 105e of the case main body 105, the movement in the X direction with respect to the outer case 101 is also restricted. Accordingly, the single cell B hardly shakes in the XY direction.

  Moreover, since it is not necessary to secure the space for forming the hole which penetrates the volt | bolt for fixation like the prior art (for example, refer patent document 1) in the exterior case 101 or the single cell B, the single cell B In addition, it is possible to prevent the outer case 101 and thus the secondary battery pack 100 from being enlarged. Further, by providing the fixing device 110 on the lid 106 of the outer case 101, the unit cell B itself does not need to be processed to be fixed to the outer case 101, so that the structure of the single cell B becomes special. The versatility of the single cell B can be improved.

Further, since the fixture 110 protrudes from the inner surface of the lid 106 with a dimension larger than the protruding amount of the terminals 1t and 2t provided on the upper surface of the single cell B, the single cell provided with the terminals 1t and 2t is provided. Even the outer surface of B can be pressed.
The fixture 110 is made of a material having a rigidity that can limit the vertical movement of the single cell B. For example, the fixture 110 can be formed of the same material as the lid body 106, for example, an aluminum alloy.
It is preferable to employ a configuration that prevents relative sliding between the lower end portion of the fixture 110 and the upper surface of the single cell B. For example, it is possible to employ a configuration in which an adsorption member such as a suction cup is provided at the lower end of the fixture 110 and the adsorption member is adsorbed on the upper surface of the single cell B. Further, it is possible to employ a configuration in which a member having a large friction coefficient such as rubber or a member having adhesiveness is provided at the lower end portion of the fixture 110 and these members are brought into contact with the upper surface of the single cell B. However, it is preferable to employ a member with little vertical deformation so that any member does not hinder the restriction of the vertical movement of the single cell B.

  Since the reaction force when the fixing tool 110 presses down the single cell B is applied to the lid body 106, it is desirable that the lid body 106 has a rigidity that does not cause distortion due to the reaction force. For example, the lid body 106 can be increased in rigidity by being formed thicker than the bottom plate 105a and the side plates 105b to 105e constituting the case main body 105.

[Second Embodiment of Secondary Battery Pack]
FIG. 7 is an exploded perspective view showing the lid body 106 and the fixture 120 of the secondary battery pack 100 according to the second embodiment of the present invention, and FIG. 8 is a lid body 106 of the secondary battery pack 100. It is a longitudinal cross-sectional view which expands and shows the fixing tool 120.
In the present embodiment, the fixing tool 120 is provided so that its position can be adjusted in a direction (horizontal direction) along the inner surface of the lid body 106. Specifically, a long hole 106a that is long in the X direction is formed in the lid body 106, and a fixing bolt 121 is inserted into the long hole 106a. Further, a female screw hole 120 a into which the fixing bolt 121 can be screwed is formed in the upper end surface of the fixing tool 120. Then, by fixing the fixing bolt 121 inserted into the long hole 106 a into the female screw hole 120 a of the fixing tool 120, the fixing tool 120 is attached to the lid body 106.

Therefore, the position of the fixture 120 can be adjusted in the X direction within the range of the long hole 106a, and the positions of the terminals 1t and 2t provided on the upper surface of the single cell B and the position of the electrical wiring provided in the vicinity thereof. The position of the fixing device 120 can be adjusted appropriately so as to avoid them.
Note that a washer 122 is preferably attached to the fixing bolt 121 in order to reduce the contact surface pressure with respect to the upper surface of the lid 106. Moreover, it is preferable to provide a shim (position adjusting member) 123 that also serves as a washer between the lid 106 and the fixture 120. By changing the thickness and number of the shims 123, the position of the fixture 120 in the vertical direction (Z direction perpendicular to the lid 106) can be adjusted, and it can cope with errors in the height dimension of the single cell B. It becomes possible to do.

  In the present embodiment, the fixture 120 may be provided so that the position thereof can be adjusted in the X direction. Moreover, the fixture 120 may be configured to be position adjustable in both the X direction and the Y direction. In addition, the fixture 120 may be configured to be position-adjustable in both or only one of the XY directions, or only in the Z direction. In addition, a plurality of holes may be formed in the lid body 106 instead of the long holes 106a, and one of the holes may be selected and the fixture 120 may be attached.

[Third Embodiment of Secondary Battery Pack]
FIG. 9 is a longitudinal sectional view showing a secondary battery pack 100 according to the third embodiment of the present invention.
In this embodiment, each fixing tool 130 provided on the lid body 106 of the exterior case 101 is provided in a range extending over the plurality of single cells B, and each fixing tool 130 presses and fixes the plurality of single cells B. doing. More specifically, each fixture 130 is formed in an inverted T shape by a leg portion 130a extending downward from the lid body 106 and a pressing portion 130b extending from the lower end of the leg portion 130a to both sides in the Y direction. . And the both ends of the holding | suppressing part 130b hold down the upper surface of the two single cells B, and are fixing these simultaneously. Therefore, in this embodiment, four fixtures 130 are provided for eight unit cells B.

In the present embodiment, the number of fixtures 130 can be reduced as compared to the first embodiment. Therefore, the number of parts and the number of steps for attaching the fixing tool 130 to the lid 106 can be reduced, which contributes to a reduction in manufacturing cost.
In addition, the fixing tool 130 in this embodiment may be provided in the range over three or more single cells B. The fixture provided in the range over all the single cells B will be exemplified in the following fourth embodiment. Also in the present embodiment, the fixture 130 may be configured to be position-adjustable as in the second embodiment.

[Fourth Embodiment of Secondary Battery Pack]
FIG. 10 is a longitudinal sectional view of a secondary battery pack 100 according to the fourth embodiment of the present invention, and FIG. 11 is a perspective view showing the lid 106 of the secondary battery pack 100 upside down.
In the present embodiment, the fixture 140 provided on the lid 106 of the outer case 101 is provided in a range extending over all the single cells B, and one fixture 140 presses and fixes all the single cells B. ing. More specifically, the fixture 140 is formed in a strip shape long in the Y direction.

  In the present embodiment, the number of fixtures 140 can be reduced as compared to the first embodiment. Therefore, the number of parts and the number of steps for attaching the fixing tool 140 to the lid 106 can be reduced, which contributes to a reduction in manufacturing cost. Also in this embodiment, the fixture 140 may be configured to be position-adjustable as in the second embodiment.

[Fifth Embodiment of Secondary Battery Pack]
FIG. 12 is a longitudinal sectional view of a secondary battery pack 100 according to the fifth embodiment of the present invention, and FIG. 13 is an enlarged longitudinal sectional view showing a part of FIG.
In the present embodiment, the fixtures 150A and 150B provided on the lid body 106 of the outer case 101 not only press the upper surface of the single cell B, but are arranged between the adjacent single cells B and at both ends in the Y direction. It also has a function as a spacer that forms a gap S between the single cell B and the side plates 105b and 105c of the outer case 101. Specifically, as shown in FIG. 13, the fixtures 150A other than the fixtures 150B at both ends in the Y direction in FIG. 12 are provided with holding parts 150a that hold the upper surface of the single cell B at one end in the Y direction. The other end in the Y direction is provided with an insertion portion 150b that protrudes below the pressing portion 150a and is inserted between the two single cells B. In addition, the fixture 150B at both ends in the Y direction in FIG. 12 is provided with a pressing portion 150a for pressing the upper surface of the single cell B at one end portion in the Y direction, and below the pressing portion 150a at the other end portion in the Y direction. An insertion portion 150b1 that protrudes and is inserted between the side plates 105b and 105c of the outer case 101 and the single cell B is provided. The insertion portions 150b and 150b1 are outer peripheries of the side surfaces of the adjacent single cells B facing each other and the side surfaces of the single cells B facing the side plates 105b and 105c of the outer case 101 (hereinafter also simply referred to as “opposing side surfaces”). It is inserted into only a part of the upper end of the part. Therefore, the gap S is formed at least in the central portion of the opposing side surface of the single cell B.

  The fixtures 150 </ b> A and 150 </ b> B of the present embodiment not only fix the single cell B, but also form a gap S between the adjacent single cells B and between the outer case 101 and the single cell B. Therefore, as shown by a two-dot chain line in FIG. 13, even when the side surface of the single cell B swells during charging or the like, this can be absorbed and is caused by the bulge of each single cell B. Thus, deformation of the outer case 101 can be suppressed. Further, since the insertion portions 150b and 150b1 of the fixtures 150A and 150B are inserted into the outer peripheral portion on the opposite side surface of the single cell B, a gap S can be formed in the central portion of the opposite side surface that bulges most. The bulge can be reliably absorbed by the gap S. Further, when the insertion portions 150b and 150b1 are formed integrally with the fixtures 150A and 150B, the insertion portions 150b and 150b1 are formed separately from the fixtures 150A and 150B (for example, the insertion portion 150b). , 150b1 can be reduced in number of parts as compared to the case of the spacer 161 of the sixth embodiment described later). In the present embodiment, the fixtures 150A and 150B can be configured integrally with ones adjacent to each other.

  As shown in FIG. 13, the width a of the gap Sa formed between the opposing side surfaces of adjacent unit cells B is the maximum expected expansion when the opposing side surfaces of both unit cells B bulge and deform. The dimension is set to be larger than the sum of the projected dimensions. Further, the width b of the gap Sb formed between the single cell B and the side plates 105b and 105c of the outer case 101 is an estimated maximum bulging dimension when the opposing side surface of the single cell B is bulged and deformed. Is set to a larger dimension. Therefore, even if the opposing side surfaces of the single cells B bulge and deform, the adjacent single cells B and the single cells B and the side plates 105b and 105c of the outer case 101 do not contact each other. Further, due to the difference in thickness between the insertion portions 150b and 150b1, the width b of the gap Sb is formed smaller than the width a of the gap Sa, and is about ½ of the width a. By comprising in this way, the increase in the dimension of the Y direction of the exterior case 101 accompanying provision of the clearance gap S can be suppressed.

[Sixth Embodiment of Secondary Battery Pack]
FIG. 14 is a longitudinal sectional view taken along one direction (Y direction) of the secondary battery pack 100 according to the sixth embodiment of the present invention, and FIG. 15 shows another direction (X FIG. 16 is a schematic perspective view showing one end portion of the secondary battery pack 100 in an exploded manner.
In this embodiment, the configuration of the fixture 110 is the same as that of the first embodiment, and a spacer 161 is provided separately from the fixture 110. The spacers 161 are respectively inserted between the adjacent single cells B and between the single cells B arranged at both ends in the Y direction and the side plates 105b and 105c of the exterior case, so that a gap S is formed therebetween.

  The spacer 161 is made of a metal material such as an aluminum alloy or a hard synthetic resin material. In addition, the spacer 161 is formed on the outer peripheral portion of the side surface of the adjacent single cell B facing each other or the side surface of the single cell B facing the side plates 105b and 105c of the outer case 101 (hereinafter also simply referred to as “opposing side surfaces”). It is formed in a substantially ring shape (annular) or frame shape along. Therefore, a gap S is formed corresponding to the central portion on the opposite side surface of the single cell B. Further, the corner portion 161b on the inner peripheral side of the spacer 161 is formed in an R shape, and stress concentration at the corner portion 161b is prevented. A notch 161 a is formed on the spacer 161. This notch 161a is formed in order to draw out the wiring of electrical components, such as the temperature sensor 163 attached to the opposing side surface of the single cell B, upward.

  As shown in FIG. 16, the side plate 105 c disposed at one end portion in the Y direction of the case main body 105 in the outer case 101 is configured to be detachable by fixing screws 162 with respect to the other side plates 105 d and 105 e that are orthogonal to each other. Yes. Specifically, the side plate 105c is formed with an insertion hole 105c1 through which the fixing screw 162 is inserted, and the other side plates 105d and 105e are formed with female screw holes 105d1 and 105e1 into which the fixing screw 162 is screwed. Then, the side plate 105c is attached to the other side plates 105d and 105e by screwing the fixing screw 162 inserted through the insertion hole 105c1 into the female screw holes 105d1 and 105e1. Then, by adjusting the fastening torque (screwing amount) of the fixing screw 162, the pressure in the Y direction applied to the single cell B and the spacer 161 can be adjusted, and the Y of the single cell B in the outer case 101 can be adjusted. Shaking of the direction can be suitably prevented. In addition, since the spacer 161 is provided on the outer peripheral portion of the opposing side surface of the single cell B, the gap S can be formed in the central portion of the opposing side surface that bulges most, and the bulging is surely performed by the gap S. Can be absorbed into.

  Also in the present embodiment, as shown in FIG. 14, the width a of the gap Sa formed between the opposing side surfaces of the adjacent single cells B is such that the opposing side surfaces of both single cells B bulge and deform. Is set to a size larger than the sum of the assumed maximum bulge dimensions. Further, the width b of the gap Sb formed between the single cell B and the side plates 105b and 105c of the outer case 101 is an estimated maximum bulging dimension when the opposing side surface of the single cell B is bulged and deformed. Is set to a larger dimension. Therefore, even if the opposing side surfaces of the single cells B bulge and deform, the adjacent single cells B and the single cells B and the side plates 105b and 105c of the outer case 101 do not contact each other. Further, due to the difference in the thickness of the spacer 161, the width b of the gap Sb is formed smaller than the width a of the gap Sa, and is about ½ of the width a. By comprising in this way, the increase in the dimension of the Y direction of the exterior case 101 accompanying provision of the clearance gap S can be suppressed.

Note that the fixture in the present embodiment is not limited to the fixture 110 described in the first embodiment, and may be the fixtures 120, 130, and 140 described in the second to fourth embodiments. Further, the notch 161a is not limited to the upper part of the spacer 161, and may be formed in the side part or the lower part, or may be omitted. In addition, the spacer 161 may not be provided continuously over substantially the entire circumference of the outer peripheral portion on the opposite side surface of the single cell B, and on the upper, lower, and both sides of the outer peripheral portion on the opposite side surface of the single cell B. Each may be provided in a separated form. Moreover, you may provide only in the upper part of the outer peripheral part in the opposing side surface of the single cell B, a lower part, and a part of both side parts.
Further, in the present embodiment and the fifth embodiment, the spacer 161 and the insertion portions 150b and 150b1 are not provided between the adjacent single cells B and between the single cell B and the side plates 105b and 105c of the outer case 101. It may be inserted in a part.

[Application of battery pack]
FIG. 17 is a schematic diagram showing an electric vehicle 200 on which the secondary battery pack 100 is mounted. In addition, although illustration is abbreviate | omitted, in order to maintain the heat insulation with the periphery, the secondary battery pack 100 is covered with a heat insulating material and the outermost case which covers it.
In the secondary battery pack 100, the vertical movement of the single cell B in the outer case 101 is restricted by the fixtures 110, 120, 130, 140, 150A, and 150B described above. Therefore, the single cell B will not be lifted upward in the outer case 101 due to vibration accompanying the traveling of the electric vehicle 200.
Further, the secondary battery pack 100 is suitable as a power source for driving a main motor used for traveling or cargo handling in general electric propulsion vehicles including industrial vehicles such as forklifts in addition to electric vehicles. . Furthermore, it is suitable as a power source mounted on a moving body including a ship and an aircraft.

  Moreover, it cannot be overemphasized that the secondary battery pack 100 can be used not for a moving body but for a stationary use. Also in this case, since the secondary battery pack 100 restricts the movement of the fixture in the vertical direction of the single cell B in the outer case 101, even if the secondary battery pack 100 vibrates greatly due to an earthquake, for example, the single cell B Can be prevented.

[Others]
In the above embodiment, the secondary battery pack using the molten salt battery has been described. However, the secondary battery pack is not necessarily limited to the molten salt battery. For example, the secondary battery pack such as a lithium ion battery used in a cold region is used. The present invention is also applicable. However, the present invention according to the embodiment including the spacer 161 and the insertion portions 150b and 150b1 is particularly effective when applied to a secondary battery pack in which the expansion of the single cell B is increased by being heated by the heater 104. .
In addition, the exterior case 101 of the above embodiment has a configuration in which the opening 105f provided on the upper surface portion of the case main body 105 is closed by the lid 106, but the side surface portion (for example, the side plate in FIG. The portion provided with 105d or 105e) is used as an opening, and the opening is closed with a lid 106. A space is provided between the lid 106 and the side surface of the single cell B, and the side surface is covered with the lid 106. The structure which presses down with the fixing tool provided in may be sufficient. That is, in this embodiment, the secondary battery pack 100 shown in FIG. 6 is tilted sideways (rotated 90 degrees) so that the lid 106 is positioned on the side surface of the case main body 105. In this case, the fixing tool fixes the single cell B by pressing the side surface of the single cell B.
In the fifth embodiment, the fixtures 150A and 150B can be configured integrally with ones adjacent to each other. In the fifth and sixth embodiments, the spacer 161 and the insertion portions 150b and 150b1 are inserted between the adjacent single cells B and between the single cells B and the side plates 105b and 105c of the outer case 101. However, it may be inserted between some parts.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1: Positive electrode 1a: Positive electrode current collector 1b: Positive electrode material 1t: Terminal 2: Negative electrode 2a: Negative electrode current collector 2b: Negative electrode material 2t: Terminal 3: Separator 10: Molten salt battery main body 11: Battery container 100: Secondary battery Pack 101: exterior case 103: assembled battery 104: heater 105: case body 105a: bottom plate 105b: side plate 105c: side plate 105c1: insertion hole 105d: side plate 105d1: female screw hole 105e: side plate 105e1: female screw hole 105f: opening 106: lid Body 106a: Long hole 110: Fixing tool 120: Fixing tool 120a: Female screw hole 121: Fixing bolt 122: Washer 123: Shim 130: Fixing tool 130a: Leg part 130b: Pressing part 140: Fixing tool 150A: Fixing tool 150B: Fixing Tool 150a: Holding part 150b: Insertion part 150b1: Insertion part 161: Spare Sa 161a: notch 161b: corners 162: fixing screw 163: temperature sensor 200: electric vehicle a: gap width b: gap width B: unit cell S (Sa, Sb): Clearance

Claims (10)

An exterior case having an openable / closable lid, and a plurality of single cells accommodated in the exterior case,
The lid is provided with a fixture that protrudes to the inner side of the outer case and fixes the single cell to the outer case by pressing the outer surface of the single cell .
The said fixing tool is a secondary battery pack provided so that position adjustment is possible in the direction along the inner surface of the said cover body . An exterior case having an openable / closable lid, and a plurality of single cells accommodated in the exterior case,
The lid is provided with a fixture that protrudes to the inside of the outer case and fixes the single cell to the outer case by pressing the outer surface of the single cell .
Inserted between at least one of the unit cells adjacent to each other and between the unit cell disposed at the end of the unit cell in the arrangement direction and the side plate of the exterior case adjacent to the unit cell, A spacer for forming a gap for absorbing the bulging deformation of the side surface of the single cell,
The said spacer is a secondary battery pack currently formed in the cyclic | annular form or frame shape along the outer peripheral part in the side surface of the said single cell . The secondary battery pack according to claim 2 , wherein the fixture is provided so that its position can be adjusted in a direction along the inner surface of the lid. The secondary battery pack according to any one of claims 1 to 3 , wherein one of the fixtures is provided in a range extending over a plurality of single cells. Wherein the outer surface of the single cell and the terminal electrode is protruded, the fixture, protrudes from the inner surface of the lid at a greater protruding amount than the amount of projection of the terminal, any of claim 1 to claim 4 The secondary battery pack according to claim 1. Inserted between at least one of the unit cells adjacent to each other and between the unit cell disposed at the end of the unit cell in the arrangement direction and the side plate of the exterior case adjacent to the unit cell, The secondary battery pack according to claim 1, further comprising a spacer that forms a gap for absorbing bulging deformation of a side surface of the single cell. The secondary battery pack according to claim 6 , wherein the fixture has an insertion portion that constitutes the spacer. It mounted as a power source a secondary battery pack according to claim 1 or 2, mobile. A method of accommodating and fixing a single cell of a secondary battery in an exterior case having a lid that can be opened and closed,
The outer surface of the single cell is pressed against the outer case by a fixture that protrudes from the lid to the inner side of the outer case and is adjustable in position along the inner surface of the lid. Fix the secondary battery. A method of accommodating and fixing a single cell of a secondary battery in an exterior case having a lid that can be opened and closed,
By fixing the single cell to the exterior case by pressing the outer surface of the single cell by a fixture projecting from the lid to the inside of the exterior case,
A side surface of the unit cell is provided between at least one of the unit cells adjacent to each other and between the unit cell disposed at an end portion in the arrangement direction of the unit cells and a side plate of the exterior case adjacent to the unit cell. A method for fixing a secondary battery, comprising inserting a spacer that is formed in an annular shape or a frame shape along the outer periphery of the battery cell and that forms a gap for absorbing the bulging deformation of the side surface of the single cell.

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