A case and a battery
By setting a first functional layer and a porous second functional layer on the inside of the secondary battery casing, and inserting a wire between the two layers, the problem of insufficient cycle life and safety performance caused by the casing structure is solved, and the battery achieves high safety and long cycle life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SO-FUN TECH CORP LTD
- Filing Date
- 2025-05-26
- Publication Date
- 2026-06-30
AI Technical Summary
The cycle life and safety performance of existing secondary batteries cannot meet customer needs due to limitations in the structural composition of the casing.
Two functional layers are applied to the inside of the shell using a spraying process. The first functional layer is used to enhance resistance to deformation and adhesion, while the second functional layer has a porous structure for electrolyte absorption. A wire is placed between the two layers to construct a mechanical support system.
It improves the battery's mechanical protection, cycle life, and safety performance, prevents thermal runaway, and enhances its resistance to needle penetration.
Smart Images
Figure CN224437723U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of secondary battery technology, and in particular to a casing and a battery. Background Technology
[0002] Rechargeable batteries are batteries that can be recharged and reused repeatedly by an external power source. Unlike disposable primary batteries (such as dry cell batteries), their core advantages lie in their cycle life and environmental friendliness. Storage batteries, lithium-ion batteries, and sodium-ion batteries are all types of rechargeable batteries. Storage batteries, in particular, have a history of over a century. Their significant characteristics include excellent safety performance and the ability to be recharged, making a vital contribution to human civilization. However, their application is limited due to their low energy density and the presence of heavy metal pollution.
[0003] With the continuous innovation of secondary battery technology, secondary batteries such as lithium-ion batteries and sodium-ion batteries have developed rapidly, with lithium-ion batteries being the most prominent. However, the requirements for their cycle life and safety performance are becoming increasingly stringent, which is also the focus of public attention. However, the current technology of such batteries is limited by the structure of their casing, resulting in the current battery cycle life and safety performance still being lacking and unable to meet customer needs. Utility Model Content
[0004] Based on this, the purpose of this utility model is to overcome the shortcomings of existing secondary batteries in terms of cycle life and safety performance, which cannot meet customer needs, and to provide a casing and battery that have the advantages of improving battery cycle life and safety performance.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0006] A shell is provided, comprising a shell body for support; a first functional layer for enhancing deformation resistance and adhesion; and a second functional layer for electrolyte absorption, having a porous structure; the first functional layer and the second functional layer are both located inside the shell body and are arranged sequentially.
[0007] The casing of this invention provides overall support, and its interior primarily houses lithium-ion or sodium-ion bare battery cells. Preferably, the casing is made of steel or aluminum, giving it good hardness and resistance to deformation. The first functional layer, formed using a spray coating process, is applied to the inner surface of the casing. This effectively prevents deformation of the casing, avoids the generation of metal particles during manufacturing, enhances its mechanical properties, and improves safety. It also effectively increases the bonding strength between the casing and the second functional layer. The second functional layer, also formed using a spray coating process, is applied to the inner surface of the first functional layer. The first functional layer is located between the casing and the second functional layer. The porous structure of the second functional layer can store electrolyte, facilitating electrolyte absorption and effectively preventing the loss of free electrolyte during vacuum sealing. The electrolyte absorbed by the second functional layer provides support for later stages of cycling, complementing its hydrophilic properties to ensure a long-term electrolyte supply, thereby improving the battery's cycle performance. This invention avoids direct contact between the casing and the bare battery cell when the casing is subjected to external impact, by sequentially spraying two functional layers onto the casing body. The functional layers can effectively buffer and reduce external impact, thereby improving the mechanical protection of the battery.
[0008] Compared to existing technologies that use adhesive bonding, the first and second functional layers formed by spraying have a more uniform coating thickness, resulting in better product consistency. The non-contact spraying process effectively avoids direct contact between the spray nozzle and the shell surface, reducing contamination. Furthermore, the thickness of the functional layers can be flexibly adjusted, with precise control from micrometers to millimeters, leading to superior product performance.
[0009] Furthermore, a wire is inserted between the first functional layer and the second functional layer. The functional layer and the wire together form a mechanical support system. During needle penetration, energy is absorbed through the plastic deformation of the functional layer, preventing thermal runaway and improving the needle penetration resistance of the battery product.
[0010] Furthermore, there are two wires, located on opposite sides of the first functional layer. One end of each wire is embedded between the first and second functional layers, while the other end protrudes from both layers. The wire's embedded position between the first and second functional layers facilitates ion conduction, while its connection to the positive and negative tabs of the bare battery cell enhances the battery's resistance to needle penetration.
[0011] Furthermore, the conductor is any one of copper wire, aluminum wire, nickel wire, or aluminum wire with an electroplated nickel surface. Conductors made of any of these materials all possess good conductivity.
[0012] Furthermore, the porous structure of the second functional layer has a pore size of 0.1 μm to 0.5 μm and a porosity of 30% to 60%. This configuration can improve the performance of electrolyte absorption and storage, and in combination with the hydrophilic properties, ensure a long-term electrolyte supply, thereby improving the cycle performance of the battery.
[0013] Furthermore, the material of the second functional layer is any one of polyethylene terephthalate, polyethylene oxide, lithium polyacrylate, sodium polyacrylate, polyurethane, polymethyl methacrylate, and polyacrylonitrile. All of these materials possess superior pore size and porosity, meeting the requirements.
[0014] Furthermore, the material of the first functional layer is any one of polyamide, polyamide-imide, polyvinylidene fluoride (PVDF), and carboxymethyl cellulose (CMC). These materials can function as both adhesives and possess good environmental resistance.
[0015] Furthermore, the thickness of the first functional layer is 0.5 μm to 50 μm, and / or the thickness of the second functional layer is 0.5 μm to 50 μm. By controlling the thickness of the first functional layer and / or the second functional layer, the shell of this invention can have better performance.
[0016] Furthermore, the first functional layer is a first coating structure sprayed onto the inner surface of the shell body, and the second functional layer is a second coating structure sprayed onto the surface of the first functional layer. Specifically, the second functional layer is sprayed onto the surface of the first functional layer by heating to a molten state. Compared with the existing technology that uses adhesive bonding, this forming method can make the coating thickness more uniform and the product consistency better; the spraying process is non-contact, effectively avoiding direct contact with the workpiece surface and effectively reducing problems such as workpiece contamination; the thickness of the functional layer can be flexibly adjusted, and its coating thickness can be precisely controlled from the micrometer level to the millimeter level, so the product performance obtained by the spraying process is better. The first functional layer has the following characteristics: 1) Adhesion strength > 5MPa, preventing coating peeling; 2) Electrolyte contact angle < 30°, which is beneficial to improving its wettability; 3) Ionic conductivity > 1×10 -4 S / cm is beneficial for promoting ion transport.
[0017] This invention also provides a battery, comprising a casing as described above and a bare cell encapsulated with electrolyte, the bare cell being installed within the casing. The battery of this invention has the advantages of longer cycle life and higher safety performance.
[0018] Furthermore, the wires are connected to the positive and negative tabs of the bare battery cell, respectively. The stacked / wound bare battery cell is placed in a housing containing a functional layer, and then the wires are connected to the positive and negative tabs. After welding, encapsulating, and baking the bare battery cell, a certain amount of electrolyte is injected. After settling and formation, a battery is obtained. Connecting the wires to the positive and negative tabs of the bare battery cell reduces the current density at the tabs and allows the wires and functional layer to jointly construct a mechanical support system, forming a composite reinforced structure. During needle penetration, the plastic deformation of the functional layer is transformed from disordered destruction into a controllable energy absorption process, thereby rapidly absorbing heat and preventing thermal runaway.
[0019] Compared with the prior art, the beneficial effects of this utility model are:
[0020] (1) By setting the first functional layer and using the spraying process to form it, the coating is applied to the inner surface of the shell body. On the one hand, it can effectively prevent the shell body from deforming, effectively avoid the generation of metal particles in the shell during the processing and manufacturing process, enhance its mechanical properties, and improve its safety performance; on the other hand, it can effectively increase the bonding strength between the shell and the second functional layer.
[0021] (2) By setting a second functional layer, it has a micron-level porous structure that can absorb and store electrolyte. Combined with its hydrophilic properties, it ensures a long-term supply of electrolyte for cycling, thereby improving the cycle performance of the battery.
[0022] (3) By inserting a wire between the first functional layer and the second functional layer, the functional layer and the wire together form a mechanical support system. When punctured, the energy is absorbed through the plastic deformation of the functional layer, which can prevent the battery from thermal runaway and improve its resistance to puncture. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the external structure of a shell;
[0024] Figure 2 This is a schematic diagram of the top cross-sectional structure of the shell;
[0025] Figure 3 This is a schematic diagram of the bare battery cell structure;
[0026] Figure 4 This is a schematic diagram of the structure of a battery after the top has been removed.
[0027] The markings in the diagram are explained as follows:
[0028] 1. Shell body; 2. First functional layer; 3. Second functional layer; 4. Wire; 5. Electrode; 101. Shell; 102. Bare cell. Detailed Implementation
[0029] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.
[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0031] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0032] Example 1
[0033] like Figures 1 to 2 The image shown is a first embodiment of a housing according to the present invention, comprising:
[0034] Shell body 1, used for support;
[0035] The first functional layer 2 is used to enhance resistance to deformation and adhesion.
[0036] The second functional layer 3 is used for electrolyte absorption and has a porous structure.
[0037] The first functional layer 2 and the second functional layer 3 are both located inside the shell body 1 and are arranged sequentially.
[0038] The shell body 1 of this invention provides support for the entire structure. The shell body 1 primarily houses lithium-ion or sodium-ion bare battery cells. Preferably, the shell body 1 is made of steel or aluminum, giving it good hardness and resistance to deformation. The first functional layer 2 is formed using a spray coating process and is applied to the inner surface of the shell body 1. This effectively prevents deformation of the shell body 1, avoids the generation of metal particles during manufacturing, enhances its mechanical properties, and improves safety. It also effectively increases the bonding strength between the shell body 1 and the second functional layer 3. The second functional layer 3 is also formed using a spray coating process and is applied to the inner surface of the first functional layer 2. The first functional layer 2 is located between the shell body 1 and the second functional layer 3. The porous structure of the second functional layer 3 can store electrolyte, facilitating electrolyte absorption and effectively preventing the loss of free electrolyte during vacuum sealing. The electrolyte absorbed by the second functional layer 3 provides support for later stages of cycling, complementing its hydrophilic properties to ensure a long-term electrolyte supply and thus improve the battery's cycle performance. This invention avoids the bare battery cell 102 from being directly contacted and damaged when the shell body 1 is subjected to external impact by spraying two functional layers sequentially on the shell body 1. The functional layers can effectively buffer and reduce external impact, thereby improving the mechanical protection of the battery.
[0039] The first functional layer 2 is a first coating structure sprayed onto the inner surface of the shell body 1, and the second functional layer 3 is a second coating structure sprayed onto the surface of the first functional layer 2. The second functional layer 3 is sprayed onto the surface of the first functional layer 2 by heating to a molten state. Compared with the existing technology that uses bonding to form the first functional layer 2 and the second functional layer 3, the spraying process results in a more uniform coating thickness, leading to better product consistency. The spraying process is non-contact, effectively avoiding direct contact with the workpiece surface and reducing contamination. Furthermore, the thickness of the functional layers can be flexibly adjusted, with precise control from micrometers to millimeters, resulting in better product performance. The first functional layer 2 has the following characteristics: 1) Bond strength > 5 MPa, preventing coating peeling; 2) Electrolyte contact angle < 30°, improving wettability; 3) Ionic conductivity > 1 × 10⁻⁶. -4 S / cm is beneficial for promoting ion transport.
[0040] In one embodiment of this invention, the porous structure of the second functional layer 3 has a pore size of 0.1 μm to 0.5 μm and a porosity of 30% to 60%. This configuration can improve the performance of absorbing and storing electrolyte, with an absorption rate of >150%, and further, combined with its hydrophilic properties, ensures a long-term electrolyte supply, thereby improving the cycle performance of the battery.
[0041] In one embodiment of this invention, the second functional layer 3 is made of any one of polyethylene terephthalate, polyethylene oxide, lithium polyacrylate, sodium polyacrylate, polyurethane, polymethyl methacrylate, and polyacrylonitrile. All of these materials possess superior pore size and porosity, meeting the requirements.
[0042] In one embodiment of this invention, the first functional layer 2 is made of any one of polyamide, polyamide-imide, polyvinylidene fluoride (PVDF), or carboxymethyl cellulose (CMC). These materials can function as both adhesives and possess good environmental resistance.
[0043] In one embodiment of this invention, the thickness of the first functional layer 2 is 0.5 μm to 50 μm, and / or the thickness of the second functional layer 3 is 0.5 μm to 50 μm. By controlling the thickness of the first functional layer 2 and / or the second functional layer 3, the housing 101 of this invention can have better performance.
[0044] Example 2
[0045] This embodiment is similar to Embodiment 1, except that a wire 4 is placed between the first functional layer 2 and the second functional layer 3. The functional layers and the wire 4 together form a mechanical support system. During needle puncture, energy is absorbed through the plastic deformation of the functional layers, preventing thermal runaway and improving the product's resistance to needle puncture.
[0046] In one embodiment of this utility model, there are two wires 4, located on opposite sides of the first functional layer 2. One end of each wire 4 is embedded between the first functional layer 2 and the second functional layer 3, while the other end protrudes from both layers. The embedded end of the wire 4 facilitates ion drainage, while the other end connects to the positive and negative tabs 5 of the bare battery cell 102, thereby enhancing the product's resistance to needle penetration.
[0047] In one embodiment of this utility model, the conductor 4 is any one of copper wire, aluminum wire, nickel wire, or aluminum wire with an electroplated nickel surface layer. Conductors 4 made of any of the above materials all have good conductivity.
[0048] Example 3
[0049] like Figures 3 to 4 The illustration shows an embodiment of a battery according to this invention, comprising a casing 101 as described above, and a bare battery cell 102 encapsulated with electrolyte, the bare battery cell 102 being installed inside the casing 101. The battery of this invention has the advantages of long cycle life and high safety performance.
[0050] Furthermore, the wires 4 are connected to the positive and negative tabs 5 of the bare cell 102, respectively. The stacked / wound bare cell 102 is placed in the housing 101 containing the functional layer, and then the wires 4 are connected to the positive and negative tabs 5, respectively. After the bare cell 102 is welded, packaged, baked, and then a certain amount of electrolyte is injected. After standing and formation, the battery is obtained. Connecting the wires 4 to the positive and negative tabs 5 of the bare cell 102 can reduce the current density at the tabs 5; it also allows the wires 4 and the functional layer to jointly construct a mechanical support system, forming a composite reinforced structure. During needle penetration, the plastic deformation of the functional layer is transformed from disordered destruction into a controllable energy absorption process, thereby rapidly absorbing heat and preventing thermal runaway.
[0051] Compared with the prior art, the beneficial effects of this utility model are:
[0052] (1) By setting the first functional layer 2 and using the spraying process to form it, it is sprayed on the inner surface of the shell body 1. On the one hand, it can effectively prevent the shell body 1 from deforming, effectively avoid the generation of metal particles in the shell 101 during the processing and manufacturing process, enhance its mechanical properties, and improve its safety performance; on the other hand, it can effectively increase the bonding strength between the shell body 1 and the second functional layer 3.
[0053] (2) By setting the second functional layer 3, it has a micron-level porous structure that can absorb and store electrolyte. Combined with the hydrophilic properties, it ensures the supply of electrolyte for long-term cycling, thereby improving the cycle performance of the battery.
[0054] (3) By inserting a wire 4 between the first functional layer 2 and the second functional layer 3, a mechanical support system is jointly constructed between the functional layer and the wire 4. When punctured, the energy is absorbed through the plastic deformation of the functional layer, which can prevent the battery from thermal runaway and improve its resistance to puncture.
[0055] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A housing, characterized in that, include Shell body (1), used for support; The first functional layer (2) is formed by spraying and sprayed on the inner surface of the shell body to enhance the deformation resistance and adhesion performance. The second functional layer (3) is used for electrolyte absorption and has a porous structure. The first functional layer (2) and the second functional layer (3) are both located inside the shell body (1) and are arranged sequentially; A wire (4) is placed between the first functional layer (2) and the second functional layer (3).
2. The housing according to claim 1, characterized in that, There are two wires (4), which are located on both sides of the first functional layer (2). One end of the wire (4) is embedded between the first functional layer (2) and the second functional layer (3), and the other end protrudes from the first functional layer (2) and the second functional layer (3).
3. The housing according to claim 1, characterized in that, The porous structure of the second functional layer (3) has a pore size of 0.1μm~0.5μm and a porosity of 30%~60%.
4. The housing according to claim 3, characterized in that, The material of the second functional layer (3) is any one of polyethylene terephthalate, polyethylene oxide, lithium polyacrylate, sodium polyacrylate, polyurethane, polymethyl methacrylate, and polyacrylonitrile.
5. The housing according to claim 1, characterized in that, The material of the first functional layer (2) is any one of polyamide, polyamide-imide, polyvinylidene fluoride, and carboxymethyl cellulose.
6. The housing according to any one of claims 1 to 5, characterized in that, The thickness of the first functional layer (2) is 0.5μm to 50μm, and / or the thickness of the second functional layer (3) is 0.5μm to 50μm.
7. The housing according to claim 1, characterized in that, The first functional layer (2) is a first coating structure sprayed on the inner surface of the shell body (1), and the second functional layer (3) is a second coating structure sprayed on the surface of the first functional layer (2).
8. A battery, characterized in that, It includes a housing (101) as described in claim 1 and a bare battery cell (102) encapsulated with electrolyte, wherein the bare battery cell (102) is installed inside the housing (101).
9. A battery, characterized in that, Includes a housing (101) as described in any one of claims 2 to 7, and a bare battery cell (102) encapsulated with electrolyte, wherein the bare battery cell (102) is installed inside the housing (101), and the wires (4) are respectively connected to the positive and negative tabs (5) of the bare battery cell (102).