Battery cell expansion self-adaptive structure and module thereof

Abstract

The utility model discloses a battery cell expansion self-adaptive structure and a module thereof. The battery cell expansion self-adaptive structure comprises a battery cell and an expansion absorption assembly, an expansion absorption assembly is arranged between the two battery cells, the expansion absorption assembly comprises a first buffer unit, a second buffer unit and a fire fighting unit, the first buffer unit comprises a first buffer plate and a second buffer plate, the first buffer plate and the second buffer plate are oppositely arranged, and a buffer mounting cavity is formed between the first buffer plate and the second buffer plate; buffer ribs are arranged at the ends of every two adjacent buffer mounting cavities, one side of each buffer rib is fixedly connected with one plate face of the first buffer plate, the other side of each buffer rib is fixedly connected with one plate face of the second buffer plate, the area of the cross section of each buffer rib is gradually reduced from the two sides to the middle, and the cross section of each buffer rib is a first cross section; the first cross section is parallel to the plate face of the first buffer plate, and the concave arc faces of the two buffer ribs are oppositely arranged to form a pressure reduction cavity. According to the utility model, the cycle service life and the safety performance of the battery cell are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy energy storage applications, and particularly relates to a core expansion adaptive structure and its module. Background Art

[0002] At present, with the rapid development of the energy storage industry, lithium battery chemical energy storage has gradually become the main energy storage method. And as the core component of energy storage, the battery module will expand due to the reaction of the positive and negative electrode plates inside the battery cell during charging and discharging. As the battery cycles, the expansion force of the battery cell gradually increases. Currently, the overall size of the module is generally limited in the market to fix the module, and the expansion force cannot be released. If the expansion force of the battery cell is too high, it will seriously affect the cycle service life and safety of the battery system. Therefore, a structure that can absorb the expansion force is needed to release the expansion force of the battery cell so that the battery cell is always in the best expansion force range. Summary of the Utility Model

[0003] The purpose of the utility model is to overcome the above technical deficiencies, and provide a core expansion adaptive structure and its module, so as to solve the technical problems of low safety and low life in the technical field of new energy energy storage applications due to the inability to release the expansion force in the battery module.

[0004] To achieve the above technical purpose, the technical solution of the utility model provides a core expansion adaptive structure and its module, including:

[0005] A battery cell and an expansion absorption component; the expansion absorption component is arranged between two battery cells; the expansion absorption component includes a first buffer unit, a second buffer unit and a fire protection unit; the first buffer unit includes a first buffer plate and a second buffer plate; the first buffer plate and the second buffer plate are arranged oppositely; a buffer installation cavity is formed between the first buffer plate and the second buffer plate; buffer ribs are arranged at the ends of two adjacent buffer installation cavities; one side of the buffer rib is fixedly connected to one plate surface of the first buffer plate; the other side of the buffer rib is fixedly connected to one plate surface of the second buffer plate; the cross-sectional area of the buffer rib gradually decreases from both sides to the middle, and the cross-section of the buffer rib is a first cross-section; the first cross-section is parallel to the plate surface of the first buffer plate, and the concave arc surfaces of the two buffer ribs are arranged oppositely to form a pressure reduction cavity.

[0006] Compared with the prior art, the beneficial effects of the utility model include:

[0007] 1. Long cycle service life: The core expansion adaptive structure and its module provided by the utility model are provided with an expansion absorption component, which gradually absorbs and releases the expansion force caused by the battery cell cycle, so that the battery cell always maintains the best stress environment and improves the cycle life of the battery system.

[0008] 2. High safety performance: The cell expansion self-adaptive structure and its module provided by the utility model gradually release the cell expansion force through the expansion absorption component, avoiding the explosion-proof valve of the cell from erupting due to excessive internal pressure of the cell, thereby improving the safety performance. At the same time, a fire protection unit is integrated in the buffer absorption component, which can absorb a large amount of heat when the cell undergoes thermal runaway, and release inert gas at the same time to isolate oxygen and improve the safety performance of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a three-dimensional structure schematic diagram of the cell expansion self-adaptive structure and its module provided by the utility model;

[0010] Figure 2 is a three-dimensional structure schematic diagram of the expansion absorption component in the cell expansion self-adaptive structure and its module provided by the utility model;

[0011] Figure 3 is a top view structure schematic diagram of the expansion absorption component provided by the utility model;

[0012] Figure 4 is a top view structure schematic diagram of the buffer rib provided by the utility model;

[0013] Figure 5 is a three-dimensional structure schematic diagram of the series-connected aluminum busbar provided by the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model, and are not used to limit the present utility model.

[0015] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used herein in the description of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0017] Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 , this embodiment provides a self - adapting structure for cell expansion and its module, including: cell 1, expansion absorption component 2, series aluminum row 3, end plate 4, insulating gasket 5, and steel strip 6.

[0018] Further, the expansion absorption component 2 is arranged between the two cells 1. The expansion absorption component 2 includes a first buffer unit 21, a second buffer unit 22, and a fire protection unit 23. The first buffer unit 21 includes a first buffer plate 211 and a second buffer plate 212. The first buffer plate 211 and the second buffer plate 212 are arranged oppositely. A buffer installation cavity 2a is formed between the first buffer plate 211 and the second buffer plate 212. Buffer ribs 213 are arranged at the ends of two adjacent buffer installation cavities 2a. One side of the buffer rib 213 is fixedly connected to one plate surface of the first buffer plate 211, and the other side of the buffer rib 213 is fixedly connected to one plate surface of the second buffer plate 212. The cross - sectional area of the buffer rib 213 gradually decreases from both sides to the middle, and the cross - section of the buffer rib 213 is the first cross - section 213a; the first cross - section 213a is parallel to the plate surface of the first buffer plate 211. The concave arc surfaces of the two buffer ribs 213 are arranged oppositely to form a decompression cavity 213b.

[0019] Specifically, as can be seen from the attached Figure 4 , the first cross - section 213a gradually shrinks from cross - section S1 to S5, that is, the cross - sectional area of the buffer rib 213 gradually decreases from both sides to the middle, that is, the cross - sectional area at S1 is greater than the cross - sectional area at S2, the cross - sectional area at S2 is greater than the cross - sectional area at S3, the cross - sectional area at S3 is greater than the cross - sectional area at S4, and the cross - sectional area at S4 is greater than the cross - sectional area at S5.

[0020] Preferably, the first buffer plate 211 and the second buffer plate 213 are set as plates to increase the contact area with the cell 1 and reduce the pressure generated by impact.

[0021] Specifically, since the cross - sectional area of the buffer rib 213 gradually decreases from both sides to the middle, a concave arc surface is formed at the middle end of the buffer rib 213. When the expansion force of the cell increases, the concave arc surface structure of the buffer rib 213 is bent under force to absorb the expansion force.

[0022] Further, the first buffer unit 21 is made of high - strength and high - temperature - resistant plastic, which has the characteristics of good insulation performance, high structural strength and toughness, and good high - temperature resistance. The second buffer unit 22 is made of high - rebound foam.

[0023] Preferably, the second buffer unit 22 is made of foamed silicone foam, CR foam, etc., and it has the following advantages: 1. Cushioning property: It has good elasticity and cushioning performance, and can be used to reduce vibration and absorb shock; 2. Temperature resistance: Foamed silicone foam can withstand a large temperature range, usually between -60°C and 250°C, and can reach a higher temperature in the short term; 3. Electrical insulation: It has good electrical insulation and is suitable for the insulation and cushioning of various electrical products; 4. Aging resistance: It has excellent anti-aging performance and can be used outdoors for a long time.

[0024] Specifically, in the initial state, the second buffer unit 22 is not stressed. However, as the expansion force generated by the battery cell 1 increases, the concave arc surface of the buffer rib 213 is stressed and deformed to absorb the expansion force. When the expansion force continues to increase, the concave arc surface of the buffer rib 213 is stressed and deformed to the limit. At this time, the second buffer unit 22 is gradually stressed and starts to absorb the expansion force of the battery cell.

[0025] Furthermore, two buffer ribs 213 with opposite concave arc surfaces are provided between adjacent second buffer units 22 and the fire protection unit 23.

[0026] Specifically, four fire protection units 23, two second buffer units 22 and six buffer ribs 213 are provided in the two buffer installation cavities 2a, and two adjacent buffer ribs 213 are arranged oppositely.

[0027] Furthermore, one side of the second buffer unit 22 abuts against the fire protection unit 23, and the other side of the second buffer unit 22 abuts against another fire protection unit 23. Several groups of fire protection units 23 and second fire protection units 22 are provided in the buffer installation cavity 2a.

[0028] Furthermore, two adjacent battery cells 1 are connected in series and laser welded through a series aluminum row 3 for overcurrent in series of the battery cells 1. The series aluminum row 3 is provided with a plurality of expansion absorption ribs 31, and the cross section of the expansion absorption rib 31 is concave arc-shaped. When the distance between two adjacent battery cells 1 increases due to the expansion force, the expansion absorption rib 31 is stressed and deformed, thereby reducing the stress on the weld scar and avoiding the risk of welding detachment.

[0029] Preferably, the material of the series aluminum row 3 is AL1060-O state, and it is laser welded to the battery cell 1.

[0030] Furthermore, it further includes a steel strip 6, an insulating gasket 5 and an end plate 4. The insulating gasket 5 is fixedly arranged at the corners of the battery cell 1 to protect the battery cell 1. A plurality of battery cells 1 are arranged side by side, and the end plates 4 are arranged at both ends thereof. A plurality of battery cells 1 and the end plates 4 are fixedly connected through the steel strip 6.

[0031] Specifically, the end plate 4 is made of die-cast aluminum alloy or extruded profile, and is used together with the steel strip 6 to limit a plurality of the battery cells 1. An insulating gasket 5 is placed between the end plate 4 and the battery cell 1 for insulation between the battery cell 1 and the end plate 4, thus forming the entire module.

[0032] Further, the fire protection unit 23 is of an airbag structure, which is a cavity for accommodating a flame retardant gas. Specifically, when thermal runaway occurs in the battery cell 1, the fire protection unit 23 decomposes upon heating, absorbs a large amount of heat, reduces the temperature of the battery cell, and releases an inert gas, such as a perfluoroketone capsule layer, which not only reduces the heat of the battery cell but also isolates oxygen, reduces the severity of thermal runaway of the battery cell 1, and improves the safety performance of the battery system.

[0033] Working principle: The battery cell expansion self-adaptive structure and its module provided by the utility model include a battery cell 1 and an expansion absorption assembly 2. The expansion absorption assembly 2 is arranged between two of the battery cells 1. The expansion absorption assembly 2 includes a first buffer unit 21, a second buffer unit 22, and a fire protection unit 23. The first buffer unit 21 includes a first buffer plate 211 and a second buffer plate 212. The first buffer plate 211 and the second buffer plate 212 are arranged oppositely. A buffer installation cavity 2a is formed between the first buffer plate 211 and the second buffer plate 212. Buffer ribs 213 are arranged at the ends of two adjacent buffer installation cavities 2a. One side of the buffer rib 213 is fixedly connected to one plate surface of the first buffer plate 211, and the other side of the buffer rib 213 is fixedly connected to one plate surface of the second buffer plate 212. The cross-sectional area of the buffer rib 213 gradually decreases from both sides to the middle, and the cross-section of the buffer rib 213 is a first cross-section 213a; the first cross-section 213a is parallel to the plate surface of the first buffer plate 211. The concave arc surfaces of two of the buffer ribs 213 are arranged oppositely to form a decompression cavity 213b.

[0034] Specifically, the expansion absorption assembly 2 is placed in the middle of the battery cells 1. Usually, the initial pressure between the battery cells 1 is 3000 - 5000N. As the battery cells 1 undergo charge and discharge cycles, the expansion force of the battery cells 1 gradually increases, and the expansion force absorption component deforms under stress, resulting in the structural deformation of the buffer rib 213 under stress. At the same time, as the middle spacing of the second buffer unit 22 decreases, it gradually bears force. When the expansion force of the battery cell 1 reaches the threshold of the buffer rib 213, the arc-shaped stress structure fails due to fracture. When the expansion force of the battery cell 1 is released to the initial pressure, the second buffer unit 22 is fully stressed. By means of gradually releasing the pressure, the expansion force generated by the battery cell 1 during charge and discharge is absorbed, enabling the battery to always be in the optimal pressure range, thereby extending the cycle life of the battery system.

[0035] The specific embodiments of the present utility model described above do not constitute a limitation on the protection scope of the present utility model. Any other corresponding changes and deformations made according to the technical concept of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims

1. A battery cell expansion adaptive structure and module thereof, characterized in that: include: Battery cell and expansion absorption component; the expansion absorption component is arranged between two battery cells; the expansion absorption component includes a first buffer unit, a second buffer unit and a fire fighting unit; the first buffer unit includes a first buffer plate and a second buffer plate; the first buffer plate and the second buffer plate are arranged relatively to each other; a buffer installation cavity is formed between the first buffer plate and the second buffer plate; buffer ribs are arranged at the ends of two adjacent buffer installation cavities; one side of the buffer rib is fixedly connected to a plate surface of the first buffer plate; the other side of the buffer rib is fixedly connected to a plate surface of the second buffer plate; the cross-sectional area of ​​the buffer rib gradually decreases from both sides to the middle, and the cross-sectional area of ​​the buffer rib is a first cross-sectional area; the first cross-sectional area is parallel to the plate surface of the first buffer plate, and the concave arc surfaces of the two buffer ribs are arranged relatively to form a decompression cavity.

2. The cell expansion adaptive structure and module thereof according to claim 1, characterized in that: The adjacent second buffer unit and the fire fighting unit are provided with the buffer ribs with two concave arc surfaces arranged opposite to each other.

3. The cell expansion adaptive structure and module thereof according to claim 2, characterized in that: One side of the second buffer unit abuts against the fire fighting unit; the other side of the second buffer unit abuts against another fire fighting unit; and the buffer installation cavity is provided with a plurality of groups of the fire fighting units and the second fire fighting unit.

4. The cell expansion adaptive structure and module thereof according to claim 3, characterized in that: Two adjacent battery cells are connected by laser welding through a series of aluminum bars; the series of aluminum bars are provided with a plurality of expansion absorbing ribs; the cross section of the expansion absorbing ribs is in a concave arc shape.

5. The cell expansion adaptive structure and module thereof according to claim 4, characterized in that: It also includes a steel belt, an insulating gasket and an end plate; the insulating gasket is fixedly arranged at the corners of the battery cell to protect the battery cell; a plurality of the battery cells are arranged side by side, and the end plates are arranged at both ends; the plurality of the battery cells and the end plates are fixedly connected by the steel belt.

6. The cell expansion adaptive structure and module thereof according to claim 5, characterized in that: The first buffer unit is made of high-strength and high-temperature resistant plastic; the second buffer unit is made of high-rebound performance foam.

7. The cell expansion adaptive structure and module thereof according to claim 6, characterized in that: The fire fighting unit is an air bag structure, which is a cavity for containing flame retardant gas.

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