Battery case and square battery

Abstract

This application provides a battery casing and a square battery, comprising: a first casing; a second casing disposed within the first casing, forming a cavity between the second casing and the first casing capable of containing electrolyte, the second casing having a through hole; and a pressure-sensitive sheet inserted into the through hole to close the through hole, the pressure-sensitive sheet being capable of deforming in response to pressure within the first casing to open the through hole. The battery casing provided by this application can prevent electrolyte overflow during the electrolyte filling process, reduce material waste, shorten the soaking time during the electrolyte filling process, and improve electrolyte filling efficiency.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery casing and a square battery. Background Technology

[0002] Due to the rapid development of the energy storage field, the current market demand for the capacity of energy storage systems and batteries is increasing. For large-capacity cells, as the size increases, the amount of electrolyte injected also increases. In order to ensure that there is still a sufficient amount of electrolyte inside the cell in the later stages of the cycle, the existing electrolyte injection process injects an excessive amount of electrolyte. During the injection process, because the electrolyte is difficult to be absorbed by the core within a limited time, a large amount of electrolyte cannot penetrate into the core or electrode in time, which will cause electrolyte overflow and waste. Furthermore, the excessive electrolyte will increase the standing and soaking time during the injection process, prolong the production line time, and reduce production efficiency. Utility Model Content

[0003] To overcome the shortcomings of the prior art, this utility model provides a battery casing and a square battery, which can avoid leakage during the liquid injection process, reduce material waste, shorten the standing soaking time during the liquid injection process, and improve the liquid injection efficiency.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] The first aspect of this utility model discloses a battery casing, comprising:

[0006] First shell;

[0007] The second housing is disposed inside the first housing, and a cavity capable of containing electrolyte is formed between the second housing and the first housing. The second housing is provided with a through hole.

[0008] A pressure-sensitive sheet is inserted into the through hole to close the through hole. The pressure-sensitive sheet can deform in response to pressure in the first housing to open the through hole.

[0009] The battery casing provided in this application, by providing a cavity between the first and second casings, allows for the storage of a fixed amount of electrolyte within the cavity before cell assembly. This ensures sufficient electrolyte for later stages of cycling, allowing for a reduction in the amount of electrolyte injected during the primary and secondary electrolyte injection processes. This avoids overflow caused by insufficient electrolyte to wet the cells in time, reducing electrolyte waste and shortening the soaking time during injection, thus improving injection efficiency. Furthermore, because the through-hole is sealed by a pressure-sensitive sheet, pressure is generated inside the battery during cycling. When the pressure reaches a preset value, the pressure-sensitive sheet is deformed by the pressure, creating a gap between it and the second casing. Electrolyte flows into the second casing from the cavity through this gap, achieving automatic electrolyte replenishment during cycling and effectively increasing battery life.

[0010] Furthermore, the second housing is formed by a baffle connected to the bottom of the first housing, and the through hole is at least located on the baffle with a relatively large area. This structural design of the second housing avoids a space between its bottom and the bottom of the first housing, allowing the electrolyte in the cavity to completely enter the interior of the second housing, effectively reducing electrolyte waste. Placing the through hole on the baffle with a relatively large area significantly increases the rate at which the electrolyte enters the second housing, thereby improving the overall wetting efficiency of the battery cell.

[0011] Furthermore, the through-holes are multiple, and the bottom edge of at least one through-hole is at the same height as the bottom of the first housing. This allows the electrolyte in the cavity to completely enter the interior of the second housing, avoiding the problem of electrolyte accumulation or insufficient wetting caused by the through-hole being too high. Additionally, providing multiple through-holes increases the electrolyte flow rate, allowing the electrolyte to wet the battery cell more quickly.

[0012] Furthermore, the surface area of ​​each side of the second housing and the cross-sectional area of ​​the through hole satisfy the following relationship: 0.25S1≤S2≤0.5S1, where S1 is the area of ​​the side where the through hole is located, and S2 is the sum of the cross-sectional areas of all through holes on that side. By setting the ratio range between the total area of ​​the through holes and the surface area of ​​the second housing, it is possible to avoid a decrease in the strength of the second housing due to excessively large through hole areas, and to ensure that the electrolyte can enter the interior of the second housing efficiently and quickly.

[0013] Furthermore, the through hole is circular or polygonal.

[0014] Furthermore, the pressure-sensitive sheet is disposed between the first housing and the second housing, with one end of the pressure-sensitive sheet located inside the through hole and the other end connected to the first housing. This positioning of the pressure-sensitive sheet fully utilizes the internal space of the housing, avoiding the use of additional volume that could reduce battery density.

[0015] Furthermore, the height of the second housing is less than the height of the first housing. After the electrolyte is injected into the cavity, a sealing strip is provided between the first end of the second housing and the first housing. The sealing strip forms a seal on the cavity, effectively preventing electrolyte leakage and ensuring the sealing performance of the cavity.

[0016] Furthermore, a connecting strip is provided between the first housing and the second housing. The connecting strip enhances the stability of the connection between the first housing and the second housing, and improves the overall strength and durability of the battery housing.

[0017] Furthermore, the first housing has a first opening, and the second housing has a second opening. The first opening and the second opening are oriented in the same direction. The first opening is used to install the second housing inside the first housing, and the second opening is used to install the battery cell inside the second housing.

[0018] The second aspect of this utility model discloses a square battery, comprising the battery casing described in any one of the first aspects, and further comprising:

[0019] The battery cell is disposed within the second housing;

[0020] A cover plate, the cover plate including an electrode post and an injection hole, the cover plate being connected to a first housing and sealing the first opening.

[0021] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0022] 1. The battery casing provided in this application, by providing a cavity between the first casing and the second casing, can store a certain amount of electrolyte in the cavity before the battery cell is assembled, which can ensure the electrolyte demand in the later stages of the cycle. This allows the amount of electrolyte injected to be appropriately reduced in the primary and secondary electrolyte injection processes, thereby avoiding the overflow problem caused by a large amount of electrolyte not being able to wet the battery cell in time. This not only reduces electrolyte waste, but also reduces the standing and wetting time in the electrolyte injection process and improves the electrolyte injection efficiency.

[0023] 2. This application sets up a pressure-sensitive sheet to seal the through hole. During the cycle, pressure will be generated inside the battery. When the pressure reaches a preset value, the pressure-sensitive sheet will be squeezed and deformed by the pressure, creating a gap between it and the second shell. The electrolyte will flow from the cavity into the second shell through the gap, realizing automatic replenishment of electrolyte during the cycle, which can effectively increase the battery's service life.

[0024] To make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a structural diagram of a battery casing provided in an embodiment of this application;

[0027] Figure 2 This is a longitudinal sectional view of a battery casing provided in an embodiment of this application;

[0028] Figure 3 This is a top view of a battery casing provided in an embodiment of this application;

[0029] Figure 4 This is a cross-sectional view of a battery casing provided in an embodiment of this application;

[0030] Figure 5 This is a battery structure diagram provided in an embodiment of this application.

[0031] The reference numerals in the above figures are as follows: 1. First housing; 2. Second housing; 3. Cavity; 4. Through hole; 5. Pressure-sensitive sheet; 6. Baffle; 7. Connecting strip; 8. Cover plate. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In addition, the accompanying drawings of the present invention are only simple schematic illustrations and are not depictions based on actual dimensions, as stated in advance.

[0033] In this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "forward," "backward," "between," "nearer," and "farthest" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0035] Reference Figures 1-5 This application provides a battery housing, including a first housing 1, a second housing 2 disposed inside the first housing 1, and a pressure-sensitive sheet 5. A cavity 3 for containing electrolyte is formed between the second housing 2 and the first housing 1. The second housing 2 is provided with a through hole 4. The pressure-sensitive sheet 5 is inserted into the through hole 4 to close the through hole 4. When the internal pressure of the first housing 1 reaches a preset value, the pressure-sensitive sheet 5 responds to the pressure and has a gap with the second housing 2 to open the through hole 4.

[0036] With the above structure, the battery casing of this application embodiment can solve the problem of electrolyte overflow during the liquid injection process, reduce electrolyte waste, reduce the standing soaking time during the liquid injection process, improve liquid injection efficiency, and can automatically replenish electrolyte during the cycle, effectively increasing the battery's service life.

[0037] Specifically, such as Figure 1 As shown, the first housing 1 has a first opening for containing the electrolyte in the second housing 2 and the cavity 3. The open end of the first opening can be connected to the cover plate 8. Optionally, the first housing 1 is made of a corrosion-resistant, high-strength metal material, such as stainless steel or aluminum alloy, to ensure the overall strength and corrosion resistance of the battery housing.

[0038] The second housing 2 has a second opening, which faces the same direction as the first opening. The second housing 2 is used to accommodate the battery cell and electrolyte. The volume of the second housing 2 is smaller than that of the first housing 1, thus forming a cavity 3 between the second housing 2 and the first housing 1. The height of the second housing 2 is less than the height of the first housing 1. After electrolyte is injected into the cavity 3, a sealing strip is provided between the first end of the second housing 2 and the first housing 1 to seal the cavity 3. Optionally, the sealing strip is made of a corrosion-resistant material, such as fluororubber. The first end of the second housing 2 is its open end.

[0039] Optionally, the second housing 2 may be made of a corrosion-resistant, high-strength metal material, such as stainless steel or aluminum alloy, to ensure the overall performance of the battery housing.

[0040] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, in this embodiment, the second housing 2 is formed by four baffles 6 connected to the bottom of the first housing 1, and the through hole 4 is provided on the baffle 6 with a relatively larger area among the four baffles.

[0041] In this embodiment, a connecting strip 7 is provided between the first housing 1 and the second housing 2. The connecting strip 7 is used to strengthen the connection between the first housing 1 and the second housing 2, and improve the overall stability of the battery housing. The size and shape of the connecting strip 7 can be flexibly set. The connecting strip 7 can be evenly distributed or non-uniformly distributed. For example, the connecting strip 7 is set along the height direction of the first housing 1 and the second housing 2, dividing the cavity 3 into multiple independent small cavities. Optionally, the connecting strip 7 is made of a corrosion-resistant, high-strength metal material.

[0042] The through holes 4 are multiple, and the multiple through holes 4 can be evenly or non-uniformly distributed on one or more baffles 6. The bottom edge of at least one through hole 4 is at the same height as the bottom of the first housing 1, so that the electrolyte in the cavity 3 can flow completely into the interior of the second housing 2, thereby maximizing the utilization rate of the electrolyte, reducing material waste, and lowering production costs.

[0043] The shape and size of the through hole 4 can be flexibly set according to actual needs. Optionally, the through hole 4 can be circular or polygonal. Circular through holes have a simple structure and are easy to process, while polygonal through holes can increase the structural strength of the through hole 4 while ensuring the flow of electrolyte, and prevent the through hole 4 from deforming or breaking due to electrolyte pressure.

[0044] Optionally, the diameter of the circular through hole 4 is 5 to 15 mm, which can ensure the smooth flow of electrolyte and maintain the structural stability of the through hole.

[0045] The relationship between the sum of the cross-sectional areas of the through holes 4 on one side of the second housing 2 and the area of ​​that side is: 0.25S1≤S2≤0.5S1, where S1 is the area of ​​one side of the second housing 2 where the through hole 4 is located, and S2 is the sum of the cross-sectional areas of multiple through holes 4 on that side.

[0046] The pressure-sensitive sheet 5 is made of pressure-sensitive material. Optionally, the pressure-sensitive sheet 5 is formed by casting the pressure-sensitive material. The pressure-sensitive material can be cast in a mold and then inserted into the through hole 4, or it can be directly cast into the through hole 4. The material and thickness of the pressure-sensitive sheet 5 can be adjusted according to actual needs to ensure that when the internal pressure of the battery reaches a preset value, for example, when the internal expansion force of the cell reaches 3000N, the pressure-sensitive sheet 5 will deform, creating a gap between itself and the second housing 2, thus opening the through hole 4. The electrolyte in the cavity 3 can then enter the second housing 2 through this gap, achieving automatic electrolyte replenishment. In one embodiment, the pressure-sensitive sheet 5 is inserted into the through hole 4, and its shape and size are exactly the same as those of the through hole 4.

[0047] like Figure 1 , Figure 2 and Figure 3 As shown, in this embodiment, the pressure-sensitive sheet 5 is disposed between the first housing 1 and the second housing 2. One end of the pressure-sensitive sheet 5 is inserted into the through hole 4, and the other end is connected to the first housing 1, thereby effectively preventing electrolyte leakage from the through hole 4. The connection between the pressure-sensitive sheet 5 and the first housing 1 can be a direct connection or an indirect connection, such as welding or contact with the first housing 1, etc., which is not limited in this application.

[0048] like Figure 5 As shown in the figure, this application embodiment also provides a square battery, which includes the battery casing described in the above embodiment, and also includes a cell disposed in the second casing 2 and a cover plate 8 connected to the first casing 1. The cover plate 8 includes an electrode post and an injection hole, and the cover plate 8 can close the first opening and the second opening.

[0049] This utility model uses specific embodiments to illustrate the principle and implementation of the utility model. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the utility model. Therefore, the content of this specification should not be construed as a limitation of the utility model.

Claims

1. A battery case characterized by comprising: include: First shell; The second housing is disposed inside the first housing, and a cavity capable of containing electrolyte is formed between the second housing and the first housing. The second housing is provided with a through hole. A pressure-sensitive sheet is inserted into the through hole to close the through hole. The pressure-sensitive sheet can deform in response to pressure in the first housing to open the through hole.

2. A battery case according to claim 1, wherein The second housing is formed by a baffle connected to the bottom of the first housing, and the through hole is provided on at least the baffle with a relatively large area.

3. The battery case of claim 1, wherein The through holes are multiple, and the bottom edge of at least one through hole is at the same height as the bottom of the first housing.

4. The battery case of claim 1, wherein The surface area of ​​each side of the second housing and the cross-sectional area of ​​the through hole satisfy the following condition: 0.25S1≤S2≤0.5S1, where S1 is the area of ​​the side where the through hole is located, and S2 is the sum of the cross-sectional areas of all through holes on that side.

5. The battery case of claim 1, wherein The through hole is circular or polygonal.

6. The battery case of claim 1, wherein The pressure-sensitive sheet is disposed between the first housing and the second housing, with one end of the pressure-sensitive sheet disposed in the through hole and the other end connected to the first housing.

7. The battery case of claim 1, wherein The height of the second housing is less than that of the first housing. When electrolyte is injected into the cavity, a sealing strip is provided between the first end of the second housing and the first housing.

8. The battery case of claim 1, wherein A connecting strip is provided between the first housing and the second housing.

9. The battery case of claim 1, wherein The first housing has a first opening, and the second housing has a second opening.

10. A square battery, characterized by The battery casing includes the battery casing according to any one of claims 1 to 9, and further includes: The battery cell is disposed within the second housing; A cover plate, the cover plate including an electrode post and an injection hole, the cover plate being connected to a first housing and sealing the first opening.

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