Battery monomer, battery pack and electric equipment

Abstract

The invention discloses a single battery, a battery pack and electric equipment, and belongs to the technical field of batteries, the single battery comprises a shell, the shell comprises a main body part, a first cover plate and a second cover plate, the first cover plate and the second cover plate are connected with the main body part, the main body part, the first cover plate and the second cover plate define a containing cavity, the first cover plate and the second cover plate are oppositely arranged, and the first cover plate and the second cover plate are arranged oppositely; the first cover plate is provided with an anti-explosion valve, and the second cover plate is provided with a pole. The pole and the explosion-proof valve of the battery are arranged on the first cover plate and the second cover plate which are opposite to each other, so that thermoelectric separation can be realized, and under the condition of thermal runaway of the battery, when the ratio of the distance from the inner core to the first cover plate along the thickness direction of the first cover plate to the size of the shell along the thickness direction of the first cover plate is in a corresponding range, the battery can be separated from the battery. The risk that the explosion-proof valve is blocked by the inner core can be avoided, so that normal pressure relief of the battery is ensured, and the safety of the battery is improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery cell, a battery pack and an electrical device. Background Art

[0002] The battery explosion-proof valve is a safety device used to protect the battery. Its function is to release pressure when the internal pressure of the battery is too high to prevent the battery from exploding or leaking. However, when the battery is in thermal runaway, the inner core of the battery may block the explosion-proof valve, affecting the normal pressure relief of the battery, resulting in high gas pressure inside the battery cell, and the battery cell may explode and catch fire. Summary of the invention

[0003] Purpose of the present application: An embodiment of the present application provides a battery cell, aiming to overcome the technical problem that the inner core may cause blockage of the explosion-proof valve when the battery undergoes thermal runaway; another purpose of an embodiment of the present application is to provide a battery pack; a third purpose of an embodiment of the present application is to provide an electrical device.

[0004] Technical solution: A battery cell according to an embodiment of the present application includes:

[0005] The housing comprises a main body, and a first cover plate and a second cover plate connected to the main body, wherein the main body, the first cover plate and the second cover plate enclose a receiving cavity, the first cover plate and the second cover plate are arranged opposite to each other, the first cover plate is provided with an explosion-proof valve, and the second cover plate is provided with a pole;

[0006] An inner core is disposed in the accommodating cavity, and along the thickness direction of the first cover plate, the inner core and the first cover plate are spaced apart;

[0007] The battery cell meets the following requirements:

[0008] Where B / A ≤ 0.6, H1 / A ≥ 0.4%; or,

[0009] When B / A>0.6, H1 / A≥0.26%;

[0010] Among them, H1 is the distance from the inner core to the first cover plate along the thickness direction of the first cover plate, A is the dimension of the shell along the thickness direction of the first cover plate, and B is the dimension of the shell along the length direction of the first cover plate.

[0011] In some embodiments, the battery cell satisfies:

[0012] H1 / A≤1.67%.

[0013] In some embodiments, the battery cell satisfies:

[0014] When B / A≤0.6, 0.6%≤H1 / A≤1.67%;

[0015] When B / A>0.6, 0.84%≤H1 / A≤1.67%.

[0016] In some embodiments, the battery cell satisfies: B / A≤0.6, and 2mm

[0017] In some embodiments, the battery cell satisfies: B / A>0.6, and 0.3mm≤H1≤1.5mm.

[0018] In some embodiments, the battery cell comprises:

[0019] A support member is disposed in the accommodating cavity and is located between the inner core and the first cover plate to separate the inner core and the first cover plate;

[0020] The support member has a first through hole communicating with the accommodating cavity, and the first through hole is arranged corresponding to the explosion-proof valve.

[0021] In some embodiments, the support member has a plurality of second through holes connected to the accommodating cavity, the plurality of second through holes are arranged at intervals, and along the thickness direction of the first cover plate, the explosion-proof valve and the plurality of second through holes are staggered.

[0022] In some embodiments, a dimension of the support member along the thickness direction of the first cover plate is H2, satisfying: H2≤H1.

[0023] A battery pack comprises the battery cell described in any one of the above.

[0024] An electrical device includes the battery pack described above, or includes the battery monomer described above.

[0025] ​Beneficial effects: The battery cell of the embodiment of the present application comprises: a shell, comprising a main body, and a first cover plate and a second cover plate connected to the main body, the main body, the first cover plate and the second cover plate enclose a receiving cavity, the first cover plate and the second cover plate are arranged opposite to each other, the first cover plate is provided with an explosion-proof valve, and the second cover plate is provided with a pole; an inner core is arranged in the receiving cavity, and along the thickness direction of the first cover plate, the inner core and the first cover plate are spaced apart; the battery cell satisfies: when B / A≤0.6, H1 / A≥0.4%; or, when B / A>0.6, H1 / A≥0.26%; wherein H1 is the distance from the inner core to the first cover plate along the thickness direction of the first cover plate, A is the dimension of the shell along the thickness direction of the first cover plate, and B is the dimension of the shell along the length direction of the first cover plate. By arranging the battery pole and the explosion-proof valve on the first cover plate and the second cover plate opposite to each other, thermal and electrical separation can be achieved. In the event of thermal runaway of the battery, when the ratio of the distance from the inner core to the first cover plate along the thickness direction of the first cover plate to the size of the shell along the thickness direction of the first cover plate is within a corresponding range, the risk of the inner core blocking the explosion-proof valve is avoided, thereby ensuring the normal pressure relief of the battery and improving the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the explosion structure of a battery cell provided in an embodiment of the present application;

[0028] Figure 2 A front view of a battery cell provided in an embodiment of the present application;

[0029] Figure 3 A side view of a battery cell provided in an embodiment of the present application;

[0030] Figure 4 Provided in the embodiments of this application Figure 3 Cross-sectional view in the MM direction;

[0031] Figure 5 Provided in the embodiments of this application Figure 4 A partial enlarged view of the middle C area;

[0032] Figure 6 A front view of a support member provided in an embodiment of the present application;

[0033] Figure 7 A three-dimensional diagram of a support member provided in an embodiment of the present application;

[0034] Figure numerals: 10 - shell; 11 - main body; 12 - first cover plate; 121 - explosion-proof valve; 13 - second cover plate; 131 - pole; 14 - accommodating chamber; 20 - inner core; 30 - support member; 31 - first through hole; 32 - second through hole; X - thickness direction; Y - length direction. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "plurality" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined.

[0037] As an introduction to the implementation of this application, a battery cell is introduced. With the increasing market requirements for battery safety, thermal-electric separation design has become an important design consideration for various battery manufacturers. That is, the electrode output terminal (pole) of the battery and the explosion-proof valve are designed on different sides; the explosion-proof valve is generally designed at the bottom of the shell. In the battery, when thermal runaway occurs at a position far away from the explosion-proof valve, the gas production inside the battery will push the inner core toward the explosion-proof valve, causing the inner core to block the explosion-proof valve, resulting in the explosion-proof valve being unable to release pressure normally. As the gas pressure inside the battery continues to increase, it may even cause the battery to explode and catch fire.

[0038] In view of this, an embodiment of the present application provides a battery cell to overcome at least one of the above-mentioned technical problems.

[0039] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 In the embodiment of the present application, the battery cell includes: a shell 10 and an inner core 20.

[0040] The shell 10 includes a main body 11, and a first cover plate 12 and a second cover plate 13 connected to the main body 11. The main body 11, the first cover plate 12 and the second cover plate 13 are enclosed to form a receiving chamber 14. The first cover plate 12 and the second cover plate 13 are arranged opposite to each other. The first cover plate 12 is provided with an explosion-proof valve 121, and the second cover plate 13 is provided with a pole 131. The inner core 20 is arranged in the receiving chamber 14, and along the thickness direction X of the first cover plate 12, the inner core 20 is spaced apart from the first cover plate 12. It can be understood that the shell 10 of the battery can include a main body 11, a first cover plate 12 and a second cover plate 13. The three can be enclosed to form a receiving chamber 14 for accommodating the inner core 20 and other structures. The receiving chamber 14 can provide a good use environment for the inner core 20 and other internal structures of the battery, and to a certain extent ensure that these structures will not be affected by the external environment when working. The first cover plate 12 and the second cover plate 13 are spaced apart in the thickness direction X, and are respectively arranged at the two ends of the main body 11 along the thickness direction X, so that the explosion-proof valve 121 on the first cover plate 12 and the pole 131 on the second cover plate 13 can be separately arranged, and will not be arranged on the same side of the battery, thereby realizing the thermal and electrical separation of the battery. When the battery has thermal runaway, the high-temperature gas generated inside the battery can be discharged through the explosion-proof valve 121. At the same time, the inner core 20 inside the battery is spaced apart from the first cover plate 12, and the inner core 20 will not block the explosion-proof valve 121 on the first cover plate 12, and will not affect the discharge of the high-temperature gas inside the battery through the explosion-proof valve 121. The explosion-proof valve 121 is arranged on the side of the battery opposite to the pole 131, and is far away from the pole 131. The high-temperature gas generated inside the battery flows in a direction away from the pole 131, and will not affect the pole 131, and will not affect the conductive effect of the pole 131. This structure in which the explosion-proof valve 121 and the pole 131 are arranged on different sides of the battery has the effect of thermal and electrical separation, thereby improving the safety of the battery during use.

[0041] The battery cell satisfies: when B / A≤0.6, H1 / A≥0.4%; or, when B / A>0.6, H1 / A≥0.26%; wherein H1 is the distance from the inner core 20 to the first cover plate 12 along the thickness direction X of the first cover plate 12, A is the dimension of the shell 10 along the thickness direction X of the first cover plate 12, and B is the dimension of the shell 10 along the length direction Y of the first cover plate 12. It can be understood that when the ratio of the dimension B of the shell 10 along the length direction Y of the first cover plate 12 to the dimension A of the shell along the thickness direction X of the first cover plate is greater than 0.6, the application scenarios of such batteries are mostly for vehicles. When the ratio of the dimension B of the shell 10 along the length direction Y of the first cover plate 12 to the dimension A of the shell along the thickness direction X of the first cover plate is less than or equal to 0.6, such batteries are mostly used in energy storage devices, portable electronic devices, drones and robots, portable lighting devices and other devices. H1 and A can be measured by calipers or by 3D scanners. It should be noted that the structural performance of the explosion-proof valve 121 and the inner core 20 in the embodiment of the present application can be represented by whether the battery explodes. During the specific test, the inner core 20 is set at different positions so that the distance from the inner core 20 to the explosion-proof valve 121 is different, the battery thermal runaway state is simulated, and the opening of the explosion-proof valve 121 and the state of the battery are observed. The test results of the embodiment and the comparative example are shown in Tables 1 and 2 below (Table 1 is a table showing the relationship between H1 / A and whether the battery explodes when B / A≤0.6; Table 2 is a table showing the relationship between H1 / A and whether the battery explodes when B / A>0.6).

[0042] Table 1

[0043]

[0044]

[0045] Table 2

[0046]

[0047]

[0048] Combined with Table 1 above, it can be seen from multiple embodiments that when B / A≤0.6, H1 / A is greater than or equal to 0.4%, and when the battery has thermal runaway, the explosion-proof valve 121 on the battery can release pressure normally, and the battery does not explode. Therefore, when H1 / A is within this range, the structural performance of the explosion-proof valve 121 and the inner core 20 of the battery is good. When the battery is in a state of thermal runaway, the inner core 20 of the battery will not cause blockage to the explosion-proof valve 121. Even if the inner core 20 moves toward the direction of the explosion-proof valve 121 under the push of the gas, the movement amplitude is very small, which is less than the value of the distance H1 from the inner core 20 to the first cover plate 12 along the thickness direction X of the first cover plate 12. Therefore, the inner core 20 will not contact the first cover plate 12 provided with the explosion-proof valve 121, and will not cause blockage to the explosion-proof valve 121, which can ensure the normal opening of the explosion-proof valve 121, release pressure, and improve the safety of the battery. It can be seen from multiple comparative examples that when H1 / A is within the range of less than 0.4%, the value of H1 is small. When thermal runaway occurs in the battery, even if the inner core 20 moves a small amount under the push of the gas, the inner core 20 may come into contact with the first cover plate 12, thereby blocking the explosion-proof valve 121 on the first cover plate 12, making it impossible for the gas inside the battery to be discharged through the explosion-proof valve 121, resulting in the explosion-proof valve 121 being unable to open normally, and the internal pressure of the battery being unable to be relieved.

[0049] Combined with Table 2 above, it can be known from multiple embodiments that when B / A>0.6, H1 / A is greater than or equal to 0.26%. When the battery has thermal runaway, the explosion-proof valve 121 on the battery can release pressure normally, which can prevent the pressure inside the battery from being too high and causing explosion. Therefore, when H1 / A is within this range, the structural performance of the explosion-proof valve 121 and the inner core 20 of the battery is good. When the battery is in a state of thermal runaway, the inner core 20 of the battery will not cause blockage to the explosion-proof valve 121. Even if the inner core 20 moves toward the direction of the explosion-proof valve 121 under the push of the gas, the movement amplitude is very small, which is less than the value of the distance H1 from the inner core 20 to the first cover plate 12 along the thickness direction X of the first cover plate 12. Therefore, the inner core 20 will not contact the first cover plate 12 provided with the explosion-proof valve 121, and will not cause blockage to the explosion-proof valve 121. The explosion-proof valve 121 can be opened normally to release pressure and improve the safety of the battery. It can be seen from multiple comparative examples that when H1 / A is within the range of less than 0.26%, the value of H1 is small. When thermal runaway occurs in the battery, even if the inner core 20 moves a small amount under the push of the gas, the inner core 20 may come into contact with the first cover plate 12, thereby blocking the explosion-proof valve 121 on the first cover plate 12, making it impossible for the gas inside the battery to be discharged through the explosion-proof valve 121, resulting in the explosion-proof valve 121 being unable to open normally and the internal pressure of the battery being unable to be relieved, resulting in an explosion.

[0050] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , combined with the above embodiments, in some embodiments, the battery cell satisfies: H1 / A≤1.67%. It can be understood that H1 / A is less than or equal to 1.67%, which can make the battery have a higher capacity (battery capacity refers to the measure of the amount of electrical energy that the battery can store and release, usually in ampere-hours. The battery capacity represents the relationship between the current and the use time that the battery can provide under specific conditions), increase the discharge time of the battery, and better meet the needs of battery design and use. H1 and A can be measured by a caliper or by a three-dimensional scanner. It should be noted that the battery capacity is generally measured by a constant current discharge method. First, a constant current discharge device, a voltmeter, an ammeter and a suitable load resistor must be prepared, and the battery, the constant current discharge device, and the load resistor must be connected in series. At the same time, the voltage and discharge current of the battery are measured with a voltmeter and an ammeter respectively. Next, according to the battery specifications, a suitable constant current discharge current is set at a certain ratio (such as 0.2C, C is the rated capacity), and then the device is started to start discharging, and the voltage and current changes are closely recorded during the period. When the battery voltage drops to the specified termination voltage, the discharge is stopped, and finally the battery capacity is calculated by the formula "battery capacity (mAh) = discharge current (mA) × discharge time (h)". The test results of the embodiment are shown in Tables 3 and 4 below (Table 3 is a table showing the relationship between H1 / A and battery capacity when B / A≤0.6; Table 4 is a table showing the relationship between H1 / A and battery capacity when B / A>0.6).

[0051] Table 3

[0052]

[0053] Table 4

[0054]

[0055] Combining Table 3 and Table 4, it can be seen that for multiple batteries with the same size in the length direction Y and the same size in the thickness direction X, when B / A≤0.6, H1 / A≤1.67%. When H1 / A is greater than 1.67%, the value of H1 is larger. When designing the battery, if the distance between the inner core 20 and the first cover plate 12 is too large, although it will not cause the inner core 20 to block the explosion-proof valve 121, it will affect the volume of the inner core 20, resulting in a smaller volume of the inner core 20 and a lower energy density of the battery. This setting is not recommended. Therefore, when the battery does not explode, the value of H1 / A is less than or equal to 1.67%, the inner core 20 can be set to a larger volume, and the capacity of the inner core 20 changes less. When the values ​​of B and A remain unchanged, a higher capacity is always maintained, so that the battery has a higher energy density.

[0056] Similarly, for multiple batteries with the same size in the length direction Y and the same size in the thickness direction X, when B / A>0.6, H1 / A≤1.67%. When H1 / A is greater than 1.67%, the value of H1 is relatively large. When designing the battery, if the distance between the inner core 20 and the first cover plate 12 is too large, although it will not cause the inner core 20 to block the explosion-proof valve 121, it will affect the volume of the inner core 20, resulting in a smaller volume of the inner core 20 and a lower energy density of the battery. This setting is not recommended. Therefore, when the battery does not explode, the value of H1 / A is less than or equal to 1.67%, the inner core 20 can be set to a larger volume, and the capacity of the inner core 20 changes less. When the values ​​of B and A remain unchanged, a higher capacity is always maintained, so that the battery has a higher energy density.

[0057] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 In the embodiment of the present application, the battery cell satisfies: when B / A≤0.6, 0.6≤H1 / A≤1.67%; or, when B / A>0.6, 0.84≤H1 / A≤1.67%.

[0058] It can be understood that when B / A≤0.6, 0.6%≤H1 / A≤1.67%, when the battery is in thermal runaway (the battery also has a large capacity at this time), the explosion-proof valve 121 thereon has a better exhaust effect when it is opened. H1 / A is generally in the range of 0.6% to 1.67%, and can be any vertical value or a range value between any two values ​​of 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.67%. When B / A>0.6, 0.84%≤H1 / A≤1.67%, when the battery is in thermal runaway, the explosion-proof valve 121 thereon also has a better exhaust effect when it is opened. H1 / A is generally in the range of 0.84% ​​to 1.67%, and can be any vertical value or range value between any two values ​​among 0.84%, 1.0%, 1.2%, 1.4%, 1.6%, and 1.67%. H1 and A can be measured by a caliper or by a three-dimensional scanner. It should be noted that the exhaust effect of the battery is generally represented by the relationship between the gas production V0 per unit time when the inner core 20 has thermal runaway and the exhaust gas volume V1 per unit time of the explosion-proof valve 121. The measurement of V0 is generally measured by measuring parameters such as pressure change and temperature change during the thermal runaway of the battery, combining the volume of the battery, gas state equation and other information, and establishing a mathematical model to indirectly infer the gas production. For example, a pressure sensor is used to monitor the internal pressure change of the battery in real time, and a temperature sensor is used to measure the temperature. According to the ideal gas state equation (where is pressure, is volume, is the amount of gas substance, is the gas constant, and is temperature), when the internal volume of the battery is known, the change in the amount of gas substance is estimated, thereby obtaining the gas production V0. For the measurement of V1, a suitable flow sensor, such as a thermal mass flow sensor, a vortex flow sensor, etc., is generally installed at the exhaust port of the explosion-proof valve 121. These sensors can measure the flow rate of the gas in real time, and by integrating the flow rate over time, the exhaust gas volume V1 can be obtained. However, it is necessary to select a flow sensor that can adapt to high temperature, high pressure and complex gas environments, and ensure that the installation position does not affect the normal operation of the explosion-proof valve. When testing the exhaust effect of the battery under thermal runaway, it can be stipulated that when the value of V1 / V0 is greater than or equal to 85%, the battery has a good exhaust effect (the opening size of the explosion-proof valve 121 is fixed). The test results of the embodiment are shown in Tables 5 and 6 (Table 5 is: When B / A≤0.6, the relationship table of H1 / A and V1 / V0; Table 6 is: When B / A>0.6, the relationship table of H1 / A and V1 / V0).

[0059] Table 5

[0060]

[0061]

[0062] Table 6

[0063]

[0064]

[0065] Combined with Table 5, it can be seen that when B / A≤0.6, H1 / A is in the range of 0.6% to 1.67%, and the value of V1 / V0 is above 85%. Under the premise that the battery does not explode and has a high capacity, the battery at this time can meet the battery's exhaust requirements. When the explosion-proof valve 121 thereon is opened, it has a good exhaust effect, which can further reduce the risk of battery explosion. Combined with Table 6, it can be seen that when B / A>0.6, H1 / A is in the range of 0.84% ​​to 1.67%, and the value of V1 / V0 is also above 85%. Under the premise that the battery does not explode and has a high capacity, the battery at this time can meet the battery's exhaust requirements. When the explosion-proof valve 121 thereon is opened, it has a good exhaust effect, which can further reduce the risk of battery explosion and improve safety.

[0066] See also Figure 1 , Figure 2 , Figure 4 and Figure 5 , combined with the above embodiments, in some embodiments, the battery cell satisfies: B / A≤0.6, and 2mm

[0067] See also Figure 1 , Figure 2 , Figure 4 and Figure 5 , combined with the above embodiments, in some embodiments, the battery cell satisfies: B / A>0.6, and 0.3mm≤H1≤1.5mm. It can be understood that, combined with Table 1 and Table 2, for the battery applied to the vehicle, when the ratio of the dimension B of the shell 10 along the length direction Y to the dimension A of the shell along the thickness direction X is greater than 0.6, H1 is in the range of 0.3mm to 1.5mm, and when the battery has thermal runaway, the inner core 20 will not block the explosion-proof valve 121 on the battery, ensuring that the explosion-proof valve 121 can smoothly release the pressure on the battery.

[0068] See also Figure 1 ,​ Figure 4 , Figure 6 and Figure 7 In combination with the above embodiments, in some embodiments, the battery cell includes a support member 30. The support member 30 is disposed in the accommodating cavity 14 and is located between the inner core 20 and the first cover plate 12 to separate the inner core 20 and the first cover plate 12. The support member 30 has a first through hole 31 connected to the accommodating cavity 14, and the first through hole 31 is arranged corresponding to the explosion-proof valve 121. It can be understood that the support member 30 can be arranged between the inner core 20 and the first cover plate 12, and the support member 30 can be connected to the shell 10, for example, it can be connected to the main body 11. The support member 30 can be used to play a certain supporting role for the inner core 20. When the battery has thermal runaway, the gas generated by the battery will push the inner core 20. If the inner core 20 moves in the direction of the explosion-proof valve 121 under the push of the gas, the support member 30 can block the inner core 20 to prevent the inner core 20 from contacting the first cover plate 12 and blocking the explosion-proof valve 121 on the first cover plate 12. The support member 30 is provided with a first through hole 31 connecting the accommodating chamber 14 and the explosion-proof valve 121. The gas in the accommodating chamber 14 can flow to the explosion-proof valve 121 through the first through hole 31, impacting the explosion-proof valve 121, so that the explosion-proof valve 121 is normally opened. The inner core 20 and the first cover plate 12 are arranged at intervals, and the inner core 20 will not cause blockage to the explosion-proof valve 121, while ensuring that the battery can be normally depressurized, thereby improving the safety of the battery. The support member 30 can be made of high temperature resistant materials such as alumina fiber and polyimide. A first protrusion facing the inner core 20 can be provided on the support member 30. When the battery has thermal runaway, the inner core 20 moves toward the support member 30 under the push of the gas, and will contact the first protrusion. Due to the support of the first protrusion, the inner core 20 can be prevented from blocking the first through hole 31 on the support member 30, ensuring that the gas generated by the battery can pass through the first through hole 31.

[0069] See also Figure 1 , Figure 4 , Figure 6 and Figure 7In combination with the above embodiments, in some embodiments, the support member 30 has a plurality of second through holes 32 connected to the accommodating cavity 14, the plurality of second through holes 32 are arranged at intervals, and along the thickness direction X of the first cover plate 12, the explosion-proof valve 121 and the plurality of second through holes 32 are arranged in a staggered manner. It can be understood that the plurality of second through holes 32 are arranged on the support member 30, and the gas inside the accommodating cavity 14 can flow to the position of the explosion-proof valve 121 through the plurality of second through holes 32. By providing a plurality of second through holes 32, the flow rate of the support member 30 can be increased, and the exhaust effect of the support member 30 can be improved, so that when the battery has thermal runaway, there is enough gas to reach the position of the explosion-proof valve 121 through the support member 30 in time, squeeze the explosion-proof valve 121, so that the explosion-proof valve 121 can be opened in time, and the pressure inside the battery is relieved to prevent the explosion-proof valve 121 from being unable to open in time due to insufficient gas pressure at the position of the explosion-proof valve 121 due to the obstruction of the support member 30; or the exhaust efficiency of the explosion-proof valve 121 after opening is poor due to the obstruction of the support member 30. Since the second through hole 32 and the explosion-proof valve 121 are staggered in the thickness direction X, a certain gap can be set between the support member 30 and the first cover plate 12, so that the gas passing through the second through hole 32 can flow to the position of the explosion-proof valve 121 and squeeze the explosion-proof valve 121. A second protrusion facing the first cover plate 12 may be provided on the support member 30, and the second protrusion may contact the first cover plate 12. When the battery has thermal runaway, the gas generated by the inner core 20 or the battery may squeeze the support member 30. If the connection between the support member 30 and the main body 11 is not good, the support member 30 may move toward the first cover plate 12, causing the first cover plate 12 to block the multiple second through holes 32. The second protrusion is supported between the support member 30 and the first cover plate 12, so that the multiple second through holes 32 will not be blocked by the first cover plate 12. Even if the support member 30 moves toward the first cover plate 12, the gas inside the battery can still flow to the position of the explosion-proof valve 121 through the multiple second through holes 32 and be discharged through the explosion-proof valve 121.

[0070] See also Figure 1 , Figure 4 and Figure 5In combination with the above embodiments, in some embodiments, the dimension of the support member 30 along the thickness direction X of the first cover plate 12 is H2, satisfying: H2≤H1. It can be understood that the dimension of the support member 30 along the thickness direction X of the first cover plate 12 can be less than or equal to the distance from the inner core 20 to the first cover plate 12 along the thickness direction X of the first cover plate 12. By setting the support member 30, when the battery has thermal runaway, the situation that the explosion-proof valve 121 is blocked due to the small distance from the inner core 20 to the first cover plate 12 along the thickness direction X can be avoided. When H2=H1, the two sides of the support member 30 along the thickness direction X are in contact with the inner core 20 and the first cover plate 12 respectively. In the case of thermal runaway, due to the obstruction of the support member 30, the inner core 20 will not move in the direction of the explosion-proof valve 121, ensuring that the gas can be discharged smoothly through the explosion-proof valve 121. When H2 is less than H1, in the event of thermal runaway, the inner core 20 may move toward the explosion-proof valve 121 under the push of the gas, but after moving a certain distance, it will contact the support member 30 and be blocked by the support member 30, unable to move further, thereby failing to block the explosion-proof valve 121, and ensuring that the gas can be discharged smoothly through the explosion-proof valve 121.

[0071] A battery pack for storing and releasing electric energy comprises a box and a plurality of the above-mentioned battery cells, wherein the plurality of battery cells are accommodated in the box. When a plurality of battery cells are stacked to form a battery pack, the explosion-proof valves 121 on different battery packs are arranged relative to each other, so that when the explosion-proof valve 121 is ejected, the ejected material will not affect the poles 131 on other battery packs, and the risk of short circuit failure of other battery packs can be reduced. The explosion-proof valves 121 on the two corresponding battery packs can be staggered, so as to avoid affecting the opposite explosion-proof valve 121 when the explosion-proof valve 121 is opened. Among them, the battery pack can be a battery module, a battery pack, a battery cluster, a battery stack, a battery tower, a battery array, etc., which is a charging and discharging structure composed of a plurality of battery cells. Battery cells include but are not limited to lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present disclosure are not limited to this.

[0072] An electrical device, including the battery pack mentioned above, or including the battery cell mentioned above. The battery pack or the battery cell is the power supply of the electrical device. The electrical device can be a mobile phone, a portable device, a laptop computer, an electric vehicle, an electric car, a ship, a spacecraft, an electric toy, an electric tool, etc. For example, a spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft; an electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy; an electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer.

[0073] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] The battery cells, battery packs and electrical equipment provided in the embodiments of the present application are introduced in detail above, and the principles and implementation methods of the present application are explained by using specific examples. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: The housing (10) comprises a main body (11), and a first cover plate (12) and a second cover plate (13) connected to the main body (11), wherein the main body (11), the first cover plate (12) and the second cover plate (13) enclose a receiving cavity (14), the first cover plate (12) and the second cover plate (13) are arranged opposite to each other, the first cover plate (12) is provided with an explosion-proof valve (121), and the second cover plate (13) is provided with a pole (131); an inner core (20) disposed in the accommodating cavity (14), and along a thickness direction (X) of the first cover plate (12), the inner core (20) and the first cover plate (12) are spaced apart from each other; The battery cell meets the following requirements: Where B / A ≤ 0.6, H1 / A ≥ 0.4%; or, When B / A>0.6, H1 / A≥0.26%; Wherein, H1 is the distance from the inner core (20) to the first cover plate (12) along the thickness direction (X) of the first cover plate (12), A is the dimension of the shell (10) along the thickness direction (X) of the first cover plate (12), and B is the dimension of the shell (10) along the length direction (Y) of the first cover plate (12).

2. The battery cell according to claim 1, characterized in that: The battery cell meets the following requirements: H1 / A≤1.67%.

3. The battery cell according to claim 2, characterized in that: The battery cell meets the following requirements: In the case of B / A≤0.6, 0.6%≤H1 / A≤1.67%; or, When B / A>0.6, 0.84%≤H1 / A≤1.67%.

4. The battery cell according to claim 1, characterized in that: The battery cell satisfies: B / A≤0.6, and 2mm<H1≤8.4mm.

5. The battery cell according to claim 1, characterized in that: The battery cell satisfies: B / A>0.6, and 0.3mm≤H1≤1.5mm.

6. The battery cell according to claim 1, characterized in that: The battery cell comprises: a support member (30) disposed in the accommodating cavity (14) and located between the inner core (20) and the first cover plate (12) so as to separate the inner core (20) and the first cover plate (12); The support member (30) has a first through hole (31) communicating with the accommodating cavity (14), and the first through hole (31) is arranged corresponding to the explosion-proof valve (121).

7. The battery cell according to claim 6, characterized in that: The support member (30) has a plurality of second through holes (32) connected to the accommodating cavity (14); the plurality of second through holes (32) are arranged at intervals; and along the thickness direction (X) of the first cover plate (12), the explosion-proof valve (121) and the plurality of second through holes (32) are arranged in a staggered manner.

8. The battery cell according to claim 6, characterized in that: The dimension of the support member (30) along the thickness direction (X) of the first cover plate (12) is H2, satisfying: H2≤H1.

9. A battery pack, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The method comprises a battery cell as claimed in any one of claims 1 to 8, or a battery pack as claimed in claim 9.

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