SECONDARY BATTERY

Abstract

A secondary battery contains an electrode housed in a casing. The casing is a vacuum container with a vessel-shaped inner wall section and a vessel-shaped outer wall section configured to receive the inner wall section, with a vacuum space defined between the inner and outer wall sections. The electrode is stored in a storage space defined within the inner wall section. A heat dissipation element is provided on a surface of the inner wall section facing the vacuum space.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present invention relates to a secondary battery. 2. Description of the related prior art

[0002] The unexamined Japanese patent application disclosure no. 2017-222239 (JP 2017-222239 A) discloses a device for heating a secondary battery, which heats a secondary battery through a latent heat storage material covering the secondary battery. SUMMARY OF THE INVENTION

[0003] If the secondary battery is heated from the outside of its housing, excessive temperature rise or heat transfer loss is likely to occur. Therefore, it is difficult to heat the secondary battery efficiently.

[0004] The present invention was made with regard to the above problem, and one objective of the present invention is to provide a secondary battery that can be heated efficiently while suppressing an excessive temperature rise.

[0005] To solve the above problem and achieve the above goal, a secondary battery according to the present invention is a secondary battery with an electrode stored in a housing. The housing is a vacuum container with a container-shaped inner wall section and a container-shaped outer wall section configured to accommodate the inner wall section, with a vacuum space defined between the inner and outer wall sections. The electrode is stored in a storage space defined within the inner wall section. A heat dissipation element is provided on a surface of the inner wall section facing the vacuum space.

[0006] In this way, the secondary battery according to the present invention can be heated efficiently, suppressing excessive temperature increases.

[0007] In this case, the electrode can only be in contact with the inner section of the housing.

[0008] This can improve the thermal insulation effect.

[0009] In this case, the electrode must not be in contact with the housing.

[0010] In this way, the insulating thermal insulation effect can be improved.

[0011] A secondary battery according to the present invention is a secondary battery comprising a plurality of battery cells stored in a housing. The housing is a vacuum container with a container-shaped inner wall section and a container-shaped outer wall section configured to receive the inner wall section, wherein a vacuum space is defined between the inner wall section and the outer wall section. The battery cells are stored in a storage space defined within the inner wall section. A heat dissipation element is provided on a surface of the inner wall section facing the vacuum space.

[0012] In this way, the secondary battery according to the present invention can be heated efficiently, suppressing excessive temperature increases.

[0013] The secondary battery according to the present invention can efficiently maintain a high temperature by storing the heat generated during charging and discharging due to the heat-insulating structure of the casing. Furthermore, the heat dissipation element has the effect of suppressing excessive heat storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Features, advantages and technical and industrial significance of embodiments of the invention are described below with reference to the accompanying drawings, in which the same symbols denote the same elements and wherein: Fig. is a sectional view showing a schematic configuration of a battery cell according to a first embodiment; Fig. is a sectional view showing a schematic configuration of a battery cell according to a second embodiment; Fig. is a sectional view showing a schematic configuration of a battery cell according to a third embodiment; and Fig. is a sectional view showing a schematic configuration of a battery set according to a fourth embodiment. DETAILED DESCRIPTION OF THE EXAMPLES First example of implementation

[0015] A secondary battery according to a first embodiment of the present invention is described below. The present invention is not limited to the present embodiment.

[0016] Fig. is a sectional view showing a schematic configuration of a battery cell 1 according to the first embodiment. The "vertical direction" in Fig. is the vertical direction of battery cell 1, and the "lateral direction" in Fig. is the lateral direction of the battery cell 1.

[0017] As in Fig. As shown, the battery cell 1 according to the first embodiment comprises an electrode 2, an electrolyte 3, a battery cell housing 4, a heat dissipation element 5 and an airtight connector 6. The battery cell 1 according to the first embodiment is a secondary battery that stores the electrode 2 and the electrolyte 3 in the battery cell housing 4.

[0018] The battery cell housing 4, for example, is made of a metal material and comprises an inner wall section 41, an outer wall section 42, and a cover section 43. The inner section 41 is in the shape of a box-like container, open on one side, namely the top. The outer wall section 42 is also box-shaped, open on one side, namely the top, and has a container shape that is larger than that of the inner wall section 41, so that the inner wall section 41 can be accommodated inside the housing with a gap between it and the inner wall section 42. The cover section 43 is plate-shaped and closes the openings of the inner wall section 41 and the outer wall section 42. The cover section 43 is connected to the upper ends of the inner wall section 41 and the outer wall section 42.The battery cell housing 4 is a vacuum container enclosed by the inner wall section 41, the outer wall section 42 and the lid section 43, wherein a vacuum space 401 is defined in the width direction between an outer surface 41a of the inner wall section 41 and an inner surface 42b of the outer wall section 42.

[0019] In the housing 4 of the battery cell, a storage chamber 402, enclosed by the inner wall section 41 and the cover section 43, stores the electrode 2 and is filled with the electrolyte 3, such that at least part of the electrode 2 is immersed. In the battery cell 1 according to the first embodiment, the electrode 2 stored in the storage chamber 402 is in contact with only one inner surface 41b of the inner wall section 41, located laterally outside the inner wall section 41 and the cover section 43 that define the storage chamber 402. Therefore, the outer surface 41a of the inner wall section 41 is in contact with the vacuum space 401 of the battery cell housing 4, but not in contact with the external environment around the battery cell housing 4 (space outside the battery cell housing 4).This allows the thermal insulation effect to be improved compared to the case in which the electrode 2 is in contact with the cover section 43, which is in contact with the external environment.

[0020] The heat dissipation element 5 is provided on the outer surface 41a, which is the surface of the inner wall section 41 facing the vacuum space 401. In the battery cell 1 according to the first embodiment, a Peltier element is used as the heat dissipation element 5. The heat dissipation element 5 is not limited to the Peltier element. It is preferable to use an element that has a high heat-absorbing capacity, as in the case of the Peltier element.

[0021] In the battery cell 1 according to the first embodiment, the heat dissipation element 5 is provided in contact with a position on the outer surface 41a of the inner wall section 41 that corresponds to the section of the inner surface 41b of the inner wall section 41 that is in contact with the electrode 2. A wire 51 is connected to the heat dissipation element 5, which causes a current flow from a power supply (not shown) to the heat dissipation element 5. The wire 51 is led from the vacuum space 401 in which the heat dissipation element 5 is provided, via the airtight connector 6, which is provided on the outer wall section 42, to the outside of the battery cell housing 4 (outside an outer surface 42a of the outer wall section 42).In order not to impair the thermal insulation effect, the heat dissipation element 5 is positioned outside of contact with the outer wall section 42 and the airtight connector 6, which are in contact with the external environment.

[0022] In the battery cell 1 according to the first embodiment, the heat dissipation element 5 can dissipate the heat generated by charging and discharging and transferred from the electrode 2 to the inner wall section 41 by sending a current from the power supply through the wire 51 to the heat dissipation element 5 at any suitable time. Examples of suitable times include when a predetermined charging period has elapsed, when a predetermined discharging period has elapsed, and when the temperature of the battery cell 1, as measured by a temperature sensor (not shown), has reached a predetermined temperature or a higher temperature. By positioning the heat dissipation element 5 at the aforementioned location, it is possible to maximize its heat dissipation effect.

[0023] In the battery cell 1 according to the first embodiment, a vacuum space 401 is provided between the external environment and the storage space 402 of the battery cell housing 4, in which the electrode 2 is stored. This provides thermal insulation for the storage space 402 from the external environment. Therefore, in the battery cell 1 according to the first embodiment, the heat generated in the electrode 2 during charging and discharging is less likely to be dissipated from the storage space 402 to the external environment due to the vacuum space 401. Thus, the heat can be stored in the storage space 402. In the battery cell 1 according to the first embodiment, the heat dissipation element 5 is provided on the outer surface 41a of the inner wall section 41 and dissipates the heat at any suitable time.Therefore, it is possible to reduce the risk of excessive temperature rise in storage space 402, which can occur when heat dissipation from storage space 402 is less likely. Thus, according to the first embodiment, battery cell 1 can be heated efficiently while suppressing excessive temperature rise.

[0024] Particularly during fast charging, the charging power decreases when the temperature of the electrode 2 is low. By providing the vacuum space 401 in the housing of the battery cell 4 for thermal insulation, as is the case in the battery cell 1 according to the first embodiment, cooling of the electrode 2 becomes less likely. Therefore, the situation in which the temperature of the electrode 2 is low can be reduced, and the charging power can be improved. In the battery cell 1 according to the first embodiment, the heat dissipation function is provided by the heat dissipation element 5. Therefore, excessive heat storage can be suppressed, and abnormal deterioration of the battery cell 1 can be prevented. Second embodiment

[0025] A secondary battery according to a second embodiment of the present invention is described below. In the second embodiment, the same description as in the first embodiment will be omitted if necessary.

[0026] Fig. is a sectional view showing a schematic configuration of a battery cell 1 according to the second embodiment.

[0027] As in Fig. As shown, in the second embodiment of the battery cell 1, the electrode 2 stored in the storage space 402 of the battery cell housing 4 is arranged out of contact with the battery cell housing 4. In particular, the electrode 2 stored in the storage space 402 is arranged out of contact with both the inner wall section 41 and the cover section 43, which define the storage space 402 in the battery cell housing 4. In the battery cell 1 according to the second embodiment, the electrode 2 can be supported within the storage space 402, for example by a support element (not shown) that has heat-insulating properties.

[0028] Since the electrode 2 stored in the storage space 402 is arranged in the battery cell 1 according to the second embodiment out of contact with the battery cell housing 4, the thermal insulation effect can be improved compared to the case in which the electrode 2 is in contact with the battery cell housing 4. Therefore, in the battery cell 1 according to the second embodiment, the situation in which the temperature of the electrode 2 is low can be further reduced and the charging performance can be further improved.

[0029] Since the electrode 2 stored in the storage space 402 in the battery cell 1, according to the second embodiment, is not in contact with the housing 4 of the battery cell (inner surface 41b of the inner wall section 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 excessive temperature rise. Therefore, in the battery cell 1, according to the second embodiment, the heat dissipation element 5 is positioned on the outer surface 41a of the inner wall section 41, corresponding to the section of the inner surface 41b of the inner wall section 41 that is in contact with the electrolyte 3.In the battery cell 1 according to the second embodiment, the heat dissipation element 5 can dissipate the heat generated by charging and discharging and transferred from the electrode 2 to the electrolyte 3 via the inner wall section 41 by causing a current flow from the wire 51 to the heat dissipation element 5 at any suitable time. Therefore, in the battery cell 1 according to the second embodiment, it is possible to reduce the risk of an excessive temperature rise in the storage space 402, which can occur when heat dissipation from the storage space 402 to the external environment is less likely. Thus, the battery cell 1 according to the second embodiment can be heated efficiently while suppressing the excessive temperature rise. Third example

[0030] A secondary battery according to a third embodiment of the present invention is described below. In the third embodiment, the description that is the same as in the first embodiment may be omitted. In the battery cell 1 according to the third embodiment, a plurality of electrodes 2 are stored in the storage space 402 of the battery cell housing 4, in contrast to the battery cell 1 according to the first embodiment, in which one electrode 2 is stored in the storage space 402 of the battery cell housing 4.

[0031] Fig. is a sectional view showing a schematic configuration of battery cell 1 according to the third embodiment.

[0032] As in Fig. As shown, in the third embodiment of the battery cell 1, the electrodes 2 are stored as an electrode group 20 in the storage space 402 of the battery cell housing 4. In this group, the electrodes 2 are arranged side by side and in contact with each other in the lateral direction of the battery cell 1. In the battery cell 1 of the third embodiment, none of the electrodes 2 forming the electrode group 20 are in contact with the cover section 43 that delimits the storage space 402. Of the electrodes 2 forming the electrode group 20, two electrodes 2, located at both ends in the lateral direction, are in contact with the inner surface 41b of the inner wall section 41 that defines the storage space 402.Therefore, in the third embodiment of battery cell 1, the heat generated by charging and discharging in the electrodes 2 forming the electrode group 20 is less likely to be dissipated from the storage space 402 to the external environment due to the vacuum space 401. Thus, the heat can be stored in the storage space 402.

[0033] In battery cell 1 according to the third embodiment, as in Fig. As shown, the heat dissipation element 5 is positioned on the outer surface 41a of the inner wall section 41 corresponding to the section of the inner surface 41b of the inner wall section 41 that is in contact with the electrode 2 and the electrolyte 3. In the battery cell 1 according to the third embodiment, the heat dissipation element 5 can dissipate the heat generated by charging and discharging and transferred from the electrodes 2 and the electrolyte 3 to the inner wall section 41 by causing a current to flow from the wire 51 to the heat dissipation element 5 at any suitable time. Therefore, in the battery cell 1 according to the third embodiment, it is possible to reduce the risk of an excessive temperature rise in the storage space 402, which can occur when heat dissipation from the storage space 402 to the external environment is less likely.The heat dissipation element 5 is preferably provided at a position on the outer surface 41a of the inner wall section 41 which corresponds at least to the section of the inner surface 41b of the inner wall section 41 which is in contact with the electrode 2.

[0034] As described above, according to the third embodiment, the battery cell 1 can be efficiently heated while suppressing excessive temperature rise.

[0035] In the battery cell 1 according to the third embodiment, all the electrodes 2 forming the electrode group 20 can be kept away from the housing 4, as in the battery cell 1 according to the second embodiment. In this case, the heat dissipation element 5 is preferably provided on the outer surface 41a of the inner wall section 41, which corresponds to the section of the inner surface 41b of the inner wall section 41 that is in contact with the electrolyte 3. Fourth embodiment

[0036] A secondary battery according to a fourth embodiment of the present invention is described below. The present invention is not limited to the present embodiment.

[0037] Fig. This is a sectional view showing a schematic configuration of a battery pack of 100 according to the fourth embodiment. The "vertical direction" in Fig. The vertical direction of the battery pack is 100, and the "latitude direction" is in Fig. The width direction of the battery pack is 100.

[0038] As in Fig.As shown, the battery pack 100 according to the fourth embodiment comprises a battery assembly 10, a battery pack housing 7, a heat dissipation element 8, and an airtight connector 9. The battery pack 100 according to the fourth embodiment is a secondary battery that houses the battery assembly 10 in the housing 7 of the battery pack. In the battery assembly 10, a plurality of battery cells 1 are arranged side by side in the width direction of the battery pack 100.

[0039] The battery cell 1 is not limited to the battery cell 1 according to any one of the first to third embodiments, i.e., the battery cell 1 provided with the vacuum space 401 within the battery cell housing 4. In the present embodiment, the vertical direction of the battery pack 100 corresponds to the vertical direction of the battery cell 1, and the horizontal direction of the battery pack 100 corresponds to the horizontal direction of the battery cell 1.

[0040] The housing 7 of the battery pack, for example, is made of metal and comprises an inner wall section 71, an outer wall section 72, and a lid section 73. The inner section 71 is in the shape of a box-like container, open on one side, namely the top. The outer wall section 72 is also box-shaped, open on one side, namely the top, and is larger than the inner wall section 71, allowing the inner wall section 71 to be positioned inside the housing with a gap between it and the inner wall section 72. The lid section 73 is plate-shaped and closes the openings of the inner wall section 71 and the outer wall section 72. The lid section 73 is connected to the upper ends of the inner wall section 71 and the outer wall section 72.The housing 7 of the battery pack is a vacuum container enclosed by the inner wall section 71, the outer wall section 72 and the lid section 73, with a vacuum space 701 defined in the width direction between an outer surface 71a of the inner wall section 71 and an inner surface 72b of the outer wall section 72.

[0041] In the housing 7 of the battery pack, the battery assembly 10 is stored in a storage space (space within the inner wall section 71) 702, which is enclosed by the inner wall section 71 and the cover section 73. In the battery pack 100 according to the fourth embodiment, the battery assembly 10 (each battery cell 1) stored in the storage space 702 is in contact with only one inner surface 71b of the inner wall section 71 at the bottom, vertically outside the inner wall section 71 and the cover section 73, which define the storage space 702. Therefore, the outer surface 71a of the inner wall section 71 is in contact with the vacuum space 701 of the housing 7 of the battery pack, but not with the external environment around the housing 7 of the battery pack (space outside the housing 7 of the battery pack).This can improve the thermal insulation effect compared to the case in which the battery arrangement 10 (each battery cell 1) is in contact with the lid section 73 of the housing of the battery pack 7, which is in contact with the external environment.

[0042] The heat dissipation element 8 is provided on the outer surface 71a, which is the surface of the inner wall section 71 facing the vacuum space 701. In the battery pack 100 according to the fourth embodiment, a Peltier element is used as the heat dissipation element 8. The heat dissipation element 8 is not limited to the Peltier element. It is preferable to use an element that has a high heat-absorbing effect, as in the case of the Peltier element.

[0043] In the battery pack 100 according to the fourth embodiment, the heat dissipation element 8 is provided in contact with the outer surface 71a in the width direction on the inner wall section 71, which is in contact with the bottom surface of the battery assembly 10 (each battery cell 1). A wire 81 is connected to the heat dissipation element 8, which causes a current flow from a power supply (not shown) to the heat dissipation element 8. The wire 81 is guided from the vacuum space 701 in which the heat dissipation element 8 is provided, via the airtight connector 9, which is provided on the outer wall section 72, to the outside of the housing 7 of the battery pack (outside an outer surface 72a of the outer wall section 72).In order not to impair the thermal insulation effect, the heat dissipation element 8 is installed outside of contact with the outer wall section 72 and the airtight connector 9, which are in contact with the external environment of the battery pack 100.

[0044] In the battery pack 100 according to the fourth embodiment, the heat dissipation element 8 can dissipate heat generated by charging and discharging and transferred from the battery assembly 10 (each battery cell 1) to the inner wall section 71 by sending a current from the power supply via the wire 81 to the heat dissipation element 8 at any suitable time. Examples of suitable times include when a predetermined charging period has elapsed, when a predetermined discharging period has elapsed, and when the temperature of the battery assembly 10 (each battery cell 1), as measured by a temperature sensor (not shown), has reached a predetermined temperature or higher.

[0045] In the battery pack 100 according to the fourth embodiment, a vacuum space 701 is provided between the external environment and the storage space 702 of the battery pack housing 7, in which the battery assembly 10 is stored, thus thermally insulating the storage space 702 from the external environment. Therefore, in the battery pack 100 according to the fourth embodiment, it is less likely that the heat generated in the battery assembly 10 (each battery cell 1) by charging and discharging will be dissipated from the storage space 702 to the external environment due to the vacuum space 701. Thus, the heat can be stored in the storage space 702. In the battery pack 100 according to the fourth embodiment, the heat dissipation element 8 is provided on the outer surface 71a of the inner wall section 71 and dissipates the heat at any suitable time.Therefore, it is possible to reduce the risk of an excessive temperature increase in storage room 702, which can be caused if heat removal from storage room 702 is less likely.

[0046] Thus, the battery pack 100 can be efficiently heated according to the fourth embodiment, while the excessive temperature increase is suppressed.

[0047] By providing the vacuum space 701 in the housing 7 of the battery pack for thermal insulation, as is the case in the battery pack 100 according to the fourth embodiment, it is less likely that the battery unit 10 (each battery cell 1) will cool down. Therefore, in the battery pack 100 according to the fourth embodiment, the situation in which the temperature of the battery assembly 10 (each battery cell 1) is low can be reduced and the charging performance improved. In the battery pack 100 according to the fourth embodiment, the heat dissipation function is provided by the heat dissipation element 8. Therefore, excessive heat storage can be suppressed and abnormal deterioration of the battery assembly 10 (each battery cell 1) can be prevented. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2017-222239 A

[0002]

Claims

[1] Secondary battery comprising an electrode (2) which is stored in a housing (4), wherein: the housing (4) is a vacuum container comprising a container-shaped inner wall section (41) and a container-shaped outer wall section (42) configured to accommodate the inner wall section (41), with a vacuum space (401) defined between the inner wall section (41) and the outer wall section (42); the electrode (2) is stored in a storage space (402) defined within the inner wall section (41); and a heat dissipation element (5) is provided on a surface of the inner wall section (41) facing the vacuum space (401). [2] Secondary battery according to claim 1, wherein the electrode (2) is in contact only with the inner wall section (41) of the housing (4). [3] Secondary battery according to claim 1, wherein the electrode (2) is not in contact with the housing (4). [4] Secondary battery comprising a plurality of battery cells (1) stored in a housing (7), wherein: the housing (7) is a vacuum container comprising a container-shaped inner wall section (71) and a container-shaped outer wall section (72) configured to accommodate the inner wall section (71), with a vacuum space (701) defined between the inner wall section (71) and the outer wall section (72); the battery cells (1) are stored in a storage space (702) defined within the inner wall section (71); and a heat dissipation element (8) is provided on the surface of the inner wall section (71) facing the vacuum space (701).

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