A self-regulating lithium-ion battery and battery pack

Abstract

The present invention discloses a self-adjustable lithium-ion battery and battery pack, which relates to the technical field of lithium-ion batteries. Specifically, it comprises: a lithium-ion battery body, wherein a deformable core box capable of absorbing or releasing heat from the core is provided at the center of the core of the lithium-ion battery body. The purpose is to avoid the hysteresis problem when adjusting the battery, effectively control the internal pressure of the battery, and avoid thermal runaway.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion batteries, and in particular to a self-regulating lithium ion battery and a battery pack. Background Art

[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 batteries are mainly composed of components such as anode, cathode, electrolyte and diaphragm, among which lithium metal or lithium alloy is used as anode material and non-aqueous electrolyte solution is used as electrolyte, which constitutes the core working principle of lithium batteries. Lithium-ion battery systems have high energy density and can meet the needs of high power and long-term discharge, so they have been widely used in electric vehicles and other power storage devices.

[0004] However, lithium batteries have poor temperature adaptability, and their performance will change significantly under different ambient temperature conditions. In general, the operating temperature range of lithium batteries is between 5℃ and 40℃, and the battery performance is best in the temperature range of 10℃ to 30℃. If lithium batteries are charged at a high rate in an environment below 0℃, or charged and discharged in an environment above 60℃, it will cause instability in the chemical reaction inside the battery, increase the internal pressure of the battery, and even cause an internal short circuit in the battery, causing serious safety problems such as thermal runaway of the battery. At the same time, the stress of the internal core of the battery is the expansion internal pressure of the battery. As the number of cycles increases, the pressure continues to increase, which will also cause changes in the battery's thermal runaway safety and cycle life. When the battery has a thermal runaway or other safety issue, a large amount of heat is released in a short period of time, and the temperature of the internal eruption can reach thousands of degrees, and it is often accompanied by fire and explosion.

[0005] However, in order to meet users' growing demand for device endurance, technicians are still constantly improving the energy density of lithium-ion batteries and reducing the space occupied by other parts in the battery. This means that when faced with battery safety issues, technicians can only set a temperature control device on the outside of the battery to achieve temperature management of the battery through a cooling or heating system. However, the external temperature control device has obvious hysteresis problems and cannot respond quickly to changes in the internal temperature of the battery. For example, when the battery is rapidly charged and discharged or is subject to drastic changes in ambient temperature, the adjustment speed of the external device often cannot match the rapid increase or decrease in the internal temperature of the battery. At the same time, the external adjustment device cannot adjust the internal expansion pressure, which greatly shortens the service life of the battery.

[0006] Therefore, how to avoid the lag problem when adjusting the battery, effectively control the internal pressure of the battery, and avoid thermal runaway has become a technical problem that needs to be solved urgently. Summary of the invention

[0007] The main purpose of the present invention is to provide a self-regulating lithium-ion battery and battery pack, aiming to avoid the hysteresis problem when adjusting the battery, effectively control the internal temperature and pressure of the battery, avoid the risk of thermal runaway and ensure the battery life.

[0008] In order to achieve the above object, the present invention provides a self-regulating lithium-ion battery, comprising: A lithium-ion battery body, wherein a deformable core box capable of absorbing or releasing heat from the core is provided at the center of the core of the lithium-ion battery body.

[0009] By setting a deformable core box at the center of the battery body's winding core, the heat during the battery operation process can be effectively regulated, thereby avoiding battery performance degradation or safety hazards caused by excessively high or low temperatures. At the same time, the heat absorption and release function of the deformable core box can effectively extend the battery's service life, prevent aging of the battery's internal materials or structural damage caused by excessive temperature fluctuations, thereby improving the battery's cycle performance and safety.

[0010] In one embodiment of the present application, at least one support bar is provided in the deformable core box for supporting the deformable core box to improve the support strength of the deformable core box.

[0011] The addition of the support bar improves the support strength of the deformable core box, enabling it to withstand more external forces and internal pressures, and prevents the deformable core box from deformation or damage under high temperature and high rate discharge conditions, thereby ensuring the stable performance of the battery's thermal regulation function. At the same time, the design of the support bar enhances the durability of the deformable core box during long-term use, prolongs the battery's service life, and reduces battery failure caused by damage to the deformable core box.

[0012] In one embodiment of the present application, the support bar is at least one of a straight line shape, an S shape, and a broken line shape.

[0013] The straight support bar is a simple linear structure with a long length and arranged in a straight line. It is evenly distributed on the inner wall of the deformable core box to provide balanced support. The straight support bar is suitable for situations where the deformable core box has a relatively regular structure and a relatively uniform force. The straight support bar can be fixed to the inner wall of the deformable core box by one-piece molding, welding, bonding or embedding to ensure that the support bar forms a stable connection with the deformable core box, so that the support bar can effectively disperse the pressure from the inside and outside and enhance the mechanical strength of the deformable core box. The straight support bar has a simple structure and a low manufacturing cost.

[0014] The S-shaped support bar is a curved structure composed of multiple curved segments, shaped like the letter "S". This shape of support bar can better adapt to the complex spatial layout inside the battery while providing support force. The S-shaped support bar can form a more complex support network inside the deformable core box, enhancing the stability of the deformable core box in multiple directions. The connection method of the S-shaped support bar can be connected to the inner wall of the deformable core box through one-piece molding, fixings 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 bar, it can effectively disperse the forces from all directions and enhance the compression and deformation resistance of the deformable core box.

[0015] The zigzag support bar is formed by connecting multiple straight line segments at angles. The zigzag support bar not only retains the simplicity of the straight line support bar, but also increases the flexibility and adaptability of the support bar through multiple folding angles. The zigzag support bar can provide better support in a limited space while reducing the risk of damage caused by uneven pressure.

[0016] In one embodiment of the present 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.

[0017] The safety and stability of lithium-ion batteries are improved by setting a pressure relief port on the top of the deformable core box and using it in conjunction with an explosion-proof valve. The design of the pressure relief port ensures that when the battery is over-expanded or the internal gas pressure is too high, the deformable core box can release some of the pressure, reducing the risk of thermal runaway of the battery. The synergy of the explosion-proof valve and the pressure relief port ensures that the battery can be effectively regulated and released in the event of overheating or abnormal conditions, preventing safety incidents such as explosions or fires due to pressure accumulation.

[0018] In one embodiment of the present application, the deformable core box is rectangular, and the side surface of the rectangular deformable core box is an arc surface.

[0019] 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.

[0020] In one embodiment of the present application, the lithium-ion battery body comprises: An outer shell having a positive electrode post and a negative electrode post, wherein an electrolyte is disposed in the outer shell; and The winding core is arranged in the outer shell, 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 the outer shell, positive and negative electrode posts, electrolyte, winding core and other components, high-efficiency operation and safety performance of the battery are achieved.

[0021] In one embodiment of the present application, the outer shell is made of aluminum alloy. Aluminum alloy has a low density, which can effectively reduce the weight of the battery as a whole. At the same time, a dense oxide film is 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 outer shell.

[0022] The present application also discloses a battery pack, comprising a plurality of self-regulating lithium-ion batteries as described above, which are connected in series and / or in parallel. Traditional battery packs rely on external temperature control devices, such as air cooling, liquid cooling systems, etc., to maintain a safe temperature of the battery. However, these external devices have hysteresis and cannot respond to the rapid changes in the internal temperature of the battery in a timely manner, which can easily cause the battery temperature to exceed the standard or be uneven. By using a deformable core box, the battery body can quickly absorb or release heat while internal heat is generated, thereby achieving effective thermal management of the battery body and reducing the problems of overheating and cooling lag. Since the core box can adaptively adjust the temperature and stress inside the battery, complex external temperature control devices are no longer required between the individual battery cells in the battery pack. The complexity of the system is reduced.

[0023] By adopting the above technical solution, by setting a deformable core box at the center of the core of the battery body, it is possible to effectively regulate the heat during the operation of the battery, thereby avoiding battery performance degradation or safety hazards caused by excessively high or low temperatures. At the same time, the deformable core box can effectively absorb the expansion requirements of the core during charging and discharging by using its own deformation function, and effectively balance the internal stress of the battery during operation. Combined with the heat absorption and release function of the deformable core box, it can effectively extend the service life of the battery, prevent aging of the internal materials of the battery or structural damage caused by excessive fluctuations in temperature and internal stress, thereby improving the battery's cycle performance and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 It is a schematic diagram of the three-dimensional structure of the first embodiment of the present invention; Figure 2 for Figure 1 A front cross-sectional view of Figure 3 for Figure 1 A bottom sectional view of 10. Outer shell; 11. Positive pole; 12. Negative pole; 13. Explosion-proof valve; 14. Winding core; 20. Deformable core box; 21. Support bar; 22. Pressure relief port. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and do not constitute a limitation to the present invention.

[0026] like Figures 1 to 3 As shown, in order to achieve the above-mentioned purpose, the present invention provides a self-regulating lithium-ion battery, comprising: The lithium-ion battery body has a deformable core box 20 at the center of the winding core 14 that can absorb or release heat from the winding core 14 .

[0027] Specifically, the lithium-ion battery body includes key components such as the battery's electrodes, diaphragms, and electrolytes, which constitute the basic functional units of the battery. The outer shell of the lithium-ion battery body is made of metal materials, such as aluminum alloy or stainless steel, etc., which protects the internal components. The outer shell of the lithium-ion battery body is a sealed design to prevent electrolyte leakage. The winding core 14 of the lithium-ion battery body is located inside the outer shell of the ion battery body. The winding core 14 is formed by winding the positive and negative electrode materials through the diaphragm, and the electrolyte is filled between the positive and negative electrodes to provide an ion conduction channel.

[0028] The deformable core box 20 is located at the center of the core 14 of the lithium-ion battery body. Its function is to adjust the temperature of the lithium-ion battery by absorbing or releasing heat, and to balance the internal stress of the battery when it is working. A phase change material is arranged in the deformable core box 20, and the phase change material undergoes a solid-liquid-gas three-phase phase change. Therefore, during the battery charging and discharging process, especially during high-power discharge or charging, the temperature of the battery body can be effectively controlled to avoid safety risks or performance degradation caused by excessive temperature. The deformable core box 20 is in contact with the core 14 in the battery body, and absorbs or releases heat from the core 14 through its built-in heat exchange or heat conduction function. At the same time, the deformable core box can absorb the tension generated when the core 14 expands by generating deformation, thereby improving the safety of the core 14. It can be imagined that the deformation is an elastic deformation, so that the deformable core box 20 has a long service life.

[0029] The working principle of the deformable core box 20 is: The appropriate working temperature of the winding core 14 is maintained by adjusting the internal temperature of the deformable core box 20. In a high temperature environment, the deformable core box 20 absorbs excess heat through the built-in phase change material to reduce the battery temperature; in a low temperature environment, the deformable core box 20 can introduce external heat into the battery body through the thermal conductive material to prevent the battery from affecting performance due to low temperature. The deformation function of the deformable core box is used to balance the internal stress of the battery during operation. In the fully charged state, the winding core expands and compresses the deformable core box to reduce its volume, reducing the internal stress of the winding core; in the empty state, the winding core contracts and the deformable core box rebounds to increase its volume; so that the winding core is always within a range of balanced force, preventing the battery safety and cycle performance from deteriorating due to changes in the mechanical stress of the battery.

[0030] By adopting the above technical solution, by setting a deformable core box 20 at the center of the winding core 14 of the battery body, it is possible to effectively regulate the heat during the operation of the battery, thereby avoiding the degradation of battery performance or safety hazards caused by excessively high or low temperatures. At the same time, the deformable core box can effectively absorb the expansion requirements of the winding core during charging and discharging by using its own deformation function, and effectively balance the internal stress of the battery during operation. Combined with the heat absorption and release function of the deformable core box 20, it can effectively extend the service life of the battery, prevent the aging of the internal materials of the battery or structural damage caused by excessive fluctuations in temperature and internal stress, thereby improving the cycle performance and safety of the battery.

[0031] In one embodiment of the present application, the deformable core box 20 is provided with at least one support bar 21 which can support the deformable core box 20 to improve the support strength of the deformable core box 20 .

[0032] Specifically, the support bar 21 is located inside the deformable core box 20, and its function is to enhance the support strength of the deformable core box 20 to prevent the deformable core box 20 from being deformed or damaged when subjected to high temperature, external force or battery expansion. The support bar 21 can be made of materials such as metal or high-strength plastic to ensure that it can provide sufficient support force during the operation of the battery. The support bar 21 is fixedly connected to the inner wall of the deformable core box 20 to form a stable support structure inside the deformable core box 20. The support bar 21 can be a single support bar 21 or a combination of multiple support bars 21. The arrangement of the support bars 21 can be evenly distributed or concentrated in certain areas as needed to ensure that the deformable core box 20 can maintain a stable shape when subjected to external pressure or temperature changes.

[0033] By adopting the above technical solution, the addition of the support bar 21 improves the support strength of the deformable core box 20, enabling it to withstand more external forces and internal pressures, and prevents the deformable core box 20 from being deformed or damaged under high temperature and high rate discharge conditions, thereby ensuring that the thermal regulation function of the battery can be stably exerted. At the same time, the design of the support bar 21 enhances the durability of the deformable core box 20 during long-term use, prolongs the service life of the battery, and reduces battery failure caused by damage to the deformable core box 20.

[0034] In an embodiment of the present application, the support bar 21 is at least one of a straight line shape, an S shape, and a broken line shape.

[0035] Specifically, the straight support bar 21 is a simple linear structure with a long length and arranged in a straight line. It is evenly distributed on the inner wall of the deformable core box 20 to provide balanced support force. The straight support bar 21 is suitable for the case where the deformable core box 20 has a relatively regular structure and is subjected to relatively uniform force. The straight support bar 21 can be fixed to the inner wall of the deformable core box 20 by integral molding, welding, bonding or embedding, ensuring that the support bar 21 forms a stable connection with the deformable core box 20, so that the support bar 21 can effectively disperse the pressure from the inside and outside, and enhance the mechanical strength of the deformable core box 20. The straight support bar 21 has a simple structure and a low manufacturing cost.

[0036] The S-shaped support bar 21 is a curved structure composed of multiple curved segments, shaped like the letter "S". This shape of support bar 21 can better adapt to the complex spatial layout inside the battery while providing support force. The S-shaped support bar 21 can form a more complex support network inside the deformable core box 20, enhancing the stability of the deformable core box 20 in multiple directions. The connection method of the S-shaped support bar 21 can be connected to the inner wall of the deformable core box 20 through one-piece molding, fixings or welding, etc., to ensure that it will not loosen or fall off under thermal expansion and pressure changes. Due to the curved design of the S-shaped support bar 21, it can effectively disperse the forces from all directions, thereby improving the compression and deformation resistance of the deformable core box 20.

[0037] The zigzag support bar 21 is formed by connecting a plurality of straight line segments at angles. The zigzag support bar 21 retains the simplicity of the straight line support bar 21, and can increase the flexibility and adaptability of the support bar 21 through a plurality of folded angles. The zigzag support bar 21 can provide better support force in a limited space, while reducing the risk of damage caused by uneven pressure.

[0038] In one embodiment of the present 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.

[0039] Specifically, the pressure relief port 22 is an opening structure provided at the top and / or the bottom of the deformable core box 20 , and is used for the deformable core box 20 to automatically release the pressure when the internal pressure of the battery reaches a certain threshold.

[0040] The 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 is too high, so as to prevent the battery from rupture, explosion or fire due to excessive expansion. The explosion-proof valve 13 is composed of high-temperature resistant materials and sealing devices, which can withstand the internal pressure of the battery and release it when the 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. The cooperation of the two ensures that the pressure of the deformable core box 20 can be quickly released when the battery is overheated or under high pressure.

[0041] By adopting the above technical solution, the safety and stability of the lithium-ion battery are improved by setting a pressure relief port 22 at the top or / and bottom of the deformable core box 20 and using it in conjunction with the explosion-proof valve 13. The design of the pressure relief port 22 ensures that when the battery is over-expanded or the internal gas pressure is too high, the deformable core box 20 can release part of the pressure, reducing the risk of thermal runaway of the battery. The synergistic effect of the explosion-proof valve 13 and the pressure relief port 22 ensures that the battery can be effectively regulated and released in the event of overheating or abnormal conditions, preventing safety incidents such as explosion or fire due to pressure accumulation.

[0042] In one embodiment of the present application, the deformable core box 20 is rectangular, and the side surface of the rectangular deformable core box 20 is an arc surface.

[0043] Specifically, the side surface of the deformable core box 20 is designed with an arc surface, which can effectively avoid the risk of lithium deposition caused by the curvature of the winding core 14 being too small.

[0044] By adopting the above technical solution, the thermal management performance and structural stability of the battery are improved by optimizing the shape design of the deformable core box 20, thereby effectively enhancing the safety and reliability of the battery while ensuring the battery performance.

[0045] In one embodiment of the present application, the lithium-ion battery body comprises: An outer shell 10 having a positive electrode column 11 and a negative electrode column 12, wherein an electrolyte is provided in the outer shell 10; and The winding core 14 is disposed in the outer shell 10 . The positive electrode tab of the winding core 14 is connected to the positive electrode post 11 , and the negative electrode tab of the winding core 14 is connected to the negative electrode post 12 .

[0046] Specifically, the outer shell 10 is the external closed structure of the lithium-ion battery body, which is made of metal materials such as aluminum or stainless steel. The main function of the outer shell 10 is to provide physical protection, ensure the safety and stability of internal components, and prevent the external environment from damaging the internal structure of the battery. An electrolyte is provided in the outer shell 10, which is the core chemical reaction medium of the lithium-ion battery. The electrolyte is composed of an organic solvent and a lithium salt and plays a role in charge transfer. A plurality of diaphragms are also provided in the outer shell 10 to ensure that the positive and negative electrodes do not directly contact and short-circuit. A positive pole 11 and a negative pole 12 are provided on the top or side of the outer shell 10 for connecting the battery to an external circuit. The positive pole 11 and the negative pole 12 are made of highly conductive metal materials (such as copper or aluminum) to ensure smooth current conduction during the charging and discharging process of the battery.

[0047] The core 14 is composed of positive electrode material, negative electrode material and diaphragm, which are arranged together in a curled shape. The core 14 is located in the outer shell 10 and acts as the active material part of the battery. The positive electrode material is generally composed of lithium cobalt oxide, lithium iron phosphorus, etc., and the negative electrode material is often graphite. The diaphragm is a thin film between the positive and negative electrodes. Its main function is to prevent direct contact between the positive and negative electrode materials, avoid short circuits, and allow lithium ions to pass freely. The positive electrode tab of the core 14 is connected to the positive electrode column 11, and the negative electrode tab is connected to the negative electrode column 12. The tabs are fixed to the two ends of the core 14 by welding, providing external connection points for the positive and negative electrodes of the battery, ensuring that the charging and discharging processes of the battery can proceed smoothly.

[0048] By adopting the above technical solution, the high-efficiency operation and safety performance of the battery are achieved through the reasonable layout and connection of the outer shell 10, the positive and negative electrode poles 12, the electrolyte, the winding core 14 and other components.

[0049] In one embodiment of the present application, the outer shell 10 is made of aluminum alloy.

[0050] By adopting the above technical solution, the density of aluminum alloy is low, which can effectively reduce the overall weight of the battery. At the same time, a dense oxide film is 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.

[0051] The present application also discloses a battery pack, comprising a plurality of self-regulating lithium-ion batteries as described above connected in series and / or in parallel.

[0052] Specifically, a battery pack achieves efficient thermal management and internal stress regulation by combining self-regulating lithium-ion batteries, thereby solving the temperature regulation hysteresis and complex structure problems existing in traditional battery packs. The battery pack includes a plurality of self-regulating lithium-ion batteries connected in series and / or in parallel. A deformable core box 20 that can absorb or release heat from the core is provided at the center of the core of the lithium-ion battery body. The deformable core box 20 can automatically achieve temperature regulation according to the temperature changes inside the battery through phase change materials, thereby effectively controlling the heat distribution of the battery body and keeping the battery within the optimal operating temperature range.

[0053] Using the above technical solution, traditional battery packs rely on external temperature control devices, such as air cooling, liquid cooling systems, etc., to maintain a safe temperature of the battery. However, these external devices have hysteresis and cannot respond to the rapid changes in the internal temperature of the battery in a timely manner, which can easily cause the battery temperature to exceed the standard or be uneven. By using a deformable core box 20, the battery body can quickly absorb or release heat while internal heat is generated, thereby achieving effective thermal management of the battery body and reducing the problems of overheating and cooling lag. Since the core box can adaptively adjust the temperature and stress inside the battery, complex external temperature control devices are no longer required between the individual battery cells in the battery pack. The complexity of the system is reduced.

[0054] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A self-regulating lithium-ion battery, characterized in that: include: A lithium-ion battery body, wherein a deformable core box capable of absorbing or releasing heat from the core is provided at the center of the core of the lithium-ion battery body.

2. The self-regulating lithium-ion battery according to claim 1, characterized in that: The deformable core box is provided with at least one support bar which can support the deformable core box to improve the support strength of the deformable core box.

3. The self-regulating lithium-ion battery according to claim 2, characterized in that: When the support bar is at least one of a straight line shape, an S shape, and a broken line shape.

4. The self-regulating lithium-ion battery according to claim 1, wherein: 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.

5. The self-regulating lithium-ion battery according to claim 1, wherein: The deformable core box is rectangular, and the side surface of the rectangular deformable core box is an arc surface.

6. The self-regulating lithium-ion battery according to any one of claims 1 to 5, characterized in that: The lithium-ion battery body comprises: An outer shell having a positive electrode post and a negative electrode post, wherein an electrolyte is disposed in the outer shell; and The winding core is arranged in the outer shell, 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.

7. The self-regulating lithium-ion battery according to claim 6, characterized in that: The outer shell is made of aluminum alloy material.

8. A battery pack, characterized in that: The invention comprises a plurality of self-regulating lithium-ion batteries as claimed in any one of claims 1 to 7 connected in series and / or in parallel.

Images