Fuse of battery pack, battery pack and electric equipment

Abstract

The invention relates to the technical field of batteries, and discloses a fuse of a battery pack, the battery pack and electric equipment, the fuse comprises a shell, an electric conductor, a cut-off piece and an actuating piece; the electric conductor is at least partially arranged in the shell; the cut-off piece is arranged in the shell; and the actuating piece is arranged in the shell and is used for driving the cutting piece to move to cut off the electric conductor, so that the battery cell module of the battery pack is in an open-circuit state. Compared with a mode of passively fusing the resistance wire of the fuse, the embodiment of the invention can cut off the fuse more quickly, so that the technical problem that the response time is too long when the fuse of the battery pack needs to be fused is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a fuse of a battery pack, a battery pack and a power-using device. BACKGROUND

[0002] The battery pack is widely used in power and commercial energy storage systems, ship energy storage systems and the like.

[0003] In the related art, a fuse is arranged in the battery pack, when the current entering the battery pack exceeds a certain value, the current passing through the resistance wire inside the fuse will also increase, so that the heat generation of the resistance wire inside the fuse increases. When the heat generation of the resistance wire continuously increases to exceed a certain threshold, the resistance wire will be burned out, thereby preventing the thermal runaway of the battery cell module inside the battery pack. However, this passive fusing mode of the resistance wire causes the response time of the fuse to be too long when the fuse needs to be fused. SUMMARY

[0004] The embodiments of the present application provide a fuse of a battery pack, a battery pack and a power-using device, which can improve the technical problem of the response time being too long when the fuse needs to be fused.

[0005] In a first aspect, the embodiments of the present application provide a fuse of a battery pack, comprising: a housing; a conductive body, the conductive body being at least partially arranged in the housing; a cutting member, the cutting member being arranged in the housing; and an actuating member, the actuating member being arranged in the housing, the actuating member being configured to drive the cutting member to cut the conductive body, so that the battery cell module is in an open circuit state, thereby shortening the response time of the fuse when the fuse needs to be fused.

[0006] In an embodiment, the actuating member is configured to deform to drive the cutting member to cut the conductive body, so that the structure of the actuating member is simple.

[0007] In an embodiment, the actuating member comprises an electromechanical coupling material, thereby shortening the response time of the fuse when the fuse needs to be fused.

[0008] In an embodiment, the electromechanical coupling material comprises at least one of a piezoelectric material, an electrostatic polymer material and a magnetostrictive material, thereby shortening the response time of the fuse when the fuse needs to be fused.

[0009] In an embodiment, the fuse further comprises a first mounting member, the first mounting member comprising a connecting end and a free end arranged oppositely, the first mounting member being connected to the housing through the connecting end, so that the free end forms a cantilever structure. The cutting member is arranged on the first mounting member, and the actuating member is configured to drive the first mounting member to vibrate, so that the first mounting member drives the cutting member to cut the conductive body, thereby shortening the response time when the fuse is blown.

[0010] In an embodiment, the cutting member is arranged on the free end, or the cutting member is closer to the free end than to the connecting end; and / or, The actuating member is arranged on one side of the cutting member close to the connecting end, so as to shorten the response time when the fuse is blown.

[0011] In the direction from the free end to the connecting end, the length of the first mounting member is L1, and the distance from the cutting member to the end surface 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 as to facilitate the cutting member to quickly cut the conductive body.

[0012] In an embodiment, the fuse further comprises a second mounting member, wherein the second mounting member comprises: a first mounting portion arranged between the cutting member and the actuating member and connected to the cutting member; a first connecting portion connected between one end of the actuating member and the first mounting portion; and a second connecting portion connected between the other end of the actuating member and the first mounting portion, and the actuating member is capable of driving the first connecting portion and the second connecting portion to converge or diverge, so that the first mounting portion drives the cutting member to move away from the actuating member to cut the conductive body, thereby facilitating the actuating member to drive the cutting member to cut the conductive body.

[0013] In an embodiment, one end of the first connecting portion close to the actuating member and one end of the second connecting portion close to the actuating member are arranged to be inclined away from each other; the actuating member is capable of contraction 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 actuating member to cut the conductive body, thereby facilitating the actuating member to drive the cutting member to cut the conductive body; or, one end of the first connecting portion close to the actuating member and one end of the second connecting portion close to the actuating member are arranged to be inclined towards each other; the actuating member is capable of elongation 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 actuating member to cut the conductive body, thereby facilitating the actuating member to drive the cutting member to cut the conductive body.

[0014] In an embodiment, the fuse further comprises a third mounting member, the third mounting member comprising: a second mounting portion located on a side of the actuating member away from the cutting member and connected to an inner wall of the housing; a third connecting portion connected between one end of the actuating member and the second mounting portion; and, a fourth connecting portion connected between the other end of the actuating member and the second mounting portion, the third connecting portion and the fourth connecting portion being capable of being gathered or spread apart to allow the actuating member to deform so as to drive the cutting member to cut the electrically conductive body.

[0015] In an embodiment, the electrically conductive body is provided with score grooves, the score grooves being provided in correspondence with the cutting members so as to be cut by the cutting members from the score grooves, so as to allow the actuating member to drive the cutting members to cut the electrically conductive body.

[0016] In an embodiment, the score grooves and the cutting members are both provided in a plurality, at least part of the score grooves being arranged along a direction of current flow in the electrically conductive body, each of the cutting members being provided in correspondence with one of the score grooves, so as to allow the actuating member to drive the cutting members to cut the electrically conductive body.

[0017] In an embodiment, the score grooves are provided in a plurality, the electrically conductive body being provided with the score grooves on a side of the electrically conductive body close to the cutting members and on a side of the electrically conductive body away from the cutting members, and the score grooves on the side of the electrically conductive body close to the cutting members being provided in symmetry with the score grooves on the side of the electrically conductive body away from the cutting members, so as to allow the cutting members to cut the electrically conductive body more conveniently and labor-savingly; and / or, a cross section of the score groove is trapezoidal, so as to allow the cutting members to be accurately inserted into the corresponding score grooves, thereby cutting the electrically conductive body.

[0018] In an embodiment, a groove depth of the score groove is L5, a thickness of the electrically conductive body is L6, a ratio of L5 to L6 is greater than or equal to 0.1 and less than or equal to 0.48, so as to allow the cutting members to cut the electrically conductive body through the score grooves, and to avoid the electrically conductive body being too weak at the score grooves, thereby improving reliability of the electrically conductive body; and / or, a width of an end face of the cutting member facing the score groove is L7, a width of a groove bottom of the score groove is L8, a ratio of L7 to L8 is greater than or equal to 0.08 and less than or equal to 1, so as to allow the cutting members to be inserted into the groove bottom of the score groove, thereby cutting the electrically conductive body.

[0019] In a second aspect, an embodiment of the present application further provides a battery pack comprising the above-mentioned fuse, so as to have all the technical effects of the above-mentioned fuse.

[0020] In one embodiment, the battery pack further includes: Box; A battery cell module, the battery cell module is arranged in the box, and the battery cell module includes a plurality of battery cells; a power interface, the power interface being exposed outside the box; and A power harness connected between the battery module and the power interface; Wherein, the fuse is arranged in the power harness so that the cutting piece can cut off the conductor and thus put the power harness into an open circuit state, so that the fuse can disconnect the battery module.

[0021] In one embodiment, the battery pack further includes: a detection unit, the detection unit being used to detect parameter information of the battery cell; and, A control unit is electrically connected to the detection unit and the actuating member, so that the control unit can control the fuse to blow in time.

[0022] In one embodiment, the detection unit and the fuse are arranged on the same side close to the battery cell module, so that the connecting cable between the detection unit and the fuse can be shorter, thereby shortening the blowing time of the fuse and improving the energy density of the battery pack.

[0023] In one embodiment, the detection unit includes a first detection unit, and the battery pack also includes a force amplification structure, which 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 is used to detect the expansion force parameters of the battery cell to improve the sensitivity of the first detection unit.

[0024] In one embodiment, the battery cell module further includes at least two end plates, a plurality of the battery cells are arranged between the two end plates, and the force amplification structure is arranged between the end plates and the battery cells to improve the sensitivity of the first detection unit.

[0025] In one embodiment, the number of the force amplification structure and the first detection unit are both one, the force amplification structure is arranged between the end plate and the battery cell, and the first detection unit is arranged in the force amplification structure, so as to avoid an excessive number of the force amplification structures and the first detection units reducing the energy density of the battery pack; or, The number of the force amplification structures and the first detection units is two, the force amplification structure is arranged between each end plate and the adjacent battery cell, and each force amplification structure is provided with the first detection unit, so that the sensitivity of the first detection unit can be improved, and the energy density of the battery pack can be improved.

[0026] In an embodiment, the force amplification structure comprises a first force transmission component, the first force transmission component comprises a first force receiving part, a fifth connecting part and a sixth connecting part, and the fifth connecting part and the sixth connecting part are connected to the first force receiving part on the side close to the first detection unit. When the first force receiving part is pushed by the force generated by the expansion of the battery cell, the fifth connecting part and the sixth connecting part are driven to open by the first force receiving part, so as to amplify and transmit the force generated by the expansion of the battery cell to the first detection unit, and the sensitivity of the first detection unit is improved.

[0027] In an embodiment, the force amplification structure comprises a second force transmission component, the second force transmission component comprises 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 force receiving part relative to the first detection unit, and the second force receiving part is located on the side close to the end plate relative to the first detection unit, and the seventh connecting part and the eighth connecting part are connected to the second force receiving part on the side close to the first detection unit. When the first force receiving part is pushed by the force generated by the expansion of the battery cell, the second force receiving part can receive the reaction force applied by the end plate, and the second force receiving part can drive the seventh connecting part and the eighth connecting part to open by the reaction force applied by the end plate, so as to amplify and transmit the force generated by the expansion of the battery cell to the first detection unit, and the sensitivity of the first detection unit is improved.

[0028] In an embodiment, the force amplification structure further comprises a mounting rod, a first sliding part and a second sliding part, the first sliding part and the second sliding part are slidingly mounted on the mounting rod, the fifth connecting part and the seventh connecting part are rotationally connected to the first sliding part, and the sixth connecting part and the eighth connecting part are rotationally connected to the second sliding part. The first detection unit is arranged on the mounting rod, and the first detection unit is located between the first sliding part and the second sliding part, so 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 integrated installation of the first force transmission component, the second force receiving part and the first detection unit.

[0029] In an embodiment, the first detection unit comprises a pressure sensor to realize detection of the expansion force of the battery cell; or, The first detection unit comprises a magnetic element and an induction coil, which are arranged along the axial direction of the mounting rod, so that when the fifth connecting part and the sixth connecting part are opened, the magnetic element and the induction coil are pushed to move towards each other, and when the seventh connecting part and the eighth connecting part are opened, the magnetic element and the induction coil are pushed to move towards each other, to realize detection of the expansion force of the battery cell.

[0030] In an embodiment, one end of the first detection unit is connected with the fifth connecting part and the seventh connecting part respectively, and the other end of the first detection unit is connected with the sixth connecting part and the eighth connecting part respectively, to realize integrated installation of the first force transmission part, the second force receiving part and the first detection unit.

[0031] In an embodiment, the force amplification structure comprises a third force receiving part and a fourth force receiving part arranged at intervals along a first direction, the third force receiving part is provided with a first inclined surface on one side facing the fourth force receiving part, the first inclined surface is inclined to the first direction, the fourth force receiving part is provided with a second inclined surface on one side facing the third force receiving part, the second inclined surface is parallel to the first inclined surface; The first detection unit is arranged between the first inclined surface and the second inclined surface, and the force of the battery cell expansion can push the third force receiving part and the fourth force receiving part to gather along the first direction, so that the first inclined surface and the second inclined surface amplify the force of the battery cell expansion and transmit it to the first detection unit, to improve the sensitivity of the first detection unit.

[0032] In an embodiment, the force amplification structure further comprises a guide rod, one of the third force receiving part and the fourth force receiving part is fixedly connected with the guide rod, and the other of the third force receiving part and the fourth force receiving part is slidingly connected with the guide rod, to improve the reliability of the movement of the third force receiving part and the fourth force receiving part.

[0033] In an embodiment, the force amplification structure comprises a variable cross-section beam, the variable cross-section beam comprises 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 of the battery cell expansion, and the small cross-section end is used to amplify the force of the battery cell expansion and then transmit it to the first detection unit, to improve the sensitivity of the first detection unit.

[0034] In an embodiment, the number of the variable cross-section beams is at least two, so that the force amplification structure comprises a first variable cross-section beam and a second variable cross-section beam arranged at intervals, the first variable cross-section beam and the second variable cross-section beam being arranged at intervals so that the first variable cross-section beam and the second variable cross-section beam can cooperate to clamp the first detection unit, so as to improve the sensitivity of the first detection unit.

[0035] In an embodiment, the force amplification structure further comprises: a first clamping portion connected to the small cross-section end of the first variable cross-section beam; and a second clamping portion connected to the small cross-section end of the second variable cross-section beam, the first detection unit being clamped between the second clamping portion and the first clamping portion, so as to realize the clamping valley bottom of the first detection unit by the variable cross-section beam.

[0036] In an embodiment, the second clamping portion is hingedly fixed away from one end of the second variable cross-section beam and the first clamping portion is hingedly fixed away from one end of the second variable cross-section beam, so as to improve the sensitivity of the first detection unit.

[0037] In an embodiment, the first variable cross-section beam and the second variable cross-section beam are clamped in the battery cell module, and the second clamping portion and the first clamping portion protrude out of the battery cell module, so as to improve the sensitivity of the first detection unit.

[0038] In a third aspect, the embodiments of the present application further provide a power utilization device comprising the battery pack as described above, so as to have all the technical effects of the battery pack.

[0039] The embodiments of the present application have the following beneficial effects: In the embodiments of the present application, the fuse can drive the cutting member to move to cut the conductive body by the actuating member, so that the battery cell module of the battery pack is in an open circuit state. Therefore, compared with the passive fusing mode of the resistance wire of the fuse, the embodiments of the present application can cut the fuse more quickly, thereby improving the technical problem of long response time of the fuse of the battery pack when the fuse needs to be fused. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0041] Figure 1 is a structural schematic diagram of a battery pack provided by the embodiments of the present application.

[0042] Figure 2 This is a schematic diagram of the first structure of the fuse provided in the embodiment of the present application.

[0043] Figure 3 This is a second structural diagram of the fuse provided in an embodiment of the present application.

[0044] Figure 4 This is a third structural diagram of the fuse provided in the embodiment of the present application.

[0045] Figure 5 This is a first structural diagram of a battery cell module and a detection unit provided in an embodiment of the present application.

[0046] Figure 6 yes Figure 5 A connection principle diagram of the detection unit shown.

[0047] Figure 7 yes Figure 5 A partial enlarged view of the force amplification structure.

[0048] Figure 8 yes Figure 7 Schematic diagram of another installation structure of the force amplification structure shown.

[0049] Figure 9 It is a structural schematic diagram of the second force amplification structure of an embodiment of the present application.

[0050] Figure 10 yes Figure 7 A perspective view of the force amplification structure shown.

[0051] Figure 11 yes Figure 7 The force amplification structure shown is a schematic structural diagram of another first detection unit installed.

[0052] Figure 12 It is a structural schematic diagram of the third force amplification structure provided in an embodiment of the present application.

[0053] Figure 13 This is a schematic diagram of the installation structure of the fourth force amplification structure provided in an embodiment of the present application.

[0054] Figure 14 yes Figure 13 Structural diagram of the force amplification structure shown Figure 1 .

[0055] Figure 15 yes Figure 13 Structural diagram of the force amplification structure shown Figure 2 .

[0056] Figure 16 This is a connection principle diagram of the second detection unit provided in an embodiment of the present application.

[0057] Figure 17 is a second connection principle diagram of the detection unit in the embodiment of the application.

[0058] Legend: 100, box body; 200, battery cell module; 21, battery cell; 22, end plate; 23, first partition plate; 24, second partition plate; 300, power supply interface; 400, power harness; 41, first part; 42, second part; 500, fuse; 51, housing; 52, electrically conductive body; 521, score groove; 53, cutting member; 54, actuating member; 55, first mounting member; 551, connecting end; 552, free end; 56, second mounting member; 561, first mounting portion; 562, first connecting portion; 563, second connecting portion; 57, third mounting member; 571, second mounting portion; 572, third connecting portion; 573, fourth connecting portion; 600, detection unit; 61, first detection unit; 611, magnetic member; 612, induction coil; 62, second detection unit; 700, control unit; 800, force amplification structure; 81, first force transmission member; 811, first force receiving portion; 812, fifth connecting portion; 813, sixth connecting portion; 82, second force transmission member; 821, second force receiving portion; 822, seventh connecting portion; 823, eighth connecting portion; 83, mounting rod; 831, first sliding member; 832, second sliding member; 84, third force receiving member; 841, first inclined surface; 85, fourth force receiving member; 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 portion; 89, second clamping portion 900, BMS assembly; L1, length of the first mounting member; L2, distance from the cutting member to the end surface 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 score groove; L6, thickness of the electrically conductive body; L7, width of the end surface of the side of the cutting member facing the score groove; L8, width of the groove bottom of the score groove; H1, first direction; H2, second direction. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0060] Embodiments of the present application provide a fuse for a battery pack, a battery pack, and an electrical device to increase the fusing speed when the battery pack experiences thermal runaway.

[0061] Below, before introducing the fuse of the embodiment of the present application, an overall introduction to the technical solution of the present application is first made in conjunction with the battery pack.

[0062] The battery pack can be used in electrical devices. Electrical devices can include vehicles, such as vehicles, ships, and aircraft. Electrical devices can also include weight scales, body fat scales, nutrition scales, body composition analyzers, charging devices, mobile terminals, and smart home devices, although this embodiment of the present application does not limit this.

[0063] Please refer to Figure 1 The battery pack may include a box body 100 and a battery cell module 200. The battery cell module 200 is disposed in the box body 100 and includes a plurality of battery cells 21 for storing and providing electric energy.

[0064] The battery pack also includes a power interface 300 and a power harness 400. The power interface 300 is exposed on the outside of the housing 100. The power harness 400 connects between the battery module 200 and the power interface 300. Furthermore, the battery module 200 can power a device using the power interface 300, or an external charging device can charge the battery module 200 through the power interface 300, thereby fulfilling the battery pack's functions of storing and providing electrical energy.

[0065] Please refer to Figure 2 The battery pack may further include a fuse 500, which is used to blow to disconnect the cell module 200. Furthermore, the fuse 500 may blow when thermal runaway of the cell module 200 is detected, or the fuse 500 may blow in advance when thermal runaway of the cell module 200 is detected.

[0066] For example, the fuse 500 can be arranged in the power harness 400, and the fuse 500 can be fused to make the power harness 400 in an open circuit state. Then, when the state of the battery cell module 200 is abnormal, the fuse 500 can timely disconnect the battery cell module 200 from the power interface 300, thereby avoiding the external device from continuing to charge the battery cell module 200, so as to improve the reliability and stability of the battery pack.

[0067] For example, the fuse 500 is arranged in the positive main power harness or the negative main power harness.

[0068] Optionally, the fuse 500 can also be arranged in the battery cell module 200, for example, the fuse 500 is arranged in the busbar of the battery cell module 200. Of course, the fuse 500 can also be arranged in the BMS assembly 900, and the embodiments of the present application do not limit this.

[0069] In the related art, when the current entering the battery pack exceeds a certain value, the current passing through the resistance wire inside the fuse 500 will also increase, thereby increasing the heat generation of the resistance wire inside the fuse 500. When the heat generation of the resistance wire continuously increases to exceed a certain threshold, the resistance wire will be burned out, thereby preventing the battery cell module 200 inside the battery pack from thermal runaway. However, this passive fusing mode of the resistance wire causes the response time of the fuse 500 to be too long when the fuse 500 needs to be fused.

[0070] In order to realize the rapid fusing inside the fuse 500, an electronic ignition form can be used to ignite gunpowder, thereby generating an explosive impact inside the fuse 500 to break the resistance wire inside the fuse 500. This form of igniting gunpowder has a shorter response time than the passive fusing mode of the resistance wire, but the form of igniting gunpowder at least needs 3 milliseconds of time, and the gunpowder inside the fuse 500 will cause safety hazards in the process of transportation and subsequent use of the battery pack.

[0071] Based on this, the embodiments of the present application provide a fuse 500, which can include a housing 51, a conductive body 52, a cutting member 53, and an actuating member 54.

[0072] The conductive body 52 is at least partially arranged in the housing 51. The cutting member 53 is arranged in the housing 51. The actuating member 54 is arranged in the housing 51. The actuating member 54 is used to drive the cutting member 53 to move to cut the conductive body 52, so that the battery cell module 200 of the battery pack is in an open circuit state.

[0073] Further, compared with the form of fusing the fuse 500 by the passive fusing of the resistance wire, in the embodiments of the present application, the battery pack can drive the cutting member 53 to quickly cut the conductive body 52 by the actuating member 54, so as to shorten the response time of the fuse 500, thereby timely making the battery cell module 200 in an open circuit state.

[0074] Moreover, compared to blowing the fuse 500 by igniting gunpowder, in the embodiment of the present application, on the one hand, the actuator 54 can drive the cutting member 53 to cut off the conductor 52 in about 10 microseconds, that is, the blowing response time of the fuse 500 is 10 microseconds, thereby greatly shortening the response time of the fuse 500; on the other hand, since there is no need to set gunpowder inside the fuse 500, the safety of the battery pack during transportation and subsequent use can be improved.

[0075] In addition, since the cutting piece 53 and the actuator 54 are both arranged in the shell 51, other parts of the battery pack can be prevented from colliding with the cutting piece 53 and the actuator 54, thereby preventing the cutting piece 53 from accidentally cutting off the conductor 52 during the transportation and use of the battery pack, thereby improving the reliability and stability of the fuse 500.

[0076] It should be noted that the conductor 52 can be connected to the power harness 400, the BMS assembly 900 or the bus, and this embodiment of the application does not limit this.

[0077] Exemplarily, 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, the second part 42 is connected to the battery cell 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.

[0078] Furthermore, when the conductor 52 is cut off by the cutting piece 53 , the power harness 400 can be disconnected, so that the battery module 200 is in an open circuit state.

[0079] Next, the technical solution of the embodiment of the present application will be introduced in conjunction with the actuator 54.

[0080] The actuating member 54 is used to drive the cutting member 53 to cut the conductor 52 by deformation. Then, the battery pack can quickly cut the conductor 52 by the deformation of the actuating member 54.

[0081] For example, the actuator 54 includes a piece of electromechanical coupling material.

[0082] It is understood that an electromechanical coupling material is a functional material that can convert 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 driving the cutting member 53 to cut off the conductor 52.

[0083] It can be understood that the electromechanical coupling material has the advantage of fast response speed, so that the cutting member 53 can cut the conductor 52 in about 10 microseconds. Thus, the response time of the fuse 500 can be shortened.

[0084] In addition, compared with using a motor, a motor, or the like as the actuating member 54, the electromechanical coupling material has the advantages of being light and thin and low in cost, so that the volume of the fuse 500 can be reduced by using a light and thin electromechanical coupling material, so that more space can be reserved in the battery pack to install a larger battery cell module 200, thereby improving the energy density of the battery pack.

[0085] In some embodiments, the electromechanical coupling material includes at least one of a piezoelectric material, an electrostatic polymer material, and a magnetostrictive material.

[0086] The magnetostrictive material can include Tefernol-D alloy, etc., which is not limited in the embodiments of the present application.

[0087] Taking the piezoelectric material as an example, the piezoelectric material has the characteristics of high driving precision and fast response speed, so that the displacement control precision of the cutting member 53 can reach 0.01 microns, and the cutting member 53 can cut the conductor 52 in about 10 microseconds.

[0088] Of course, in some other embodiments, the actuating member 54 can also include a motor, etc., which is not limited in the embodiments of the present application.

[0089] The fuse 500 further includes a first mounting member 55, which includes a connecting end 551 and a free end 552 arranged oppositely, and 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 member 53 is arranged on the first mounting member 55, and the actuating member 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 the conductor 52.

[0090] Further, the first mounting member 55 forms a cantilever beam structure, so that the actuating member 54 can more easily drive the first mounting member 55 to vibrate, so as to facilitate the actuating member 54 to quickly drive the cutting member 53 to move through the first mounting member 55, thereby shortening the response time of the fuse 500.

[0091] In some embodiments, the cutting member 53 is arranged on the free end 552, or the cutting member 53 is closer to the free end 552 than the connecting end 551.

[0092] It can be understood that when the actuating member 54 drives the first mounting member 55 to vibrate, the vibration amplitude of the free end 552 is greater than that of the connecting end 551 for the cantilever structure of the first mounting member 55; therefore, the cutting member 53 is arranged at the free end 552, or the cutting member 53 is arranged close to the free end 552, so that 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 conductive body 52.

[0093] For example, in the direction from the free end 552 to the connecting end 551, the length of the first mounting member 55 is L1, the distance from the cutting member 53 to the end surface 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.

[0094] For example, when the cutting member 53 is arranged at the free end 552, the free end 552 is the position of the first mounting member 55 with the largest displacement under the first-order vibration mode of the piezoelectric material member or the like actuating member 54, so that the cutting member 53 can quickly cut the conductive body 52.

[0095] Alternatively, when the ratio of L2 to L1 is equal to one-third, the region where the cutting member 53 is located is the position of the first mounting member 55 with the largest displacement under the second-order vibration mode of the piezoelectric material member or the like actuating member 54, so that the cutting member 53 can quickly cut the conductive body 52.

[0096] In some embodiments, the actuating member 54 can be attached to the first mounting member 55, so that the first mounting member 55 provides certain support and protection for the actuating member 54.

[0097] For example, the actuating member 54 can be adhesively fixed to the first mounting member 55.

[0098] In some embodiments, the first mounting member 55 can be a metal sheet.

[0099] 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 simple assembly.

[0100] Of course, the first mounting member 55 and the cutting member 53 can also be separately formed, which is not limited in the embodiments of the present application.

[0101] In some embodiments, the actuating member 54 is arranged on one side of the cutting member 53 close to the connecting end 551. Then, since the part of the first mounting member 55 away from the connecting end 551 has a larger displacement than the part close to the connecting end 551, when the actuating member 54 drives the first mounting member 55 to vibrate, the displacement of the cutting member 53 can be greater than that of the actuating member 54, so that the cutting member 53 can cut the conductive body 52 more quickly.

[0102] In some embodiments, the actuating member 54 can also be used to retract to drive the cutting member 53 to cut the conductor 52.

[0103] Please continue to refer to Figure 3 For example, the fuse 500 further comprises a second mounting member 56, which comprises a first mounting portion 561, a first connecting portion 562 and a second connecting portion 563.

[0104] The first mounting portion 561 is located between the cutting member 53 and the actuating member 54, and is connected to the cutting member 53. The first connecting portion 562 is connected between one end of the actuating member 54 and the first mounting portion 561. The second connecting portion 563 is connected between the other end of the actuating member 54 and the first mounting portion 561. Further, the actuating member 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 actuating member 54 to cut the conductor 52.

[0105] For example, the first connecting portion 562 and the second connecting portion 563 close to one end of the actuating member 54 are inclined to the direction away from each other, so that the included angle between the first connecting portion 562 and the first mounting portion 561 is obtuse, and the included angle between the second connecting portion 563 and the first mounting portion 561 is obtuse. Then, when the actuating member 54 retracts, the first connecting portion 562 and the second connecting portion 563 can be driven to converge, so that the first mounting portion 561 drives the cutting member 53 to move away from the actuating member 54 to cut the conductor 52.

[0106] Alternatively, the first connecting portion 562 and the second connecting portion 563 close to one end of the actuating member 54 are inclined to the direction close to each other, so that the included angle between the first connecting portion 562 and the first mounting portion 561 is acute, and the included angle between the second connecting portion 563 and the first mounting portion 561 is acute. Then, when the actuating member 54 extends, the first connecting portion 562 and the second connecting portion 563 can be driven to diverge, so that the first mounting portion 561 drives the cutting member 53 to move away from the actuating member 54 to cut the conductor 52.

[0107] It should be noted that the first mounting portion 561 can be circular or square, and the embodiments of the present application do not limit it.

[0108] In some embodiments, the fuse 500 further comprises a third mounting member 57, which comprises a second mounting portion 571, a third connecting portion 572 and a fourth connecting portion 573.

[0109] The second mounting part 571 is located on the side of the actuating part 54 away from the cutting part 53 and is connected to the inner wall of the shell 51. The third connecting part 572 is connected between one end of the actuating part 54 and the second mounting part 571. The fourth connecting part 573 is connected between the other end of the actuating part 54 and the second mounting part 571. The third connecting part 572 and the fourth connecting part 573 can be gathered or spread apart to allow the actuating part 54 to deform.

[0110] For example, the third connecting part 572 and the fourth connecting part 573 close to one end of the actuating part 54 are inclined to the direction away from each other, so that the included angle between the third connecting part 572 and the second mounting part 571 is obtuse, and the included angle between the fourth connecting part 573 and the second mounting part 571 is obtuse.

[0111] Alternatively, the third connecting part 572 and the fourth connecting part 573 close to one end of the actuating part 54 are inclined to the direction close to each other, so that the included angle between the third connecting part 572 and the second mounting part 571 is acute, and the included angle between the fourth connecting part 573 and the second mounting part 571 is acute. The embodiments of the present application do not limit this.

[0112] In some embodiments, the second mounting part 56 and the third mounting part 57 are arranged on opposite sides of the actuating part 54, so that the second mounting part 56, the third mounting part 57 and the actuating part 54 form a cymbal structure.

[0113] Then, the cymbal structure can make the force on each part of the second mounting part 56 and the third mounting part 57 more uniform, thereby facilitating the actuating part 54 to accurately control the cutting part 53 to cut the conductive body 52.

[0114] In some embodiments, the conductive body 52 is provided with a score groove 521, and the score groove 521 is arranged corresponding to the cutting part 53, so as to cut the conductive body 52 from the score groove 521. Further, the structure of the score groove 521 can facilitate the cutting part 53 to cut the conductive body 52 more simply and quickly.

[0115] Please continue to refer to Figure 4 In some embodiments, the number of score grooves 521 and the number of cutting parts 53 are both multiple, and at least part of the score grooves 521 are arranged along the flow direction of the current in the conductive body 52. Each cutting part 53 is arranged corresponding to one score groove 521.

[0116] It should be noted that the number of score grooves 521 can be greater than the number of cutting parts 53, and the embodiments of the present application do not limit this.

[0117] Further, the plurality of cutting members 53 can simultaneously cut the conductor 52. At this time, even if one of the cutting members 53 is not installed in the notch groove 521, the conductor 52 can be cut by the other cutting members 53, thereby improving the reliability of the fuse 500.

[0118] In some embodiments, the conductor 52 is provided with a plurality of notch grooves 521 on the side close to the cutting member 53 and on the side away from the cutting member 53. Further, by providing the notch grooves 521 on both sides of the conductor 52, the strength of the conductor 52 provided with the notch grooves 521 can be reduced, thereby facilitating the cutting of the conductor 52 by the cutting member 53.

[0119] In some embodiments, the notch groove 521 on the side of the conductor 52 close to the cutting member 53 is symmetrically arranged with the notch groove 521 on the side of the conductor 52 away from the cutting member 53. Further, during the cutting of the conductor 52 by the cutting member 53, the stress generated by the conductor 52 can be more concentrated on the groove bottom wall of the notch groove 521, thereby facilitating the cutting of the conductor 52 by the cutting member 53.

[0120] In some embodiments, the cross section of the notch groove 521 is trapezoidal. Further, on the one hand, the cutting member 53 can be conveniently inserted into the corresponding notch groove 521, and on the other hand, during the cutting of the conductor 52 by the cutting member 53, the stress generated by the conductor 52 can be more concentrated on the groove bottom wall of the notch groove 521, thereby facilitating the cutting of the conductor 52 by the cutting member 53.

[0121] In some embodiments, the depth of the notch 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. Further, the conductor 52 can be conveniently cut by the cutting member 53 through the notch groove 521, and the strength of the conductor 52 at the notch groove 521 can be avoided to be too low, thereby improving the reliability of the conductor 52.

[0122] 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.

[0123] In some embodiments, the ratio of L5 to L6 is greater than or equal to 0.2 and less than or equal to 0.4.

[0124] It should be noted that the depth direction of the notch groove 521 is the same as the thickness direction of the conductor 52.

[0125] In some embodiments, the width of the one side end face of the cutting member 53 towards the score groove 521 is L7, the width of the groove bottom of the score groove 521 is L8, and 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 groove bottom of the score groove 521 to cut the conductive body 52.

[0126] The above is a brief introduction to the structure of the fuse 500 in the embodiments of the present application. The following will continue to introduce some other structures in the battery pack.

[0127] Please continue to refer to Figure 5 and Figure 6 In some embodiments, the battery pack further comprises a detection unit 600, and the detection unit 600 is configured to detect parameter information of the battery cell 21. In turn, the battery pack can detect the working state of the battery cell 21 through the detection unit 600, so as to determine whether the battery cell 21 is abnormal.

[0128] The battery pack can further comprise a control unit 700, and the control unit 700 is electrically connected with the detection unit 600 and the fuse 500 respectively. In turn, the control unit 700 can control the fuse 500 according to the working state of the battery cell 21.

[0129] For example, the control unit 700 can be electrically connected with the actuating member 54 of the fuse 500.

[0130] In turn, when the battery cell 21 is abnormal, the control unit 700 can send an electrical signal to the actuating member 54 to make the actuating member 54 deform to drive the cutting member 53 to cut the conductive body 52.

[0131] In some embodiments, the detection unit 600 and the fuse 500 are arranged on the same side of the battery cell module 200. In turn, compared with the detection unit 600 and the fuse 500 being respectively located on the opposite sides of the battery cell module 200, the embodiments of the present application can shorten the connection cable between the detection unit 600 and the fuse 500, so as to shorten the fusing time of the fuse 500 and improve the energy density of the battery pack.

[0132] Next, the technical solutions of the embodiments of the present application will be introduced in combination with the detection unit 600.

[0133] The detection unit 600 can be configured to detect at least one of the impedance parameter, the swelling force parameter, the temperature parameter and the voltage parameter of the battery cell 21.

[0134] The detection unit 600 can be arranged in the box body 100, so as to detect the battery cell 21.

[0135] Please continue to refer to Figure 7 , Figure 8 and Figure 9For example, the detection unit 600 can include a first detection unit 61 configured to detect an 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 exerted on the outside when the battery cell 21 expands.

[0136] It can be understood that, compared with early warning of whether the battery cell 21 is in thermal runaway by detecting the voltage signal or the temperature signal of the battery cell module 200, the expansion force parameter can be detected to early warn the thermal runaway of the battery cell 21 for 2 to 10 minutes, so as to facilitate the battery pack to control the fuse 500 to be fused, and thus the safety of the battery pack can be improved.

[0137] The first detection unit 61 can include a pressure sensor, for example, a strain pressure sensor, a piezoelectric pressure sensor, a magnetic pressure sensor, or a capacitive pressure sensor, and the like, which is not limited in the embodiment of the application.

[0138] For example, the battery cell module 200 includes n battery cells 21 arranged in the first direction H1 in sequence. Assuming that the normal thickness of a single battery cell 21 is l, and the thickness of the n battery cells 21 is nl. When one of the battery cells 21 is in thermal runaway, the mechanical change amount (i.e., the expansion force) of the battery cell 21 is x, the relative change amount of the single battery cell 21 in the first direction H1 is (x+l) / l = 1+x / l, and the change of the n battery cells 21 in the first direction H1 is (x+nl) / (nl) = 1+x / (nl). Therefore, the change x caused by thermal runaway is “diluted” in the first direction H1 of the battery cell module 200. Thus, the difficulty of sensing the change by the detection unit 600 increases, and the sensitivity of the sensor decreases.

[0139] Therefore, in the embodiment of the application, the battery pack further includes a force amplification structure 800 configured to amplify the force generated by the expansion of the battery cell 21 and then transmit the amplified force to the first detection unit 61.

[0140] Further, the expansion force of the single battery cell 21 diluted by the entire battery cell module 200 is amplified again by the force amplification structure 800 to improve the sensitivity of the detection unit 600.

[0141] In the actual design process, the total expansion force generated by all the battery cells 21 in the battery cell module 200 is 2000N, so that the tensile force and the compressive force of the force amplification structure 800 and the first detection unit 61 are designed accordingly.

[0142] The first detection unit 61 can be arranged on the force amplification structure 800, so that the force amplification structure 800 can directly transmit the expansion force of the battery cell 21 to the first detection unit 61 after amplifying the expansion force, thereby shortening the transmission path of the force between the force amplification structure 800 and the first detection unit 61, improving the loss of the force in the transmission process, and improving the sensitivity of the first detection unit 61.

[0143] The force amplification structure 800 can be arranged on the battery cell module 200, so as to shorten the transmission path of the force between the force amplification structure 800 and the battery cell module 200, thereby improving the loss of the force in the transmission process, and improving the sensitivity of the first detection unit 61.

[0144] The force amplification structure 800 can be arranged on the surface of the battery cell module 200.

[0145] Optionally, the force amplification structure 800 can also be at least partially arranged inside the battery cell module 200. For example, the force amplification structure 800 can be at least partially arranged inside the battery cell module 200, so that the expansion force of the battery cell 21 in the battery cell module 200 can be more quickly and accurately transmitted to the force amplification structure 800.

[0146] For example, the battery cell module 200 further includes at least two end plates 22, a plurality of battery cells 21 are arranged between the two end plates 22, and the force amplification structure 800 is arranged between the end plates 22 and the battery cells 21. In this way, the expansion force of the battery cell 21 can be more quickly and accurately transmitted to the force amplification structure 800.

[0147] In some embodiments, the number of the force amplification structure 800 and the first detection unit 61 is one, the force amplification structure 800 is arranged between the end plate 22 and the battery cell 21, and the first detection unit 61 is arranged on the force amplification structure 800. In this way, it can be avoided that too many force amplification structures 800 and first detection units 61 are arranged in the battery pack, thereby reducing the energy density of the battery pack.

[0148] Optionally, the number of the force amplification structure 800 and the first detection unit 61 is two, the force amplification structure 800 is arranged between each end plate 22 and the adjacent battery cell 21, and the first detection unit 61 is arranged on each force amplification structure 800. In this way, the sensitivity of detection can be improved by the two first detection units 61, and it can be avoided that too many force amplification structures 800 and first detection units 61 are arranged in the battery pack, thereby reducing the energy density of the battery pack.

[0149] As shown in FIG. 1, Figure 9 The force amplification structure 800 can be directly in contact with the battery cell 21.

[0150] Optionally, as shown in FIG. 1, Figure 8As shown, the battery cell module 200 may further include a first separator 23, which is sandwiched between the force amplifying structure 800 and the battery cell 21. The contact area between the first separator 23 and the battery cell 21 is greater than the contact area between the first separator 23 and the force amplifying structure 800. Furthermore, when the battery cell 21 expands, the expansion force from a larger area of ​​its surface can act on the first separator 23. This allows the first separator 23 to collect the expansion force from a larger area of ​​the battery cell 21 surface and transmit it to the force amplifying structure 800, thereby improving the detection accuracy of the detection unit 600.

[0151] In some embodiments, the thickness of the first separator 23 is greater than or equal to 3 mm.

[0152] It is understood that if the thickness of the first separator 23 is too thin, the rigidity of the first separator 23 will be reduced, and the first separator 23 will be significantly deformed to absorb part of the expansion force of the battery cell 21. In contrast, in the embodiment of the present application, the thickness of the first separator 23 is greater than or equal to 3 mm, which can effectively prevent the first separator 23 from significantly deforming and absorbing most of the expansion force of the battery cell 21, thereby improving the detection accuracy of the detection unit 600.

[0153] Illustratively, the thickness of the first partition 23 may 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, which is not limited in the embodiments of the present application.

[0154] The first partition plate 23 can be a steel plate or a plate made of other hard materials, which is not limited in this embodiment of the present application.

[0155] like Figure 9 As shown, the force amplifying structure 800 may be in direct contact with the end plate 22 .

[0156] Optional, such as Figure 8 As shown, the battery 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 battery cell 21 expands, the reaction force on the surface of the end plate 22 can act on the second separator 24, so that the second separator 24 can collect the reaction force from a larger area of ​​the surface of the end plate 22 and transmit it to the force amplification structure 800, thereby improving the detection accuracy of the detection unit 600.

[0157] In some embodiments, the thickness of the second separator 24 is greater than or equal to 3 mm.

[0158] It can be understood that if the thickness of the second partition plate 24 is too thin, the rigidity of the second partition plate 24 will decrease, and then the second partition plate 24 will be deformed greatly to absorb part of the reaction force of the end plate 22. In contrast, in the embodiment of the present application, the thickness of the second partition plate 24 is greater than or equal to 3 mm, which can effectively prevent the second partition plate 24 from being deformed greatly to absorb most of the reaction force of the end plate 22, thereby improving the detection accuracy of the detection unit 600.

[0159] For example, the thickness of the second partition plate 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, which is not limited in the embodiment of the present application.

[0160] The second partition plate 24 can be a steel plate or other hard material plate, which is not limited in the embodiment of the present application.

[0161] Of course, the force amplification structure 800 can also be interposed between two adjacent battery cells 21, which is not limited in the embodiment of the present application.

[0162] Next, the technical solutions of the present application will be introduced in combination with the first structure of the force amplification structure 800.

[0163] The force amplification structure 800 includes a first force transmission component 81, and the first force transmission component 81 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 connected to the side of the first force receiving part 811 close to the first detection unit 61. Under the action of the expansion force of the battery cell 21 pushing the first force receiving part 811, the fifth connecting part 812 and the sixth connecting part 813 are driven by the first force receiving part 811 to open, so as to amplify and transmit the expansion force of the battery cell 21 to the first detection unit 61.

[0164] In some embodiments, one end of the fifth connecting part 812 close to the first detection unit 61 and one end of the sixth connecting part 813 close to the first detection unit 61 are inclined to be away from each other, so that the included angle between the fifth connecting part 812 and the first force receiving part 811 is obtuse, and the included angle between the sixth connecting part 813 and the first force receiving part 811 is obtuse.

[0165] In some embodiments, the included angle between the fifth connecting part 812 and the first force receiving part 811 and the included angle between the sixth connecting part 813 and the first force receiving part 811 are the same, so as to facilitate the calculation of the actual expansion force of the battery cell 21 according to the data detected by the first detection unit 61.

[0166] For example, the angle between the side of the fifth connecting part 812 facing the sixth connecting part 813 and the first detection unit 61 is θ, and the angle between the side of the sixth connecting part 813 facing the fifth connecting part 812 and the first detection unit 61 is also θ. Then, the force amplification structure 800 can amplify the expansion force of the battery cell 21 by 1 / tanθ times.

[0167] 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 relative to the first detection unit 61, and is located on the side of the first detection unit 61 close 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 close to the first detection unit 61. Under the action of the expansion force of the battery cell 21 pushing the first force receiving part 811, the second force receiving part 821 can receive the reaction force applied by the end plate 22, and the second force receiving part 821 can drive the seventh connecting part 822 and the eighth connecting part 823 to open by the reaction force applied by the end plate 22, so as to amplify and transmit the expansion force of the battery cell 21 to the first detection unit 61.

[0168] In some embodiments, the end of the seventh connecting part 822 close to the first detection unit 61 and the end of the eighth connecting part 823 close to the first detection unit 61 are inclinedly arranged in directions away from each other, so that the angle between the seventh connecting part 822 and the second force receiving part 821 is an obtuse angle, and the angle between the eighth connecting part 823 and the second force receiving part 821 is an obtuse angle.

[0169] 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, so as to facilitate calculation of the actual expansion force of the battery cell 21 according to the data detected by the first detection unit 61.

[0170] For example, the angle between the side of the seventh connecting part 822 facing the eighth connecting part 823 and the first detection unit 61 is θ, and the angle between the side of the eighth connecting part 823 facing the seventh connecting part 822 and the first detection unit 61 is also θ. Then, the force amplification structure 800 can amplify the expansion force of the battery cell 21 by 1 / tanθ times.

[0171] 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 the cymbal structure is subjected to the expansion force of the battery cell 21, the force applied to the cymbal structure as a whole becomes more uniform. Therefore, the force amplifying structure 800 can withstand a greater expansion force of 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.

[0172] The first force-bearing portion 811 and the second force-bearing portion 821 are sandwiched in the battery cell module 200 .

[0173] Illustratively, the first force-bearing portion 811 and the second force-bearing portion 821 may be disposed between the end plate 22 and the battery cell 21 .

[0174] For example, the first force-bearing portion 811 faces the battery cell 21, and the second force-bearing portion 821 faces the end plate 22. It is understood that the first force-bearing portion 811 can directly abut the battery cell 21 or the first partition 23; the second force-bearing portion 821 can directly abut the end plate 22 or the second partition 24, and this embodiment of the application does not limit this.

[0175] In some embodiments, when θ is less than 45°, it is possible to avoid the spacing between the first force-bearing portion 811 and the second force-bearing portion 821 being too large and wasting too much space between the end plate 22 and the battery cell 21, thereby improving the energy density of the battery pack.

[0176] It should be noted that the first force transmission component 81 and the second force transmission component 82 can be used to squeeze the first detection unit 61 or to stretch the first detection unit 61, and this embodiment of the present application does not limit this.

[0177] Please continue to refer to Figure 10 Taking the first force transmission component 81 and the second force transmission component 82 for squeezing the first detection unit 61 as an example, 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 installed 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, and the sixth connecting part 813 and the eighth connecting part 823 are rotatably connected to the second sliding member 832.

[0178] The first detection unit 61 is arranged on the mounting rod 83 and is located between the first sliding member 831 and the second sliding member 832 so 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.

[0179] Further, when the battery cell 21 and the end plate 22 of the battery cell module 200 jointly press the first force receiving part 811 and the second force receiving part 821, the first sliding part 831 and the second sliding part 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.

[0180] For example, the first detection unit 61 includes a pressure sensor. The pressure sensor can be sleeved on the mounting rod 83.

[0181] Please continue to refer to Figure 11 Optionally, the first detection unit 61 includes a magnetic piece 611 and an induction coil 612, and the magnetic piece 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, the magnetic piece 611 and the induction coil 612 can be pushed to move towards each other, and when the seventh connecting part 822 and the eighth connecting part 823 are opened, the magnetic piece 611 and the induction coil 612 can be pushed to move towards each other.

[0182] For example, the first force transmission part 81 and the second force transmission part 82 are used to stretch the first detection unit 61, one end of the first detection unit 61 is connected with the fifth connecting part 812 and the seventh connecting part 822 respectively, and the other end of the first detection unit 61 is connected with the sixth connecting part 813 and the eighth connecting part 823 respectively.

[0183] Further, 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.

[0184] It can be understood that the first force transmission part 81 and the first detection unit 61 can be fixed by bonding, or can be fixed by screwing, clamping or welding, and the embodiments of the present application do not limit this.

[0185] The second force transmission part 82 and the first detection unit 61 can be fixed by bonding, or can be fixed by screwing, clamping or welding, and the embodiments of the present application do not limit this.

[0186] In some embodiments, the first force transmission part 81 is an integral molding structure; and / or, the second force transmission part 82 is an integral molding structure. Further, the integral molding structure of the first force transmission part 81 and / or the second force transmission part 82 can make the force amplification structure 800 have the advantages of less parts and easy assembly.

[0187] For example, the first force transmission part 81 and the second force transmission part 82 are both integral molding structures.

[0188] Exemplarily, the fifth connecting part 812 and the sixth connecting part 813 are rotationally connected with the first force receiving part 811, and the second force transmission part 82 is an integral molding structure.

[0189] Exemplarily, the first force transmission part 81 is an integral molding structure, and the seventh connecting part 822 and the eighth connecting part 823 are rotationally connected with the second force receiving part 821.

[0190] Optionally, the fifth connecting part 812 and the sixth connecting part 813 are rotationally connected with the first force receiving part 811, and the seventh connecting part 822 and the eighth connecting part 823 are rotationally connected with the second force receiving part 821, which is not limited in the embodiment of the application.

[0191] Next, the technical solutions of the embodiment of the application will be introduced in combination with the second structure of the force amplification structure 800.

[0192] Please continue to refer to Figure 12 The force amplification structure 800 includes a third force receiving part 84 and a fourth force receiving part 85 which are spaced apart along the first direction H1, the third force receiving part 84 is provided with a first inclined surface 841 on the side facing the fourth force receiving part 85, the first inclined surface 841 is inclined to the first direction H1, and the fourth force receiving part 85 is provided with a second inclined surface 851 on the side facing the third force receiving part 84, the second inclined surface 851 is parallel to the first inclined surface 841.

[0193] The first detection unit 61 is arranged between the first inclined surface 841 and the second inclined surface 851, and the force of the swelling of the battery cell 21 can push the third force receiving part 84 and the fourth force receiving part 85 to gather along the first direction H1, so that the first inclined surface 841 and the second inclined surface 851 amplify and transmit the force of the swelling of the battery cell 21 to the first detection unit 61.

[0194] Further, the third force receiving part 84 and the fourth force receiving part 85 can amplify the swelling force of the battery cell 21 through the mechanical amplification mechanism of the angle of the bevel and then transmit it to the pressure sensor.

[0195] In some embodiments, the third force receiving part 84 and the fourth force receiving part 85 are clamped in the battery cell module 200.

[0196] Exemplarily, the third force receiving part 84 and the fourth force receiving part 85 can be arranged between the end plate 22 and the battery cell 21.

[0197] For example, the third force receiving part 84 faces the battery cell 21, and the fourth force receiving part 85 faces the end plate 22. It can be understood that the third force receiving part 84 can be directly abutted to the battery cell 21, or can be abutted to the first partition plate 23; the fourth force receiving part 85 can be directly abutted to the end plate 22, or can be abutted to the second partition plate 24, which is not limited in the embodiment of the application.

[0198] In some embodiments, the angle between the first inclined surface 841 and the second direction H2 is β, and the second direction H2 is perpendicular to the first direction H1. Then, the force amplification structure 800 can amplify the expansion force of the battery cell 21 by 1 / tan β times.

[0199] In some embodiments, β is less than 45°, so as to avoid that the space between the third force receiving component 84 and the fourth force receiving component 85 is too large to waste the space between the end plate 22 and the battery cell 21, thereby improving the energy density of the battery pack.

[0200] In some embodiments, the force amplification structure 800 further includes a guide rod 86, one of the second force receiving component 821 and the third force receiving component 84 is fixedly connected with the guide rod 86, and the other of the second force receiving component 821 and the third force receiving component 84 is slidingly connected with the guide rod 86.

[0201] In this way, the third force receiving component 84 and the fourth force receiving component 85 can be slidingly connected through the guide rod 86. Then, the movement of the third force receiving component 84 and the fourth force receiving component 85 can be more stable when the battery cell 21 expands.

[0202] Next, the technical solutions of the embodiments of the present application will be introduced in combination with the third structure of the force amplification structure 800.

[0203] Please continue to refer to Figure 13 and Figure 14 The force amplification structure 800 further includes a variable cross-section beam 87, the variable cross-section beam 87 includes a large cross-section end 871 and a small cross-section end 872, and 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 generated when the battery cell 21 expands, and the small cross-section end 872 is used to amplify the force generated when the battery cell 21 expands and then transmit the amplified force to the first detection unit 61.

[0204] In some embodiments, along the direction from the large cross-section end 871 to the small cross-section end 872, the cross-sectional area of the variable cross-section beam 87 is arranged in a decreasing manner.

[0205] For example, the variable cross-section beam 87 can be a trapezoidal plate structure, and the small cross-section end 872 forms the upper base of the trapezoid, and the large cross-section end 871 forms the lower base of the trapezoid.

[0206] In some embodiments, the number of variable cross-section beams 87 is at least two, such that the force amplification structure 800 comprises a first variable cross-section beam 87a and a second variable cross-section beam 87b arranged in a spaced manner, that is, one of the at least two variable cross-section beams 87 is the first variable cross-section beam 87a and the other is the second variable cross-section beam 87b. The first variable cross-section beam 87a and the second variable cross-section beam 87b are arranged in a spaced manner, such 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.

[0207] Further, the first variable cross-section beam 87a and the second variable cross-section beam 87b can be clamped in the battery cell module 200, so that the force of the battery cell 21 when swelling can act on the force amplification structure 800 along a shorter force transmission path.

[0208] For example, the first variable cross-section beam 87a and the second variable cross-section beam 87b can be arranged between the end plate 22 and the battery cell 21.

[0209] 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 can be understood that the first variable cross-section beam 87a can directly abut the battery cell 21, or can abut the first partition plate 23; the second variable cross-section beam 87b can directly abut the end plate 22, or can abut the second partition plate 24, and the embodiments of the present application do not limit this.

[0210] The first detection unit 61 can be directly clamped between 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.

[0211] Optionally, the force amplification structure 800 further comprises a first clamping portion 88 and a second clamping portion 89. The first clamping portion 88 is connected to the small cross-section end 872 of the first variable cross-section beam 87a. The second clamping portion 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 portion 89 and the first clamping portion 88.

[0212] In some embodiments, the second clamping portion 89 is hingedly fixed away from one end of the second variable cross-section beam 87b, and the first clamping portion 88 is hingedly fixed away from one end of the second variable cross-section beam 87b.

[0213] Therefore, taking the hinged part of the first clamping portion 88 and the second clamping portion 89 as a fulcrum, the first clamping portion 88 and the first variable cross-section beam 87a form a lever, so that the first clamping portion 88 and the first variable cross-section beam 87a can amplify the swelling force of the battery cell 21 and transmit it to the first detection unit 61.

[0214] The second clamping part 89 and the second variable cross-section beam 87b constitute a lever with the hinge position of the first clamping part 88 and the second clamping part 89 as the fulcrum, 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 then transmit the expansion force to the first detection unit 61.

[0215] Please continue to refer to 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. In this way, the large cross-section end 871 can be prevented from protruding outside the end plate 22, thereby reducing the energy density of the battery pack.

[0216] In some embodiments, L3 is greater than or equal to 180 mm, so that the large cross-section end 871 is not too small, thereby preventing the variable cross-section beam 87 from reducing the direction multiple of the expansion force of the battery cell 21.

[0217] For example, L3 is 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, which are not limited in the embodiments of the present application.

[0218] 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, and L4 is greater than or equal to 3 mm. In this way, the small cross-section end 872 can have sufficient rigidity to effectively amplify the expansion force of the battery cell 21 and then transmit the expansion force to the first detection unit 61.

[0219] In some embodiments, L4 is less than or equal to 20 mm, so that the small cross-section end 872 is not too small, thereby preventing the variable cross-section beam 87 from reducing the direction multiple of the expansion force of the battery cell 21.

[0220] For example, L4 is 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, which are not limited in the embodiments of the present application.

[0221] In some embodiments, the length of the variable cross-section beam 87 in the direction from the large cross-section end 871 to the small cross-section end 872 is L5, and L5 is less than 207 mm. In this way, the small cross-section end 872 or the large cross-section end 871 of the variable cross-section beam 87 can be prevented from protruding outside the end plate 22, thereby reducing the energy density of the battery pack.

[0222] In some embodiments, L5 is greater than or equal to 80 mm, so that the variable cross-section beam 87 forms a lever long enough to effectively amplify the expansion force of the battery cell 21.

[0223] For example, L5 is 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, which is not limited in the embodiments of the present application.

[0224] 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 of the force amplification structure 800 is more uniform and reasonable.

[0225] In some embodiments, the first clamping portion 88 and the second clamping portion 89 are symmetrically arranged, so that the force of the force amplification structure 800 is more uniform and reasonable.

[0226] The above is some introduction to the detection of the expansion force of the battery cell 21 by the detection unit 600 (i.e. the first detection unit 61) in the embodiments of the present application.

[0227] Please continue to refer to Figure 16 In some embodiments, the detection unit 600 further includes a second detection unit 62, which is used for the impedance parameter of the battery cell 21.

[0228] It can be understood that, compared with the early warning of whether the battery cell 21 is in thermal runaway by detecting the voltage signal or the temperature signal of the battery cell module 200, the thermal runaway of the battery cell 21 can be warned 2 to 10 minutes in advance by detecting the impedance parameter, so that the battery pack control fuse 500 can be blown conveniently, and thus the safety of the battery pack can be improved.

[0229] In some embodiments, the second detection unit 62 can include an EIS (electrochemical impedance spectroscopy) chip.

[0230] For example, the second detection unit 62 can be connected to the positive output row of the battery cell module 200.

[0231] Further, the second detection unit 62 can detect the impedance parameter of the entire battery cell module 200 from the total positive electrode of the battery cell module 200. Then, compared with setting one second detection unit 62 at each battery cell 21, the cost of the battery pack can be reduced in the embodiments of the present application.

[0232] Alternatively, the second detection unit 62 can be connected to the negative output row of the battery cell module 200.

[0233] Further, the second detection unit 62 can detect the impedance parameter of the whole battery cell module 200 from the total negative electrode of the battery cell module 200. Then, compared with setting one second detection unit 62 at each battery cell 21, the embodiment of the present application can reduce the cost of the battery pack.

[0234] The above is some introduction of the detection unit 600 (i.e. the second detection unit 62) detecting the swelling force of the battery cell 21 in the embodiment of the present application.

[0235] In some embodiments, the detection unit 600 can be used to detect at least one of the swelling force parameter, the temperature parameter and the voltage parameter of the battery cell 21, and the detection unit 600 is also used to detect the impedance parameter of the battery cell 21. Further, the detection unit 600 can detect the state of the battery cell 21 from at least two different dimensions, so as to timely control the fuse 500 to be fused.

[0236] For example, the detection unit 600 can include the first detection unit 61 and the second detection unit 62, so as to detect the swelling force parameter of the battery cell 21 through the first detection unit 61, and detect the impedance parameter of the battery cell 21 through the second detection unit 62.

[0237] Please continue to refer to Figure 17 In some embodiments, the battery cell module 200 can also include a BMS assembly 900 (Battery Monitoring and Management System), which is used to monitor, control and manage the performance of the battery.

[0238] The control unit 700 can be part of the BMS assembly 900.

[0239] Alternatively, the control unit 700 and the BMS assembly 900 can also be different components.

[0240] For example, the control unit 700 and the BMS assembly 900 are respectively connected to the fuse 500, and the control unit 700 and the BMS assembly 900 are respectively connected to the detection unit 600.

[0241] Then, when the detection unit 600 detects that the parameter of the battery cell 21 is abnormal, the BMS assembly 900 can send a first signal to the fuse 500 to drive the fuse 500 to be fused. At this time, if the fuse 500 is not fused in time, the control unit 700 can send a second signal to the fuse 500 to drive the fuse 500 to be fused.

[0242] Optionally, when the detection unit 600 detects the parameter abnormality of the battery cell 21, the control unit 700 can also send a second signal to the fuse 500 to drive the fuse 500 to fuse. At this time, if the fuse 500 does not fuse in time, the BMS assembly 900 can send a first signal to the fuse 500 to drive the fuse 500 to fuse.

[0243] Therefore, when any one of the control unit 700 and the BMS assembly 900 fails, the other one of the control unit 700 and the BMS assembly 900 can still control the fuse 500 to fuse, thereby improving the reliability of the battery pack.

[0244] Of course, in some other embodiments, the BMS assembly 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.

[0245] The parameter information of the battery cell 21 can include at least one of the expansion force parameter, the temperature parameter, the voltage parameter and the impedance parameter of the battery cell 21.

[0246] The external device can include a processor of a power consumption device, a high-voltage box of a battery cluster, a cloud server or a mobile terminal, etc., and the embodiments of the present application do not limit this.

[0247] In some embodiments, the external device can perform hierarchical alarm based on the parameter information of the battery cell 21.

[0248] For example, when the size of the parameter information of the battery cell 21 is within a first threshold range, the external device performs first-level alarm; when the size of the parameter information of the battery cell 21 is within a second threshold range, the external device performs second-level alarm; and when the size of the parameter information of the battery cell 21 is within a third threshold range, the external device performs third-level alarm.

[0249] For example, when the temperature information of the battery cell 21 is 45°, the external device performs first-level alarm; when the temperature information of the battery cell 21 is 50℃, the external device performs second-level alarm; and when the temperature information of the battery cell 21 is 55℃, the external device performs third-level alarm.

[0250] For example, when the voltage information of the battery cell 21 is 3.75 V, the external device performs first-level alarm; when the temperature information of the battery cell 21 is 3.8 V, the external device performs second-level alarm; and when the temperature information of the battery cell 21 is 3.85 V, the external device performs third-level alarm.

[0251] In some embodiments, when the rate of change of the parameter information of the battery cell 21 is within a first threshold range, the external device performs a first level alarm; when the rate of change of the parameter information of the battery cell 21 is within a second threshold range, the external device performs a second level alarm; and when the rate of change of the parameter information of the battery cell 21 is within a third threshold range, the external device performs a third level alarm.

[0252] For example, when the current expansion force growth rate of the battery cell 21 exceeds three times of the expansion force growth rate of the battery cell 21 during normal charging and discharging, the external device performs a first level alarm; when the current expansion force growth rate of the battery cell 21 exceeds five times of the expansion force growth rate of the battery cell 21 during normal charging and discharging, the external device performs a second level alarm; and when the current expansion force growth rate of the battery cell 21 exceeds seven times of the expansion force growth rate of the battery cell 21 during normal charging and discharging, the external device performs a third level alarm.

[0253] In some embodiments, the external device can also perform an alarm when the real part, the imaginary part or the impedance angle of the impedance in the impedance information changes from negative to positive.

[0254] The above detailed the embodiments of the present application, and the principles and embodiments of the present application are described by applying specific examples; the above embodiment descriptions are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific embodiments and application ranges can be changed, and the above description should not be understood as limiting the present application.

Claims

1. A fuse (500) for a battery pack, characterized by, The fuse (500) comprises: a housing (51); an electrically conductive body (52) at least partially arranged in the housing (51); a cutting member (53) arranged in the housing (51); and an actuating member (54) arranged in the housing (51) and configured to drive the cutting member (53) to cut the electrically conductive body (52) so that a battery pack is in an open circuit state. The actuating member (54) is configured to drive the cutting member (53) to cut the electrically conductive body (52) by deformation.

2. The fuse (500) according to claim 1, characterized in that The actuating member (54) comprises an electromechanical coupling material.

3. The fuse (500) according to claim 2, characterized in that The electromechanical coupling material comprises at least one of a piezoelectric material, an electrostatic polymer material, and a magnetostrictive material.

4. The fuse (500) according to claim 3, characterized in that The fuse (500) further comprises a first mounting member (55) comprising a connecting end (551) and a free end (552) arranged oppositely, the first mounting member (55) being connected to the housing (51) by the connecting end (551) so that the free end (552) forms a cantilever structure.

5. The fuse (500) according to any one of claims 1 to 4, characterized in that The cutting member (53) is arranged on the first mounting member (55), and the actuating member (54) is configured to drive the first mounting member (55) to vibrate so that the first mounting member (55) drives the cutting member (53) to cut the electrically conductive body (52). The cutting member (53) is arranged on the free end (552), or the cutting member (53) is closer to the free end (552) than to the connecting end (551); and / or 6. The fuse (500) according to claim 5, characterized in that The actuating member (54) is arranged on a side of the cutting member (53) close to the connecting end (551). In a direction from the free end (552) to the connecting end (551), a length of the first mounting member (55) is L1, and a distance from the cutting member (53) to an end surface of the free end (552) is L2, L2 is greater than or equal to 0, and a ratio of L2 to L1 is less than or equal to two-fifths.

7. The fuse (500) of claim 5, characterized in that The fuse (500) further comprises a second mounting member (56) comprising:

8. The fuse (500) according to any one of claims 1 to 4, characterized in that a first mounting portion (561) arranged between the cutting member (53) and the actuating member (54) and connected to the cutting member (53); a first connecting portion (562) connected between one end of the actuating member (54) and the first mounting portion (561); and a second connecting portion (563) connected between the other end of the actuating member (54) and the first mounting portion (561), the actuating member (54) being capable of driving 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 actuating member (54) to cut the electrically conductive body (52). ​ 9. The fuse (500) according to claim 8, characterized in that The first connecting part (562) and the second connecting part (563) are arranged to be inclined towards each other at the end of the actuating member (54); the actuating member (54) can be contracted to drive the first connecting part (562) and the second connecting part (563) to converge, so that the first mounting part (561) drives the cutting member (53) to move away from the actuating member (54) to cut the conductive body (52); or, The first connecting part (562) and the second connecting part (563) are arranged to be inclined towards each other at the end of the actuating member (54); the actuating member (54) can be contracted to drive the first connecting part (562) and the second connecting part (563) to converge, so that the first mounting part (561) drives the cutting member (53) to move away from the actuating member (54) to cut the conductive body (52).

10. The fuse (500) of claim 8, characterized in that The fuse (500) further comprises a third mounting part (57), which comprises: A second mounting part (571) is located on the side of the actuating member (54) away from the cutting member (53) and connected to the inner wall of the shell (51); A third connecting part (572) is connected between one end of the actuating member (54) and the second mounting part (571); and, A fourth connecting part (573) is connected between the other end of the actuating member (54) and the second mounting part (571), and the third connecting part (572) and the fourth connecting part (573) can converge or expand to allow the actuating member (54) to deform.

11. The fuse (500) according to any one of claims 1 to 4, characterized in that The conductive body (52) is provided with a notch groove (521), which is arranged corresponding to the cutting member (53) to cut the conductive body (52) from the notch groove (521).

12. The fuse (500) according to claim 11, characterized in that The number of notch grooves (521) and cutting members (53) is multiple, at least part of the notch grooves (521) are arranged along the direction of current flow of the conductive body (52), and each cutting member (53) is arranged corresponding to one notch groove (521).

13. The fuse (500) of claim 11, characterized in that, The number of notch grooves (521) is multiple, the side of the conductive body (52) close to the cutting member (53) and the side of the conductive body (52) away from the cutting member (53) are provided with the notch groove (521), and the notch groove (521) on the side of the conductive body (52) close to the cutting member (53) is symmetrically arranged with the notch groove (521) on the side of the conductive body (52) away from the cutting member (53); and / or, The cross section of the notch groove (521) is trapezoidal.

14. The fuse (500) of claim 11, characterized in that, A ratio of L5 to L6 is greater than or equal to 0.1 and less than or equal to 0.48; and / or, A ratio of L7 to L8 is greater than or equal to 0.08 and less than or equal to 1.

15. A battery pack, characterized by The fuse (500) according to any one of claims 1 to 14.

16. The battery pack of claim 15, wherein, The battery pack further comprises: a box body (100); a battery cell module (200) disposed in the box body (100), the battery cell module (200) comprising a plurality of battery cells (21); a power supply interface (300) exposed outside the box body (100); and a power harness (400) connected between the battery cell module (200) and the power supply interface (300); wherein the fuse (500) is disposed in the power harness (400) so that the cutting member (53) can cut off the conductive body (52) to make the power harness (400) in an open circuit state.

17. The battery pack of claim 16, wherein, The battery pack further comprises: a detection unit (600) for detecting parameter information of the battery cells (21); and a control unit (700) electrically connected with the detection unit (600) and the actuating member (54), respectively.

18. The battery pack of claim 17, wherein, The detection unit (600) and the fuse (500) are disposed close to the same side of the battery cell module (200).

19. The battery pack of claim 17, wherein, The detection unit (600) comprises a first detection unit (61), and the battery pack further comprises a force amplification structure (800) for amplifying the force generated by the expansion of the battery cells (21) and then transmitting the amplified force to the first detection unit (61) so that the first detection unit (61) is used for detecting the expansion force parameter of the battery cells (21).

20. The battery pack of claim 19, wherein, The battery cell module (200) further comprises at least two end plates (22), and a plurality of battery cells (21) are arranged between the two end plates (22), and the force amplification structure (800) is disposed between the end plates (22) and the battery cells (21).

21. The battery pack of claim 20, wherein, The number of the force amplification structure (800) and the first detection unit (61) is one, the force amplification structure (800) is disposed between the end plates (22) and the battery cells (21), and the first detection unit (61) is disposed in the force amplification structure (800); or The number of the force amplification structure (800) and the first detection unit (61) is two, the force amplification structure (800) is arranged between each end plate (22) and the adjacent battery cell (21), and the first detection unit (61) is arranged in each force amplification structure (800).

22. The battery pack of claim 21, wherein, The force amplification structure (800) comprises a first force transmission component (81), the first force transmission component (81) 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 connected to the first force receiving part (811) on the side close to the first detection unit (61); In the case that the first force receiving part (811) is pushed by the acting force of the expansion of the battery cell (21), the fifth connecting part (812) and the sixth connecting part (813) are driven to open by the first force receiving part (811), so as to amplify and transmit the acting force of the expansion of the battery cell (21) to the first detection unit (61).

23. The battery pack of claim 22, wherein, The force amplification structure (800) comprises a second force transmission component (82), the second force transmission component (82) comprises 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) with respect to the first detection unit (61), and the second force receiving part (821) is located on the side close to the end plate (22) with respect to the first detection unit (61), the seventh connecting part (822) and the eighth connecting part (823) are connected to the second force receiving part (821) on the side close to the first detection unit (61); In the case that the first force receiving part (811) is pushed by the acting force of the expansion of the battery cell (21), the second force receiving part (821) can receive the counteracting force applied by the end plate (22), and the second force receiving part (821) can drive the seventh connecting part (822) and the eighth connecting part (823) to open by the counteracting force applied by the end plate (22), so as to amplify and transmit the acting force of the expansion of the battery cell (21) to the first detection unit (61).

24. The battery pack of claim 23, wherein, The force amplification structure (800) further comprises a mounting rod (83), a first sliding part (831) and a second sliding part (832), the first sliding part (831) and the second sliding part (832) are slidingly installed on the mounting rod (83), the fifth connecting part (812) and the seventh connecting part (822) are rotationally connected with the first sliding part (831), and the sixth connecting part (813) and the eighth connecting part (823) are rotationally connected with the second sliding part (832); The first detection unit (61) is arranged on the mounting rod (83), and the first detection unit (61) is located between the first sliding part (831) and the second sliding part (832), so 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).

25. The battery pack of claim 24, wherein, The first detection unit (61) comprises a pressure sensor; or, The first detection unit (61) includes a magnetic piece (611) and an induction coil (612), the magnetic piece (611) and the induction coil (612) are arranged along the axial direction of the mounting rod (83), so that the fifth connecting part (812) and the sixth connecting part (813) are opened, the magnetic piece (611) and the induction coil (612) can be pushed to move towards each other, and the seventh connecting part (822) and the eighth connecting part (823) are opened, the magnetic piece (611) and the induction coil (612) can be pushed to move towards each other.

26. The battery pack of claim 23, wherein, One end of the first detection unit (61) is connected with the fifth connecting part (812) and the seventh connecting part (822) respectively, and the other end of the first detection unit (61) is connected with the sixth connecting part (813) and the eighth connecting part (823) respectively.

27. The battery pack of claim 20, wherein, The force amplification structure (800) includes a third force receiving component (84) and a fourth force receiving component (85) arranged at intervals along a first direction (H1), one side of the third force receiving component (84) is provided with a first inclined surface (841) inclined to the first direction (H1), and one side of the fourth force receiving component (85) is provided with a second inclined surface (851) parallel to the first inclined surface (841). The first detection unit (61) is arranged between the first inclined surface (841) and the second inclined surface (851), and the force of the swelling of the battery cell (21) can push the third force receiving component (84) and the fourth force receiving component (85) to gather along the first direction (H1), so that the first inclined surface (841) and the second inclined surface (851) amplify the force of the swelling of the battery cell (21) and transmit it to the first detection unit (61).

28. The battery pack of claim 27, wherein, The force amplification structure (800) further includes a guide rod (86), one of the third force receiving component (84) and the fourth force receiving component (85) is fixedly connected with the guide rod (86), and the other of the third force receiving component (84) and the fourth force receiving component (85) is slidingly connected with the guide rod (86).

29. The battery pack of claim 19, wherein, The force amplification structure (800) includes a variable cross-section beam (87), the variable cross-section beam (87) 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 for receiving the force of the swelling of the battery cell (21), and the small cross-section end (872) is used for amplifying the force of the swelling of the battery cell (21) and transmitting it to the first detection unit (61).

30. The battery pack of claim 29, wherein, The number of the variable cross-section beams (87) is at least two, so that the force amplification structure (800) comprises a first variable cross-section beam (87a) and a second variable cross-section beam (87b) arranged at intervals, the first variable cross-section beam (87a) and the second variable cross-section beam (87b) being arranged at intervals 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).

31. The battery pack of claim 30, wherein, The force amplification structure (800) further comprises: a first clamping portion (88) connected to the small cross-section end (872) of the first variable cross-section beam (87a); and a second clamping portion (89) connected to the small cross-section end (872) of the second variable cross-section beam (87b), the first detection unit (61) being clamped between the second clamping portion (89) and the first clamping portion (88).

32. The battery pack of claim 31, wherein, The second clamping portion (89) is hingedly fixed to the end of the second variable cross-section beam (87b) away from the first clamping portion (88).

33. The battery pack of claim 31, wherein, The first variable cross-section beam (87a) and the second variable cross-section beam (87b) are clamped in the battery cell module (200), and the second clamping portion (89) and the first clamping portion (88) protrude out of the battery cell module (200).

34. An electrical device, comprising: A battery pack comprising the battery pack of any one of claims 15 to 33. A battery pack comprising the battery pack of any one of claims 15 to 33.

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