Self-adjustable lithium ion battery and battery pack

Abstract

The utility model discloses a self-adjustable lithium ion battery and a battery pack, and relates to the technical field of lithium ion batteries. The lithium ion battery specifically comprises a lithium ion battery body, and a deformable core box capable of absorbing or releasing heat of a roll core is arranged at the center of the roll core of the lithium ion battery body. The utility model aims to avoid the hysteresis problem when the battery is adjusted, effectively control the internal pressure of the battery and avoid the thermal runaway phenomenon.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery technology, and in particular to a self-adjustable lithium-ion battery and battery pack. Background Technology

[0002] With the development of new energy technologies, lithium batteries, as a high-energy-density energy storage device, have been widely used in electric vehicles, consumer electronics, energy storage systems and other fields.

[0003] Lithium-ion batteries are mainly composed of components such as an anode, cathode, electrolyte, and separator. Lithium metal or lithium alloy serves as the anode material, and a non-aqueous electrolyte solution is used as the electrolyte, forming the core working principle of a lithium-ion battery. Lithium-ion battery systems have high energy density, meeting the demands of high power and long-term discharge, and are therefore widely used in electric vehicles and other energy storage devices.

[0004] However, lithium batteries have poor temperature adaptability, and their performance varies significantly under different ambient temperatures. Generally, lithium batteries operate within a temperature range of 5℃ to 40℃, with optimal performance occurring between 10℃ and 30℃. High-rate charging below 0℃ or charging / discharging above 60℃ can lead to instability in the internal chemical reactions, increasing internal pressure and potentially causing internal short circuits and serious safety issues such as thermal runaway. Furthermore, the stress on the battery's internal core, representing its expansion pressure, increases with the number of cycles, also contributing to thermal runaway and changes in cycle life. When thermal runaway occurs, a large amount of heat is released in a short time, with internal ejecta reaching temperatures of thousands of degrees Celsius, often accompanied by fire and explosion.

[0005] However, to meet users' ever-increasing demands for device battery life, engineers are continuously improving the energy density of lithium-ion batteries and reducing the space occupied by other components within the battery. This means that when facing battery safety issues, engineers can only install external temperature control devices to manage battery temperature through cooling or heating systems. However, external temperature control devices suffer from significant lag, failing to respond quickly to changes in the battery's internal temperature. For example, during rapid charging and discharging or when subjected to drastic changes in ambient temperature, the adjustment speed of the external device often cannot keep up with the rapid rise or fall of the battery's internal temperature. Furthermore, the external control device cannot regulate the internal expansion pressure, greatly shortening the battery's lifespan.

[0006] Therefore, how to avoid the lag problem in battery regulation, effectively control the internal pressure of the battery, and avoid thermal runaway has become an urgent technical problem to be solved. Utility Model Content

[0007] The main purpose of this invention is to provide a self-adjustable lithium-ion battery and battery pack, which aims to avoid the lag problem in battery adjustment, effectively control the internal temperature and pressure of the battery, avoid the risk of thermal runaway, and ensure battery life.

[0008] To achieve the above objectives, this utility model proposes a self-adjusting lithium-ion battery, comprising:

[0009] The lithium-ion battery body has a deformable core box at the center of the core, which can absorb or release heat from the core.

[0010] By incorporating a deformable core box at the center of the battery core, heat generation during battery operation can be effectively regulated, preventing performance degradation or safety hazards caused by excessively high or low temperatures. Simultaneously, the heat absorption and release functions of the deformable core box effectively extend battery life, preventing aging of internal materials or structural damage due to excessive temperature fluctuations, thereby improving battery cycle performance and safety.

[0011] In one embodiment of this application, the deformable core box is provided with at least one support bar that can support the deformable core box to improve the support strength of the deformable core box.

[0012] The addition of support strips enhances the structural strength of the deformable cell, enabling it to withstand greater external forces and internal pressures. This prevents deformation or damage to the deformable cell under high temperatures and high-rate discharge conditions, thus ensuring the stable operation of the battery's thermal regulation function. Simultaneously, the support strip design improves the durability of the deformable cell during long-term use, extending battery life and reducing battery failures caused by damage to the deformable cell.

[0013] In one embodiment of this application, the support bar is at least one of a straight line, an S-shape, or a broken line.

[0014] Linear support bars are simple linear structures, relatively long, and arranged in a straight line. They are evenly distributed on the inner wall of the deformable core box to provide balanced support. Linear support bars are suitable for deformable core boxes with relatively regular structures and relatively uniform stress. The linear support bars can be connected to the inner wall of the deformable core box through integral molding, welding, bonding, or embedding, ensuring a stable connection between the support bars and the deformable core box. This allows the support bars to effectively distribute pressure from both inside and outside, enhancing the mechanical strength of the deformable core box. Linear support bars have a simple structure and low manufacturing cost.

[0015] The S-shaped support strip is a curved structure composed of multiple curved segments, shaped like the letter "S". This shape allows the support strip to provide support while better adapting to the complex spatial layout inside the battery. The S-shaped support strip can form a relatively complex support network within the deformable cell, enhancing its stability in multiple directions. The S-shaped support strip can be connected to the inner wall of the deformable cell through integral molding, fasteners, or welding, ensuring it will not loosen or detach under thermal expansion and pressure changes. Due to the curved design of the S-shaped support strip, it effectively disperses forces from all directions, improving the deformable cell's resistance to pressure and deformation.

[0016] The polygonal support bar is formed by connecting multiple straight segments at angles. It retains the simplicity of a straight support bar while increasing its flexibility and adaptability through multiple angles. The polygonal support bar can provide better support in limited space while reducing the risk of damage caused by uneven pressure.

[0017] In one embodiment of this application, the top of the deformable core box is provided with at least one pressure relief port corresponding to the explosion-proof valve of the lithium-ion battery body.

[0018] By incorporating a pressure relief vent on the top of the deformable cell and using it in conjunction with an explosion-proof valve, the safety and stability of lithium-ion batteries are enhanced. The pressure relief vent design ensures that the deformable cell can release some pressure when the battery over-expands or the internal gas pressure becomes too high, reducing the risk of thermal runaway. The synergistic effect of the explosion-proof valve and the pressure relief vent ensures effective pressure regulation and release in the event of overheating or abnormal conditions, preventing safety incidents such as explosions or fires caused by pressure buildup.

[0019] In one embodiment of this application, the deformable core box is rectangular, and the side surface of the rectangular deformable core box is a rounded surface.

[0020] By optimizing the shape design of the deformable core box, the thermal management performance and structural stability of the battery are improved, thereby effectively enhancing its safety and reliability while ensuring battery performance.

[0021] In one embodiment of this application, the lithium-ion battery body includes:

[0022] An outer casing with a positive electrode and a negative electrode, wherein an electrolyte is disposed within the outer casing; and

[0023] A winding core is disposed within the outer casing. The positive electrode tab of the winding core is connected to the positive electrode post, and the negative electrode tab of the winding core is connected to the negative electrode post. By rationally arranging and connecting components such as the outer casing, positive and negative electrode posts, electrolyte, and winding core, high-efficiency operation and safety performance of the battery are achieved.

[0024] In one embodiment of this application, the outer casing is made of aluminum alloy. Aluminum alloy has a low density, which effectively reduces the overall weight of the battery. Furthermore, a dense oxide film easily forms on the surface of the aluminum alloy, effectively preventing corrosion of the battery casing by the external environment and extending the service life of the casing.

[0025] This application also discloses a battery pack comprising multiple self-regulating lithium-ion batteries connected in series and / or parallel as described in any of the above claims. Traditional battery packs rely on external temperature control devices, such as air cooling or liquid cooling systems, to maintain a safe battery temperature. However, these external devices are lag-dependent and cannot respond promptly to rapid changes in the battery's internal temperature, easily leading to excessive or uneven battery temperatures. By using a deformable core, the battery body can rapidly absorb or release heat while internal heat is generated, thereby achieving effective thermal management of the battery body and reducing overheating and cooling lag problems. Because the core can adaptively adjust the internal temperature and stress of the battery, complex external temperature control devices are no longer needed between the individual battery cells within the battery pack, reducing system complexity.

[0026] By employing the above technical solution, a deformable core box is installed at the center of the battery core, effectively regulating heat during battery operation. This prevents performance degradation or safety hazards caused by excessively high or low temperatures. Simultaneously, the deformable core box, utilizing its deformation function, effectively absorbs the expansion requirements of the core during charging and discharging, effectively balancing the internal stress of the cell during operation. Combined with the heat absorption and release functions of the deformable core box, this effectively extends battery life and prevents aging or structural damage to internal battery materials caused by excessive temperature and internal stress fluctuations, thereby improving battery cycle performance and safety. Attached Figure Description

[0027] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein:

[0028] Figure 1 This is a three-dimensional structural diagram of the first embodiment of the present utility model;

[0029] Figure 2 for Figure 1 Front sectional view;

[0030] Figure 3 for Figure 1 A bottom sectional view;

[0031] 10. Outer casing; 11. Positive terminal; 12. Negative terminal; 13. Explosion-proof valve; 14. Core; 20. Deformable core box; 21. Support bar; 22. Pressure relief port. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain this utility model and do not constitute a limitation on this utility model.

[0033] like Figures 1 to 3 As shown, in order to achieve the above objectives, this utility model proposes a self-adjusting lithium-ion battery, comprising:

[0034] The lithium-ion battery body has a deformable core box 20 at the center of the core 14 of the lithium-ion battery body, which can absorb or release heat from the core 14.

[0035] Specifically, the lithium-ion battery body includes key components such as electrodes, separators, and electrolytes, forming the basic functional unit of the battery. The outer casing of the lithium-ion battery body is made of metal materials, such as aluminum alloy or stainless steel, which protects the internal components. The outer casing of the lithium-ion battery body is a sealed design to prevent electrolyte leakage. The core 14 of the lithium-ion battery body is located inside the outer casing. The core 14 is formed by winding the positive and negative electrode materials through the separator, and the electrolyte fills the space between the positive and negative electrodes, providing an ion conduction channel.

[0036] The deformable core box 20 is located at the center of the wound core 14 of the lithium-ion battery body. Its function is to regulate the temperature of the lithium-ion battery by absorbing or releasing heat, and to balance the internal stress of the battery during operation. The deformable core box 20 contains a phase change material that undergoes a solid-liquid-gas three-state phase change. This effectively controls the temperature of the battery body during charging and discharging, especially during high-power discharge or charging, avoiding safety risks or performance degradation caused by excessive temperature. The deformable core box 20 is in contact with the wound core 14 in the battery body and absorbs or releases heat from the wound core 14 through its built-in heat exchange or heat conduction function. Simultaneously, the deformable core box can absorb the tension generated when the wound core 14 expands by deforming, thereby improving the safety of the wound core 14. It is conceivable that this deformation is elastic, thus giving the deformable core box 20 a long service life.

[0037] The working principle of the deformable core box 20 is as follows:

[0038] The suitable operating temperature of the core 14 is maintained by regulating the internal temperature of the deformable core box 20. In high-temperature environments, the deformable core box 20 absorbs excess heat through its built-in phase change material, reducing the battery temperature. In low-temperature environments, the deformable core box 20 uses thermally conductive materials to transfer external heat to the battery body, preventing performance degradation due to excessively low temperatures. The deformation function of the deformable core box balances the internal stress of the battery during operation. When fully charged, the core expands and compresses the deformable core box, reducing its volume and internal stress. When depleted, the core contracts, and the deformable core box rebounds, increasing its volume. This ensures the core remains within a balanced force range, preventing degradation of battery safety and cycle performance caused by changes in mechanical stress.

[0039] By employing the above technical solution, a deformable core box 20 is installed at the center of the core 14 in the battery body, which effectively regulates the heat during battery operation, thereby avoiding performance degradation or safety hazards caused by excessively high or low temperatures. Simultaneously, the deformable core box, utilizing its own deformation function, effectively absorbs the expansion requirements of the core during charging and discharging, effectively balancing the internal stress of the cell during operation. Combined with the heat absorption and release functions of the deformable core box 20, this effectively extends the battery's lifespan and prevents aging or structural damage to internal battery materials caused by excessive temperature and internal stress fluctuations, thereby improving the battery's cycle performance and safety.

[0040] In one embodiment of this application, the deformable core box 20 is provided with at least one support bar 21 that can support the deformable core box 20 to improve the support strength of the deformable core box 20.

[0041] Specifically, the support strip 21 is located inside the deformable core box 20, and its function is to enhance the supporting strength of the deformable core box 20, preventing deformation or damage to the deformable core box 20 under high temperature, external force, or battery expansion. The support strip 21 can be made of materials such as metal or high-strength plastic to ensure that it can provide sufficient supporting force during battery operation. The support strip 21 is fixedly connected to the inner wall of the deformable core box 20, forming a stable supporting structure inside the deformable core box 20. The support strip 21 can be a single support strip 21 or a combination of multiple support strips 21. The arrangement of the support strips 21 can be uniformly distributed or concentrated in certain areas as needed to ensure that the deformable core box 20 can maintain a stable shape under external pressure or temperature changes.

[0042] By adopting the above technical solution, the addition of the support strip 21 improves the support strength of the deformable core box 20, enabling it to withstand more external forces and internal pressures. Under high temperature and high-rate discharge conditions, it prevents the deformable core box 20 from deforming or breaking, thereby ensuring the stable operation of the battery's thermal regulation function. At the same time, the design of the support strip 21 enhances the durability of the deformable core box 20 during long-term use, extends the battery's lifespan, and reduces battery failure caused by damage to the deformable core box 20.

[0043] In one embodiment of this application, the support bar 21 is at least one of a straight line, an S-shape, or a broken line.

[0044] Specifically, the linear support strips 21 are simple linear structures with relatively long lengths, arranged in a straight line. They are evenly distributed on the inner wall of the deformable core box 20 to provide balanced support force. The linear support strips 21 are suitable for deformable core box 20 structures that are relatively regular and subject to relatively uniform stress. The linear support strips 21 can be connected to the inner wall of the deformable core box 20 through integral molding, welding, bonding, or embedding, ensuring a stable connection between the support strips 21 and the deformable core box 20. This allows the support strips 21 to effectively distribute pressure from both internal and external sources, enhancing the mechanical strength of the deformable core box 20. The linear support strips 21 have a simple structure and low manufacturing cost.

[0045] The S-shaped support strip 21 is a curved structure composed of multiple curved segments, shaped like the letter "S". This shape of the support strip 21 can provide support while better adapting to the complex spatial layout inside the battery. The S-shaped support strip 21 can form a relatively complex support network within the deformable core box 20, enhancing the stability of the deformable core box 20 in multiple directions. The S-shaped support strip 21 can be connected to the inner wall of the deformable core box 20 through integral molding, fasteners, or welding, ensuring that it will not loosen or fall off under thermal expansion and pressure changes. Due to the curved design of the S-shaped support strip 21, it can effectively disperse forces from all directions, improving the compressive and deformation resistance of the deformable core box 20.

[0046] The polygonal support bar 21 is formed by connecting multiple straight segments at angles. It retains the simplicity of the straight support bar 21 while increasing its flexibility and adaptability through multiple angles. The polygonal support bar 21 can provide better support within a limited space while reducing the risk of damage due to uneven pressure.

[0047] In one embodiment of this application, the bottom of the deformable core box 20 is provided with at least one pressure relief port 22 corresponding to the explosion-proof valve 13 of the lithium-ion battery body.

[0048] Specifically, the pressure relief port 22 is an opening structure provided at the top and / or bottom of the deformable core box 20, which allows the deformable core box 20 to automatically release pressure when the internal pressure of the battery reaches a certain threshold.

[0049] An explosion-proof valve 13 is installed on the top or side of the battery casing. The function of the explosion-proof valve 13 is to automatically open and release gas or pressure when gas accumulates inside the battery or the temperature becomes too high, preventing the battery from rupturing, exploding, or catching fire due to excessive expansion. The explosion-proof valve 13 is composed of high-temperature resistant materials and a sealing device, capable of withstanding the internal pressure of the battery and releasing it when a preset threshold is reached. The explosion-proof valve 13 corresponds to the pressure relief port 22 at the bottom of the deformable core box 20; their cooperation ensures that the pressure in the deformable core box 20 can be quickly released in the event of battery overheating or high pressure.

[0050] By employing the above technical solution, and by providing a pressure relief port 22 at the top and / or bottom of the deformable core box 20 in conjunction with the explosion-proof valve 13, the safety and stability of the lithium-ion battery are improved. The design of the pressure relief port 22 ensures that the deformable core box 20 can release some pressure when the battery over-expands or the internal gas pressure is too high, reducing the risk of thermal runaway. The synergistic effect of the explosion-proof valve 13 and the pressure relief port 22 ensures that the battery can receive effective pressure regulation and release in the event of overheating or abnormal conditions, preventing safety incidents such as explosions or fires caused by pressure accumulation.

[0051] In one embodiment of this application, the deformable core box 20 is rectangular, and the side surface of the rectangular deformable core box 20 is an arc surface.

[0052] Specifically, the deformable core box 20 adopts a rounded surface design on its side, which can effectively avoid the risk of lithium plating caused by the excessive curvature of the core 14.

[0053] By adopting the above technical solution and optimizing the shape design of the deformable core box 20, the thermal management performance and structural stability of the battery are improved, thereby effectively enhancing its safety and reliability while ensuring battery performance.

[0054] In one embodiment of this application, the lithium-ion battery body includes:

[0055] The outer casing 10 has a positive electrode post 11 and a negative electrode post 12, and the outer casing 10 contains an electrolyte; and

[0056] The core 14 is disposed inside the outer casing 10. The positive electrode tab of the core 14 is connected to the positive electrode post 11, and the negative electrode tab of the core 14 is connected to the negative electrode post 12.

[0057] Specifically, the outer casing 10 is the external enclosed structure of the lithium-ion battery body, made of a metallic material such as aluminum or stainless steel. The main function of the outer casing 10 is to provide physical protection, ensuring the safety and stability of the internal components and preventing damage to the battery's internal structure from the external environment. The outer casing 10 contains an electrolyte, the core chemical reaction medium of the lithium-ion battery. The electrolyte consists of an organic solvent and lithium salt, playing a role in charge transfer. The outer casing 10 also contains multiple separators to ensure that the positive and negative electrodes do not directly contact each other, thus preventing short circuits. On the top or side of the outer casing 10, there are positive electrode posts 11 and negative electrode posts 12 for connecting the battery to an external circuit. The positive electrode posts 11 and negative electrode posts 12 are made of highly conductive metallic materials (such as copper or aluminum) to ensure smooth current conduction during the battery's charging and discharging process.

[0058] The core 14 is composed of positive electrode material, negative electrode material, and a separator, all arranged in a coiled shape. Located within the outer casing 10, the core 14 serves as the active material portion of the battery. The positive electrode material is typically composed of lithium cobalt oxide, lithium iron phosphate, etc., while graphite is commonly used as the negative electrode material. The separator is a thin film between the positive and negative electrodes, its main function being to prevent direct contact between the positive and negative electrode materials, avoiding short circuits, and allowing lithium ions to pass freely. The positive electrode tab of the core 14 is connected to the positive electrode post 11, and the negative electrode tab is connected to the negative electrode post 12. The tabs are fixed to both ends of the core 14 by welding, providing external connection points for the positive and negative electrodes of the battery, ensuring smooth charging and discharging processes.

[0059] By adopting the above technical solution, the battery achieves high-efficiency operation and safety performance assurance through the reasonable layout and connection of components such as the outer casing 10, positive and negative electrode posts 12, electrolyte, and winding core 14.

[0060] In one embodiment of this application, the outer shell 10 is made of aluminum alloy.

[0061] By adopting the above technical solution, the aluminum alloy has a low density, which can effectively reduce the overall weight of the battery. At the same time, a dense oxide film can be easily formed on the surface of the aluminum alloy, which can effectively prevent the external environment from corroding the battery shell and extend the service life of the shell 10.

[0062] This application also discloses a battery pack comprising a plurality of self-adjusting lithium-ion batteries as described in any of the above, connected in series and / or in parallel.

[0063] Specifically, a battery pack, by incorporating self-regulating lithium-ion batteries, achieves efficient thermal management and internal stress regulation, thereby solving the problems of temperature regulation lag and complex structure existing in traditional battery packs. This battery pack includes multiple self-regulating lithium-ion batteries connected in series and / or parallel. A deformable core box 20, capable of absorbing or releasing heat from the core, is located at the center of the core of the lithium-ion battery body. The deformable core box 20, through a phase change material, can automatically regulate the temperature according to changes in the internal temperature of the battery, thereby effectively controlling the heat distribution of the battery body and maintaining the battery within its optimal operating temperature range.

[0064] Using the above technical solutions, traditional battery packs rely on external temperature regulation devices, such as air cooling or liquid cooling systems, to maintain a safe battery temperature. However, these external devices are lagging and cannot respond promptly to rapid changes in the battery's internal temperature, easily leading to excessive or uneven battery temperatures. By using a deformable core box 20, the battery body can rapidly absorb or release heat while generating it internally, thereby achieving effective thermal management of the battery body and reducing overheating and cooling lag problems. Because the core box can adaptively adjust the internal temperature and stress of the battery, complex external temperature regulation devices are no longer needed between the individual battery cells within the battery pack, reducing system complexity.

[0065] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A self-adjustable lithium-ion battery, characterized in that, include: The lithium-ion battery body has a deformable core box at the center of the core that can absorb or release heat from the core. The deformable core box is provided with at least one support bar that can support the deformable core box and improve the support strength of the deformable core box; The top of the deformable core box is provided with at least one pressure relief port corresponding to the explosion-proof valve of the lithium-ion battery body.

2. The self-adjustable lithium-ion battery as described in claim 1, characterized in that, The support bar is at least one of a straight line, an S-shape, or a broken line.

3. The self-adjustable lithium-ion battery as described in claim 1, characterized in that, The deformable core box is rectangular, and the sides of the rectangular deformable core box are arc surfaces.

4. The self-adjustable lithium-ion battery according to any one of claims 1 to 3, characterized in that, The lithium-ion battery body includes: An outer casing with a positive electrode and a negative electrode, wherein an electrolyte is disposed within the outer casing; and A core is disposed within the outer casing, with the positive electrode tab of the core connected to the positive electrode post and the negative electrode tab of the core connected to the negative electrode post.

5. The self-adjustable lithium-ion battery as described in claim 4, characterized in that, The outer shell is made of aluminum alloy.

6. A battery pack, characterized in that, Includes multiple self-adjustable lithium-ion batteries as described in any one of claims 1 to 5, connected in series and / or in parallel.

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