Battery device

Abstract

The invention provides a battery device, comprising: a housing having an accommodating space; the battery module is arranged in the accommodating space; the elastic gas storage part is provided with a gas storage space, the gas storage space is communicated with the containing space, and the elastic gas storage part can expand or contract according to the temperature in the containing space so as to balance the pressure in the containing space. According to the structure, the pressure condition in the shell can be automatically balanced, so that the shell of the battery device cannot be deformed under the condition that the external environment temperature is changed, and the use safety of the battery device is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy storage technology, and in particular to a battery device. Background Art

[0002] The battery pack is an important component in new energy vehicles, and the safety of the battery pack is directly related to driving safety. The battery pack in the prior art mainly includes a box and a battery module arranged in the box, and the box is a closed environment. When the vehicle is driving in different environments with large temperature differences, the temperature in the battery pack box will also change accordingly. The increase in temperature will cause the gas in the battery pack box to expand and the pressure to increase, while the decrease in temperature will cause the gas in the battery pack box to contract and the pressure to decrease.

[0003] Since the battery pack case is usually made of thin plates, the increase and decrease of pressure inside the battery pack case can easily cause the battery pack case to deform. In particular, when the pressure inside the battery pack case decreases, the case will partially sag inward. Once the metal case wall contacts the battery module's tabs after the sag, a short circuit will occur, which can even cause a fire in severe cases. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that when the internal pressure of the battery pack box changes, the box body will deform, which easily leads to a short circuit of the battery module, thereby providing a battery device.

[0005] In order to solve the above problems, the present invention provides a battery device, including: a shell having a accommodating space; a battery module arranged in the accommodating space; an elastic gas storage member having a gas storage space, the gas storage space being connected to the accommodating space, wherein the elastic gas storage member can expand or contract according to the temperature in the accommodating space to balance the pressure in the accommodating space.

[0006] Optionally, the minimum distance between the battery module and the shell is smaller than the maximum concave deformation depth of the shell.

[0007] Optionally, the shell includes a bottom wall, an annular side wall and a top wall, a first through hole is provided on the bottom wall or the annular side wall or the top wall, and the elastic air storage member includes an air nozzle, which is connected to the first through hole.

[0008] Optionally, there are multiple shells, the accommodating spaces of the multiple shells are connected, and at least some of the shells are provided with inflation holes.

[0009] Optionally, at least part of the shell is provided with a one-way vent valve, which is used to allow gas to flow in one direction from the inside of the shell to the outside of the shell, wherein the opening pressure of the one-way vent valve is in the range of 5KPa to 100KPa.

[0010] Optionally, multiple shells are stacked, and in shells other than the topmost shell, in two adjacent shells, the bottom wall of the upper shell serves as the top wall of the lower shell, and a second through hole is provided on the bottom wall of the shell.

[0011] Optionally, the second through hole on the bottom wall of the lowermost shell is provided with a plug.

[0012] Optionally, a sealing structure is provided between adjacent shells.

[0013] Optionally, the elastic gas storage member is arranged on the top wall, and the battery device further comprises a cover body, which is arranged on the top wall and covers the elastic gas storage member, and the cover body is provided with ventilation holes.

[0014] Optionally, there are multiple shells and multiple elastic air storage members, and the air storage spaces of the multiple elastic air storage members are connected to the accommodating spaces of the multiple shells in a one-to-one correspondence.

[0015] Optionally, the elastic air storage member includes an air bag.

[0016] Optionally, the volume of the elastic gas storage component satisfies the following formula: Formula 1: V0≥(m / ρ1)-(m / ρ2); wherein V0 is the volume of the elastic gas storage component, m is the mass of the gas in the accommodating space, ρ1 is the density of the gas in the accommodating space when the battery device is in a first environment, and ρ2 is the density of the gas in the accommodating space when the battery device is in a second environment, wherein the temperature of the first environment is greater than the temperature of the second environment.

[0017] Optionally, a one-way vent valve is provided on the shell, and the one-way vent valve is used to allow gas to flow in one direction from the inside of the shell to the outside of the shell. The mass of gas in the accommodating space is obtained by the following formula: Formula 2: m=m1-m2; wherein, m is the mass of gas in the accommodating space, m1 is the initial filling mass of gas in the accommodating space, and m2 is the mass of gas discharged from the accommodating space through the one-way vent valve when the battery device is in a third environment, and the temperature of the third environment is greater than the temperature of the first environment.

[0018] The present invention has the following advantages:

[0019] Utilizing the technical solution of the present invention, the battery device includes an elastic gas storage member, and the gas storage space in the elastic gas storage member is connected to the accommodating space in the shell. A certain amount of gas is injected into the elastic gas storage member when the battery device leaves the factory. When the external environment temperature decreases, the temperature in the accommodating space of the shell decreases, causing the gas to shrink, and the gas in the gas storage space in the elastic gas storage member can be released into the accommodating space, thereby compensating for the reduced gas volume in the accommodating space and preventing the pressure in the shell from decreasing. When the external environment temperature increases, the temperature in the accommodating space of the shell increases, causing the gas to expand, and the expanded gas can enter the gas storage space of the elastic gas storage member, preventing the pressure in the shell from increasing. Therefore, the above structure can automatically balance the pressure in the shell, so that when the external environment temperature changes, the shell of the battery device will not deform, further improving the safety of the battery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram showing the structure of the battery device of the present invention is shown;

[0022] Figure 2 Shows Figure 1 A schematic diagram of the structure of the battery device and the battery module;

[0023] Figure 3 Shows Figure 1 A partial schematic diagram of the upper front side of the middle battery device;

[0024] Figure 4 Shows Figure 1 A partial schematic diagram of the upper rear side of the middle battery device;

[0025] Figure 5 Shows Figure 1 A schematic diagram of the coordination of the various layers of the shell of the battery device;

[0026] Figure 6 Shows Figure 1 A schematic cross-sectional view of a battery device;

[0027] Figure 7 Shows Figure 6 A partial schematic diagram of the upper front side of the middle battery device;

[0028] Figure 8 Shows Figure 1A schematic diagram of adjacent layer housings of a battery device;

[0029] Fig. 9 Shows Figure 8 Enlarged schematic diagram at point A in the middle.

[0030] Description of reference numerals:

[0031] 10. Shell; 11. Accommodating space; 12. Bottom wall; 13. Annular side wall; 14. Top wall; 16. First through hole; 17. Inflation hole; 18. One-way vent valve; 19. Second through hole; 110. Plug; 20. Battery module; 30. Elastic gas storage component; 31. Gas storage space; 32. Gas nozzle; 40. Sealing structure; 50. Cover body; 51. Vent hole. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The battery pack is an important component in new energy vehicles, and the safety of the battery pack is directly related to driving safety. The battery pack in the prior art mainly includes a box and a battery module arranged in the box, and the box is a closed environment. The applicant found in production practice that in the battery packs that meet various indicators in the production process, some battery packs will be found to have local short circuits in the battery modules or even catch fire during actual use after leaving the factory. The applicant analyzed the cause of the accident, and the main reason is that the latitudes and temperatures in different regions are quite different. In the central region, the ambient temperature is moderate, in the high-latitude northern region, the ambient temperature is low, and in the low-latitude southern region, the ambient temperature is high.

[0037] Therefore, when the ambient temperature of the battery pack's factory area and the vehicle's driving area are significantly different, the temperature inside the battery pack will change. For example, the battery pack is manufactured in the central region, but the vehicle is actually driving in the northern region. This will cause the external ambient temperature of the battery pack to decrease, and thus the internal temperature of the battery pack will also decrease. The decrease in temperature inside the battery pack will cause the gas inside the battery pack case to shrink and the pressure to decrease. For another example, the battery pack is manufactured in the central region, but the vehicle is actually driving in the southern region. This will cause the external ambient temperature of the battery pack to increase, and thus the internal temperature of the battery pack will also increase. The increase in temperature inside the battery pack will cause the gas inside the battery pack case to expand and the pressure to increase.

[0038] In addition, those skilled in the art will understand that when a vehicle is traveling in the north and south, or in different seasons in the same region, there will be large temperature differences in the external environment, which will also cause changes in the pressure inside the battery pack.

[0039] Furthermore, since the battery pack case is usually made of thin plates, the increase and decrease of pressure in the battery pack case can easily cause the battery pack case to deform. In particular, when the pressure in the battery pack case decreases, the case partially sags inwards. Once the metal wall of the case contacts the battery module's tabs, a short circuit will occur, which can lead to a fire in severe cases.

[0040] In order to solve the above problems, the present application provides a battery device, which is as follows:

[0041] like Figure 1 As shown, an embodiment of a battery device according to the present application includes a housing 10, a battery module 20 and an elastic gas storage member 30. The housing 10 has a storage space 11. The battery module 20 is arranged in the storage space 11. The elastic gas storage member 30 has a gas storage space 31, and the gas storage space 31 is connected to the storage space 11.

[0042] Furthermore, the elastic air storage member 30 can expand or contract according to the temperature in the accommodating space 11 to balance the pressure in the accommodating space 11 .

[0043] Using the technical solution of this embodiment, the battery device includes an elastic gas storage member 30, and the gas storage space 31 in the elastic gas storage member 30 is connected to the accommodating space in the shell 10. When the battery device leaves the factory, a certain amount of gas is injected into the elastic gas storage member 30. When the external environment temperature decreases, the temperature in the accommodating space 11 of the shell 10 decreases, causing the gas to shrink, and the gas in the gas storage space in the elastic gas storage member 30 can be released into the accommodating space 11, thereby compensating for the reduced gas volume in the accommodating space 11 and preventing the pressure in the shell 10 from decreasing. When the external environment temperature increases, the temperature in the accommodating space 11 of the shell 10 increases, causing the gas to expand, and the expanded gas can enter the gas storage space 31 of the elastic gas storage member 30, preventing the pressure in the shell 10 from increasing. Therefore, the above structure can automatically balance the pressure in the shell 10, so that the shell 10 will not be deformed when the external environment temperature of the battery device changes, further improving the safety of the battery device.

[0044] First of all, it should be noted that the battery device of the present application can be a battery pack of a new energy vehicle, an energy storage device, or other devices that can store and release electrical energy.

[0045] like Figure 1 As shown, the housing 10 is used to accommodate the battery module 20 and protect the battery module 20. The housing 10 has an accommodating space 11 therein, and the accommodating space is used to accommodate the battery module 20.

[0046] In this embodiment, the housing 10 is rectangular in shape. Of course, those skilled in the art can adjust the specific shape of the housing 10 according to actual needs.

[0047] The battery module 20 is used to store and release electrical energy. The battery module 20 includes at least one battery cell, which includes a housing and a battery cell disposed in the housing. The housing of the battery cell may be cylindrical, square, blade-shaped, etc. The battery cell of the battery cell is formed by stacking or winding a positive electrode sheet, a separator, and a negative electrode sheet stacked in sequence.

[0048] Taking the battery pack of a new energy electric vehicle as an example, the battery module 20 includes a plurality of battery cells arranged in an array of multiple rows and columns, and the plurality of battery cells are bonded and bundled to form the battery module 20 .

[0049] like Figure 1As shown, the battery device further includes an elastic gas storage member 30, at least part of which is made of elastic material, so the elastic gas storage member 30 can expand or contract. The elastic gas storage member 30 has a gas storage space 31, and the gas storage space 31 is connected to the accommodating space 11 of the shell 10, so the inside of the elastic gas storage member 30 is connected to the inside of the shell 10.

[0050] Therefore, those skilled in the art can understand that the gas in the storage space 11 in the shell 10 can enter the gas storage space 31 of the elastic gas storage component 30, or the gas in the gas storage space 31 of the elastic gas storage component 30 can also enter the storage space 11 in the shell 10.

[0051] Therefore, when the external environment of the housing 10 increases, the temperature of the housing space 11 in the housing 10 increases, causing the gas in the housing space 11 to expand. At this time, the expanded gas enters the elastic gas storage member 30, thereby preventing the pressure in the housing 10 from increasing and causing the housing 10 to deform outward.

[0052] Correspondingly, when the external environment of the housing 10 decreases, the temperature of the housing space 11 in the housing 10 decreases, causing the gas in the housing space 11 to shrink. At this time, the gas in the elastic gas storage member 30 is replenished into the housing space 11, thereby preventing the pressure in the housing 10 from decreasing and causing the housing 10 to deform inward.

[0053] It can be seen that in the battery device of this embodiment, when the external environment of the shell 10 changes, the elastic air storage member 30 can automatically compensate for the pressure inside the shell 10, so that the pressure inside the shell 10 is always maintained in a stable state, preventing the shell 10 from convexing or concave.

[0054] In addition, the elastic air storage member 30 in this embodiment can automatically compensate for the pressure in the shell 10, without the need to set up additional pressure sensors, air pumps and other equipment, and without introducing electronic control components, and does not increase the cost and control difficulty of the battery device.

[0055] like Figure 2 As shown, in the technical solution of this embodiment, the minimum distance H1 between the battery module 20 and the shell 10 is smaller than the maximum concave deformation depth H2 of the shell 10 .

[0056] First, it should be noted that the above-mentioned "minimum distance H1 between the battery module 20 and the housing 10" refers to the minimum distance between the outer wall of the battery module 20 and the inner wall of the housing 10 among the surfaces where the battery module 20 as a whole does not contact the housing 10. That is, H1 does not include the case where the bottom surface of the battery module 20 is placed on the bottom surface of the housing 10.

[0057] As described above, the shell 10 may be concave when the external temperature decreases. Under extreme temperature differences (the upper and lower limits of the normal operating temperature of the battery device), the shell 10 has a maximum concave deformation depth H2.

[0058] In conventional battery pack designs, in order to prevent the metal inner wall from contacting the battery module's tabs after the shell is concave, a certain gap is usually created between the battery module and the inner wall of the shell, and the gap must be greater than H2, thereby ensuring the safety of the battery pack. However, this design undoubtedly wastes space in the shell and reduces the energy density of the battery pack.

[0059] In the technical solution of the present application, since an elastic gas storage member 30 is additionally provided on the battery device, even if the temperature outside the shell 10 drops, the gas contracted in the shell 10 can be replenished by the gas in the elastic gas storage member 30, that is, the shell 10 does not concave when the temperature drops, or only concave to a very small extent.

[0060] Therefore, in this embodiment, the minimum distance H1 between the battery module 20 and the housing 10 can be set to be smaller than the maximum concave deformation depth H2 of the housing 10. This improves the space utilization rate in the housing 10 of the battery device, that is, increases the energy density.

[0061] Optionally, the minimum distance H1 between the battery module 20 and the housing 10 is in the range of 10 mm to 25 mm.

[0062] Specifically, the minimum distance H1 between the battery module 20 and the housing 10 cannot be too small. If the value of H1 is too small, vibration or bumping may easily cause the housing 10 and the battery module 20 to come into contact with each other.

[0063] For example, H1 can be selected as 10mm, 12mm, 15mm, 20mm, 22mm or 25mm, etc., and any value between the two values.

[0064] Further preferably, the minimum distance H1 between the battery module 20 and the housing 10 is selected to be 18 mm.

[0065] It should be noted that the maximum concave deformation depth H2 of the housing 10 can be obtained through conventional experiments, which is described below with examples.

[0066] The maximum operating temperature of a battery device of a certain specification is 40°C, and the minimum operating temperature is -25°C. During the experiment, a battery device without an elastic gas storage member 30 is selected, and gas is first filled into the shell 10 in an environment of 40°C; then the battery device is transferred to an environment of -25°C; at this time, the temperature of the gas in the shell 10 drops rapidly, and the pressure in the shell 10 decreases rapidly, causing the outer surface of the shell 10 to be concave; at this time, the depth of each concave position is recorded; after multiple tests, the maximum value of multiple concave depths is taken as the maximum concave deformation depth H2 of the shell 10.

[0067] like Figure 3 As shown, in the technical solution of this embodiment, the housing 10 includes a bottom wall 12, an annular side wall 13 and a top wall 14. The top wall 14 is provided with a first through hole 16, and the elastic gas storage member 30 includes a gas nozzle 32, which is connected to the first through hole 16.

[0068] Specifically, the bottom wall 12 , the annular side wall 13 and the top wall 14 enclose a cubic structure, and the elastic air storage member 30 is placed on the top wall 14 , thereby making the overall structure of the battery device more compact.

[0069] Furthermore, the air nozzle 32 can be directly inserted into the first through hole 16, or the air nozzle 32 can be connected to the first through hole 16 through a pipeline, as long as the accommodating space 11 in the shell 10 and the air storage space 31 of the elastic air storage member 30 can be connected.

[0070] In some embodiments not shown, the first through hole 16 may also be provided on the bottom wall 12 of the housing 10 , or the first through hole 16 may also be provided on the annular side wall 13 of the housing 10 .

[0071] like Figure 1 and Figure 5 As shown, in the technical solution of this embodiment, there are multiple shells 10, the accommodating spaces 11 of the multiple shells 10 are all connected, and at least some of the shells 10 are provided with inflation holes 17.

[0072] Specifically, the battery module 20 is disposed in each housing 10, and the storage spaces 11 in the multiple housings 10 are connected, that is, the multiple storage spaces 11 in the housing 10 have the same pressure. At the same time, the storage space 31 of the elastic gas storage member 30 is connected to the storage space 11 of one of the housings 10, that is, the storage spaces 11 of the multiple housings 10 are connected to the storage space 31 of the elastic gas storage member 30.

[0073] During the initial inflation, dry inert gas (such as nitrogen) is filled into the shell 10 through the inflation hole 17. The inert gas can effectively prevent thermal runaway of the battery module 20 and can also effectively suppress fire of the battery module 20.

[0074] Those skilled in the art will appreciate that when the inert gas is charged through the charging hole 17 , the inert gas can be charged into the accommodating space 11 of each shell 10 , and charged into the elastic gas storage member 30 through the gas nozzle 32 .

[0075] In this embodiment, a charging hole 17 is provided on each housing 10. Of course, since the accommodating spaces 11 in each housing 10 are connected, the charging hole 17 may also be provided on some of the housings 10, or only on one housing 10.

[0076] Optionally, in this embodiment, an air filling hole 17 is provided on the annular side wall 13 of each housing 10 .

[0077] Furthermore, a plug or a one-way valve may be provided at the inflation hole 17 to prevent the inert gas from escaping from the inflation hole 17 after inflation.

[0078] In an embodiment not shown, there are multiple shells 10 and multiple elastic air storage members 30 , and the air storage spaces 31 of the multiple elastic air storage members 30 are connected to the accommodating spaces 11 of the multiple shells 10 in a one-to-one correspondence.

[0079] In this embodiment, the elastic air storage member 30 is further configured to be multiple, and each elastic air storage member 30 is connected to the storage space 11 in a corresponding shell 10. And the storage spaces 11 of the multiple shells 10 can be interconnected, or they can be independent of each other, that is, not interconnected. When the storage spaces 11 of the multiple shells 10 are independent of each other, each elastic air storage member 30 is only responsible for balancing the pressure of the storage space 11 in the corresponding shell 10. The advantage of this setting is that when the pressure in one shell 10 is abnormal (too large or too small), it does not affect the pressure conditions in other shells 10.

[0080] like Figure 4 As shown, in the technical solution of this embodiment, at least some of the multiple shells 10 are provided with a one-way vent valve 18. The one-way vent valve 18 is used to allow gas to flow from the inside of the shell 10 to the outside of the shell 10 in one direction.

[0081] Furthermore, the opening pressure of the one-way vent valve 18 is in the range of 5 KPa to 100 KPa.

[0082] Specifically, the one-way vent valve 18 has a certain opening pressure, that is, when the pressure of the accommodation space 11 in the shell 10 is less than the opening pressure, the one-way vent valve 18 is closed, and the gas in the accommodation space 11 cannot be discharged through the one-way vent valve 18. When the pressure of the accommodation space 11 in the shell 10 is greater than the opening pressure, the one-way vent valve 18 is opened, and the gas in the accommodation space 11 can be discharged through the one-way vent valve 18. The one-way vent valve 18 mainly has the following two functions.

[0083] The first function is that before the battery device leaves the factory, the shell 10 and the elastic gas storage member 30 need to be filled with inert gas through the inflation hole 17. Before inflation, there is air and water vapor in the shell 10 and the elastic gas storage member 30, so the air and water vapor need to be discharged. In the process of filling with inert gas, when the pressure in the shell 10 and the elastic gas storage member 30 is greater than the above-mentioned opening pressure, the original air and water vapor in the shell 10 and the elastic gas storage member 30 are discharged through the one-way vent valve 18 until the shell 10 and the elastic gas storage member 30 are filled with inert gas. Then turn off the inflation device, and when the pressure in the shell 10 and the elastic gas storage member 30 is less than the above-mentioned opening pressure, the one-way vent valve 18 is closed.

[0084] The second function is, as mentioned above, when the external environment temperature of the battery device rises, the gas in the housing space 11 in the shell 10 expands and enters the elastic gas storage member 30. If the external environment continues to rise, the pressure in the shell 10 will continue to increase. When the pressure in the shell 10 is greater than the above-mentioned opening pressure, the one-way vent valve 18 is opened to achieve exhaust and pressure relief, thereby preventing the pressure in the shell 10 from being too high and achieving pressure balance. When the pressure in the shell 10 after exhaust and pressure relief is less than the above-mentioned opening pressure, the one-way vent valve 18 is closed.

[0085] Therefore, the opening pressure of the one-way vent valve 18 should not be too small or too large. If the opening pressure of the one-way vent valve 18 is too small, the inert gas in the housing 10 will leak easily. If the opening pressure of the one-way vent valve 18 is too large, the one-way vent valve 18 will not be easy to open, which will easily cause the pressure in the housing 10 to be too high.

[0086] Furthermore, the opening pressure of the one-way vent valve 18 in this embodiment is set to be greater than the pressure in the accommodating space 11 in the shell 10 and the air storage space 31 in the elastic air storage member 30 after the elastic air storage member 30 is fully inflated, so as to prevent air leakage.

[0087] In this embodiment, the opening pressure of the one-way vent valve 18 can be 5 KPa, 10 KPa, 25 KPa, 50 KPa, 60 KPa, 75 KPa, 80 KPa or 100 KPa, etc., and any value between two values.

[0088] Further preferably, the opening pressure of the one-way vent valve 18 is 75 KPa.

[0089] Furthermore, if Figure 3 and Figure 4 As shown, the one-way vent valve 18 in this embodiment is also arranged on the annular side wall 13 of the housing 10, and the one-way vent valve 18 and the inflation hole 17 are located on two opposite wall surfaces of the annular side wall 13, that is, the two are arranged opposite to each other. This ensures that the inert gas can fully fill the accommodating space 11 of the housing 10 during inflation.

[0090] Furthermore, in this embodiment, a one-way vent valve 18 is provided on each housing 10. However, those skilled in the art will appreciate that, since the accommodation spaces 11 of the plurality of housings 10 are interconnected, the one-way vent valve 18 may be provided on only some of the housings 10, or only on one housing 10.

[0091] like Figure 5 As shown, in the technical solution of this embodiment, a plurality of shells 10 are stacked. In the shells 10 other than the uppermost shell 10, in two adjacent shells 10, the bottom wall 12 of the upper shell 10 serves as the top wall 14 of the lower shell 10, and a second through hole 19 is provided on the bottom wall 12 of the shell 10.

[0092] Specifically, the multiple housings 10 in this embodiment are stacked in a vertical direction, so that the overall arrangement of the battery device is compact. Of course, it is also a feasible implementation that the battery device includes only one housing 10.

[0093] Among the multiple shells 10 of this embodiment, the uppermost shell 10 has the above-mentioned bottom wall 12, annular side wall 13 and top wall 14. The remaining shells 10 only include the bottom wall 12 and the annular side wall 13, and no top wall 14 is provided, and the shape is generally a box structure with an upward opening.

[0094] Therefore, after the multiple shells 10 are stacked, in the two adjacent shells 10, the bottom wall 12 of the upper shell 10 also serves as the top wall 14 of the lower shell 10, thereby simplifying the structure of the shell 10 and making it easier to assemble. The weight of at least one layer of the plate is reduced between the adjacent shells 10, thereby reducing the overall weight of the battery device. At the same time, a second through hole 19 is provided on the bottom wall 12 of each shell 10, so that the accommodating spaces 11 between the multiple shells 10 are interconnected to form an integrated environment.

[0095] like Figure 5 As shown, in the technical solution of this embodiment, the second through hole 19 on the bottom wall 12 of the bottom shell 10 is provided with a plug 110, so as to ensure that the environment inside the multiple shells 10 is in a sealed state.

[0096] Of course, it is also a feasible embodiment not to provide the second through hole 19 on the bottom wall 12 of the lowermost shell 10 .

[0097] In some embodiments not shown, each shell 10 may also include a top wall 14. In this embodiment, after multiple shells 10 are stacked, the bottom walls 12 and top walls 14 of adjacent shells 10 abut against each other, and corresponding through holes are provided on the bottom walls 12 and top walls 14 of adjacent shells 10.

[0098] like Figure 8 and Fig. 9 As shown, in the technical solution of this embodiment, a sealing structure 40 is provided between adjacent shells 10 .

[0099] Specifically, since the accommodating spaces 11 between the multiple shells 10 are interconnected to form an integrated environment, it is necessary to ensure the airtightness of the overlapping and splicing positions of the multiple shells 10 to prevent the inert gas from leaking from the splicing positions.

[0100] from Fig. 9 It can be seen that the sealing structure 40 includes a sealing ring, one of the contact surfaces of the adjacent housings 10 is provided with a protrusion and the other is provided with a recess, and the sealing ring is sandwiched between the protrusion and the recess. The sealing ring is squeezed and deformed, thereby performing a good seal on the contact surface of the adjacent housing 10.

[0101] In the embodiment, in the contact surface of the adjacent shells 10, the upper shell 10 is provided with a protrusion, and the lower shell 10 is provided with a recess. The protrusion can be provided on the lower surface of the bottom wall 12 of the upper shell 10. The lower shell 10 can be provided with a recess on the upper edge of the annular side wall 13. For example, when the annular side wall 13 of the lower shell 10 has a certain thickness (such as a profile), the recess can be directly provided on the upper surface of the annular side wall 13. If the thickness of the annular side wall 13 of the lower shell 10 is thin, the upper end of the annular side wall 13 of the lower shell 10 can be folded inward to form a flange, and the recess can be provided on the upper surface of the flange.

[0102] When multiple shells 10 are all provided with top walls 14 as described above, in adjacent shells 10 , the lower surface of the bottom wall 12 of the upper shell 10 is provided with a protrusion, and the upper surface of the top wall 14 of the lower shell 10 is provided with a depression.

[0103] like Figures 1 to 4 As shown, in the technical solution of this embodiment, the elastic gas storage member 30 is arranged on the top wall 14, and the battery device also includes a cover body 50, which is arranged on the top wall 14 and covers the elastic gas storage member 30, and a vent hole 51 is arranged on the cover body 50.

[0104] Specifically, among the multiple stacked shells 10, the elastic gas storage member 30 is arranged on the top wall 14 of the uppermost shell 10. The cover body 50 is a box structure with a downward opening, and the edge of the cover body 50 is provided with a flange connected to the top wall 14 of the shell 10, and the cover body 50 plays a role in protecting the elastic gas storage member 30.

[0105] Furthermore, a vent hole 51 is provided on the cover body 50, and the vent hole 51 serves to balance the pressure of the space inside and outside the cover body 50, so that the outside of the elastic air storage component 30 is a normal pressure environment, that is, the influence of the pressure inside the cover body 50 on the volume of the elastic air storage component 30 is eliminated, and the volume change of the elastic air storage component 30 is only affected by the temperature change inside the shell 10.

[0106] Optionally, the vent hole 51 is provided on the side wall of the cover body 50, thereby reducing the probability of foreign matter dropped from the top or dripping rain water entering the cover body 50. At the same time, a filter screen can also be added to the vent hole 51 to further reduce the probability of foreign matter entering the cover body 50.

[0107] like Figure 1 As shown, in the technical solution of this embodiment, the elastic air storage member 30 includes an airbag. Optionally, the airbag is made of a soft rubber material, so that the airbag has good ductility.

[0108] The outer surface of the airbag can be a smooth surface or a foldable form with corrugations.

[0109] In addition, the elastic air storage member 30 may also be in other forms.

[0110] For example, the top wall 14 of the housing 10 can be directly set as an elastic mold, and the elastic mold forms the elastic gas storage member 30. After the housing 10 is filled with inert gas, the extra space enclosed by the arched elastic film forms the gas storage space 31.

[0111] For another example, the elastic gas storage member 30 may include a gas storage pipeline and a piston arranged in the gas storage pipeline, and the gas storage pipeline is provided with an elastic member that can apply an elastic force to the piston. After the shell 10 is filled with inert gas, the piston moves a certain distance and the elastic member is compressed. When the temperature in the shell 10 decreases, the pressure in the accommodating space 11 decreases, the pressure on the piston is less than the elastic force of the elastic member, and the piston moves toward the shell 10, releasing the gas in the gas storage pipeline into the shell 10. When the temperature in the shell 10 increases, the pressure in the accommodating space 11 increases, the pressure on the piston is greater than the elastic force of the elastic member, and the piston moves away from the shell 10, and the expanded gas is stored in the gas storage pipeline.

[0112] Further, in the technical solution of this embodiment, the volume of the elastic gas storage member 30 satisfies the following formula:

[0113] Formula 1: V0 ≥ m / ρ1-m / ρ2;

[0114] Among them, V0 is the volume of the elastic gas storage component 30, m is the mass of the gas in the accommodating space 11, ρ1 is the density of the gas in the accommodating space 11 when the battery device is in the first environment, ρ2 is the density of the gas in the accommodating space 11 when the battery device is in the second environment, wherein the temperature of the first environment is greater than the temperature of the second environment.

[0115] The unit of V0 is m 3 , the unit of m is kg, the unit of ρ1 and ρ2 is kg / m 3 .

[0116] Specifically, V0 is used to calculate the minimum volume of the elastic gas storage member 30. As shown above, when the battery device is moved from the first environment to the second environment, the temperature inside the shell 10 decreases, which will cause the density of the inert gas to increase, that is, ρ2 will be greater than ρ1. At this time, the gas in the accommodating space 11 in the shell 10 will shrink, and the shrinkage volume is m / ρ1-m / ρ2. The minimum volume of the elastic gas storage member 30 should be greater than the above-mentioned gas shrinkage volume to ensure that the gas volume in the elastic gas storage member 30 can make up for the reduction in the gas volume in the shell 10, thereby ensuring that the pressure in the shell 10 will not be reduced due to temperature reduction.

[0117] Furthermore, the gas mass in the containing space 11 in the above formula 1 is obtained by the following formula:

[0118] Formula 2: m = m1-m2;

[0119] Wherein, m is the mass of gas in the containing space 11, m1 is the initial filling mass of gas in the containing space 11, and m2 is the mass of gas discharged from the containing space 11 through the one-way vent valve 18 when the battery device is in a third environment. The temperature of the third environment is greater than the temperature of the first environment.

[0120] The units of m1 and m2 are both kg.

[0121] From the above description of the second function of the one-way vent valve 18, it can be known that when the battery device is moved from the first environment to the third environment, the gas in the accommodation space 11 may expand due to the temperature increase, and part of the gas will be exhausted and depressurized from the one-way vent valve 18. Then, when the battery device is moved back from the third environment to the first environment, the gas will shrink, resulting in the remaining gas mass being less than the initial gas filling mass in the shell 10. After the battery device is moved from the first environment to the second environment, the remaining gas in the shell 10 will shrink again, so this extreme case should be considered in the above formula 1. That is, the following environmental changes of the battery device should be considered: first environment - move to the third environment - move back to the first environment - move to the second environment.

[0122] After combining Formula 1 and Formula 2, a person skilled in the art can perform the following parameter calculations:

[0123] 1. If the volume of the elastic gas storage member 30 is determined, the initial maximum filling amount of the inert gas is calculated by formula 1 and formula 2;

[0124] 2. If the initial maximum charging amount of the inert gas is determined, the minimum volume of the elastic gas storage member 30 is calculated by formula 1 and formula 2.

[0125] In the above formulas 1 and 2, when the composition of the inert gas filled is clear, the gas density ρ1 and ρ2 at different temperatures can be obtained by looking up the table. The above m2 can be obtained through conventional experiments. For example, in the first environment, the housing 10 of the battery device is filled with an inert gas with a mass of m1, and then the battery device is moved to the third environment. A flow meter is installed at the one-way vent valve 18 to measure the value of m2. And the final value of m2 can be determined by taking the average value through multiple experiments.

[0126] Furthermore, the first environment in this embodiment refers to a normal temperature environment, for example, an environment of 25°C, the second environment refers to a low temperature environment, and is the lowest operating temperature environment that the battery device can withstand, for example, an environment of -20°C, and the third environment refers to a high temperature environment, and is the highest operating temperature environment that the battery device can withstand, for example, an environment of 40°C.

[0127] In addition, the first environment, the second environment, and the third environment may be in different geographical locations or in the same geographical location.

[0128] In addition, according to the specific structure and specifications of the battery device, those skilled in the art can adaptively adjust the specific temperatures under the first environment, the second environment, and the third environment.

[0129] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A battery device, characterized in that: include: A housing (10) having a receiving space (11); A battery module (20) is arranged in the accommodating space (11); The elastic gas storage member (30) has a gas storage space (31), wherein the gas storage space (31) is communicated with the accommodating space (11). The elastic gas storage member (30) is capable of expanding or contracting according to the temperature in the accommodating space (11) to balance the pressure in the accommodating space (11).

2. The battery device according to claim 1, characterized in that: The minimum distance (H1) between the battery module (20) and the shell (10) is smaller than the maximum inward deformation depth (H2) of the shell (10).

3. The battery device according to claim 1 or 2, characterized in that: The shell (10) comprises a bottom wall (12), an annular side wall (13) and a top wall (14); a first through hole (16) is provided on the bottom wall (12) or the annular side wall (13) or the top wall (14); the elastic air storage member (30) comprises an air nozzle (32); and the air nozzle (32) is connected to the first through hole (16).

4. The battery device according to claim 3, characterized in that: There are a plurality of shells (10), the accommodation spaces (11) of the plurality of shells (10) are all connected, and at least some of the shells (10) are provided with inflation holes (17).

5. The battery device according to claim 4, characterized in that: A one-way vent valve (18) is provided on at least part of the shell (10), and the one-way vent valve (18) is used to allow gas to flow in one direction from the inside of the shell (10) to the outside of the shell (10). Wherein, the opening pressure of the one-way vent valve (18) is in the range of 5 KPa to 100 KPa.

6. The battery device according to claim 4, characterized in that: A plurality of the shells (10) are stacked and arranged, and in the shells (10) other than the shell (10) on the top layer, in two adjacent shells (10), the bottom wall (12) of the upper shell (10) serves as the top wall (14) of the lower shell (10), and a second through hole (19) is provided on the bottom wall (12) of the shell (10).

7. The battery device according to claim 6, characterized in that: The second through hole (19) on the bottom wall (12) of the shell (10) at the bottom layer is provided with a plug (110).

8. The battery device according to claim 6, characterized in that: A sealing structure (40) is provided between adjacent shells (10).

9. The battery device according to claim 3, characterized in that: The elastic gas storage member (30) is arranged on the top wall (14), and the battery device further comprises a cover body (50), wherein the cover body (50) is arranged on the top wall (14) and covers the outside of the elastic gas storage member (30), and a vent hole (51) is arranged on the cover body (50).

10. The battery device according to claim 1, characterized in that: There are a plurality of shells (10), there are a plurality of elastic gas storage members (30), and the gas storage spaces (31) of the plurality of elastic gas storage members (30) are connected to the accommodating spaces (11) of the plurality of shells (10) in a one-to-one correspondence.

11. The battery device according to claim 1 or 2, characterized in that: The elastic air storage member (30) comprises an air bag.

12. The battery device according to claim 1 or 2, characterized in that: The volume of the elastic gas storage member (30) satisfies the following formula: Formula 1: V0 ≥ (m / ρ1) - (m / ρ2); Wherein, V0 is the volume of the elastic gas storage member (30), m is the mass of the gas in the accommodating space (11), ρ1 is the density of the gas in the accommodating space (11) when the battery device is in a first environment, and ρ2 is the density of the gas in the accommodating space (11) when the battery device is in a second environment, wherein the temperature of the first environment is greater than the temperature of the second environment.

13. The battery device according to claim 12, characterized in that: The shell (10) is provided with a one-way vent valve (18), and the one-way vent valve (18) is used to allow gas to flow in one direction from the inside of the shell (10) to the outside of the shell (10). The mass of gas in the accommodating space (11) is obtained by the following formula: Formula 2: m = m1-m2; wherein m is the mass of gas in the storage space (11), m1 is the initial mass of gas filled in the storage space (11), and m2 is the mass of gas discharged from the storage space (11) through the one-way vent valve (18) when the battery device is in a third environment, and the temperature of the third environment is greater than the temperature of the first environment.

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