Cell structure

Abstract

The utility model belongs to the technical field of batteries, and specifically relates to a battery cell structure, comprising a first battery cell unit and a second battery cell unit electrically connected to the first battery cell unit, wherein a safety component is spaced between the first battery cell unit and the second battery cell unit, and the safety component comprises an insulator and a heat absorption layer arranged on the insulator; the first battery cell unit and the second battery cell unit both have a first part and a second part connected to the first part; the volume of the first part is greater than the volume of the second part, and the heat absorption layer is in contact with at least the first part; this design can, on the one hand, reduce the large amount of heat released by the battery cell monomer when it is formed or short-circuited by external force, and avoid the long-term existence of such heat that may cause stratification and thermal runaway, and on the other hand, the thickness of the two sides of the battery cell monomer is inconsistent, and when the battery cell is impacted, the battery cells on both sides are avoided from being short-circuited at the same time.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and specifically relates to a battery core structure. Background Art

[0002] With the rapid development of consumer batteries, the requirements for battery performance are increasing. In order to improve the voltage and battery performance, the internal series battery technology is adopted to connect the single battery cells in series to achieve the goal. However, this technology also brings greater challenges to the safety of the battery pack. Therefore, it is crucial to develop a structure that can achieve internal series connection of batteries while ensuring excellent safety performance.

[0003] In the prior art, the design of the inner series battery cells generally adopts two symmetrical winding cores, which are placed on both sides of the isolation plate. However, when the individual battery cells undergo formation or are short-circuited by external force, a large amount of heat will be released, and long-term accumulation may lead to stratification and thermal runaway. In addition, the accumulation of excessive heat may cause the battery to overheat, catch fire or even explode. However, the above design method does not provide an effective solution to these problems.

[0004] Based on this, an improvement in the battery cell structure is urgently needed to solve the aforementioned technical defects. Utility Model Content

[0005] The utility model aims to provide a battery cell structure that can cope with the large amount of heat generated by the internally connected battery cells under the impact of external forces, effectively reduce the risk of thermal runaway, and improve the safety performance of the battery.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A battery cell structure includes a first battery cell unit and a second battery cell unit electrically connected to the first battery cell unit, wherein a safety member is provided between the first battery cell unit and the second battery cell unit, and the safety member includes an insulator and a heat absorption layer provided on the insulator;

[0008] The first battery cell unit and the second battery cell unit both have a first portion and a second portion connected to the first portion; the volume of the first portion is larger than the volume accommodated by the second portion, and the heat absorption layer at least contacts the first portion.

[0009] The battery cell structure proposed by the utility model has the following technical effects:

[0010] 1. By optimizing the distribution of battery cells, not only the heat problem generated by the battery cells under external force impact in the prior art is effectively solved, the safety performance of the battery is improved, but also the energy density of the battery is improved to a certain extent.

[0011] 2. By designing a heat-absorbing layer, the cell structure can effectively absorb and disperse heat when a short circuit occurs during the cell formation process or under the action of external force, reducing the risk of thermal runaway. At the same time, the design of the heat-absorbing layer can prevent heat from accumulating between cells for a long time, avoiding stratification and thermal runaway.

[0012] As an improvement to the battery cell structure of the utility model, the first battery cell unit and the second battery cell unit are both configured as a regular-shaped structure or an irregular-shaped structure, and the first battery cell unit and the second battery cell unit are symmetrically arranged along the safety member.

[0013] As an improvement to the battery core structure of the utility model, it is characterized in that: the first part and the second part are both configured as square structures.

[0014] As an improvement to the battery core structure of the utility model, the feature is that the thickness of the heat absorption layer is 2-5 mm.

[0015] As an improvement to the battery cell structure of the utility model, the insulator includes a first insulating part, a middle part and a second insulating part. The first insulating part is connected to the second insulating part through the middle part. The first insulating part and the second insulating part are arranged in parallel, and the heat absorption layer is arranged on the first insulating part and the second insulating part.

[0016] As an improvement to the battery core structure of the utility model, the feature is that the middle portion is perpendicular to the first insulating portion and the second insulating portion.

[0017] As an improvement to the battery core structure of the utility model, the middle part includes a first connecting part, a transition part and a second connecting part, the first connecting part is connected to the transition part, the first connecting part is also connected to the first insulating part, and the second connecting part is connected to the transition part.

[0018] As an improvement to the battery cell structure of the utility model, it also includes a shell structure, the shell structure includes a main body, and the shell structure has at least one accommodating cavity extending outward from the main body to store the gas generated during the formation process and to realize the heat dissipation of the battery cell unit;

[0019] The accommodating cavity is communicated with the cavity of the main body and is arranged close to one side of the first part of the first battery cell unit or the second battery cell unit.

[0020] As an improvement to the battery cell structure of the utility model, the number of the accommodating cavities is two, and the two accommodating cavities are respectively arranged close to one side of the first portion of the first battery cell unit and the second battery cell unit.

[0021] As an improvement to the battery core structure of the utility model, the heat absorption layer is composed of insulating material and heat absorption material of equal mass, wherein the insulating material is ceramic, polyethylene, polytetrafluoroethylene, silicone rubber or glass fiber; and / or the heat absorption material is a bicarbonate compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the battery structure in an embodiment of the utility model;

[0024] Figure 2 It is a cross-sectional view of the battery cell structure in an embodiment of the utility model;

[0025] Figure 3 This is a schematic diagram of an irregular battery cell structure in an embodiment of the utility model;

[0026] Figure 4 This is a schematic diagram of the insulator structure in an embodiment of the utility model;

[0027] Figure 5 It is a schematic diagram of the overall structure of the non-vertical transition portion and the battery cell in an embodiment of the utility model;

[0028] Figure 6 This is a schematic diagram of the housing structure in the embodiment of the utility model;

[0029] in:

[0030] 1- the first battery cell;

[0031] 11-Part 1;

[0032] 12-Part 2;

[0033] 2- the second battery cell;

[0034] 3- Safety part 3;

[0035] 31- insulator;

[0036] 311- first insulating portion;

[0037] 312-middle part;

[0038] 3121-first connection part;

[0039] 3122-Transition Department;

[0040] 3123- second connection part;

[0041] 313- second insulating portion;

[0042] 32- heat absorbing layer;

[0043] 4- Shell structure;

[0044] 41-Main body;

[0045] 42-accommodating chamber;

[0046] a-diaphragm;

[0047] b-cathode;

[0048] c-anode. DETAILED DESCRIPTION

[0049] In order to make the technical solution and advantages of the utility model clearer, the utility model and its beneficial effects will be further described in detail below in conjunction with specific implementation methods and drawings of the specification, but the implementation methods of the utility model are not limited thereto.

[0050] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and "fixed" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] When the internally connected battery cells are subjected to external forces, they are prone to serious internal damage. The main reasons are mechanical deformation of the battery cells, electrolyte leakage, damage or displacement of safety components, and internal heat dissipation problems of the battery. External forces are the main cause of mechanical deformation of the battery cells, resulting in short circuits between the positive and negative electrodes or safety components, and battery overheating.

[0052] The present invention will be further described in detail below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

[0053] Embodiment 1:

[0054] like Figure 1 As shown, the mass distribution of the first battery cell unit 1 and the second battery cell unit 2 is unbalanced. This is mainly due to the fact that in the existing battery cell structure design, a battery cell with a larger mass can not only increase the energy density of the battery, but also gradually alleviate the external force borne by the battery cell structure through dense electrode layers. Figure 2As shown, the figure shows a cross-sectional view of the cell structure. It can be seen that compared with the second part 12 of the first unit, the first part 11 is composed of more pole piece monomers, so the mass and volume are relatively large. Between the first cell unit 1 and the second cell unit 2, the diaphragm a is arranged in the outermost layer, and there is a certain gap between the diaphragm a and the cathode b and the anode closely attached thereto to alleviate the influence of external force. In addition, the negative pole piece composed of the diaphragm a and the cathode b and the anode pole piece composed of the diaphragm a and the anode are arranged in sequence in the first cell unit 1 and the second cell unit 2, and the arrangement is cyclic. This design enables us to clearly see that the first part 11 with a larger volume in a single cell unit contains more cathode b pole pieces and anode pole pieces. Under the action of external force, the larger side is relied on to buffer the external force, while protecting the side with higher energy density of the cell, reducing the risk of damage to the main parts of the cell. At the same time, in the above-mentioned cell structure, a safety component composed of an insulator 31 and a heat absorption layer 32 is provided. These safety components can effectively absorb and disperse the heat generated by the cell structure under the action of external force when the cell is impacted by external force, thereby reducing the risk of thermal runaway. The insulator 31 also has the function of isolating the current between the cells to prevent the occurrence of short circuits. In addition, the heat absorption layer 32 is in contact with at least the first part 11. This is because, under the premise of saving consumables, the thicker first part 11 is provided with a heat absorption layer 32 to absorb most of the heat generated by the cell under the action of external force (due to the limited number of battery electrodes in the second part 12). Therefore, this design saves consumables and ensures the performance of the cell.

[0055] Preferably, the first battery cell unit 1 and the second battery cell unit 2 are both configured as regular shaped structures or irregular shaped structures, and the first battery cell unit 1 and the second battery cell unit 2 are symmetrically arranged along the safety member. Regular shaped battery cells are conducive to improving the stability and consistency of the battery module, thereby ensuring the performance of the entire battery pack. Figure 3 As shown, the irregularly shaped battery cell unit can optimize the internal space utilization of the battery pack, improve the energy density of the battery, and thus extend the service life of the battery. Secondly, the first battery cell unit 1 and the second battery cell unit 2 are symmetrically arranged along the safety member. This design is conducive to balancing the internal pressure of the battery pack and reducing the risk of thermal runaway of the battery. At the same time, the symmetrically arranged battery cells can also improve the shock resistance of the battery pack and reduce the loss of the battery during transportation and use.

[0056] Preferably, the first part 11 and the second part 12 are both configured as a square body structure. Figure 2As described above, the conventional design of the pole piece inside the first battery cell unit 1 is a square body structure, and the first part 11 and the second part 12 are also designed as square bodies in order to better equip the internal structure and achieve a more accurate matching degree. In addition, the first part 11 and the second part 12 are both set as square body structures, and the volume of the first part 11 is larger than the volume of the second part 12. This design is to generate a heat difference when an external force is applied or during the battery cell formation process, so that the heat absorption layer 32 acts on the first part 11 with a larger volume, and while absorbing the heat generated in the battery cell structure, it also achieves the effect of saving consumables.

[0057] Embodiment 2:

[0058] like Figure 4 As shown, the thickness of the heat absorption layer 32 is 2-5 mm. Specifically, the thickness of the heat absorption layer 32 can be set to 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, etc.

[0059] For the thickness range currently described, these specific thickness values ​​can achieve heat dissipation for the first portion 11 and will not make the battery core structure very thick. Therefore, these thickness values ​​are reasonable choices.

[0060] Embodiment 3:

[0061] As shown in Figure 4, the insulator 31 includes a first insulating part 311, a middle part 312 and a second insulating part 313. The first insulating part 311 is connected to the second insulating part 313 through the middle part 312. The first insulating part 311 and the second insulating part 313 are arranged in parallel, and the heat absorption layer 32 is arranged on the first insulating part 311 and the second insulating part 313.

[0062] As shown in Figure 4, the above design allows the insulator 31 to form a step surface. This design can not only increase the nesting and support area between the battery cells, thereby improving the mechanical stability of the entire battery pack, but also reduce the displacement and deformation of the battery cells when subjected to external forces, thereby reducing the risk of damage to internal components. At the same time, the design of the step surface can increase the contact area between the battery cells, which is helpful for the conduction and dispersion of heat. Secondly, by setting up the step surface, the risk of direct contact and short circuit between the battery cells can be reduced. If there is no step surface, the contact area between the battery cells may be large, which may easily lead to a short circuit of the electrodes, causing overheating and safety accidents. At the same time, this step surface can be set to multiple, such as Figure 5 As shown, multiple step surfaces are formed by the insulator 31, and are fixedly connected to the first battery cell unit 1 and the second battery cell unit 2. On the one hand, the structural stability of the battery pack is enhanced, and on the other hand, the spacing between the batteries is increased, effectively reducing the risk of short circuit. This design can also improve the anti-seismic performance of the battery pack and reduce the possibility of damage under external impact. In addition, the design of multiple step surfaces not only improves the overall performance of the battery pack, but also helps to achieve efficient heat dissipation of the battery pack. In areas where more heat is generated, such as the surface of the battery cell, the heat can be quickly transferred to other batteries through the step surface, thereby reducing the local temperature and avoiding overheating. At the same time, this design helps to balance the performance of each battery cell in the battery pack and extend the service life of the battery pack. In a specific embodiment, the number and shape of the step surfaces can be flexibly adjusted according to the size, shape and performance requirements of the battery cell. For example, for a large-capacity battery pack, more step surfaces can be set to improve the mechanical stability of the battery pack; while for a small-capacity battery pack, the number of step surfaces can be appropriately reduced according to the layout and performance requirements of the battery cell.

[0063] Preferably, the middle part 312 is perpendicular to the first insulating part 311 and the second insulating part 313. The vertical arrangement can make the connection between the parts closer, thereby improving the overall performance. By making the middle part 312 perpendicular to the first insulating part 311 and the second insulating part 313, the connectivity between the two can be effectively enhanced.

[0064] Preferably, the middle part 312 includes a first connection part 3121, a transition part 3122 and a second connection part 3123, the first connection part 3121 is connected to the transition part, the first connection part 3121 is also connected to the first insulating part 311, and the second connection part 3123 is connected to the second insulating part 313. In a specific embodiment, the first connection part 3121 is made of PP material, the transition part 3122 is made of Al material, and the second connection part 3123 is also made of PP material. PP material has good heat resistance and corrosion resistance, is suitable for the connection part, and can withstand a certain high temperature. Al material is selected as the transition part 3122 for its lightness and strength, which can not only ensure the stability of the connection, but also avoid affecting the overall performance due to excessive weight. In addition, the second connection part 3123 is also made of PP material, which matches the material of the first connection part 3121, ensuring the firmness and stability of the connection.

[0065] Embodiment 4:

[0066] like Figure 6As shown, the battery cell structure also includes a shell structure 4, which includes a main body 41, and the shell structure 4 has at least a single accommodating cavity that expands outward from the main body 41 and stores the gas generated during the formation process and is used to achieve heat dissipation of the battery cell unit, which is connected to the cavity of the main body 41 and is arranged close to one side of the first part 11 of the first battery cell unit 1 or the second battery cell unit 2. Specifically, during the battery cell formation process, the internal temperature of the battery cell will rise rapidly due to the heat generated by the electrochemical reaction. At this time, the accommodating cavity in the shell structure 44 plays the role of storing gas and dissipating heat. The heat is transferred to the accommodating cavity through the cavity of the shell structure 4, and then transferred to the external environment through the gas in the accommodating cavity, thereby achieving heat dissipation of the battery cell unit.

[0067] In a specific embodiment, the shell structure 4 plays a role in protecting the battery cell. Specifically, the aluminum-plastic film or rubber film can be used as the main material of the battery shell structure 4 because of its good flexibility and wear resistance, which can effectively prevent the battery cell from being damaged by the external environment during the charging and discharging process. In addition, the corners of the shell structure 4 can also be designed to be rounded, which can not only improve the anti-extrusion and anti-impact capabilities of the battery cell, but also further reduce the risk of damage or rupture of the battery cell during use.

[0068] Preferably, the number of the accommodating cavities 42 is two, and the two accommodating cavities 42 are respectively arranged close to one side of the first portion 11 of the first battery cell unit 1 and the second battery cell unit 2. Since the thicker side of the battery cell (i.e., the first portion 11) generates more heat, the two accommodating cavities are respectively arranged close to one side of the first portion 11 of the first battery cell unit 1 and the second battery cell unit 2, so that the heat dissipation effect is more significant.

[0069] Embodiment 5:

[0070] like Figure 5 As shown, the heat absorption layer 32 is composed of insulating materials and heat absorption materials of equal mass, wherein the insulating material is ceramic, polyethylene, polytetrafluoroethylene, silicone rubber or glass fiber; and / or the heat absorption material is a bicarbonate compound. The main function of the insulating material is to prevent current leakage or short circuit, thereby protecting the equipment from damage and ensuring the normal operation of the system. Different insulating materials have different technical effects and characteristics, which determine their applicability in specific applications.

[0071] Ceramics are often used in high temperature, high voltage or highly corrosive environments, such as battery separators and insulating layers of electronic devices. In batteries, ceramic layers can prevent internal short circuits in the battery and reduce heat accumulation, thereby improving the safety and stability of the battery; polyethylene is widely used in the insulating layer of wires and cables, insulating materials for capacitors and transformers, etc. Due to its good processing performance and relatively low cost; polytetrafluoroethylene is often used in high temperature, high frequency and highly corrosive electrical insulation occasions, such as the insulating layer of wires and cables, packaging materials for electronic components, etc. In batteries, polytetrafluoroethylene can be used to improve the insulation performance and stability of batteries; silicone rubber is often used in the insulating layer of wires and cables, sealing and bonding of electronic components, etc. In batteries, silicone rubber can be used to improve the sealing and insulation performance of batteries and prevent internal short circuits and leakage of batteries; glass fiber is often used to enhance the insulation performance and mechanical strength of materials such as plastics and rubber. In batteries, glass fiber can be used to strengthen the separator and insulating layer of batteries and improve the structural strength and safety of batteries.

[0072] In specific implementations, different insulating materials have their own unique technical effects and advantages. Selecting appropriate insulating materials is crucial to ensuring the normal operation and safety of electrical systems. In specific applications, it is also necessary to select appropriate insulating materials based on actual working environments and performance requirements.

[0073] In addition, bicarbonate compounds in endothermic materials, such as sodium bicarbonate, can decompose quickly when heated to produce a large amount of carbon dioxide. This carbon dioxide can not only act as a diaphragm air to reduce the oxygen concentration inside the battery, thereby inhibiting the spread of fire, but the endothermic reaction during its release process can also effectively reduce the temperature of the battery, further slowing down the thermal runaway process of the battery.

[0074] In order to further improve the safety of the battery, a layer of thermal resistance material, such as graphite, thermal resistance glue, etc., can be introduced between the heat absorption layer 32 and the battery core. These thermal resistance materials can delay the heat transfer when the battery core generates heat, provide more reaction time for the heat absorption layer 32, and thus more effectively prevent the battery from catching fire or exploding.

[0075] In general, by adopting the heat absorption layer 32 structure design and combining the advantages of insulating materials and heat absorption materials, the safety of the battery can be effectively improved and the risk of battery fire or explosion can be reduced. At the same time, this design also has certain versatility and scalability, and can be applied to different types of batteries, providing a strong guarantee for the safe use of the battery.

Claims

1. A battery cell structure, characterized in that: The invention comprises a first battery cell unit (1) and a second battery cell unit (2) electrically connected to the first battery cell unit (1), wherein a safety member (3) is provided between the first battery cell unit (1) and the second battery cell unit (2), and the safety member (3) comprises an insulator (31) and a heat absorption layer (32) arranged on the insulator (31); The first battery cell unit (1) and the second battery cell unit (2) both have a first portion (11) and a second portion (12) connected to the first portion (11); the volume of the first portion (11) is greater than the volume of the second portion (12), and the heat absorption layer (32) is in contact with at least the first portion (11).

2. The battery cell structure according to claim 1, characterized in that: The first battery cell unit (1) and the second battery cell unit (2) are both arranged as a regular-shaped structure or an irregular-shaped structure, and the first battery cell unit (1) and the second battery cell unit (2) are symmetrically arranged along the safety component (3).

3. The battery cell structure according to claim 2, characterized in that: The first part (11) and the second part (12) are both configured as square structures.

4. The battery cell structure according to claim 1, characterized in that: The thickness of the heat absorption layer (32) is 2-5 mm.

5. The battery cell structure according to claim 1, characterized in that: The insulator (31) comprises a first insulating portion (311), an intermediate portion (312) and a second insulating portion (313); the first insulating portion (311) is connected to the second insulating portion (313) via the intermediate portion (312); the first insulating portion (311) and the second insulating portion (313) are arranged in parallel; and the heat absorption layer (32) is arranged on both the first insulating portion (311) and the second insulating portion (313).

6. The battery cell structure according to claim 5, characterized in that: The middle portion (312) is perpendicular to both the first insulating portion (311) and the second insulating portion (313).

7. The battery cell structure according to claim 5, characterized in that: The middle part (312) includes a first connecting part (3121), a transition part (3122) and a second connecting part (3123), wherein the first connecting part (3121) is connected to the transition part (3122), the first connecting part (3121) is also connected to the first insulating part (311), and the second connecting part (3123) is connected to the transition part (3122).

8. The battery cell structure according to claim 1, characterized in that: It also includes a shell structure (4), the shell structure including a main body (41), and at least one accommodating cavity (42) extending outward from the main body (41) for storing gas generated during the formation process and for achieving heat dissipation of the first battery cell unit (1); The accommodating cavity (42) is communicated with the cavity of the main body portion (41) and is arranged close to one side of the first portion (11) of the first battery cell unit (1) or the second battery cell unit (2).

9. The battery cell structure according to claim 8, characterized in that: The number of the accommodating cavities (42) is two, and the two accommodating cavities (42) are respectively arranged close to one side of the first portion (11) of the first battery cell unit (1) and the second battery cell unit (2).

10. The battery cell structure according to claim 1, characterized in that: The heat absorbing layer (32) is composed of insulating material and heat absorbing material of equal mass, wherein the insulating material is ceramic, polyethylene, polytetrafluoroethylene, silicone rubber or glass fiber; and / or the heat absorbing material is a bicarbonate compound.

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