Secondary batteries

Abstract

To provide a secondary battery that can efficiently heat up while suppressing overheating. [Solution] The secondary battery of the present invention is a secondary battery configured by housing electrodes in a housing, the housing having a container-shaped inner wall portion and a container-shaped outer wall portion capable of housing the inner wall portion, and is a vacuum container with a vacuum space formed between the inner wall portion and the outer wall portion, the electrodes are housed in a storage space formed inside the inner wall portion, and a heat dissipation element is provided on the vacuum space side of the inner wall portion.

Description

Technical Field

[0006] ,

[0007] ,

[0001] The present invention relates to a secondary battery.

Background Art

[0002] Patent Document 1 discloses a secondary battery heating device that heats a secondary battery through a latent heat storage material that covers the secondary battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When heating a secondary battery from the outside of the battery case, overheating and heat transfer loss are likely to occur, and it is difficult to efficiently heat the secondary battery.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a secondary battery that can be efficiently heated while suppressing overheating.

Means for Solving the Problems

[0006] In order to solve the above - described problems and achieve the object, a secondary battery according to the present invention is a secondary battery configured by storing electrodes in a case, wherein the case is a vacuum container having an inner wall portion in a container shape and an outer wall portion in a container shape capable of accommodating the inner wall portion, a vacuum space is formed between the inner wall portion and the outer wall portion, the electrodes are stored in a storage space formed inside the inner wall portion, and a heat - radiating element is provided on a surface of the inner wall portion on the vacuum - space side.

[0007] Thereby, the secondary battery according to the present invention can be efficiently heated while suppressing overheating.

[0008] Furthermore, in the above configuration, the housing may be configured such that only the inner wall portion and the electrode are in contact.

[0009] This can improve the insulation effect.

[0010] Furthermore, in the above configuration, the electrodes may be configured so as not to come into contact with the housing.

[0011] This can improve the insulation effect.

[0012] The secondary battery according to the present invention is a secondary battery configured by housing a plurality of battery cells in a housing, wherein the housing has a container-shaped inner wall portion and a container-shaped outer wall portion capable of housing the inner wall portion, and is a vacuum container with a vacuum space formed between the inner wall portion and the outer wall portion, the plurality of battery cells are housed in a storage space formed inside the inner wall portion, and a heat dissipation element is provided on the surface of the inner wall portion facing the vacuum space.

[0013] As a result, the secondary battery according to the present invention can efficiently heat up while suppressing overheating. [Effects of the Invention]

[0014] The secondary battery according to the present invention can efficiently maintain a high temperature by storing the heat generated during charging and discharging through the heat-insulating structure of the casing. Furthermore, the heat dissipation element has the effect of suppressing excessive heat accumulation. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a cross-sectional view showing the schematic configuration of a battery cell according to Embodiment 1. [Figure 2] Figure 2 is a cross-sectional view showing the schematic configuration of a battery cell according to Embodiment 2. [Figure 3] Figure 3 is a cross-sectional view showing the schematic configuration of a battery cell according to Embodiment 3. [Figure 4] FIG. 4 is a cross-sectional view showing a schematic configuration of the battery pack according to Embodiment 4.

MODE FOR CARRYING OUT THE INVENTION

[0016] (Embodiment 1) Hereinafter, Embodiment 1 of the secondary battery according to the present invention will be described. Note that the present invention is not limited by this embodiment.

[0017] FIG. 1 is a cross-sectional view showing a schematic configuration of the battery cell 1 according to Embodiment 1. In FIG. 1, the “height direction” is the height direction of the battery cell 1, and the “width direction” in FIG. 1 is the width direction of the battery cell 1.

[0018] As shown in FIG. 1, the battery cell 1 according to Embodiment 1 includes an electrode 2, an electrolytic solution 3, a battery cell housing 4, a heat dissipation element 5, an airtight connector 6, and the like. The battery cell 1 according to Embodiment 1 is a secondary battery configured by storing the electrode 2 and the electrolytic solution 3 in the battery cell housing 4.

[0019] The battery cell housing 4 is made of, for example, a metal material, and has an inner wall portion 41, an outer wall portion 42, and a lid portion 43. The inner wall portion 41 has a box-shaped container shape with an open upper surface which is one surface. The outer wall portion 42 is box-shaped with an open upper surface which is one surface, and has a container shape larger than the inner wall portion 41 so that the inner wall portion 41 can be accommodated with a gap between the inner wall portion 41 in the inner space. The lid portion 43 is in a plate shape for closing the openings of the inner wall portion 41 and the outer wall portion 42 respectively. The lid portion 43 is connected to the upper ends of the inner wall portion 41 and the outer wall portion 42 respectively. And the battery cell housing 4 is surrounded by the inner wall portion 41, the outer wall portion 42, and the lid portion 43, and is a vacuum container in which a vacuum space 401 is formed between the outer surface 41a of the inner wall portion 41 and the inner surface 42b of the outer wall portion 42 in the width direction.

[0020] In the battery cell housing 4, in the storage space (the inner space of the inner wall portion 41) 402 surrounded by the inner wall portion 41 and the lid portion 43, the electrode 2 is stored and the electrolyte 3 is filled so that at least a part of the electrode 2 is immersed. And, in the battery cell 1 according to Embodiment 1, the electrode 2 stored in the storage space 402 is arranged so as to contact only the inner surface 41b of the inner wall portion 41 in the width direction among the inner wall portion 41 and the lid portion 43 that form the storage space 402. Thereby, the outer surface 41a of the inner wall portion 41 is in contact with the vacuum space 401 of the battery cell housing 4, but is not in contact with the external environment (the space outside the battery cell housing 4) of the battery cell housing 4. Therefore, the heat insulation effect can be enhanced as compared with the case where the electrode 2 is brought into contact with the lid portion 43 in contact with the external environment.

[0021] Further, a heat dissipation element 5 is provided on the outer surface 41a which is the surface of the inner wall portion 41 on the vacuum space 401 side. In the battery cell 1 according to Embodiment 1, a Peltier element is used as the heat dissipation element 5. Note that the heat dissipation element 5 is not limited to the Peltier element, and it is preferable to use an element having a high heat absorption effect like the Peltier element.

[0022] In the battery cell 1 according to Embodiment 1, the heat dissipation element 5 is provided in contact with the position of the outer surface 41a of the inner wall portion 41 corresponding to the portion in contact with the electrode 2 on the inner surface 41b of the inner wall portion 41. Further, a wiring 51 for flowing a current to the heat dissipation element 5 from a power source (not shown) is connected to the heat dissipation element 5. The wiring 51 is taken out from the vacuum space 401 where the heat dissipation element 5 is provided to the outside of the battery cell housing 4 (outside the outer surface 42a of the outer wall portion 42) through the airtight connector 6 provided on the outer wall portion 42. Note that in order not to impair the heat insulation effect, the heat dissipation element 5 itself is installed so as not to contact the outer wall portion 42 or the airtight connector 6 in contact with the external environment.

[0023] Furthermore, in the battery cell 1 according to Embodiment 1, by flowing current from the power source to the heat dissipation element 5 through the wiring 51 at any arbitrary timing, the heat transferred from the electrodes 2, which are heated by charging and discharging, to the inner wall portion 41 can be dissipated by the heat dissipation element 5. Examples of such arbitrary timings include the timing when a predetermined charging time has elapsed, the timing when a predetermined discharge time has elapsed, and the timing when the temperature of the battery cell 1, as measured by a temperature sensor (not shown), reaches or exceeds a predetermined temperature. In addition, by providing the heat dissipation element 5 in contact with the aforementioned position, the heat dissipation effect of the heat dissipation element 5 can be maximized.

[0024] In the battery cell 1 according to Embodiment 1, a vacuum space 401 is provided between the storage space 402 in which the electrodes 2 in the battery cell housing 4 are housed and the external environment, thereby insulating the storage space 402 from the external environment. As a result, in the battery cell 1 according to Embodiment 1, the heat generated by the electrodes 2 during charging and discharging is less likely to be dissipated from the storage space 402 to the external environment by the vacuum space 401, and heat can be stored in the storage space 402. Furthermore, in the battery cell 1 according to Embodiment 1, a heat dissipation element 5 is provided on the outer surface 41a of the inner wall portion 41, and heat dissipation by the heat dissipation element 5 is performed at any desired timing, thereby reducing the risk of overheating in the storage space 402 by making it less likely for heat to be dissipated from the storage space 402. Therefore, the battery cell 1 according to Embodiment 1 can be heated efficiently while suppressing overheating.

[0025] Furthermore, especially during rapid charging, charging performance decreases if the temperature of electrode 2 is low. However, by providing a vacuum space 401 within the battery cell housing 4 to insulate it, as in the battery cell 1 according to Embodiment 1, the electrode 2 becomes less likely to cool down. Therefore, the situation in which the temperature of electrode 2 is low can be reduced, and charging performance can be improved. In addition, in the battery cell 1 according to Embodiment 1, by providing a heat dissipation function with a heat dissipation element 5, excessive heat accumulation can be suppressed, and abnormal deterioration of the battery cell 1 can be suppressed.

[0026] (Embodiment 2) The following describes Embodiment 2 of the secondary battery according to the present invention. In Embodiment 2, descriptions similar to those in Embodiment 1 will be omitted as appropriate.

[0027] Figure 2 is a cross-sectional view showing the schematic configuration of a battery cell 1 according to Embodiment 2.

[0028] As shown in Figure 2, in the battery cell 1 according to Embodiment 2, the electrodes 2 stored in the storage space 402 of the battery cell housing 4 are arranged so as not to come into contact with the battery cell housing 4. Specifically, the electrodes 2 stored in the storage space 402 are arranged so as not to come into contact with either the inner wall portion 41 or the lid portion 43 that form the storage space 402 in the battery cell housing 4. In addition, in the battery cell 1 according to Embodiment 2, the electrodes 2 may be supported within the storage space 402 by, for example, a support member having heat insulation properties (not shown).

[0029] In the battery cell 1 according to Embodiment 2, the electrodes 2 stored in the storage space 402 are arranged so as not to come into contact with the battery cell housing 4. This allows for a greater heat insulation effect compared to when the electrodes 2 are in contact with the battery cell housing 4. As a result, the battery cell 1 according to Embodiment 2 can reduce the number of times when the temperature of the electrodes 2 is low, thereby improving charging performance.

[0030] Furthermore, in the battery cell 1 according to Embodiment 2, since the electrodes 2 stored in the storage space 402 are not in contact with the battery cell housing 4 (inner surface 41b of the inner wall portion 41), heat dissipation from the electrolyte 3 in the storage space 402 by the heat dissipation element 5 is effective in reducing the risk of overheating. For this reason, in the battery cell 1 according to Embodiment 2, the heat dissipation element 5 is provided in contact with the outer surface 41a of the inner wall portion 41, corresponding to the portion of the inner surface 41b of the inner wall portion 41 that is in contact with the electrolyte 3. In the battery cell 1 according to Embodiment 2, it is possible to flow current from the wiring 51 to the heat dissipation element 5 at any time, and to dissipate the heat transferred from the electrodes 2, which are heated by charging and discharging, to the electrolyte 3 via the inner wall portion 41 by the heat dissipation element 5. As a result, in the battery cell 1 according to Embodiment 2, the risk of overheating in the storage space 402 can be reduced because heat dissipation from the storage space 402 to the external environment becomes less likely. Therefore, the battery cell 1 according to Embodiment 2 can be heated efficiently while suppressing overheating.

[0031] (Embodiment 3) The following describes Embodiment 3 of the secondary battery according to the present invention. In Embodiment 3, explanations similar to those in Embodiment 1 will be omitted as appropriate. In the battery cell 1 according to Embodiment 3, in contrast to the battery cell 1 according to Embodiment 1, in which one electrode 2 is stored in the storage space 402 of the battery cell housing 4, multiple electrodes 2 are stored in the storage space 402 of the battery cell housing 4.

[0032] Figure 3 is a cross-sectional view showing the schematic configuration of a battery cell 1 according to Embodiment 3.

[0033] As shown in Figure 3, in the battery cell 1 according to Embodiment 3, a plurality of electrodes 2 are arranged in a line of electrodes 20 in contact with each other in the width direction of the battery cell 1, and are stored in the storage space 402 of the battery cell housing 4. In the battery cell 1 according to Embodiment 3, not all of the plurality of electrodes 2 constituting the electrode group 20 are in contact with the lid portion 43 that forms the storage space 402. Of the plurality of electrodes 2 constituting the electrode group 20, two electrodes 2 located at each end in the width direction are in contact with the inner surface 42b of the inner wall portion 41 that forms the storage space 402 in the width direction. As a result, in the battery cell 1 according to Embodiment 3, the heat generated by the plurality of electrodes 2 constituting the electrode group 20 during charging and discharging is less likely to be dissipated from the storage space 402 to the external environment by the vacuum space 401, and heat can be stored in the storage space 402.

[0034] Furthermore, in the battery cell 1 according to Embodiment 3, as shown in Figure 3, a heat dissipation element 5 is provided in contact with the outer surface 41a of the inner wall portion 41, corresponding to the portion of the inner surface 41b of the inner wall portion 41 that is in contact with the electrode 2 and the electrolyte 3. In the battery cell 1 according to Embodiment 3, it is possible to flow current from the wiring 51 to the heat dissipation element 5 at any time, thereby dissipating the heat transferred from the electrode 2 and electrolyte 3, which are heated by charging and discharging, to the inner wall portion 41 by the heat dissipation element 5. As a result, in the battery cell 1 according to Embodiment 3, the risk of overheating in the storage space 402 can be reduced because heat dissipation from the storage space 402 to the external environment becomes less likely. It is preferable that the heat dissipation element 5 be provided in a position on the outer surface 41a of the inner wall portion 41, corresponding to at least the portion of the outer surface 41a of the inner wall portion 41 that is in contact with the electrode 2.

[0035] Based on the above, the battery cell 1 according to Embodiment 3 can be heated efficiently while suppressing overheating.

[0036] In the battery cell 1 according to Embodiment 3, similar to the battery cell 1 according to Embodiment 2, all of the electrodes 2 constituting the electrode group 20 may be configured so that they do not come into contact with the battery cell housing 4. In this case, it is preferable that the heat dissipation element 5 be provided on the outer surface 41a of the inner wall portion 41, which corresponds to the portion of the inner surface 41b of the inner wall portion 41 that comes into contact with the electrolyte 3.

[0037] (Embodiment 4) The following describes Embodiment 4 of the secondary battery according to the present invention. However, the present invention is not limited to this embodiment.

[0038] Figure 4 is a cross-sectional view showing the schematic configuration of the battery pack 100 according to Embodiment 4. In Figure 4, "height direction" refers to the height direction of the battery pack 100, and "width direction" refers to the width direction of the battery pack 100.

[0039] As shown in Figure 4, the battery pack 100 according to Embodiment 4 comprises a battery pack 10, a battery pack housing 7, a heat dissipation element 8, and an airtight connector 9. The battery pack 100 according to Embodiment 4 is a secondary battery configured by housing the battery pack 10 in a battery cell housing 4. The battery pack 10 is configured by arranging a plurality of battery cells 1 in a row in the width direction of the battery pack 100.

[0040] Note that the battery cell 1 is not limited to the battery cell 1 according to any one of Embodiments 1 to 3, in other words, the battery cell 1 in which a vacuum space 401 is provided within the battery cell housing 4. Also, in this embodiment, the height direction of the battery pack 100 is the same as the height direction of the battery cell 1, and the width direction of the battery pack 100 is the same as the height direction of the battery cell 1.

[0041] The battery pack housing 7 is constructed, for example, from a metal material and has an inner wall portion 71, an outer wall portion 72, and a lid portion 73. The inner wall portion 71 is a box-shaped container with one open top surface. The outer wall portion 72 is also box-shaped with one open top surface and is larger than the inner wall portion 71 so that it can accommodate the inner wall portion 71 in its inner space with a gap between them. The lid portion 73 is a plate shape that closes the openings of the inner wall portion 71 and the outer wall portion 72. The lid portion 73 is connected to the upper ends of the inner wall portion 71 and the outer wall portion 72. The battery pack housing 7 is enclosed by the inner wall portion 71, the outer wall portion 72, and the lid portion 73, and is a vacuum container in which a vacuum space 701 is formed between the outer surface 71a of the inner wall portion 71 and the inner surface 72b of the outer wall portion 72 in the width direction.

[0042] In the battery pack housing 7, the battery pack 10 is stored in the storage space (the space inside the inner wall portion 71) 702, which is enclosed by the inner wall portion 71 and the lid portion 73. In the battery pack 100 according to Embodiment 4, the battery pack 10 (each battery cell 1) stored in the storage space 702 is arranged so that it contacts only the inner surface 71b of the inner wall portion 71 at the lower side in the height direction of the inner wall portion 71 and the lid portion 73 that form the storage space 702. As a result, the outer surface 71a of the inner wall portion 71 is in contact with the vacuum space 701 of the battery pack housing 7, but not with the external environment of the battery pack housing 7 (the space outside the battery pack housing 7). Therefore, the heat insulation effect can be improved compared to when the battery pack 10 (each battery cell 1) is in contact with the lid portion 73, which is in contact with the external environment in the battery pack housing 7.

[0043] Furthermore, a heat dissipation element 8 is provided on the outer surface 71a, which is the side of the inner wall portion 71 facing the vacuum space 701. In the battery pack 100 according to Embodiment 4, a Peltier element is used as the heat dissipation element 8. However, the heat dissipation element 8 is not limited to a Peltier element, and it is preferable to use one that has a high heat absorption effect like a Peltier element.

[0044] In the battery pack 100 according to Embodiment 4, a heat dissipation element 8 is provided in contact with the outer surface 41a in the width direction of the inner wall portion 71 that is in contact with the bottom surface of the battery pack 10 (each battery cell 1). Wiring 81 for supplying current to the heat dissipation element 8 from a power source (not shown) is connected to the heat dissipation element 8. The wiring 81 is brought out from the vacuum space 701 in which the heat dissipation element 8 is located to the outside of the battery pack housing 7 (outside the outer surface 72a of the outer wall portion 72) via an airtight connector 9 provided on the outer wall portion 72. In order not to impair the heat insulation effect, the heat dissipation element 8 itself is installed so as not to come into contact with the outer wall portion 72 or the airtight connector 9 that are in contact with the external environment of the battery pack 100.

[0045] In the battery pack 100 according to Embodiment 4, it is possible to dissipate heat transferred from the battery pack 10 (each battery cell 1), which generates heat due to charging and discharging, to the inner wall portion 71 by the heat dissipation element 8 by flowing current from the power source through the wiring 81 at any arbitrary timing. Examples of such arbitrary timings include the timing when a predetermined charging time has elapsed, the timing when a predetermined discharge time has elapsed, and the timing when the temperature of the battery pack 10 (each battery cell 1), as measured by a temperature sensor (not shown), reaches or exceeds a predetermined temperature.

[0046] In the battery pack 100 according to Embodiment 4, a vacuum space 701 is provided between the storage space 702 in which the battery pack 10 is stored in the battery pack housing 7 and the external environment, thereby insulating the storage space 702 from the external environment. As a result, in the battery pack 100 according to Embodiment 4, the heat generated by the battery pack 10 (each battery cell 1) during charging and discharging is less likely to be dissipated from the storage space 702 to the external environment by the vacuum space 701, and heat can be stored in the storage space 702. In addition, in the battery pack 100 according to Embodiment 4, a heat dissipation element 8 is provided on the outer surface 71a of the inner wall portion 71, and heat dissipation by the heat dissipation element 8 is performed at any desired timing. As a result, the risk of overheating in the storage space 702 can be reduced by making it less likely for heat to be dissipated from the storage space 702.

[0047] Therefore, the battery pack 100 according to Embodiment 4 can efficiently heat up while suppressing overheating.

[0048] Furthermore, by providing a vacuum space 701 within the battery pack housing 7 to insulate it, as in the battery pack 100 according to Embodiment 4, the battery pack 10 (each battery cell 1) becomes less likely to cool down. Therefore, in the battery pack 100 according to Embodiment 4, the situation in which the battery pack 10 (each battery cell 1) is at a low temperature can be reduced, and the charging performance can be improved. In addition, in the battery pack 100 according to Embodiment 4, by providing a heat dissipation function with a heat dissipation element 8, excessive heat accumulation can be suppressed, and abnormal deterioration of the battery pack 10 (each battery cell 1) can be suppressed. [Explanation of Symbols]

[0049] 1 battery cell 2 electrodes 3 Electrolyte 4 Battery cell housing 5.8 Heat dissipation element 6,9 Airtight connector 7 Battery pack housing 10 battery packs 20 electrode groups 41,71 Interior wall section 41a,42a,71a,72a External surface 41b, 42b, 71b, 72b Inner surface 42,72 Exterior wall 43,73 Lid 51,81 Wiring 100 Battery Pack 401,701 Vacuum space 402 Storage Space 702 Storage Space

Claims

1. A secondary battery configured by housing electrodes in a casing, The housing is a vacuum container having a container-shaped inner wall portion and a container-shaped outer wall portion capable of housing the inner wall portion, with a vacuum space formed between the inner wall portion and the outer wall portion. The electrode is housed in a storage space formed inside the inner wall portion. A heat dissipation element is provided on the vacuum space side of the inner wall portion. A secondary battery characterized by the following features.

2. In the housing described above, the electrode is configured to be in contact only with the inner wall portion. The secondary battery according to claim 1.

3. The electrodes are configured so as not to come into contact with the housing. The secondary battery according to claim 1.

4. A secondary battery comprising multiple battery cells housed in a casing, The housing is a vacuum container having a container-shaped inner wall portion and a container-shaped outer wall portion capable of housing the inner wall portion, with a vacuum space formed between the inner wall portion and the outer wall portion. The plurality of battery cells are stored in a storage space formed inside the inner wall portion. A heat dissipation element is provided on the vacuum space side of the inner wall portion. A secondary battery characterized by the following features.

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