Battery pack and electric device

Abstract

The utility model provides a kind of battery pack and electric equipment, the battery pack includes box and multiple batteries in box, at least one breather valve is equipped on box, gas inside box can be discharged to box outside by at least one breather valve, gas outside box can enter into box by at least one breather valve, at least one breather valve satisfies: 0.25V / t1≤A≤0.4V / t1;And / or 0.2V / t2≤B≤0.35V / t2, V is the clearance of box, t1 is the time of complete charging process of battery pack in low temperature environment, t2 is the time of complete discharging process of battery pack in low temperature environment, A is the exhaust rate of at least one breather valve whole in complete charging process in low temperature environment, B is the intake rate of at least one breather valve whole in complete discharging process in low temperature environment, and the temperature range of low temperature environment is-30 DEG C to 60 DEG C.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular, to a battery pack and an electrical device having the battery pack. Background Technology

[0002] Battery packs, used for storing and providing electrical energy, are widely used in various devices. During charging and discharging, battery packs generate gas and experience temperature changes, resulting in a pressure difference between the inside and outside of the pack. To alleviate this pressure difference, a vent valve is often installed on the pack. Driven by the pressure difference, the gas inside and outside the pack exchanges through the vent valve, maintaining a pressure balance between the inside and outside of the pack.

[0003] However, existing vent valves cannot meet the requirements for air intake or exhaust, which often leads to deformation of the casing and affects the safe use of the battery pack. Utility Model Content

[0004] In view of this, the present invention provides a battery pack and electrical equipment, which aims to at least improve the problem that the vent valve cannot meet the air intake or exhaust requirements, resulting in deformation of the housing.

[0005] On one hand, this utility model provides a battery pack, which includes a housing and a plurality of batteries disposed within the housing. The housing is provided with at least one vent valve, through which gas inside the housing can be discharged to the outside of the housing, and gas outside the housing can enter the housing through the at least one vent valve. The at least one vent valve satisfies: 0.25V / t1≤A≤0.4V / t1; and / or 0.2V / t2≤B≤0.35V / t2, where V is the net air volume of the housing in ml, t1 is the time of the complete charging process of the battery pack in a low-temperature environment in min, t2 is the time of the complete discharging process of the battery pack in a low-temperature environment in min, A is the exhaust rate of the at least one vent valve as a whole during the complete charging process in the low-temperature environment in ml / min, and B is the intake rate of the at least one vent valve as a whole during the complete discharging process in the low-temperature environment in ml / min. The temperature range of the low-temperature environment is -30℃ to 60℃.

[0006] On the other hand, this utility model also provides an electrical device, including the battery pack described above.

[0007] According to the battery pack and electrical equipment provided by the above technical solution, the exhaust rate A of multiple vent valves satisfies: 0.25 V / t1 ≤ A ≤ 0.4 V / t1; the intake rate B satisfies: 0.2 V / t2 ≤ B ≤ 0.35 V / t2. When the battery pack is charging, the vent valves on the battery pack can promptly and fully exhaust the gas inside the box, preventing the battery pack from expanding and deforming due to excessive gas pressure inside the box caused by gas generation and temperature rise during charging. When the battery pack is discharging, the vent valves on the battery pack can promptly allow a specific amount of air from outside the box to enter the box, preventing the battery pack from contracting and deforming due to excessive gas pressure inside the box caused by temperature drop during discharging. Attached Figure Description

[0008] It should be understood that the following figures only show some embodiments of the present invention and should not be regarded as a limitation on the scope.

[0009] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0010] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0011] Figure 1 This is a schematic diagram of an exemplary battery pack.

[0012] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0013] Figure 3 This is a schematic diagram of an exemplary vent valve.

[0014] Figure 4 for Figure 3 The exploded view of the vent valve is shown.

[0015] Figure 5 for Figure 3 The diagram shows the structure of the vent valve from one perspective.

[0016] Figure 6 for Figure 5 Cross-sectional view along the BB direction.

[0017] Explanation of reference numerals in the attached drawings: 100, battery pack; 10, housing; 11, upper housing; 12, lower housing; 20, vent valve; 21, valve body; 211, valve port; 22, cover; 23, connecting part; 24, vent slit. Detailed Implementation

[0018] Numerous specific details are set forth below to provide an understanding of the structure, function, and use of the embodiments described and illustrated in the specification and figures. It is to be understood that the embodiments described and illustrated herein are non-limiting examples, and thus it will be appreciated that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes may be made to these embodiments without departing from the scope of the claims.

[0019] In related technologies, during the charging process, a series of oxidation-reduction reactions occur inside the battery pack, generating a large amount of gas and causing the battery pack temperature to rise. Consequently, the gas pressure inside the battery pack also increases with the temperature. To achieve pressure balance between the inside and outside of the battery pack, a vent valve is used to release gas from the pack, thus relieving pressure. However, due to an improperly set vent valve exhaust rate, the gas inside the pack cannot be discharged in time, leading to excessive pressure and causing the pack to expand and deform outward.

[0020] During discharge, a series of oxidation-reduction reactions occur inside the battery pack, and the ambient temperature significantly impacts this process. Especially at low temperatures, the rate of oxidation-reduction reactions decreases, and the battery pack temperature drops accordingly. At this low temperature, the internal air pressure of the battery pack decreases. However, if the vent valve's air intake rate is improperly set, outside air cannot enter the pack in time, leading to excessively low internal pressure and causing the pack to contract and deform inwards. Significant contraction and deformation may compress the batteries inside, posing a safety hazard during use.

[0021] The inventors discovered that the cause of the above problems was that the air intake and exhaust rates of the vent valve were not set within a reasonable range. This is especially important when the battery pack is being charged or discharged in low-temperature environments, where the air intake and exhaust rates of the vent valve should be set appropriately.

[0022] To solve the above problems, the inventors made many attempts and finally creatively proposed the following technical solution: A battery pack is provided, comprising a housing and multiple batteries located inside the housing. The housing is equipped with at least one vent valve, through which gas inside the housing can be discharged to the outside of the housing, and gas outside the housing can enter the housing through at least one vent valve. The at least one vent valve satisfies: 0.25V / t1≤A≤0.4V / t1; and / or 0.2V / t2≤B≤0.35V / t2, where V is the net air volume of the housing in ml, t1 is the time of the complete charging process of the battery pack in a low-temperature environment in min, t2 is the time of the complete discharging process of the battery pack in a low-temperature environment in min, A is the exhaust rate of the at least one vent valve during the complete charging process in a low-temperature environment in ml / min, and B is the intake rate of the at least one vent valve during the complete discharging process in a low-temperature environment in ml / min. The temperature range of the low-temperature environment is -30℃ to 60℃. When the battery pack is charging, multiple vent valves can promptly and fully expel the gas inside the box, preventing the battery pack from expanding and deforming due to excessive gas pressure inside the box caused by gas generation and temperature rise during charging. When the battery pack is discharging, multiple vent valves can promptly allow a specific amount of air from outside the box to enter the box, preventing the battery pack from shrinking and deforming due to excessive gas pressure inside the box caused by temperature drop during discharging.

[0023] <Example Battery Pack> This utility model embodiment provides a battery pack 100, which includes a housing 10 and a plurality of batteries disposed within the housing 10. The housing 10 is provided with at least one vent valve 20, allowing gas inside the housing 10 to be discharged to the outside of the housing 10, and allowing gas outside the housing 10 to enter the housing 10 through the at least one vent valve 20. The at least one vent valve 20 satisfies: 0.25V / t1≤A≤0.4V / t1; and / or, 0.2V / t2≤B≤0.35V / t2, where V is the voltage of the housing 10. 0 represents the net air volume in ml; t1 represents the time of the complete charging process of the battery pack at its maximum charging rate in a low-temperature environment in min; t2 represents the time of the complete discharging process of the battery pack in a low-temperature environment in min; A represents the exhaust rate of at least one vent valve 20 during the complete charging process in a low-temperature environment in ml / min; B represents the intake rate of at least one vent valve 20 during the complete discharging process in a low-temperature environment in ml / min; and the temperature range of the low-temperature environment is -30℃ to 60℃.

[0024] For ease of understanding, the battery pack 100 provided in this embodiment will be described in detail below with reference to the accompanying drawings. The direction indicated by the X-axis in the drawings can be understood, for example, as the length direction of the battery pack 100; the direction indicated by the Y-axis in the drawings can be understood, for example, as the width direction of the battery pack 100; and the direction indicated by the Z-axis in the drawings can be understood, for example, as the height direction of the battery pack 100.

[0025] See Figure 1 The battery pack 100 includes a housing 10 and multiple batteries (not shown in the figure) located within the housing 10. The housing 10 serves to protect the multiple batteries, preventing moisture or foreign objects from the external environment from entering the battery pack 100 and ensuring the safety and stability of the battery pack 100 during use. The housing 10 can be, for example, a three-dimensional structure with a central cavity, such as a cube, cuboid, cylinder, or sphere. This embodiment uses a cuboid housing 10 as an example for illustration.

[0026] like Figure 1 As shown, the housing 10 may include an upper housing 11 and a lower housing 12. The lower housing 12 may be a cavity structure with an opening at one end, and the upper housing 11 may be a cavity structure with an opening at one end, identical to the lower housing 12. The housing 10 is formed by interlocking the open ends of the upper housing 11 and the lower housing 12. Alternatively, the upper housing 11 and the lower housing 12 may have different structures: for example, the upper housing 11 may be a cover structure that fits the lower housing 12, and the housing 10 is formed by interlocking the cover with the open end of the lower housing 12; or, for another example, the upper housing 11 may have the same open end as the lower housing 12, but its height may be less than the cavity structure of the lower housing 12. In use, the configuration of the housing 10 can be adaptively selected according to the size of the batteries and the arrangement of multiple batteries within the housing 10; this application does not impose specific limitations on this configuration.

[0027] At least one vent valve 20 is provided on the housing 10. The vent valve 20 is used to achieve pressure balance between the inside and outside of the housing 10. For example, when the battery pack 100 is charging, if the internal pressure of the housing 10 is higher than the external pressure, the gas inside the housing 10 can be discharged through the vent valve 20 until the pressure inside and outside the housing 10 is equal. This avoids the problem of the housing 10 expanding and deforming outward due to excessively high internal pressure. As another example, when the battery pack 100 is discharging, if the internal pressure of the housing 10 is lower than the external pressure, external air can enter the housing 10 through the vent valve 20 to increase the internal pressure. This prevents the housing 10 from shrinking and deforming inward due to excessively low internal pressure caused by external pressure compressing the housing 10.

[0028] It should be noted that the vent valve 20 here is a waterproof vent valve. For example, the vent valve 20 is equipped with a waterproof and breathable membrane, which allows only gas to pass through but not liquids such as water. By maintaining the air pressure balance inside and outside the housing 10, it can prevent moisture from the outside of the housing 10 from entering the interior and affecting the performance of the battery pack 100.

[0029] The vent valve 20 can be installed only on the upper housing 11 or only on the lower housing 12. When there are multiple vent valves 20, they can also be installed on both the upper housing 11 and the lower housing 12. In use, the vent valve 20 can be adapted to the specific structure of the upper housing 11 and the lower housing 12. This application does not specify the position of the vent valve 20 on the housing 10.

[0030] See Figure 1 and Figure 2 In this embodiment, multiple vent valves 20 are provided, and these multiple vent valves 20 are disposed on the lower housing 12. Specifically, the multiple vent valves 20 may be disposed on the side wall of the lower housing 12, for example. The side wall of the lower housing 12 can be understood as the sum of all surfaces adjacent to the open end of the lower housing 12. This side wall may include, for example, a first side wall, a second side wall, a third side wall, and a fourth side wall, and the first side wall, the second side wall, the third side wall, and the fourth side wall are sequentially connected to form the side wall of the lower housing 12. The multiple vent valves 20 may be evenly arranged on the side wall of the lower housing 12; or the multiple vent valves 20 may be evenly disposed on one or more of the first side wall, the second side wall, the third side wall, and the fourth side wall. The placement of the vent valves 20 on the lower housing 12 can be adaptively adjusted according to the specific structure of the lower housing 12, as long as it facilitates the passage of gas inside and outside the housing 10 and does not interfere with other structures.

[0031] The vent valve 20 and the lower housing 12 can be fixedly connected by means such as welding, bonding, or bolting. In use, the connection method between the vent valve 20 and the lower housing 12 can be determined comprehensively based on factors such as the material and specific characteristics of the vent valve 20, as long as the connection strength between the two meets the requirements. This application does not specifically limit the connection method between the vent valve 20 and the lower housing 12.

[0032] According to the ideal gas law PV=NRT, where N and R are constants; P can be defined, for example, as the gas pressure inside the housing 10; V can be defined, for example, as the net space of the battery pack 100, that is, the total volume of space available for accommodating gas after housing 10 contains solid devices such as batteries and other electrical components; T can be defined, for example, as the temperature inside the battery pack 100.

[0033] Assume that the air pressure inside the housing 10 of the battery pack 100 remains constant at P during the charging process; the initial temperature of the battery pack 100 when it starts charging is T1; the final temperature when it ends charging is T2; the initial volume of the battery pack 100 at the start of charging is V1; and the final volume after the expansion due to the temperature increase when charging ends is V2.

[0034] The ideal gas law for the battery pack 100 at the start of charging is: P*V1=N*R*T1, which is simply referred to as equation ①; The ideal gas law for battery pack 100 at the end of charging is: P*V2=N*R*T2, abbreviated as Equation ②.

[0035] According to equations ① and ②, the change in volume of the battery pack 100 during the charging process can be calculated as ΔV = V2 - V1 = (T2 - T1) * V1 / T1.

[0036] Taking the temperature rise from -30℃ to 60℃ during the charging process of battery pack 100 as an example, the change in volume of the casing 10 can be calculated as ΔV = 0.37V1. It should be noted that the Celsius temperature needs to be converted to Kelvin for this calculation.

[0037] To prevent the battery pack 100 from expanding and deforming outward during charging, the multiple vent valves 20 need to promptly expel a gas equivalent to ΔV from the casing 10 within the charging time. Therefore, the exhaust rate A of the multiple vent valves 20 can be obtained as the ratio of ΔV to the charging time. Assuming the charging time of the battery pack 100 is t1, then the exhaust rate A of the multiple vent valves 20 = ΔV / t1 = 0.37V1 / t1. Since the initial volume of the battery pack 100 at the start of charging can be approximately equal to its net clearance, the exhaust rate A of the multiple vent valves 20 is 0.37V / t1.

[0038] The charging time t1 of the battery pack 100 can be understood as the charging time required for the battery pack 100 to increase its charge from 0 to 100% when charging at the maximum charging rate. During the charging process of the battery pack 100, the charging rate of the external power supply to the battery pack 100 must be greater than or equal to the maximum allowable charging rate of the battery pack 100 itself.

[0039] It should be noted that the above calculations were performed under ideal conditions. However, the battery pack 100 is affected by various factors in the internal and external environment when charging in actual conditions. Therefore, the exhaust rates of the multiple vent valves 20 can be adaptively adjusted to suit the charging environment of the battery pack 100 under actual conditions. Through simulation and calculation, a relatively ideal state can be achieved when the exhaust rate A of the multiple vent valves 20 is within the range of 0.25 V / t1 ≤ A ≤ 0.4 V / t1. In other words, meeting this exhaust rate range ensures that the battery pack 100 can effectively and timely depressurize the housing 10 during charging, preventing the housing 10 from expanding and deforming outward due to excessive internal air pressure.

[0040] Similarly, the air intake rate B of the multiple vent valves 20 when the battery pack 100 is discharging can be calculated based on the above calculation process.

[0041] Assume that the air pressure inside the casing 10 of the battery pack 100 remains constant at P during the discharge process; the initial temperature of the battery pack 100 at the start of discharge is T3; the final temperature at the end of discharge is T4; the initial volume of the battery pack 100 at the start of discharge is V3; and the final volume after the temperature rises and the battery pack 100 expands after the discharge is over is V4.

[0042] The ideal gas law for battery pack 100 at the start of discharge is: P*V3=N*R*T3, abbreviated as Equation ③; The ideal gas law for battery pack 100 at the end of discharge is: P*V4=N*R*T4, or simply Equation ④.

[0043] According to equations ③ and ④, the change in volume of the battery pack 100 during discharge can be calculated as ΔV = V3 - V4 = (T3 - T4) * V3 / T3.

[0044] Taking the temperature drop from 60℃ to -30℃ during the discharge process of battery pack 100 as an example, the change in volume of the casing 10 can be calculated as ΔV = 0.27V³. It should be noted that the Celsius temperature needs to be converted to Kelvin for this calculation.

[0045] To prevent the battery pack 100 from expanding and deforming outwards during discharge, the multiple vent valves 20 need to allow a gas volume equivalent to ΔV to enter the housing 10 within the discharge time. Therefore, the air intake rate B of the multiple vent valves 20 can be obtained as the ratio of ΔV to the discharge time. Assuming the discharge time of the battery pack 100 is t2, the air intake rate B of the multiple vent valves 20 = ΔV / t2 = 0.27V³ / t2. Since the volume of the battery pack 100 at the start of discharge can be approximately equal to its net clearance, the air intake rate B of the multiple vent valves 20 is 0.27V / t2.

[0046] The discharge time t2 of the battery pack can be understood, for example, as the time required for the battery pack 100 to completely discharge from 100% to 0%. During the discharge process of the battery pack 100, the discharge rate can be, for example, 1 / 3C, corresponding to a discharge time of 180 minutes; the discharge rate of the battery pack 100 can be, for example, 5C, corresponding to a discharge time of 12 minutes. In use, the discharge time of the battery pack 100 can be determined based on the applied discharge rate.

[0047] It should be noted that the above calculations were performed under ideal conditions. However, the battery pack 100 is affected by various factors in the internal and external environment when discharging in actual conditions. Therefore, the air intake rates of the multiple vent valves 20 can be adaptively adjusted to adapt to the discharge environment of the battery pack 100 under actual conditions. Through simulation and calculation, a relatively ideal state can be achieved when the air intake rate B of the multiple vent valves 20 is within the range of 0.2V / t2 ≤ B ≤ 0.35V / t2. In other words, meeting this range of air intake rates can ensure that the battery pack 100 can pressurize the housing 10 in a timely and effective manner during discharge, avoiding inward contraction and deformation of the housing 10 due to excessively low internal air pressure.

[0048] The above is merely an example to simulate the charging and discharging processes of the battery pack 100, and it does not constitute a specific limitation on this application. It should be understood that during the charging process, as long as the temperature rise of the battery pack 100 is within the range of -30°C to 60°C, the exhaust rate of the aforementioned vent valve 20 can still meet the exhaust requirements of the battery pack 100. Similarly, during the discharging process, as long as the temperature drop of the battery pack 100 is within the range of 60°C to -30°C, the intake rate of the aforementioned vent valve 20 can still meet the intake requirements of the battery pack 100.

[0049] Furthermore, when there are multiple vent valves 20, each vent valve 20 satisfies the following conditions: 0.25V / (n×t1)≤a≤0.4V / (n×t1); and / or 0.2V / (n×t2)≤b≤0.35V / (n×t2), where a is the exhaust rate of the vent valve 20 during the complete charging process in a low-temperature environment, in ml / min; b is the intake rate of the vent valve 20 during the complete discharging process in a low-temperature environment, in ml / min; and n is the number of vent valves. Vent valves 20 meeting the above ranges not only meet the exhaust or intake rate requirements of the battery pack 100 during charging or discharging to prevent deformation of the housing 10, but also allow for the selection of vent valves 20 of the same specifications, thus saving production costs to some extent.

[0050] In use, the air intake rate and exhaust rate of the vent valve 20 can be adjusted using existing known methods to meet the aforementioned limits on the air intake rate and exhaust rate of a single vent valve 20, as well as the aforementioned limits on the total air intake rate and exhaust rate of all vent valves 20. For example, the air intake rate and exhaust rate of the vent valve 20 can be met by adjusting the number of vent valves 20, the material or type of the waterproof and breathable membrane corresponding to the vent valve 20, and the number or size of the vent slits 24 corresponding to each vent valve 20. This application does not impose any special limitations on the adjustment method, as long as the air intake rate and exhaust rate of the vent valve 20 can be controlled within the aforementioned limits.

[0051] In one optional embodiment, the number of vent valves 20 is X, and the energy density of the battery pack 100 is E, where 120Wh / kg ≤ E / X ≤ 180Wh / kg. A number of vent valves 20 satisfying this range allows the exhaust and intake rates of the vent valves 20 to match the energy density of the battery pack 100. That is, the number of vent valves 20 can be adaptively adjusted according to the energy density of the battery pack 100, ensuring that during charging, the battery pack 100 has a sufficient exhaust rate to promptly expel gas from the housing 10, preventing expansion and deformation of the housing 10. Similarly, during discharging, the battery pack has a sufficient intake rate to allow external air to enter the housing 10, preventing contraction and deformation of the housing 10.

[0052] In use, the number of vent valves 20 can be adjusted according to the energy density of the battery pack 100. For example, when the energy density of the battery pack 100 is high, the number of vent valves 20 can be appropriately increased; when the energy density of the battery pack 100 is low, the number of vent valves 20 can be appropriately decreased. This application does not impose specific limitations on the number of vent valves 20 or the energy density of the battery pack 100, as long as the two satisfy the above-mentioned proportional relationship.

[0053] In one optional implementation, the value of V ranges from 3 × 10⁻⁶. 4 mL to 1×10 5 mL. That is, the net volume of the battery pack 100 is 30L-100L. Meeting this range of net volume allows the battery pack 100 sufficient space to accommodate partial reversible expansion during charging or partial reversible contraction during discharging, thus maintaining stable air pressure within the housing 10. Simultaneously, it prevents the net volume from being excessively large, which could adversely affect the energy density of the battery pack 100.

[0054] Optionally, the value of V can be 40L, 45L, 50L, 55L, 60L, 65L, 70L, 80L, or 90L, etc. In use, the value of V can be adaptively selected according to parameters such as the capacity requirements of the battery pack 100. For example, when the capacity of the battery pack 100 is high, the value of V can be appropriately increased; when the capacity of the battery pack 100 is low, the value of V can be appropriately decreased.

[0055] In one optional implementation, the value of t1 ranges from 20 minutes to 80 minutes. A charging time within this range allows the battery pack 100 sufficient charging time, preventing it from overheating and ensuring the vent valve 20 has adequate time to release air, thus avoiding risks such as bulging or short circuits during charging. Simultaneously, it prevents the charging time of the battery pack 100 from becoming excessively long, which could affect its lifespan.

[0056] Optionally, t1 can be 25min, 30min, 35min, 40min, 45min, 50min, 60min, or 70min, etc. During use, the charging time can be determined based on the battery pack's capacity and charging rate, and is not limited to the times listed above.

[0057] In one optional implementation, t2 ranges from 12 min to 180 min. A discharge time within this range ensures that the battery pack 100 has sufficient discharge time, guaranteeing adequate air intake time for the vent valve 20 and further preventing the casing 10 from shrinking and deforming inwards. Simultaneously, it prevents excessively long discharge times, which could reduce the capacity of the battery pack 100.

[0058] Optionally, t2 can be 18 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 100 min, or 120 min, etc. In use, the discharge time can be determined based on the battery pack 100's capacity and discharge rate, and is not limited to the times listed above. In an optional embodiment, the housing 10 satisfies Z7 ≤ P1 ≤ Z8, where P1 is the air pressure inside the housing 10 at a specific moment during the complete charging process in a low-temperature environment. This air pressure can be understood, for example, as the range of real-time air pressure variation inside the housing 10 during the entire charging process, from the maximum value to the minimum value. A pressure value within this range ensures, on the one hand, that the air pressure inside the housing 10 is sufficiently high, allowing the gas inside the housing 10 to be smoothly discharged to the outside of the housing 10 simply through the pressure difference between the inside and outside of the housing 10. On the other hand, it prevents the air pressure inside the housing 10 from becoming too high, avoiding the risk of thermal runaway of the battery pack 100.

[0059] Optionally, the value of P1 ranges from 101.3 kPa to 138.3 kPa. That is, during the charging process, the maximum air pressure inside the casing 10 at a specific moment is 138.3 kPa, and the minimum air pressure at a specific moment is 101.3 kPa. The value of P1 can be, for example, 105 kPa, 110 kPa, 115 kPa, 120 kPa, 125 kPa, 130 kPa, or 135 kPa.

[0060] In one optional embodiment, the housing 10 satisfies 101.3 kPa ≤ P2 ≤ 138.3 kPa, where P2 is the internal pressure of the housing 10 at a certain moment during the complete discharge process in a low-temperature environment. This pressure can be understood, for example, as the range of real-time pressure variation between the maximum and minimum real-time pressure inside the housing 10 during the discharge process of the battery pack 100. A pressure value within this range ensures a sufficiently low internal pressure for the housing 10, creating a reasonable pressure difference between the inside and outside of the housing 10. This pressure difference alone allows gas from outside the housing 10 to smoothly enter, effectively mitigating the contraction and deformation caused by excessively low pressure inside the housing 10.

[0061] Optionally, the value of P2 can be, for example, 105 kPa, 110 kPa, 115 kPa, 120 kPa, 125 kPa, 130 kPa, or 135 kPa.

[0062] See Figure 3 and Figure 4 The structure of the vent valve 20 will be described in detail below. As shown in the figure, the vent valve 20 includes a valve body 21, a cover 22, and at least one connecting portion 23. The valve body 21 can be configured as a hollow cylinder open at both ends, with a valve port 211 at the end of the valve body 21 away from the housing 10. The cover 22 is connected to the end of the valve body 21 away from the housing 10 via at least one connecting portion 23, such that the cover 22 partially closes the valve port 211, allowing ventilation to occur even when the valve port 211 is not closed. It is understood that the ends of the cover 22 and the valve body 21 do not directly contact each other; that is, there is a gap between the ends of the cover 22 and the valve body 21 along the axial direction (Y-axis direction shown in the figure). This gap forms, for example, a vent slit 24, which communicates with the interior of the housing 10 through the hollow portion within the valve body 21. Gas inside the housing 10 can be discharged through the vent slit 24, and gas outside the housing 10 can also enter the housing 10 through the vent slit 24, thereby achieving pressure balance inside and outside the housing 10. At the same time, the cover 22 can also largely prevent external moisture or foreign objects from entering the housing 10 through the valve body 21.

[0063] Preferred, such as Figures 3 to 6 As shown, a vent valve 20 is provided with multiple connecting parts 23, which are located around the periphery of the cover 22 and are evenly spaced along the circumference of the cover 22. A vent slit 24 is formed between two adjacent connecting parts 23. In this way, not only can the cover 22 be evenly stressed at all positions, improving the stability between the cover 22 and the valve body 21, but also each vent slit 24 can be evenly vented or vented, more effectively achieving air pressure balance inside and outside the housing 10.

[0064] The connecting part 23 may be made of one or more materials selected from acrylonitrile-butadiene-styrene copolymer (ABS), polybutylene terephthalate (PBT), and polycarbonate (PC) combined with glass fiber. The glass fiber content is 6% to 30%.

[0065] Optionally, the glass fiber used to prepare the connector 23 has a diameter of 2μm to 20μm and a length of 0.5mm to 10mm. For example, the glass fiber selected has a diameter of 5μm, 7μm, 9μm, 10μm, 12μm or 15μm, and a length of 1mm, 1.5mm, 2mm, 3mm, 4mm or 5mm.

[0066] In one optional embodiment, the sum of the areas of the plurality of ventilating slits 24 is S1, in mm. 2 The area of ​​valve port 211 is S2, in mm. 2 0.01≤S1 / S2≤0.08. The vent slit 24 and valve port 211 satisfy the relationship, which on the one hand ensures that the vent slit 24 is large enough so that the gas inside the box 10 can be discharged smoothly; on the other hand, it will not make the vent slit 24 too large, so as to avoid the pressure difference between the inside and outside of the box 10 near the vent slit 24, which would be not conducive to the gas outside the box 10 entering the box 10, and thus cannot avoid the compression deformation of the box 10.

[0067] Optionally, the value of S1 can be in the range of 0.1 mm. 2 Up to 10mm 2 The value of S1 can be, for example, 0.5 mm. 2 1mm 2 2mm 2 3 mm 2 4mm 2 5 mm 2 6 mm 2 7 mm 2 8 mm 2 Or 9 mm 2 The value of S2 ranges from 113 mm. 2 Up to 350mm2 For example, the value of S2 can be 113mm. 2 130 mm 2 150 mm 2 160mm 2 165 mm 2 170mm 2 175mm 2 180mm 2 185mm 2 190mm 2 200mm 2 250 mm 2 280 mm 2 320 mm 2 Or 350 mm 2 wait.

[0068] For example, such as Figure 6 As shown, the vent valve 20 has four vent slits 24, and the area of ​​each vent slit 24 is equal. S1 is the sum of the areas of the four vent slits 24, and S2 is the area of ​​the valve port 211. By reasonably adjusting the areas of the four vent slits 24 and the area of ​​the valve port 211, S1 and S2 can satisfy the above relationship, ensuring that the battery pack 100 does not easily expand or deform during charging, and also ensuring that the battery pack 100 does not easily shrink or deform during discharging.

[0069] The opening at the other end of the valve body 21 is located inside the housing 10. Specifically, the housing 10 includes multiple exhaust channels, and the opening at the other end of the valve body 21 (the end furthest from the cover 22) is located within one of these exhaust channels. Here, the exhaust channel can be understood as a space within the housing 10 that is not occupied by batteries or electrical components and allows for gas flow. The multiple exhaust channels are at least partially connected; that is, at least two of the multiple exhaust channels allow for gas flow. Thus, even if one or more exhaust channels are not directly connected to the opening at the other end of the valve body 21, gas can still be discharged from the housing 10 through the connection between the exhaust channels.

[0070] Furthermore, the area of ​​each of the plurality of ventilation slits 24 ranges from 0.05 mm. 2 Up to 10 mm 2The perimeter of each of the multiple venting slits 24 ranges from 9.5 mm to 25.1 mm. Ventilating slits 24 within this range not only meet the air intake requirements of the housing 10 but also its exhaust requirements. In other words, during the charging process of the battery pack 100, venting slits 24 within the aforementioned size range allow internal gases to be smoothly exhausted solely through the air pressure within the housing 10; simultaneously, they minimize the obstruction of gas flow by the edges of the venting slits 24. Similarly, during the discharging process of the battery pack 100, venting slits 24 within the aforementioned size range allow external gases to enter smoothly solely through the air pressure outside the housing 10; simultaneously, they minimize the obstruction of gas flow by the edges of the venting slits 24.

[0071] Optionally, the area of ​​the ventilated slit 24 can be 0.06 mm. 2 0.5mm 2 1.5 mm 2 2 mm 2 3mm 2 3.5mm 2 Or 5 mm 2 The perimeter of the ventilated slit 24 can be 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 20mm or 24mm, etc.

[0072] <Example Electrical Equipment> This utility model embodiment also provides an electrical device, including the battery pack described above. This electrical device can be, for example, a vehicle, ship, aircraft, household appliance, industrial equipment, and energy storage device. The vehicle can be, for example, a passenger car, a truck, or a construction vehicle.

[0073] It should be noted that the elements described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0074] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into multiple separate components and / or parts. The use of the public designation "a" or "an" to describe a component or part is not intended to exclude other components or parts.

[0075] It should be understood that although terms such as "first" or "second" may be used in this invention to describe various elements (such as the first sidewall and the second sidewall), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0076] The basic principles of this utility model have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this utility model are merely examples and not limitations, and should not be considered as essential features of each embodiment of this utility model. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the utility model from being implemented using the aforementioned specific details.

[0077] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A battery pack, characterized in that, The enclosure includes a housing (10) and multiple batteries disposed within the housing (10). The housing (10) is equipped with at least one vent valve (20). Gas inside the housing (10) can be discharged to the outside of the housing (10) through the at least one vent valve (20), and gas outside the housing (10) can enter the housing (10) through the at least one vent valve (20). The at least one vent valve (20) satisfies the following conditions: 0.25V / t1≤A≤0.4V / t1; and / or 0.2V / t2≤B≤0.35V / t2, Wherein, V is the net clearance of the housing (10), in ml; t1 is the time of the complete charging process of the battery pack at the maximum charging rate in a low-temperature environment, in min; t2 is the time of the complete discharging process of the battery pack in a low-temperature environment, in min; A is the exhaust rate of the at least one vent valve (20) as a whole in the complete charging process in a low-temperature environment, in ml / min; B is the intake rate of the at least one vent valve (20) as a whole in the complete discharging process in a low-temperature environment, in ml / min; and the temperature range of the low-temperature environment is -30℃ to 60℃.

2. The battery pack as described in claim 1, characterized in that, The number of at least one vent valve (20) is n, and the energy density of the battery pack is E, in Wh / kg, where 120Wh / kg≤E / n≤180Wh / kg.

3. The battery pack as described in claim 1, characterized in that, The range of V is 3 × 10 4 mL to 1×10 5 mL.

4. The battery pack as described in claim 1, characterized in that, The range of t1 is 20min≤t1≤80min.

5. The battery pack as described in claim 1, characterized in that, The range of t2 is 12min≤t2≤180min.

6. The battery pack as described in claim 1, characterized in that, The at least one vent valve (20) is a plurality of vent valves (20) arranged in a dispersed manner.

7. The battery pack as described in claim 6, characterized in that, The single vent valve (20) satisfies: 0.25V / (n×t1)≤a≤0.4V / (n×t1); and / or 0.2V / (n×t2)≤b≤0.35V / (n×t2), Wherein, a is the exhaust rate of a single vent valve (20) during the complete charging process in the low-temperature environment, in ml / min; b is the intake rate of a single vent valve (20) during the complete discharge process in the low-temperature environment, in ml / min; and n is the number of the plurality of vent valves.

8. The battery pack as claimed in claim 1, characterized in that, The box (10) satisfies: 101.3 kPa ≤ P1 ≤ 138.3 kPa Wherein, P1 is the air pressure inside the box (10) at a specific moment during the complete charging process in the low temperature environment.

9. The battery pack as described in claim 1, characterized in that... The box (10) satisfies: 101.3 kPa ≤ P2 ≤ 138.3 kPa Wherein, P2 is the gas pressure inside the box (10) at a specific moment during the complete discharge process in the low temperature environment.

10. The battery pack as claimed in claim 1, characterized in that, Each of the at least one vent valve (20) includes a cover (22), a valve body (21) and at least one connecting part (23), the valve body (21) having a valve port (211), the cover (22) being connected to the valve body (21) via the at least one connecting part (23) and partially closing the valve port (211) to form at least one vent slit (24).

11. The battery pack as claimed in claim 10, characterized in that, The at least one connecting part (23) includes a plurality of connecting parts (23), which are disposed on the outer periphery of the cover (22) and are evenly distributed at intervals along the circumference of the cover (22).

12. The battery pack as claimed in claim 11, characterized in that, A ventilated slit (24) is provided between two adjacent connecting parts (23) of the plurality of connecting parts (23).

13. The battery pack as claimed in claim 10, characterized in that, The sum of the areas of the at least one breathable slit (24) is S1, in mm. 2 The area of ​​the valve port (211) is S2, in mm. 2 , 0.01≤S1 / S2≤0.

08.

14. The battery pack as claimed in claim 13, characterized in that, The value of S1 ranges from 0.1 to 10, and the unit is mm. 2 ; And / or, The value of S2 ranges from 113 to 350, and the unit is mm. 2 .

15. The battery pack as claimed in claim 13, characterized in that, The area of ​​each of the plurality of ventilating slits (24) is S3, in mm. 2 0.05mm 2 ≤S3≤10 mm 2 .

16. The battery pack as claimed in claim 13, characterized in that, The circumferential length of each of the plurality of ventilation slits (24) is L, in mm, and 9.5 mm ≤ L ≤ 25.1 mm.

17. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1-16.

Images