A fuse for a battery pack, a battery pack, and an electrical device

Abstract

The application relates to the technical field of batteries, and discloses a fuse of a battery pack, the battery pack and a power utilization device. The fuse comprises a shell, a conductor, a cutting piece and an actuating piece. The conductor is arranged at least partially in the shell. The cutting piece is arranged in the shell. The actuating piece is arranged in the shell and is used for driving the cutting piece to move to cut off the conductor, so that a battery cell module of the battery pack is in an open circuit state. Compared with a passive cutting-off mode of a resistance wire of the fuse, the fuse can be cut off more quickly, thereby improving the technical problem that the response time of the fuse of the battery pack is too long when the fuse needs to be cut off.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery pack fuse, a battery pack, and an electrical device. Background Technology

[0002] Battery packs are widely used in power and industrial energy storage systems, marine energy storage systems and other scenarios.

[0003] In related technologies, battery packs are equipped with fuses. When the current entering the battery pack exceeds a certain value, the current flowing through the resistance wire inside the fuse also increases, thereby increasing the heat generated by the resistance wire. When the heat generated by the resistance wire continues to increase and exceeds a certain threshold, the resistance wire will burn out, thus preventing thermal runaway of the battery cell modules inside the battery pack. However, this passive melting method of the resistance wire results in an excessively long response time when the fuse needs to be melted. Summary of the Invention

[0004] This application provides a fuse for a battery pack, a battery pack, and an electrical device, which can improve the technical problem of excessively long response time when the fuse needs to be blown.

[0005] In a first aspect, embodiments of this application provide a fuse for a battery pack, comprising:

[0006] case;

[0007] A conductor, wherein the conductor is at least partially disposed within the housing;

[0008] A cutting element, wherein the cutting element is disposed within the housing; and,

[0009] An actuator is disposed within the housing and is used to drive the cutting member to move to cut off the conductor, so that the battery pack cell module is in an open circuit state, thereby shortening the response time when the fuse blows.

[0010] In one embodiment, the actuator is used to drive the cutting member to cut the conductor by deformation, so that the actuator has a simple structure.

[0011] In one embodiment, the actuator includes an electromechanical coupling material to shorten the response time when the fuse blows.

[0012] In one embodiment, the electromechanical coupling material includes at least one of a piezoelectric material, an electrostatic polymer material, and a magnetostrictive material to shorten the response time when the fuse blows.

[0013] In one embodiment, the fuse further includes a first mounting member, which includes a connecting end and a free end disposed opposite to each other. The first mounting member is connected to the housing through the connecting end, such that the free end forms a cantilever structure.

[0014] The cutting element is disposed on the first mounting member, and the actuator is used to drive the first mounting member to vibrate, so that the first mounting member drives the cutting element to cut the conductor, thereby shortening the response time when the fuse blows.

[0015] In one embodiment, the cutting element is disposed at the free end, or the cutting element is closer to the free end than the connecting end; and / or,

[0016] The actuator is disposed on the side of the cut-off member near the connection end to shorten the response time when the fuse blows.

[0017] Along the direction from the free end toward the connection end, the length of the first mounting member is L1, and the distance from the cutting member to the end face of the free end is L2. L2 is greater than or equal to 0, and the ratio of L2 to L1 is less than or equal to two-fifths, so that the cutting member can quickly cut the conductor.

[0018] In one embodiment, the fuse further includes a second mounting member, the second mounting member comprising:

[0019] A first mounting part is located between the cutting member and the actuating member, and is connected to the cutting member;

[0020] A first connecting portion, the first connecting portion connecting one end of the actuator and the first mounting portion; and,

[0021] The second connecting part is connected between the other end of the actuator and the first mounting part. The actuator can drive the first connecting part and the second connecting part to converge or open, so that the first mounting part drives the cutting part to move away from the actuator to cut the conductor, so that the actuator can drive the cutting part to cut the conductor.

[0022] In one embodiment, the ends of the first connecting portion near the actuator and the ends of the second connecting portion near the actuator are inclined in a direction away from each other; the actuator can retract to drive the first connecting portion and the second connecting portion to converge, so that the first mounting portion drives the cutting member to move away from the actuator to cut the conductor, so that the actuator drives the cutting member to cut the conductor; or,

[0023] The first connecting portion near the actuator and the second connecting portion near the actuator are inclined toward each other; the actuator can extend to drive the first connecting portion and the second connecting portion to converge, so that the first mounting portion drives the cutting member to move away from the actuator to cut the conductor, so that the actuator drives the cutting member to cut the conductor.

[0024] In one embodiment, the fuse further includes a third mounting member, the third mounting member comprising:

[0025] The second mounting part is located on the side of the actuator away from the cutting member and is connected to the inner wall of the housing;

[0026] A third connecting portion, the third connecting portion being connected between one end of the actuator and the second mounting portion; and,

[0027] A fourth connecting portion is connected between the other end of the actuator and the second mounting portion. The third connecting portion and the fourth connecting portion can be brought together or opened to allow the actuator to deform so that the actuator can drive the cutting member to cut the conductor.

[0028] In one embodiment, the conductor is provided with a groove, which is correspondingly provided with the cutting member so that the cutting member cuts the conductor from the groove, so that the actuator drives the cutting member to cut the conductor.

[0029] In one embodiment, there are multiple scoring grooves and multiple cutting elements. At least some of the scoring grooves are arranged along the direction of current flow in the conductor. Each cutting element is corresponding to one scoring groove, so that the actuator can drive the cutting element to cut the conductor.

[0030] In one embodiment, the number of the scoring grooves is multiple, and the scoring grooves are provided on both the side of the conductor near the cutting member and the side of the conductor away from the cutting member. Furthermore, the scoring grooves on the side of the conductor near the cutting member and the scoring grooves on the side of the conductor away from the cutting member are symmetrically arranged, thereby allowing the cutting member to cut the conductor more conveniently and effortlessly; and / or,

[0031] The cross-section of the groove is trapezoidal so that the cutting element can be accurately inserted into the corresponding groove to cut the conductor.

[0032] In one embodiment, the groove depth is L5, the conductor thickness is L6, and the ratio of L5 to L6 is greater than or equal to 0.1 and less than or equal to 0.48. This design allows the conductor to be easily cut by the cutting member through the groove while preventing the conductor from having excessively low strength at the groove, thus improving the reliability of the conductor; and / or,

[0033] The width of the end face of the cutting member facing the groove is L7, and the width of the bottom of the groove is L8. The ratio of L7 to L8 is greater than or equal to 0.08 and less than or equal to 1, so that the cutting member can be inserted into the bottom of the groove to cut the conductor.

[0034] Secondly, embodiments of this application also provide a battery pack including the aforementioned fuse, to have all the technical effects of the aforementioned fuse.

[0035] In one embodiment, the battery pack further includes:

[0036] Box;

[0037] A battery cell module, wherein the battery cell module is disposed within the housing, and the battery cell module comprises multiple battery cells;

[0038] Power interface, which is exposed on the outside of the enclosure; and,

[0039] A power harness, which connects the battery cell module and the power interface;

[0040] The fuse is disposed on the power harness so that the cutting element can cut the conductor, thereby putting the power harness in an open circuit state, so that the fuse can disconnect the battery cell module.

[0041] In one embodiment, the battery pack further includes:

[0042] A detection unit, wherein the detection unit is used to detect parameter information of the battery cell; and,

[0043] The control unit is electrically connected to the detection unit and the actuator respectively, so that the control unit can control the fuse to blow in a timely manner.

[0044] In one embodiment, the detection unit and the fuse are located on the same side of the battery cell module, so that the connecting cable between the detection unit and the fuse can be shorter, thereby shortening the fuse's melting time and increasing the energy density of the battery pack.

[0045] In one embodiment, the detection unit includes a first detection unit, and the battery pack further includes a force amplification structure. The force amplification structure is used to amplify the force generated by the expansion of the battery cell and transmit it to the first detection unit, so that the first detection unit can detect the expansion force parameter of the battery cell, thereby improving the sensitivity of the first detection unit.

[0046] In one embodiment, the battery cell module further includes at least two end plates, with a plurality of battery cells arranged between the two end plates, and the force amplification structure is disposed between the end plates and the battery cells to improve the sensitivity of the first detection unit.

[0047] In one embodiment, the force amplification structure and the first detection unit are both one in number. The force amplification structure is disposed between the end plate and the battery cell, and the first detection unit is disposed within the force amplification structure, to avoid reducing the energy density of the battery pack by having too many force amplification structures and first detection units; or...

[0048] The force amplification structure and the first detection unit are both in pairs. Each end plate and the adjacent cell are provided with the force amplification structure, and each force amplification structure is provided with the first detection unit. This can improve the sensitivity of the first detection unit and avoid reducing the energy density of the battery pack by having too many force amplification structures and the first detection unit.

[0049] In one embodiment, the force amplification structure includes a first force transmission component, which includes a first force receiving part, a fifth connecting part, and a sixth connecting part. The fifth connecting part and the sixth connecting part are both connected to the side of the first force receiving part that is close to the first detection unit.

[0050] When the first force-receiving part is pushed by the force of the cell expansion, the fifth connection part and the sixth connection part are driven by the first force-receiving part to open, so as to amplify the force of the cell expansion and transmit it to the first detection unit, thereby improving the sensitivity of the first detection unit.

[0051] In one embodiment, the force amplification structure includes a second force transmission component, which includes a second force receiving part, a seventh connecting part, and an eighth connecting part. The second force receiving part is located on the opposite side of the first detection unit from the first force receiving part, and the second force receiving part is located on the side of the first detection unit closer to the end plate. The seventh connecting part and the eighth connecting part are both connected to the side of the second force receiving part closer to the first detection unit.

[0052] When the first force-receiving part is pushed by the force of the cell expansion, the second force-receiving part can receive the reaction force applied by the end plate. The second force-receiving part can drive the seventh connection part and the eighth connection part to open through the reaction force applied by the end plate, so as to amplify the force of the cell expansion and transmit it to the first detection unit, thereby improving the sensitivity of the first detection unit.

[0053] In one embodiment, the force amplification structure further includes a mounting rod, a first sliding member, and a second sliding member. The first sliding member and the second sliding member are both slidably mounted on the mounting rod. The fifth connecting part and the seventh connecting part are both rotatably connected to the first sliding member, and the sixth connecting part and the eighth connecting part are both rotatably connected to the second sliding member.

[0054] The first detection unit is disposed on the mounting rod and is located between the first sliding member and the second sliding member, such that the first detection unit is partially located between the fifth connecting part and the sixth connecting part, and partially located between the seventh connecting part and the eighth connecting part, so as to realize the integrated installation of the first force transmission component, the second force receiving part and the first detection unit.

[0055] In one embodiment, the first detection unit includes a pressure sensor to detect the expansion force of the battery cell; or,

[0056] The first detection unit includes a magnetic component and an induction coil. The magnetic component and the induction coil are arranged along the axial direction of the mounting rod so that when the fifth connecting part and the sixth connecting part are opened, they can push the magnetic component and the induction coil to move towards each other, and when the seventh connecting part and the eighth connecting part are opened, they can push the magnetic component and the induction coil to move towards each other, so as to realize the detection of the expansion force of the battery cell.

[0057] In one embodiment, one end of the first detection unit is connected to the fifth connecting part and the seventh connecting part, and the other end of the first detection unit is connected to the sixth connecting part and the eighth connecting part, so as to realize the integrated installation of the first force transmission component, the second force receiving part and the first detection unit.

[0058] In one embodiment, the force amplification structure includes a third force-receiving component and a fourth force-receiving component spaced apart along a first direction. The third force-receiving component has a first inclined surface on the side facing the fourth force-receiving component, and the first inclined surface is inclined to the first direction. The fourth force-receiving component has a second inclined surface on the side facing the third force-receiving component, and the second inclined surface is parallel to the first inclined surface.

[0059] The first detection unit is disposed between the first inclined plane and the second inclined plane. The force exerted by the cell expansion can push the third force-receiving component and the fourth force-receiving component to converge along the first direction, so that the first inclined plane and the second inclined plane amplify the force exerted by the cell expansion and transmit it to the first detection unit, thereby improving the sensitivity of the first detection unit.

[0060] In one embodiment, the force amplification structure further includes a guide rod, one of the third force-bearing component and the fourth force-bearing component is fixedly connected to the guide rod, and the other of the third force-bearing component and the fourth force-bearing component is slidably connected to the guide rod, so as to improve the reliability of the movement of the third force-bearing component and the fourth force-bearing component.

[0061] In one embodiment, the force amplification structure includes a variable cross-section beam, which has a large cross-section end and a small cross-section end. The cross-sectional area of ​​the large cross-section end is larger than that of the small cross-section end. The large cross-section end is used to receive the force exerted by the cell during expansion, and the small cross-section end is used to amplify the force exerted by the cell during expansion and transmit it to the first detection unit to improve the sensitivity of the first detection unit.

[0062] In one embodiment, the number of variable cross-section beams is at least two, such that the force amplification structure includes a first variable cross-section beam and a second variable cross-section beam spaced apart, such that the first variable cross-section beam and the second variable cross-section beam can cooperate to clamp the first detection unit, thereby improving the sensitivity of the first detection unit.

[0063] In one embodiment, the force amplification structure further includes:

[0064] A first clamping part, the first clamping part being connected to the small section end of the first variable cross-section beam; and,

[0065] The second clamping part is connected to the small cross-section end of the second variable cross-section beam, and the first detection unit is clamped between the second clamping part and the first clamping part to achieve the clamping valley of the variable cross-section beam on the first detection unit.

[0066] In one embodiment, the end of the second clamping portion away from the second variable cross-section beam is hinged and fixed to the end of the first clamping portion away from the second variable cross-section beam, so as to improve the sensitivity of the first detection unit.

[0067] In one embodiment, the first variable cross-section beam and the second variable cross-section beam are sandwiched inside the battery cell module, and the second clamping part and the first clamping part protrude outside the battery cell module to improve the sensitivity of the first detection unit.

[0068] Thirdly, embodiments of this application also provide an electrical device including the battery pack described above, to have all the technical effects of the battery pack described above.

[0069] The beneficial effects of the embodiments of this application are as follows:

[0070] In this embodiment, the fuse can be driven by an actuator to move a cutting element to cut off the conductor, thereby putting the battery pack's cell module in an open-circuit state. Therefore, compared to the passive melting of the fuse's resistance wire, this embodiment can cut off the fuse more quickly, thus improving the technical problem of excessively long response time when the battery pack's fuse needs to be melted. Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 This is a schematic diagram of the battery pack provided in the embodiments of this application.

[0073] Figure 2 This is a schematic diagram of the first structure of the fuse provided in the embodiments of this application.

[0074] Figure 3 This is a schematic diagram of a second structure of the fuse provided in the embodiments of this application.

[0075] Figure 4 This is a schematic diagram of the third structure of the fuse provided in the embodiments of this application.

[0076] Figure 5 This is a schematic diagram of the first structure of the battery cell module and detection unit provided in the embodiments of this application.

[0077] Figure 6 yes Figure 5 The diagram shows one connection principle of the detection unit.

[0078] Figure 7 yes Figure 5 A magnified view of a portion of the structure under medium force.

[0079] Figure 8 yes Figure 7 A schematic diagram of another installation structure for the force amplification structure shown.

[0080] Figure 9 This is a schematic diagram of the second force amplification structure according to an embodiment of this application.

[0081] Figure 10 yes Figure 7 A three-dimensional diagram of the force magnification structure shown.

[0082] Figure 11 yes Figure 7 The diagram shows a force amplification structure with another type of first detection unit installed.

[0083] Figure 12 This is a schematic diagram of the third force amplification structure provided in the embodiments of this application.

[0084] Figure 13 This is a schematic diagram of the installation structure of the fourth force amplification structure provided in the embodiments of this application.

[0085] Figure 14 yes Figure 13 The schematic diagram of the force amplification structure shown. Figure 1 .

[0086] Figure 15 yes Figure 13 The schematic diagram of the force amplification structure shown. Figure 2 .

[0087] Figure 16 This is a connection principle diagram of the second detection unit provided in the embodiments of this application.

[0088] Figure 17 This is a second connection principle diagram of the detection unit in the embodiments of this application.

[0089] Explanation of reference numerals in the attached figures:

[0090] 100. Box body;

[0091] 200. Battery cell module;

[0092] 21. Battery cell; 22. End plate; 23. First separator; 24. Second separator;

[0093] 300. Power interface;

[0094] 400. Power wiring harness;

[0095] 41. Part One; 42. Part Two;

[0096] 500. Fuse;

[0097] 51. Housing; 52. Conductor; 521. Score groove; 53. Cut-off part; 54. Actuator; 55. First mounting part; 551. Connecting end; 552. Free end; 56. Second mounting part; 561. First mounting portion; 562. First connecting portion; 563. Second connecting portion; 57. Third mounting part; 571. Second mounting portion; 572. Third connecting portion; 573. Fourth connecting portion;

[0098] 600. Detection unit; 61. First detection unit; 611. Magnetic component; 612. Induction coil; 62. Second detection unit;

[0099] 700, Control Unit;

[0100] 800. Force amplification structure;

[0101] 81. First force transmission component; 811. First force receiving part; 812. Fifth connecting part; 813. Sixth connecting part; 82. Second force transmission component; 821. Second force receiving part; 822. Seventh connecting part; 823. Eighth connecting part; 83. Mounting rod; 831. First sliding member; 832. Second sliding member; 84. Third force receiving component; 841. First inclined surface; 85. Fourth force receiving component; 851. Second inclined surface; 86. Guide rod; 87. Variable cross-section beam; 87a. First variable cross-section beam; 87b. Second variable cross-section beam; 871. Large cross-section end; 872. Small cross-section end; 88. First clamping part; 89. Second clamping part

[0102] 900, BMS components;

[0103] L1, length of the first mounting piece; L2, distance from the cut-off piece to the end face of the free end; L3, height of the large cross-section end; L4, height of the small cross-section end; L5, groove depth of the scoring groove; L6, thickness of the conductor; L7, width of the end face of the cut-off piece facing the scoring groove; L8, width of the bottom of the scoring groove.

[0104] H1, first direction; H2, second direction. Detailed Implementation

[0105] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. In the present invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0106] This application provides a fuse for a battery pack, a battery pack, and an electrical device to improve the melting speed in the event of thermal runaway of the battery pack.

[0107] Before introducing the fuse of the embodiments of this application, we will first give an overall introduction to the technical solution of this application in conjunction with the battery pack.

[0108] The battery pack can be used in electrical devices. Electrical devices can include vehicles, such as cars, ships, and airplanes. Electrical devices can also include weighing scales, body fat scales, nutrition scales, body composition analyzers, charging devices, mobile terminals, and smart home devices, etc., but this application does not limit the scope of these devices.

[0109] Please refer to Figure 1 The battery pack may include a housing 100 and a cell module 200. The cell module 200 is disposed within the housing 100 and includes a plurality of cells 21 for storing and providing electrical energy.

[0110] The battery pack may also include a power interface 300 and a power harness 400. The power interface 300 is exposed outside the housing 100. The power harness 400 connects the cell module 200 and the power interface 300. Thus, the cell module 200 can supply power to electrical devices through the power interface 300, or an external charging device can charge the cell module 200 through the power interface 300, thereby realizing the functions of battery pack storage and power supply.

[0111] Please refer to Figure 2 The battery pack may also include a fuse 500, which is used to blow the circuit to put the cell module 200 in an open-circuit state. Furthermore, the fuse 500 can blow when thermal runaway of the cell module 200 is detected, or the fuse 500 can blow in advance when thermal runaway of the cell module 200 is detected.

[0112] For example, fuse 500 can be installed in power harness 400, so that fuse 500 can blow to put power harness 400 in an open circuit state. Then, when the cell module 200 is in an abnormal state, fuse 500 can disconnect cell module 200 from power interface 300 in a timely manner, thereby preventing external devices from continuing to charge cell module 200, thus improving the reliability and stability of battery pack.

[0113] For example, the positive or negative power harness of the fuse 500.

[0114] Optionally, the fuse 500 can also be disposed in the cell module 200; for example, the fuse 500 can be disposed in the busbar of the cell module 200. Of course, the fuse 500 can also be disposed in the BMS component 900, and this embodiment of the application does not limit this.

[0115] In related technologies, when the current entering the battery pack exceeds a certain value, the current flowing through the resistance wire inside the fuse 500 also increases, thereby increasing the heat generated by the resistance wire inside the fuse 500. When the heat generated by the resistance wire continues to increase and exceeds a certain threshold, the resistance wire will burn out, thus preventing thermal runaway of the battery cell module 200 inside the battery pack. However, this passive melting method of the resistance wire results in an excessively long response time when the fuse 500 needs to melt.

[0116] To achieve rapid melting inside fuse 500, an electronic ignition method can be used to ignite the propellant, creating an explosive impact inside fuse 500 to break the resistance wire. This propellant ignition method has a shorter response time compared to the passive melting method of the resistance wire; however, ignition still requires at least 3 milliseconds, and the propellant inside fuse 500 poses a safety hazard during battery pack transportation and subsequent use.

[0117] Based on this, embodiments of this application provide a fuse 500, which may include a housing 51, a conductor 52, a cut-off element 53, and an actuator 54.

[0118] The conductor 52 is at least partially disposed within the housing 51. The cut-off member 53 is disposed within the housing 51. The actuator 54 is disposed within the housing 51. The actuator 54 is used to drive the cut-off member 53 to move to cut off the conductor 52, so that the cell module 200 of the battery pack is in an open circuit state.

[0119] Furthermore, compared to the passive melting of the resistance wire to melt the fuse 500, in this embodiment of the application, the battery pack can drive the cutting member 53 to quickly cut off the conductor 52 through the actuator 54, so as to shorten the response time of the fuse 500 and thus promptly put the cell module 200 in an open circuit state.

[0120] Furthermore, compared to igniting gunpowder to melt the fuse 500, in this embodiment, on the one hand, the actuator 54 can drive the cutting element 53 to cut off the conductor 52 in about 10 microseconds, that is, the melting response time of the fuse 500 is 10 microseconds, thereby significantly shortening the response time of the fuse 500; on the other hand, since there is no need to put gunpowder inside the fuse 500, the safety of the battery pack during transportation and subsequent use can be improved.

[0121] Furthermore, since both the cut-off element 53 and the actuator 54 are housed within the housing 51, collisions between other parts of the battery pack and the cut-off element 53 and the actuator 54 can be avoided. This prevents the cut-off element 53 from accidentally cutting off the conductor 52 during battery pack transportation and use, thereby improving the reliability and stability of the fuse 500.

[0122] It should be noted that the conductor 52 can be connected to the power harness 400, the BMS component 900, or the busbar, and this embodiment does not limit this.

[0123] For example, the power harness 400 includes a first part 41 and a second part 42. The first part 41 is connected to the power interface 300, and the second part 42 is connected to the battery module 200. One end of the conductor 52 is connected to the first part 41, and the other end of the conductor 52 is connected to the second part 42, so that the first part 41 and the second part 42 of the power harness 400 can be connected through the conductor 52.

[0124] Furthermore, when the conductor 52 is cut off by the cut-off member 53, the power harness 400 can be disconnected, so that the battery cell module 200 is in an open circuit state.

[0125] The technical solutions of the embodiments of this application will now be described in conjunction with actuator 54.

[0126] The actuator 54 is used to cut the conductor 52 by deforming the cutting member 53. Thus, the battery pack can quickly cut the conductor 52 by the deformation of the actuator 54.

[0127] For example, actuator 54 includes electromechanical coupling material components.

[0128] It is understandable that electromechanical coupling materials are functional materials capable of converting mechanical energy into electrical energy or vice versa. Therefore, by applying an electrical signal to the electromechanical coupling material, the battery pack can quickly drive the actuator 54 to deform, thereby causing the cutting element 53 to cut off the conductor 52.

[0129] Understandably, electromechanical coupling materials have the advantage of fast response speed, allowing the cutting element 53 to cut the conductor 52 in about 10 microseconds. This shortens the response time of the fuse 500.

[0130] In addition, compared with using motors and other devices as actuators 54, electromechanical coupling materials have the advantages of being thin, light and low cost. Thus, the volume of the fuse 500 can be reduced by using thin electromechanical coupling materials, so that more space can be reserved in the battery pack to install larger cell modules 200, thereby improving the energy density of the battery pack.

[0131] In some embodiments, the electromechanical coupling material includes at least one of piezoelectric material, electrostatic polymer material, and magnetostrictive material.

[0132] Magnetostrictive material components may include Tefernol-D alloys, etc., but this application does not limit the scope of the embodiments.

[0133] Taking piezoelectric material components as an example, piezoelectric materials have the characteristics of high driving precision and fast response speed, which enables the displacement control precision of the cutting component 53 to reach 0.01 micrometers, and enables the cutting component 53 to cut the conductor 52 in about 10 microseconds.

[0134] Of course, in some other implementations, the actuator 54 may also include a motor, etc., and this application embodiment does not limit this.

[0135] The fuse 500 also includes a first mounting member 55, which includes a connecting end 551 and a free end 552 disposed opposite to each other. The first mounting member 55 is connected to the housing 51 through the connecting end 551, so that the free end 552 forms a cantilever structure. A cutting member 53 is disposed on the first mounting member 55, and an actuator 54 is used to drive the first mounting member 55 to vibrate, so that the first mounting member 55 drives the cutting member 53 to cut off the conductor 52.

[0136] Furthermore, the first mounting member 55 forms a cantilever beam structure, which makes it easier for the actuator 54 to drive the first mounting member 55 to vibrate, so that the actuator 54 can quickly drive the cutting member 53 to move through the first mounting member 55, thereby shortening the response time of the fuse 500.

[0137] In some embodiments, the cut-off element 53 is disposed at the free end 552, or the cut-off element 53 is closer to the free end 552 than the connecting end 551.

[0138] It is understandable that when the actuator 54 drives the first mounting member 55 to vibrate, the vibration amplitude of the free end 552 of the first mounting member 55 of the cantilever structure is greater than the vibration amplitude of the connecting end 551. Therefore, by placing the cutting member 53 at the free end 552, or by placing the cutting member 53 close to the free end 552, the first mounting member 55 can drive the cutting member 53 to move a greater distance, so that the cutting member 53 can cut the conductor 52.

[0139] For example, along the direction from the free end 552 toward the connecting end 551, the length of the first mounting member 55 is L1, the distance from the cutting member 53 to the end face of the free end 552 is L2, L2 is greater than or equal to 0, and the ratio of L2 to L1 is less than or equal to two-fifths.

[0140] For example, when the cutting element 53 is located at the free end 552, the piezoelectric material component and other actuator 54 are in the first vibration mode, and the free end 552 is the position with the largest displacement of the first mounting component 55. Therefore, the cutting element 53 can quickly cut off the conductor 52.

[0141] Alternatively, when the ratio of L2 to L1 is one-third, the area where the cutting element 53 is located in the second-order vibration mode of the piezoelectric material actuator 54 is the position where the displacement of the first mounting element 55 is the largest, so the cutting element 53 can quickly cut off the conductor 52.

[0142] In some embodiments, the actuator 54 may be fitted to the first mounting member 55, thereby providing some support and protection for the actuator 54 through the first mounting member 55.

[0143] For example, the actuator 54 can be bonded and fixed to the first mounting member 55.

[0144] In some implementations, the first mounting element 55 may be a metal sheet.

[0145] In some embodiments, the first mounting member 55 and the cutting member 53 can be integrally formed, so that the fuse 500 has the advantages of fewer parts and simpler assembly.

[0146] Of course, the first mounting component 55 and the cutting component 53 can also be formed separately, and this application embodiment does not limit this.

[0147] In some embodiments, the actuator 54 is disposed on the side of the cut-off member 53 near the connection end 551. Therefore, since the portion of the first mounting member 55 furthest from the connection end 551 has a greater displacement than the portion near the connection end 551, when the actuator 54 drives the first mounting member 55 to vibrate, the displacement of the cut-off member 53 can be greater than the displacement of the actuator 54, so that the cut-off member 53 can cut off the conductor 52 more quickly.

[0148] In some embodiments, the actuator 54 may also be used to extend or retract to drive the cutter 53 to move to cut the conductor 52.

[0149] Please continue to refer to this. Figure 3 For example, the fuse 500 also includes a second mounting member 56, which includes a first mounting portion 561, a first connecting portion 562, and a second connecting portion 563.

[0150] The first mounting portion 561 is located between the cutting member 53 and the actuator 54, and is connected to the cutting member 53. The first connecting portion 562 is connected between one end of the actuator 54 and the first mounting portion 561. The second connecting portion 563 is connected between the other end of the actuator 54 and the first mounting portion 561. Furthermore, the actuator 54 can drive the first connecting portion 562 and the second connecting portion 563 to converge or diverge, so that the first mounting portion 561 drives the cutting member 53 to move away from the actuator 54 to cut off the conductor 52.

[0151] For example, the ends of the first connecting portion 562 near the actuator 54 and the second connecting portion 563 near the actuator 54 are inclined in a direction away from each other, such that the included angle between the first connecting portion 562 and the first mounting portion 561 is an obtuse angle, and the included angle between the second connecting portion 563 and the first mounting portion 561 is also an obtuse angle. Therefore, when the actuator 54 retracts, the first connecting portion 562 and the second connecting portion 563 can be driven to converge, thereby causing the first mounting portion 561 to move the cutting member 53 away from the actuator 54 to cut off the conductor 52.

[0152] Optionally, the ends of the first connecting portion 562 near the actuator 54 and the second connecting portion 563 near the actuator 54 are inclined towards each other, such that the included angle between the first connecting portion 562 and the first mounting portion 561 is an acute angle, and the included angle between the second connecting portion 563 and the first mounting portion 561 is also an acute angle. Then, when the actuator 54 extends, it can drive the first connecting portion 562 and the second connecting portion 563 to open, thereby causing the first mounting portion 561 to move the cutting member 53 away from the actuator 54 to cut off the conductor 52.

[0153] It should be noted that the first mounting part 561 can be circular or square, and this application embodiment does not limit it in this respect.

[0154] In some embodiments, the fuse 500 further includes a third mounting member 57, which includes a second mounting portion 571, a third connecting portion 572, and a fourth connecting portion 573.

[0155] The second mounting portion 571 is located on the side of the actuator 54 opposite to the cutting member 53 and is connected to the inner wall of the housing 51. The third connecting portion 572 is connected between one end of the actuator 54 and the second mounting portion 571. The fourth connecting portion 573 is connected between the other end of the actuator 54 and the second mounting portion 571. The third connecting portion 572 and the fourth connecting portion 573 can be brought together or opened to allow the actuator 54 to deform.

[0156] For example, the end of the third connecting portion 572 near the actuator 54 and the end of the fourth connecting portion 573 near the actuator 54 are inclined in a direction away from each other, so that the included angle between the third connecting portion 572 and the second mounting portion 571 is an obtuse angle, and the included angle between the fourth connecting portion 573 and the second mounting portion 571 is an obtuse angle.

[0157] Optionally, the end of the third connecting portion 572 near the actuator 54 and the end of the fourth connecting portion 573 near the actuator 54 are inclined toward each other, so that the included angle between the third connecting portion 572 and the second mounting portion 571 is an acute angle, and the included angle between the fourth connecting portion 573 and the second mounting portion 571 is an acute angle. This embodiment of the application does not limit this.

[0158] In some embodiments, the second mounting member 56 and the third mounting member 57 are disposed on opposite sides of the actuator 54, such that the second mounting member 56, the third mounting member 57 and the actuator 54 form a cymbal structure.

[0159] Therefore, the cymbal structure can make the force on the second mounting member 56 and the third mounting member 57 more uniform, which makes it easier for the actuator 54 to accurately control the cutting member 53 to cut the conductor 52.

[0160] In some embodiments, the conductor 52 is provided with a scoring groove 521, which is correspondingly provided with the cutting member 53 so that the cutting member 53 can cut the conductor 52 from the scoring groove 521. Furthermore, the structure of the scoring groove 521 can facilitate the cutting member 53 to cut the conductor 52 more easily and quickly.

[0161] Please continue to refer to this. Figure 4 In some embodiments, there are multiple scoring grooves 521 and cutting elements 53, with at least some of the scoring grooves 521 arranged along the direction of current flow in the conductor 52. Each cutting element 53 corresponds to one scoring groove 521.

[0162] It should be noted that the number of notched grooves 521 can be greater than the number of cut pieces 53, and this application embodiment does not limit this.

[0163] Furthermore, the conductor 52 can be cut simultaneously using multiple cutting elements 53. In this case, even if one of the notched grooves 521 is missing a cutting element 53, the conductor 52 can still be cut using other cutting elements 53, thereby improving the reliability of the fuse 500.

[0164] In some embodiments, there are multiple scoring grooves 521, with scoring grooves 521 provided on both the side of the conductor 52 near the cutting member 53 and the side of the conductor 52 away from the cutting member 53. Furthermore, by providing scoring grooves 521 on both sides of the conductor 52, the strength of the portion of the conductor 52 with scoring grooves 521 can be reduced, making it easier for the cutting member 53 to cut the conductor 52.

[0165] In some embodiments, the scoring groove 521 on the side of the conductor 52 near the cutting member 53 is symmetrically arranged with the scoring groove 521 on the side of the conductor 52 away from the cutting member 53. Furthermore, during the process of the cutting member 53 cutting the conductor 52, the stress generated by the conductor 52 can be more concentrated at the bottom wall of the scoring groove 521, facilitating the cutting member 53 in cutting the conductor 52.

[0166] In some embodiments, the cross-section of the scoring groove 521 is trapezoidal. This allows the cutting member 53 to be easily inserted into the corresponding scoring groove 521, and also allows the stress generated by the conductor 52 during the cutting process to be more concentrated at the bottom wall of the scoring groove 521, facilitating the cutting member 53's cutting of the conductor 52.

[0167] In some embodiments, the groove depth of the scoring groove 521 is L5, the thickness of the conductor 52 is L6, and the ratio of L5 to L6 is greater than or equal to 0.1 and less than or equal to 0.48. This allows the conductor 52 to be easily cut by the cutting member 53 through the scoring groove 521, while also preventing the conductor 52 from having excessively low strength at the scoring groove 521, thereby improving the reliability of the conductor 52.

[0168] For example, the ratio of L5 to L6 is 0.1, 0.12, 0.15, 0.2, 0.23, 0.255, 0.297, 0.3, 0.34, 0.39, 0.4, 0.41, 0.45, 0.46 or 0.48.

[0169] In some implementations, the ratio of L5 to L6 is greater than or equal to 0.2 and less than or equal to 0.4.

[0170] It should be noted that the groove depth direction of the groove 521 is the same as the thickness direction of the conductor 52.

[0171] In some embodiments, the width of the end face of the cutting member 53 facing the groove 521 is L7, and the width of the bottom of the groove 521 is L8. The ratio of L7 to L8 is greater than or equal to 0.08 and less than or equal to 1, so that the cutting member 53 can be inserted into the bottom of the groove 521 to cut the conductor 52.

[0172] The above is a description of the structure of the fuse 500 in the embodiments of this application. The following will continue to describe some other structures in the battery pack.

[0173] Please continue to refer to this. Figure 5 and Figure 6 In some embodiments, the battery pack further includes a detection unit 600, which is used to detect parameter information of the battery cell 21. Furthermore, the battery pack can use the detection unit 600 to detect the operating status of the battery cell 21, thereby determining whether there is any abnormality in the battery cell 21.

[0174] The battery pack may also include a control unit 700, which is electrically connected to the detection unit 600 and the fuse 500. Furthermore, the control unit 700 can control the fuse 500 according to the operating state of the battery cell 21.

[0175] For example, the control unit 700 can be electrically connected to the actuator 54 of the fuse 500.

[0176] Furthermore, when the battery cell 21 malfunctions, the control unit 700 can send an electrical signal to the actuator 54 to deform the actuator 54, thereby driving the cut-off member 53 to cut off the conductor 52.

[0177] In some embodiments, the detection unit 600 and the fuse 500 are disposed on the same side of the cell module 200. Furthermore, compared to the detection unit 600 and the fuse 500 being located on opposite sides of the cell module 200, the embodiments of this application can shorten the connecting cable between the detection unit 600 and the fuse 500, thereby both shortening the fuse 500's melting time and increasing the energy density of the battery pack.

[0178] The technical solutions of the embodiments of this application will now be described in conjunction with the detection unit 600.

[0179] The detection unit 600 can be used to detect at least one of the impedance parameter, expansion force parameter, temperature parameter and voltage parameter of the battery cell 21.

[0180] The detection unit 600 can be installed inside the housing 100 to facilitate the detection of the battery cell 21.

[0181] Please continue to refer to this. Figure 7 , Figure 8 and Figure 9For example, the detection unit 600 may include a first detection unit 61, which is used to detect the expansion force parameter of the battery cell 21. It should be noted that the expansion force parameter of the battery cell 21 is the force applied to the outside when the battery cell 21 expands.

[0182] Understandably, compared to detecting the voltage or temperature signal of the cell module 200 to warn of whether the cell 21 is experiencing thermal runaway, detecting the expansion force parameter can provide an early warning of thermal runaway of the cell 21 2 to 10 minutes in advance, thereby facilitating the battery pack to control the fuse 500 to blow, and thus improving the safety of the battery pack.

[0183] The first detection unit 61 may include a pressure sensor, such as a strain gauge pressure sensor, a piezoelectric pressure sensor, a magnetic pressure sensor, or a capacitive pressure sensor, etc., and this application embodiment does not limit it.

[0184] Taking a battery cell module 200 comprising n battery cells 21 arranged sequentially along the first direction H1 as an example, assuming the normal thickness of a single battery cell 21 is l, and the overall thickness of the n battery cells 21 is nl, then when one of the battery cells 21 experiences thermal runaway, the mechanical change (i.e., expansion force) of that battery cell 21 is x. The relative change in deformation of a single battery cell 21 along the first direction H1 is (x+l) / l = 1+x / l. Therefore, the overall change of the n battery cells 21 along the first direction H1 is (x+nl) / (nl) = 1+x / (nl). Thus, the change x caused by thermal runaway is "diluted" along the first direction H1 of the battery cell module 200. Consequently, the detection unit 600 faces increased difficulty in sensing this change, resulting in lower sensor sensitivity.

[0185] Based on this, in this embodiment of the application, the battery pack also includes a force amplification structure 800, which is used to amplify the force generated by the expansion of the battery cell 21 and transmit it to the first detection unit 61.

[0186] Furthermore, the force amplification structure 800 amplifies the expansion force of a single cell 21 after it has been "diluted" by the entire cell module 200, thereby improving the detection sensitivity of the detection unit 600.

[0187] In the actual design process, the total expansion force generated by all the cells 21 in the cell module 200 is taken as 2000N, so as to design the tensile and compressive strength of the force amplification structure 800 and the first detection unit 61.

[0188] The first detection unit 61 can be disposed in the force amplification structure 800, so that the force amplification structure 800 can amplify the expansion force of the cell 21 and directly transmit it to the first detection unit 61, thereby shortening the force transmission path between the force amplification structure 800 and the first detection unit 61, thereby reducing the loss of force during transmission and improving the sensitivity of the first detection unit 61.

[0189] The force amplification structure 800 can be set in the cell module 200 to shorten the force transmission path between the force amplification structure 800 and the cell module 200, thereby reducing the loss of force during transmission and thus improving the sensitivity of the first detection unit 61.

[0190] The force amplification structure 800 can be set on the surface of the cell module 200.

[0191] Optionally, the force amplification structure 800 may also be at least partially disposed inside the cell module 200. For example, the force amplification structure 800 may be at least partially sandwiched inside the cell module 200 so that the expansion force of the cell 21 in the cell module 200 can be transmitted to the force amplification structure 800 more quickly and accurately.

[0192] For example, the battery module 200 also includes at least two end plates 22, with a plurality of battery cells 21 arranged between the two end plates 22, and a force amplification structure 800 disposed between the end plates 22 and the battery cells 21. Furthermore, the expansion force of the battery cell 21 can be transmitted to the force amplification structure 800 more quickly and accurately.

[0193] In some embodiments, the force amplification structure 800 and the first detection unit 61 are both one. The force amplification structure 800 is disposed between the end plate 22 and the cell 21, and the first detection unit 61 is disposed within the force amplification structure 800. This avoids the problem of excessively low energy density in the battery pack due to the presence of too many force amplification structures 800 and first detection units 61 within the battery pack.

[0194] Optionally, there are two force amplification structures 800 and two first detection units 61. Each end plate 22 is provided with a force amplification structure 800 between it and the adjacent cell 21, and each force amplification structure 800 is provided with a first detection unit 61. Thus, the detection sensitivity can be improved by using two first detection units 61, while avoiding the problem of excessive force amplification structures 800 and first detection units 61 in the battery pack, which would result in excessively low energy density of the battery pack.

[0195] like Figure 9 As shown, the force amplification structure 800 can directly contact the battery cell 21.

[0196] Optional, such as Figure 8As shown, the battery cell module 200 may further include a first separator 23, which is sandwiched between the force amplification structure 800 and the battery cell 21. The contact area between the first separator 23 and the battery cell 21 is larger than the contact area between the first separator 23 and the force amplification structure 800. Furthermore, when the battery cell 21 expands, the expansion force of a larger area on its surface can act on the first separator 23, allowing the first separator 23 to collect the expansion force of a larger area on the surface of the battery cell 21 and transmit it to the force amplification structure 800, thereby improving the detection accuracy of the detection unit 600.

[0197] In some embodiments, the thickness of the first partition 23 is greater than or equal to 3 millimeters.

[0198] It is understandable that if the thickness of the first partition 23 is too thin, the rigidity of the first partition 23 will decrease, and the first partition 23 will deform significantly to absorb part of the expansion force of the battery cell 21. In contrast, in this embodiment, the thickness of the first partition 23 is greater than or equal to 3 mm, which can effectively prevent the first partition 23 from deforming significantly and absorbing most of the expansion force of the battery cell 21, thereby improving the detection accuracy of the detection unit 600.

[0199] For example, the thickness of the first partition 23 can be 3 mm, 3.2 mm, 3.34 mm, 3.5 mm, 3.7 mm, 4.5 mm, 5.3 mm or 5.5 mm, and this application embodiment does not limit it.

[0200] The first partition 23 can be a steel plate or other rigid material plate, and this application embodiment does not limit it.

[0201] like Figure 9 As shown, the force amplification structure 800 can directly contact the end plate 22.

[0202] Optional, such as Figure 8 As shown, the cell module 200 may further include a second separator 24, which is sandwiched between the force amplification structure 800 and the end plate 22, and the contact area between the second separator 24 and the end plate 22 is larger than the contact area between the second separator 24 and the end plate 22. Furthermore, when the cell 21 expands, the reaction force on the surface of the end plate 22 can act on the second separator 24, allowing the second separator 24 to collect the reaction force from a larger area of ​​the end plate 22 surface and transmit it to the force amplification structure 800, thereby improving the detection accuracy of the detection unit 600.

[0203] In some embodiments, the thickness of the second partition 24 is greater than or equal to 3 millimeters.

[0204] Understandably, if the second partition 24 is too thin, its rigidity will decrease, causing it to deform significantly to absorb some of the reaction force from the end plate 22. In contrast, in this embodiment, the thickness of the second partition 24 is greater than or equal to 3 mm, which effectively prevents it from deforming significantly and absorbing most of the reaction force from the end plate 22, thereby improving the detection accuracy of the detection unit 600.

[0205] For example, the thickness of the second partition 24 can be 3 mm, 3.2 mm, 3.34 mm, 3.5 mm, 3.7 mm, 4.5 mm, 5.3 mm or 5.5 mm, and this application embodiment does not limit it.

[0206] The second partition 24 can be a steel plate or other rigid material plate, and this application embodiment does not limit it.

[0207] Of course, the force amplification structure 800 can also be sandwiched between two adjacent cells 21, and this application embodiment does not limit this.

[0208] Below, we will first introduce the technical solution of the embodiment of this application in conjunction with the first structure of the force amplification structure 800.

[0209] The force amplification structure 800 includes a first force transmission component 81, which comprises a first force receiving part 811, a fifth connecting part 812, and a sixth connecting part 813. The fifth connecting part 812 and the sixth connecting part 813 are both connected to the first force receiving part 811 on the side closest to the first detection unit 61. When the first force receiving part 811 is pushed by the force of the expansion of the battery cell 21, the fifth connecting part 812 and the sixth connecting part 813 are driven by the first force receiving part 811 to open, thereby amplifying and transmitting the force of the expansion of the battery cell 21 to the first detection unit 61.

[0210] In some embodiments, the end of the fifth connecting portion 812 near the first detection unit 61 and the end of the sixth connecting portion 813 near the first detection unit 61 are inclined in a direction away from each other, so that the angle between the fifth connecting portion 812 and the first force-receiving portion 811 is an obtuse angle, and the angle between the sixth connecting portion 813 and the first force-receiving portion 811 is also an obtuse angle.

[0211] In some embodiments, the angle between the fifth connecting part 812 and the first force-receiving part 811 and the angle between the sixth connecting part 813 and the first force-receiving part 811 are the same, thereby facilitating the calculation of the actual expansion force of the cell 21 based on the data detected by the first detection unit 61.

[0212] For example, the angle between the side of the fifth connection portion 812 facing the sixth connection portion 813 and the first detection unit 61 is θ, and the angle between the side of the sixth connection portion 813 facing the fifth connection portion 812 and the first detection unit 61 is also θ. Therefore, the force amplification structure 800 can amplify the expansion force of the battery cell 21 by a factor of 1 / tanθ.

[0213] In some embodiments, the force amplification structure 800 includes a second force transmission component 82, which includes a second force receiving part 821, a seventh connecting part 822, and an eighth connecting part 823. The second force receiving part 821 is located on the opposite side of the first force receiving part 811 to the first detection unit 61, and the second force receiving part 821 is located on the side of the first detection unit 61 closer to the end plate 22. The seventh connecting part 822 and the eighth connecting part 823 are both connected to the side of the second force receiving part 821 closer to the first detection unit 61. When the first force receiving part 811 is pushed by the force of the expansion of the battery cell 21, the second force receiving part 821 can receive the reaction force applied by the end plate 22. The second force receiving part 821 can drive the seventh connecting part 822 and the eighth connecting part 823 to open through the reaction force applied by the end plate 22, so as to amplify and transmit the force of the battery cell 21 during expansion to the first detection unit 61.

[0214] In some embodiments, the end of the seventh connecting portion 822 near the first detection unit 61 and the end of the eighth connecting portion 823 near the first detection unit 61 are inclined in a direction away from each other, so that the included angle between the seventh connecting portion 822 and the second force-receiving portion 821 is an obtuse angle, and the included angle between the eighth connecting portion 823 and the second force-receiving portion 821 is an obtuse angle.

[0215] In some embodiments, the angle between the seventh connecting part 822 and the second force-receiving part 821 and the angle between the eighth connecting part 823 and the second force-receiving part 821 are the same, thereby facilitating the calculation of the actual expansion force of the battery cell 21 based on the data detected by the first detection unit 61.

[0216] For example, the angle between the side of the seventh connection portion 822 facing the eighth connection portion 823 and the first detection unit 61 is θ, and the angle between the side of the eighth connection portion 823 facing the seventh connection portion 822 and the first detection unit 61 is also θ. Therefore, the force amplification structure 800 can amplify the expansion force of the battery cell 21 by a factor of 1 / tanθ.

[0217] In some embodiments, the first force transmission component 81 and the second force transmission component 82 are symmetrically arranged so that the first force transmission component 81, the second force transmission component 82, and the first detection unit 61 form a cymbal structure. Furthermore, after being subjected to the expansion force of the battery cell 21, the force distribution on the cymbal structure becomes more uniform. Therefore, the force amplification structure 800 can withstand a greater expansion force from the battery cell 21, and the first detection unit 61 can more accurately detect the magnitude of the expansion force of the battery cell 21.

[0218] The first force-receiving part 811 and the second force-receiving part 821 are sandwiched inside the battery cell module 200.

[0219] For example, the first force-receiving part 811 and the second force-receiving part 821 may be disposed between the end plate 22 and the battery cell 21.

[0220] For example, the first force-receiving part 811 faces the battery cell 21, and the second force-receiving part 821 faces the end plate 22. It is understood that the first force-receiving part 811 can directly abut against the battery cell 21 or against the first partition 23; the second force-receiving part 821 can directly abut against the end plate 22 or against the second partition 24. This application embodiment does not limit this.

[0221] In some embodiments, when θ is less than 45°, it is possible to avoid excessive spacing between the first force-bearing part 811 and the second force-bearing part 821, which would waste too much space between the end plate 22 and the cell 21, thereby improving the energy density of the battery pack.

[0222] It should be noted that the first force transmission component 81 and the second force transmission component 82 can be used to compress the first detection unit 61 or to stretch the first detection unit 61. This application embodiment does not limit this.

[0223] Please continue to refer to this. Figure 10 Taking the first force transmission component 81 and the second force transmission component 82 as examples of extruding the first detection unit 61, the force amplification structure 800 also includes a mounting rod 83, a first sliding member 831 and a second sliding member 832. The first sliding member 831 and the second sliding member 832 are both slidably mounted on the mounting rod 83. The fifth connecting part 812 and the seventh connecting part 822 are rotatably connected to the first sliding member 831. The sixth connecting part 813 and the eighth connecting part 823 are rotatably connected to the second sliding member 832.

[0224] The first detection unit 61 is disposed on the mounting rod 83. The first detection unit 61 is located between the first sliding member 831 and the second sliding member 832, such that the first detection unit 61 is partially located between the fifth connecting part 812 and the sixth connecting part 813, and partially located between the seventh connecting part 822 and the eighth connecting part 823.

[0225] Furthermore, when the battery cell 21 and end plate 22 of the battery cell module 200 jointly press the first force-bearing part 811 and the second force-bearing part 821, the first sliding member 831 and the second sliding member 832 can slide in opposite directions, so that the fifth connecting part 812, the sixth connecting part 813, the seventh connecting part 822 and the eighth connecting part 823 can jointly press the first detection unit 61.

[0226] For example, the first detection unit 61 includes a pressure sensor. The pressure sensor may be fitted onto the mounting rod 83.

[0227] Please continue to refer to this. Figure 11 Optionally, the first detection unit 61 includes a magnetic element 611 and an induction coil 612. The magnetic element 611 and the induction coil 612 are arranged along the axial direction of the mounting rod 83, so that when the fifth connecting part 812 and the sixth connecting part 813 are opened, they can push the magnetic element 611 and the induction coil 612 to move towards each other, and when the seventh connecting part 822 and the eighth connecting part 823 are opened, they can push the magnetic element 611 and the induction coil 612 to move towards each other.

[0228] Taking the first force transmission component 81 and the second force transmission component 82 for stretching the first detection unit 61 as an example, one end of the first detection unit 61 is connected to the fifth connecting part 812 and the seventh connecting part 822 respectively, and the other end of the first detection unit 61 is connected to the sixth connecting part 813 and the eighth connecting part 823 respectively.

[0229] Furthermore, the fifth connecting part 812 and the sixth connecting part 813 can stretch the first detection unit 61, and the seventh connecting part 822 and the eighth connecting part 823 can stretch the first detection unit 61.

[0230] It is understood that the first force transmission component 81 and the first detection unit 61 can be glued or fixed, or they can be screwed, snapped or welded. This application embodiment does not limit this.

[0231] The second force transmission component 82 and the first detection unit 61 can be bonded together, or they can be screwed, snapped together or welded together. This application embodiment does not limit this.

[0232] In some embodiments, the first force transmission component 81 is a one-piece molded structure; and / or, the second force transmission component 82 is a one-piece molded structure. Furthermore, the one-piece molded structure of the first force transmission component 81 and / or the second force transmission component 82 allows the force amplification structure 800 to have the advantages of fewer parts and easier assembly.

[0233] For example, both the first force transmission component 81 and the second force transmission component 82 are integrally formed structures.

[0234] For example, the fifth connecting part 812 and the sixth connecting part 813 are both rotatably connected to the first force-receiving part 811, and the second force transmission component 82 is an integrally formed structure.

[0235] For example, the first force transmission component 81 is an integrally formed structure, and the seventh connecting part 822 and the eighth connecting part 823 are rotatably connected to the second force receiving part 821.

[0236] Optionally, the fifth connecting part 812 and the sixth connecting part 813 may both be rotatably connected to the first force-receiving part 811, and the seventh connecting part 822 and the eighth connecting part 823 may both be rotatably connected to the second force-receiving part 821. This application embodiment does not limit this.

[0237] The technical solutions of the embodiments of this application will now be described in conjunction with the second structure of the force amplification structure 800.

[0238] Please continue to refer to this. Figure 12 The force amplification structure 800 includes a third force-receiving component 84 and a fourth force-receiving component 85 spaced apart along a first direction H1. The third force-receiving component 84 has a first inclined surface 841 on the side facing the fourth force-receiving component 85. The first inclined surface 841 is inclined with the first direction H1. The fourth force-receiving component 85 has a second inclined surface 851 on the side facing the third force-receiving component 84. The second inclined surface 851 is parallel to the first inclined surface 841.

[0239] The first detection unit 61 is disposed between the first inclined surface 841 and the second inclined surface 851. The force exerted by the expansion of the battery cell 21 can push the third force-receiving component 84 and the fourth force-receiving component 85 to converge along the first direction H1, so that the first inclined surface 841 and the second inclined surface 851 amplify the force exerted by the expansion of the battery cell 21 and transmit it to the first detection unit 61.

[0240] Furthermore, the third force-bearing component 84 and the fourth force-bearing component 85 can amplify the expansion force of the battery cell 21 and transmit it to the pressure sensor through the mechanical amplification mechanism of the oblique angle.

[0241] In some embodiments, the third force-bearing component 84 and the fourth force-bearing component 85 are sandwiched within the battery cell module 200.

[0242] For example, the third force-bearing component 84 and the fourth force-bearing component 85 may be disposed between the end plate 22 and the battery cell 21.

[0243] For example, the third force-bearing component 84 faces the battery cell 21, and the fourth force-bearing component 85 faces the end plate 22. It is understood that the third force-bearing component 84 can directly abut against the battery cell 21 or against the first partition 23; the fourth force-bearing component 85 can directly abut against the end plate 22 or against the second partition 24. This application embodiment does not limit this.

[0244] In some embodiments, the angle between the first inclined plane 841 and the second direction H2 is β, and the second direction H2 is perpendicular to the first direction H1. Therefore, the force amplification structure 800 can amplify the expansion force of the cell 21 by a factor of 1 / tanβ.

[0245] In some implementations, when β is less than 45°, it is possible to avoid excessive spacing between the third force-bearing component 84 and the fourth force-bearing component 85, which would waste too much space between the end plate 22 and the cell 21, thereby improving the energy density of the battery pack.

[0246] In some embodiments, the force amplification structure 800 further includes a guide rod 86, one of the second force-receiving part 821 and the third force-receiving part 84 being fixedly connected to the guide rod 86, and the other of the second force-receiving part 821 and the third force-receiving part 84 being slidably connected to the guide rod 86.

[0247] Furthermore, the third force-bearing component 84 and the fourth force-bearing component 85 can be slidably connected by the guide rod 86. Therefore, the movement of the third force-bearing component 84 and the fourth force-bearing component 85 can be more stable when the battery cell 21 expands.

[0248] The technical solutions of the embodiments of this application will now be described in conjunction with the third structure of the force amplification structure 800.

[0249] Please continue to refer to this. Figure 13 and Figure 14 The force amplification structure 800 also includes a variable cross-section beam 87, which includes a large cross-section end 871 and a small cross-section end 872. The cross-sectional area of ​​the large cross-section end 871 is larger than that of the small cross-section end 872. The large cross-section end 871 is used to receive the force exerted by the expansion of the battery cell 21, and the small cross-section end 872 is used to amplify the force exerted by the expansion of the battery cell 21 and transmit it to the first detection unit 61.

[0250] In some embodiments, the cross-sectional area of ​​the variable cross-section beam 87 is reduced along the direction from the large cross-section end 871 to the small cross-section end 872.

[0251] For example, the variable cross-section beam 87 can be a trapezoidal plate structure, with the small cross-section end 872 forming the upper base of the trapezoid and the large cross-section end 871 forming the lower base of the trapezoid.

[0252] In some embodiments, the number of variable cross-section beams 87 is at least two, such that the force amplification structure 800 includes a first variable cross-section beam 87a and a second variable cross-section beam 87b spaced apart. That is, one of the at least two variable cross-section beams 87 is a first variable cross-section beam 87a, and the other is a second variable cross-section beam 87b. The first variable cross-section beam 87a and the second variable cross-section beam 87b are spaced apart so that the first variable cross-section beam 87a and the second variable cross-section beam 87b can cooperate to clamp the first detection unit 61.

[0253] Furthermore, the first variable cross-section beam 87a and the second variable cross-section beam 87b can be sandwiched within the cell module 200 so that the force exerted by the cell 21 during expansion can act on the force amplification structure 800 along a shorter force transmission path.

[0254] For example, the first variable cross-section beam 87a and the second variable cross-section beam 87b can be disposed between the end plate 22 and the battery cell 21.

[0255] For example, the first variable cross-section beam 87a faces the battery cell 21, and the second variable cross-section beam 87b faces the end plate 22. It is understood that the first variable cross-section beam 87a can directly abut against the battery cell 21 or against the first partition plate 23; the second variable cross-section beam 87b can directly abut against the end plate 22 or against the second partition plate 24. This application embodiment does not limit this.

[0256] The first detection unit 61 can be directly clamped at the small cross-section end 872 of the first variable cross-section beam 87a and the small cross-section end 872 of the second variable cross-section beam 87b.

[0257] Optionally, the force amplification structure 800 further includes a first clamping part 88 and a second clamping part 89. The first clamping part 88 is connected to the small cross-section end 872 of the first variable cross-section beam 87a. The second clamping part 89 is connected to the small cross-section end 872 of the second variable cross-section beam 87b, and the first detection unit 61 is clamped between the second clamping part 89 and the first clamping part 88.

[0258] In some embodiments, the end of the second clamping part 89 away from the second variable cross-section beam 87b is hinged and fixed to the end of the first clamping part 88 away from the second variable cross-section beam 87b.

[0259] Therefore, with the hinge of the first clamping part 88 and the second clamping part 89 as the fulcrum, the first clamping part 88 and the first variable cross-section beam 87a form a lever, so that the first clamping part 88 and the first variable cross-section beam 87a can amplify the expansion force of the battery cell 21 and transmit it to the first detection unit 61.

[0260] With the hinge joint of the first clamping part 88 and the second clamping part 89 as the fulcrum, the second clamping part 89 and the second variable cross-section beam 87b form a lever, so that the second clamping part 89 and the second variable cross-section beam 87b can amplify the expansion force of the battery cell 21 and transmit it to the first detection unit 61.

[0261] Please continue to refer to this. Figure 15 In some embodiments, the height direction of the large cross-section end 871 is the same as the height direction of the end plate 22. The height of the large cross-section end 871 is L3, and L3 is less than or equal to 352 mm. This prevents the large cross-section end 871 from extending beyond the end plate 22, thus avoiding a decrease in the energy density of the battery pack.

[0262] In some implementations, L3 is greater than or equal to 180 mm, thereby avoiding the large cross-section end 871 being too small, which would cause the direction multiple of the expansion force of the variable cross-section beam 87 on the cell 21 to become smaller.

[0263] For example, L3 can be 180 mm, 187 mm, 190 mm, 194.5 mm, 200 mm, 213 mm, 244.3 mm, 250 mm, 265 mm, 273 mm, 289 mm, 299.9 mm, 305 mm, 314 mm, 326 mm, 340 mm, 350 mm, or 352 mm, and this application embodiment does not limit it.

[0264] In some embodiments, the height direction of the small cross-section end 872 is the same as the height direction of the end plate 22. The height of the small cross-section end 872 is L4, which is greater than or equal to 3 mm. This ensures that the small cross-section end 872 has sufficient rigidity to effectively transmit the amplified expansion force of the cell 21 to the first detection unit 61.

[0265] In some implementations, L4 is less than or equal to 20 mm, thereby avoiding the small cross-section end 872 being too small, which would cause the direction multiple of the expansion force of the variable cross-section beam 87 on the cell 21 to become smaller.

[0266] For example, L4 can be 3 mm, 5.5 mm, 6.7 mm, 8 mm, 9 mm; 10 mm, 13 mm, 15 mm, 17.2 mm, 18.13 mm or 20 mm, and this application embodiment does not limit it.

[0267] In some embodiments, the length of the variable cross-section beam 87 is L5 along the direction from the large cross-section end 871 to the small cross-section end 872, where L5 is less than 207 mm. This prevents either the small cross-section end 872 or the large cross-section end 871 of the variable cross-section beam 87 from extending beyond the end plate 22, thus avoiding a decrease in the energy density of the battery pack.

[0268] In some implementations, L5 is greater than or equal to 80 mm, thereby making the lever formed by the variable cross-section beam 87 long enough to effectively amplify the expansion force of the cell 21.

[0269] For example, L5 can be 80 mm, 84 mm, 85 mm, 89 mm, 90 mm, 95.5 mm, 97.13 mm, 109 mm, 114 mm, 127 mm, 140 mm, 156 mm, 160.4 mm, 175 mm, 183 mm, 191 mm, 200 mm, 204 mm, or 207 mm, and this application embodiment does not limit it.

[0270] In some embodiments, the first variable cross-section beam 87a and the second variable cross-section beam 87b are symmetrically arranged so that the force amplification structure 800 is subjected to more uniform and reasonable forces.

[0271] In some embodiments, the first clamping part 88 and the second clamping part 89 are symmetrically arranged so that the force amplification structure 800 is subjected to more uniform and reasonable force.

[0272] The above is an introduction to the detection unit 600 (i.e., the first detection unit 61) detecting the expansion force of the battery cell 21 in the embodiments of this application.

[0273] Please continue to refer to this. Figure 16 In some embodiments, the detection unit 600 further includes a second detection unit 62, which is used for the impedance parameters of the cell 21.

[0274] Understandably, compared to detecting the voltage or temperature signal of the cell module 200 to warn of whether the cell 21 has thermal runaway, detecting the impedance parameter can provide an early warning of thermal runaway of the cell 21 2 to 10 minutes in advance, thereby facilitating the battery pack to control the fuse 500 to blow, and thus improving the safety of the battery pack.

[0275] In some implementations, the second detection unit 62 may include an EIS (electrochemical impedance spectroscopy) chip.

[0276] For example, the second detection unit 62 can be connected to the positive output terminal of the cell module 200.

[0277] Furthermore, the second detection unit 62 can detect the impedance parameters of the entire cell module 200 from the total positive terminal of the cell module 200. Therefore, compared to setting a second detection unit 62 at each cell 21, the embodiments of this application can reduce the cost of the battery pack.

[0278] Optionally, the second detection unit 62 can be connected to the negative output terminal of the cell module 200.

[0279] Furthermore, the second detection unit 62 can detect the impedance parameters of the entire cell module 200 from the total negative terminal of the cell module 200. Therefore, compared to setting a second detection unit 62 at each cell 21, the embodiments of this application can reduce the cost of the battery pack.

[0280] The above is an introduction to the detection unit 600 (i.e., the second detection unit 62) detecting the expansion force of the battery cell 21 in the embodiments of this application.

[0281] In some embodiments, the detection unit 600 can be used to detect at least one of the expansion force parameter, temperature parameter, and voltage parameter of the battery cell 21. The detection unit 600 is also used to detect the impedance parameter of the battery cell 21. Furthermore, the detection unit 600 can detect the state of the battery cell 21 from at least two different dimensions in order to control the fuse 500 to blow in a timely manner.

[0282] For example, the detection unit 600 may include a first detection unit 61 and a second detection unit 62, so as to detect the expansion force parameter of the cell 21 through the first detection unit 61 and the impedance parameter of the cell 21 through the second detection unit 62.

[0283] Please continue to refer to this. Figure 17 In some embodiments, the cell module 200 may also include a BMS component 900 (Battery Monitoring and Management System), which is used to monitor, control and manage various performance aspects of the battery.

[0284] The control unit 700 can be part of the BMS component 900.

[0285] Optionally, the control unit 700 and the BMS component 900 can also be different parts.

[0286] For example, the control unit 700 and the BMS component 900 are both connected to the fuse 500, and the control unit 700 and the BMS component 900 are both connected to the detection unit 600.

[0287] When the detection unit 600 detects an abnormality in the parameters of the battery cell 21, the BMS component 900 can send a first signal to the fuse 500 to drive the fuse 500 to blow. If the fuse 500 does not blow in time, the control unit 700 can send a second signal to the fuse 500 to drive the fuse 500 to blow.

[0288] Optionally, when the detection unit 600 detects an abnormality in the parameters of the battery cell 21, the control unit 700 may first send a second signal to the fuse 500 to drive the fuse 500 to blow. At this time, if the fuse 500 does not blow in time, the BMS component 900 may send a first signal to the fuse 500 to drive the fuse 500 to blow.

[0289] Therefore, if either the control unit 700 or the BMS component 900 fails, the other of the control unit 700 and the BMS component 900 can still control the fuse 500 to blow, thereby improving the reliability of the battery pack.

[0290] Of course, in some other implementations, the BMS component 900 can also be connected to an external device to send the parameter information of the battery cell 21 detected by the detection unit 600 to the external device, so that the external device can determine whether the parameter information of the battery cell 21 is abnormal, so that the external device can alarm the abnormal state of the battery cell 21 based on the parameter information of the battery cell 21.

[0291] The parameter information of cell 21 may include at least one of the following: expansion force parameter, temperature parameter, voltage parameter and impedance parameter of cell 21.

[0292] External devices may include the processor of the power-consuming equipment, the high-voltage box of the battery cluster, the cloud server or the mobile terminal, etc., and this application embodiment does not limit them.

[0293] In some implementations, external devices can perform graded alarms based on the parameter information of the battery cell 21.

[0294] For example, if the parameter information of the battery cell 21 is within the first threshold range, the external device will issue a level one alarm; if the parameter information of the battery cell 21 is within the second threshold range, the external device will issue a level two alarm; if the parameter information of the battery cell 21 is within the third threshold range, the external device will issue a level three alarm.

[0295] For example, when the temperature of cell 21 is 45°C, the external device will issue a level 1 alarm; when the temperature of cell 21 is 50°C, the external device will issue a level 2 alarm; and when the temperature of cell 21 is 55°C, the external device will issue a level 3 alarm.

[0296] For example, when the voltage information of cell 21 is 3.75 V, the external device will issue a level one alarm; when the temperature information of cell 21 is 3.8 V, the external device will issue a level two alarm; when the temperature information of cell 21 is 3.85 V, the external device will issue a level three alarm.

[0297] In some implementations, if the rate of change of the parameter information of the battery cell 21 is within a first threshold range, the external device will issue a level one alarm; if the rate of change of the parameter information of the battery cell 21 is within a second threshold range, the external device will issue a level two alarm; if the rate of change of the parameter information of the battery cell 21 is within a third threshold range, the external device will issue a level three alarm.

[0298] For example, if the current expansion force growth rate of cell 21 exceeds three times the expansion force growth rate of cell 21 during normal charging and discharging, the external device will issue a level one alarm; if the current expansion force growth rate of cell 21 exceeds five times the expansion force growth rate of cell 21 during normal charging and discharging, the external device will issue a level two alarm; if the current expansion force growth rate of cell 21 exceeds seven times the expansion force growth rate of cell 21 during normal charging and discharging, the external device will issue a level three alarm.

[0299] In some implementations, an external device may trigger an alarm when the real part, imaginary part, or impedance angle in the impedance information changes from negative to positive.

[0300] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A battery pack, characterized in that, include: Box (100); A battery cell module (200) is disposed within the housing (100), and the battery cell module (200) includes a plurality of battery cells (21); A fuse (500) is disposed within the housing (100). The fuse (500) includes a housing (51), a conductor (52), a cut-off element (53), and an actuator (54). The conductor (52) is at least partially disposed within the housing (51). The cut-off element (53) and the actuator (54) are both disposed within the housing (51). The actuator (54) includes an electromechanical coupling material component. and, A detection unit (600) is used to detect the parameter information of the battery cell (21). The detection unit (600) includes a first detection unit (61), which includes a magnetic component (611) and an induction coil (612). A control unit (700) is electrically connected to the detection unit (600) and the actuator (54) respectively. The control unit (700) is used to apply an electrical signal to the actuator (54) so ​​that the actuator (54) drives the cutting member (53) to move to cut off the conductor (52), thereby putting the battery cell module (200) in an open circuit state. and, A force amplification structure (800) includes a first force-receiving part (811), a fifth connecting part (812), and a sixth connecting part (813). The fifth connecting part (812) and the sixth connecting part (813) are both connected to the side of the first force-receiving part (811) near the first detection unit (61). When the first force-receiving part (811) is pushed by the force of the expansion of the battery cell (21), the fifth connecting part (812) and the sixth connecting part (813) are connected to the side of the first force-receiving part (811) near the first detection unit (61). The sixth connecting part (813) is opened by the first force receiving part (811). When the fifth connecting part (812) and the sixth connecting part (813) are opened, they can drive the magnetic component (611) and the induction coil (612) to move relative to each other, so that the force amplification structure (800) amplifies the force of the cell (21) when it expands and transmits it to the first detection unit (61) so that the first detection unit (61) can detect the expansion force parameter of the cell (21).

2. The battery pack according to claim 1, characterized in that, The electromechanical coupling material includes at least one of piezoelectric material, electrostatic polymer material, and magnetostrictive material.

3. The battery pack according to claim 1, characterized in that, The fuse (500) further includes a first mounting member (55), which includes a connecting end (551) and a free end (552) disposed opposite to each other. The first mounting member (55) is connected to the housing (51) through the connecting end (551) so that the free end (552) forms a cantilever structure. The cutting element (53) is disposed on the first mounting member (55), and the actuator (54) is used to drive the first mounting member (55) to vibrate, so that the first mounting member (55) drives the cutting element (53) to cut the conductor (52).

4. The battery pack according to claim 3, characterized in that, The cutting element (53) is disposed at the free end (552), or the cutting element (53) is closer to the free end (552) than the connecting end (551); and / or, The actuator (54) is disposed on the side of the cut-off member (53) near the connecting end (551).

5. The battery pack according to claim 3, characterized in that, Along the direction from the free end (552) toward the connecting end (551), the length of the first mounting member (55) is L1, the distance from the cutting member (53) to the end face of the free end (552) is L2, L2 is greater than or equal to 0, and the ratio of L2 to L1 is less than or equal to two-fifths.

6. The battery pack according to claim 1, characterized in that, The fuse (500) further includes a second mounting member (56), the second mounting member (56) comprising: A first mounting part (561) is located between the cutting member (53) and the actuator (54) and is connected to the cutting member (53); A first connecting portion (562) is connected between one end of the actuator (54) and the first mounting portion (561); and, The second connecting part (563) is connected between the other end of the actuator (54) and the first mounting part (561). The actuator (54) can drive the first connecting part (562) and the second connecting part (563) to converge or open, so that the first mounting part (561) drives the cutting part (53) to move away from the actuator (54) to cut off the conductor (52).

7. The battery pack according to claim 6, characterized in that, The first connecting portion (562) is inclined at one end near the actuator (54), and the second connecting portion (563) is inclined at one end near the actuator (54) in a direction away from each other; the actuator (54) can retract to drive the first connecting portion (562) and the second connecting portion (563) to converge, so that the first mounting portion (561) drives the cutting member (53) to move away from the actuator (54) to cut off the conductor (52); or, The first connecting portion (562) is inclined at one end near the actuator (54) and the second connecting portion (563) is inclined at one end near the actuator (54) towards each other; the actuator (54) can extend to drive the first connecting portion (562) and the second connecting portion (563) to converge, so that the first mounting portion (561) drives the cutting member (53) to move away from the actuator (54) to cut off the conductor (52).

8. The battery pack according to claim 6, characterized in that, The fuse (500) further includes a third mounting member (57), the third mounting member (57) comprising: The second mounting part (571) is located on the side of the actuator (54) away from the cut-off member (53) and is connected to the inner wall of the housing (51). A third connecting portion (572) is connected between one end of the actuator (54) and the second mounting portion (571); and, The fourth connecting part (573) is connected between the other end of the actuator (54) and the second mounting part (571). The third connecting part (572) and the fourth connecting part (573) can be brought together or opened to allow the actuator (54) to deform.

9. The battery pack according to any one of claims 1 to 8, characterized in that, The conductor (52) is provided with a scoring groove (521), which is correspondingly provided with the cutting member (53) so that the cutting member (53) can cut the conductor (52) from the scoring groove (521).

10. The battery pack according to claim 9, characterized in that, The number of the scoring grooves (521) and the cutting members (53) are both multiple. At least some of the scoring grooves (521) are arranged along the direction of current flow in the conductor (52), and each cutting member (53) is corresponding to one scoring groove (521).

11. The battery pack according to claim 9, characterized in that, The number of the scoring grooves (521) is multiple. The conductor (52) is provided with scoring grooves (521) on both the side near the cut member (53) and the side of the conductor (52) away from the cut member (53). The scoring grooves (521) on the side of the conductor (52) near the cut member (53) are symmetrically arranged with the scoring grooves (521) on the side of the conductor (52) away from the cut member (53); and / or, The cross-section of the groove (521) is trapezoidal.

12. The battery pack according to claim 9, characterized in that, The groove depth of the groove (521) is L5, the thickness of the conductor (52) is L6, and the ratio of L5 to L6 is greater than or equal to 0.1 and less than or equal to 0.48; and / or, The width of the end face of the cut-off piece (53) facing the groove (521) is L7, and the width of the bottom of the groove (521) is L8. The ratio of L7 to L8 is greater than or equal to 0.08 and less than or equal to 1.

13. The battery pack according to any one of claims 1 to 8, characterized in that, The battery pack also includes: A power interface (300) is exposed outside the housing (100); and, A power harness (400) is connected between the battery cell module (200) and the power interface (300); The fuse (500) is disposed on the power harness (400) so that the cutting member (53) can cut the conductor (52) so that the power harness (400) is in an open circuit state.

14. The battery pack according to any one of claims 1 to 8, characterized in that, The detection unit (600) and the fuse (500) are located on the same side of the battery cell module (200).

15. The battery pack according to any one of claims 1 to 8, characterized in that, The battery cell module (200) further includes at least two end plates (22), and a plurality of battery cells (21) are arranged between the two end plates (22). The force amplification structure (800) is disposed between the end plates (22) and the battery cells (21).

16. The battery pack according to claim 15, characterized in that, The force amplification structure (800) and the first detection unit (61) are both one in number. The force amplification structure (800) is disposed between the end plate (22) and the battery cell (21), and the first detection unit (61) is disposed within the force amplification structure (800); or, The force amplification structure (800) and the first detection unit (61) are both two in number. Each end plate (22) and the adjacent battery cell (21) are provided with the force amplification structure (800), and each force amplification structure (800) is provided with the first detection unit (61).

17. The battery pack according to claim 15, characterized in that, The force amplification structure (800) includes a second force transmission component (82), which includes a second force receiving part (821), a seventh connecting part (822), and an eighth connecting part (823). The second force receiving part (821) and the first force receiving part (811) are located on opposite sides of the first detection unit (61), and the second force receiving part (821) is located on the side of the first detection unit (61) near the end plate (22). The seventh connecting part (822) and the eighth connecting part (823) are both connected to the side of the second force receiving part (821) near the first detection unit (61). When the first force-receiving part (811) is pushed by the expansion force of the battery cell (21), the second force-receiving part (821) can receive the reaction force applied by the end plate (22). The second force-receiving part (821) can drive the seventh connection part (822) and the eighth connection part (823) to open through the reaction force applied by the end plate (22). When the seventh connection part (822) and the eighth connection part (823) open, they can drive the magnetic component (611) and the induction coil (612) to move relative to each other, so as to amplify the force of the battery cell (21) when it expands and transmit it to the first detection unit (61).

18. The battery pack according to claim 17, characterized in that, The force amplification structure (800) further includes a mounting rod (83), a first sliding member (831), and a second sliding member (832). The first sliding member (831) and the second sliding member (832) are both slidably mounted on the mounting rod (83). The fifth connecting part (812) and the seventh connecting part (822) are both rotatably connected to the first sliding member (831). The sixth connecting part (813) and the eighth connecting part (823) are both rotatably connected to the second sliding member (832). The first detection unit (61) is disposed on the mounting rod (83). The first detection unit (61) is located between the first slider (831) and the second slider (832), such that the first detection unit (61) is partially located between the fifth connecting part (812) and the sixth connecting part (813), and partially located between the seventh connecting part (822) and the eighth connecting part (823).

19. The battery pack according to claim 18, characterized in that, The magnetic element (611) and the induction coil (612) are arranged along the axial direction of the mounting rod (83) so that when the fifth connecting part (812) and the sixth connecting part (813) are opened, they can push the magnetic element (611) and the induction coil (612) to move towards each other, and when the seventh connecting part (822) and the eighth connecting part (823) are opened, they can push the magnetic element (611) and the induction coil (612) to move towards each other.

20. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1 to 19.

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