Fuse, battery pack and electrical equipment

Abstract

This application provides a fuse, a battery pack, and an electrical device, relating to the field of fuse technology. The fuse includes a device body and an electrical connector. The device body includes a fusible element. The electrical connector is electrically connected to the end of the fusible element and is also configured to be electrically connected to an external circuit. The material used to make the electrical connector includes elemental aluminum with a purity greater than 99%. The fuse of this application uses elemental aluminum with a purity greater than 99% to make the electrical connector, reducing the production cost and weight of the connector, thereby reducing the production cost and overall weight of the fuse and contributing to its lightweight design.

Description

Technical Field

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

[0002] As a core overcurrent protection device in power systems and electrical equipment, the fuse is designed to quickly melt and break the circuit when abnormal current conditions such as overload or short circuit occur in the circuit, thus preventing damage to downstream electrical equipment caused by continuous overcurrent.

[0003] However, the overall production cost of fuses in related technologies is relatively high. Summary of the Invention

[0004] This application provides a fuse, a battery pack, and an electrical device that reduces the production cost of the fuse.

[0005] In a first aspect, this application provides a battery cover, comprising:

[0006] The device body includes a fusible molten material;

[0007] An electrical connector, which is electrically connected to an end of the melt, is configured to also be electrically connected to an external circuit, and is made of elemental aluminum with a purity greater than or equal to 99%.

[0008] This application provides a fuse, including a device body and an electrical connector. The device body includes a fusible element, and the electrical connector electrically connects an external circuit to the fusible element to protect the external circuit. In this embodiment, the electrical connector of the fuse is made of high-purity elemental aluminum. Compared to electrical connectors made of copper, copper alloys, or zinc-aluminum alloys, aluminum electrical connectors have lower hardness and better ductility. This allows the electrical connector to be integrally formed into a thin-walled structure using a common stamping process, eliminating the need for high-pressure die-casting and complex forming processes, thus helping to reduce the production cost of the electrical connector. Simultaneously, aluminum has a lower density than copper, copper alloys, and zinc-aluminum alloys, effectively reducing the weight of the electrical connector, thereby reducing the weight of the fuse and further contributing to a reduction in the overall weight of the battery pack, improving the driving range of electric vehicles.

[0009] In one possible implementation, the device body further includes a housing and a metal adapter, the molten material is disposed within the housing, the electrical connector and the metal adapter are located at the ends of the housing in a first direction and correspond to the ends of the molten material; the metal adapter is located between the housing and the electrical connector to connect the housing and the electrical connector;

[0010] The electrical connector is electrically connected to the end of the melt via the metal adapter.

[0011] In one possible implementation, the metal adapter is welded to the end of the molten material, and the housing and the electrical connector are respectively interference-fitted with the metal adapter;

[0012] The electrical connector includes a first assembly portion and a first connecting portion, the first assembly portion being interference-fitted with the metal adapter; the first connecting portion is located on the side of the first assembly portion opposite to the metal adapter, and the first connecting portion is configured to be electrically connected to an external circuit.

[0013] In one possible implementation, the device body further includes a housing, in which at least a portion of the molten material is disposed; the electrical connector is disposed at an end of the housing in a first direction and welded to the end of the molten material.

[0014] In one possible implementation, the electrical connector includes a second assembly portion and a second connection portion, the second assembly portion being detachably connected to the housing, and the end of the molten material being welded to the second assembly portion; the second connection portion is located on the side of the second assembly portion opposite to the housing, and the second connection portion is configured to be electrically connected to the external circuit.

[0015] And / or, the melt includes a fused portion and a non-fused portion, and the fused portion and the non-fused portion are alternately arranged along the extension direction of the melt, with a portion of the non-fused portion forming the end of the melt; the non-fused portion is an aluminum melt portion, the aluminum melt portion includes aluminum element with a purity greater than or equal to 99.95%, the fused portion is a metallic structure, and the melting point of the metallic structure is higher than that of the aluminum melt portion.

[0016] In one possible implementation, the metal structure is a silver melt portion comprising elemental silver with a purity greater than or equal to 99.95%.

[0017] In one possible implementation, a copper-clad layer is formed on the second assembly part, and the end of the molten material is welded to the copper-clad layer;

[0018] The materials used to make the melt do not include aluminum.

[0019] In one possible implementation, the melt includes a fused portion and a non-fused portion, which are alternately arranged along the extension direction of the melt, with a portion of the non-fused portion forming an end of the melt.

[0020] In one possible implementation, both the fused portion and the non-fused portion include a silver melt portion, which contains elemental silver with a purity greater than or equal to 99.95%.

[0021] Alternatively, both the fused portion and the non-fused portion include a copper melt portion, wherein the copper melt portion includes elemental copper with a purity greater than or equal to 99.95%.

[0022] Alternatively, the fused portion may be a silver melt portion, and the non-fused portion may be a copper melt portion, wherein the silver melt portion comprises elemental silver with a purity greater than or equal to 99.95%, and the copper melt portion comprises elemental copper with a purity greater than or equal to 99.95%.

[0023] In one possible implementation, the copper-clad layer is located on the side of the second assembly portion away from the housing, and the end of the molten material is bent to the side of the second assembly portion where the copper-clad layer is disposed and welded to the copper-clad layer.

[0024] In one possible implementation, along a second direction of the housing, the copper-clad layer is located on at least one sidewall of the second assembly, and the end of the molten material is bent to the side of the second assembly where the copper-clad layer is disposed and welded to the copper-clad layer; the second direction intersects the first direction.

[0025] In one possible implementation, the copper-clad layer and the second assembly have a copper-aluminum alloy layer on the side that contacts each other;

[0026] And / or, the thickness of the copper cladding layer is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0027] Secondly, this application also provides a battery pack, comprising:

[0028] Battery cells and aluminum busbars;

[0029] The aforementioned fuse has its electrical connector electrically connected to the external circuit.

[0030] Thirdly, this application also provides an electrical device, including a device body and the aforementioned battery pack, wherein the device body has an installation compartment and the battery pack is disposed within the installation compartment.

[0031] The electrical equipment provided in this application has the aforementioned battery pack, thus achieving the effect of the aforementioned battery pack, which can improve and reduce the weight of the battery pack and the weight of the equipment itself. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0033] Figure 1 This is a schematic diagram of the structure of the first type of fuse provided in the embodiments of this application;

[0034] Figure 2 for Figure 1 A schematic diagram of an explosion of a fuse;

[0035] Figure 3 This is a schematic diagram of the structure of the second type of fuse provided in the embodiments of this application;

[0036] Figure 4 for Figure 3 A schematic diagram of an explosion of a fuse;

[0037] Figure 5 This is a schematic diagram of the structure of the third type of fuse provided in the embodiments of this application;

[0038] Figure 6 for Figure 5 A schematic diagram of an explosion of a fuse;

[0039] Figure 7 This is a schematic diagram of the structure of the fourth type of fuse provided in the embodiments of this application;

[0040] Figure 8 for Figure 7 A schematic diagram of an explosion of a fuse;

[0041] Figure 9 This is a schematic diagram of the structure of the fusible element of the fuse provided in the embodiments of this application;

[0042] Figure 10 for Figure 9 Another structural schematic diagram of the middle melt;

[0043] Figure 11 This is a schematic diagram of the structure of a first type of electrical connector for a fuse provided in an embodiment of this application;

[0044] Figure 12 This is a schematic diagram of the structure of the second type of electrical connector for a fuse provided in an embodiment of this application;

[0045] Figure 13 This is a schematic diagram showing the unfolded fifth type of fuse provided in the embodiments of this application;

[0046] Figure 14 for Figure 13 A schematic diagram of an explosion of a fuse;

[0047] Figure 15 This is a schematic diagram showing the unfolded sixth type of fuse provided in the embodiments of this application;

[0048] Figure 16 for Figure 15 A schematic diagram of an explosion of a fuse.

[0049] Figure label:

[0050] 100 - Device body; 110 - Fusible element; 111 - Fuse; 112 - Non-fuse; 120 - Housing; 130 - Metal adapter; 140 - Arc extinguishing material;

[0051] 200 - Electrical connector; 210 - First assembly part; 220 - First connection part; 230 - Second assembly part; 231 - Copper cladding layer; 240 - Second connection part;

[0052] X - First direction; Y - Second direction.

[0053] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] This application provides an electrical device, which can be a vehicle, such as a sedan, bus, or truck. For example, the vehicle can be an electric vehicle, a pure electric vehicle, a hybrid electric vehicle, a range-extended electric vehicle, a plug-in hybrid electric vehicle, a new energy vehicle, or any vehicle equipped with a battery.

[0056] The following explanation uses a vehicle as an example of an electrical appliance.

[0057] The vehicle may also include a body, a motor, and a battery pack, wherein the electronic control components, battery pack, axles, and motor can all be mounted on the body. The battery pack can be electrically connected to the motor, and the motor can be connected to the axles. The battery pack supplies power to the motor, enabling it to rotate, which in turn drives the axles, thus allowing the vehicle to move. The vehicle may also have other electrical components, and the battery pack can supply power to these other components as well.

[0058] A battery pack can contain multiple batteries, which are the core energy storage units and are typically lithium-ion or nickel-metal hydride batteries. A battery may include a battery casing, a battery cover, and battery cells. The cells are housed inside the battery casing, and the battery cover seals and protects the cells. Multiple batteries can be connected in series or parallel to increase the overall voltage and capacity of the battery pack.

[0059] Battery packs typically contain fuses, which usually consist of an electrical connector (conductive terminal) and a fusible element. The electrical connector connects the fusible element to an external circuit, such as the battery cells or aluminum busbars within the battery pack. In the event of an overload, short circuit, or other abnormal current condition within the battery pack, the fusible element inside the fuse quickly melts, cutting off the circuit and preventing damage to the downstream battery pack due to continuous overcurrent.

[0060] New energy vehicles face stringent requirements for overall vehicle weight control, and lightweight design is one of the key ways to improve driving range and reduce energy consumption. In high-power fuses, to accommodate circuit layout space, thin-walled and bent electrical connectors are often required. However, copper alloys have high hardness, making the molding of thin-walled or bent structures difficult. Related technologies often employ die casting to manufacture thin-walled copper alloy components. This process requires high-precision molds, high molding pressure, and complex post-processing, resulting in high production costs.

[0061] Meanwhile, in applications such as new energy battery systems, fuses often need to be connected to aluminum busbars to form a conductive circuit. Since copper and aluminum are dissimilar metals, welding the electrical connections of fuses is difficult. Furthermore, the difference in electrode potential between copper and aluminum is significant. Under harsh conditions such as high temperature, high humidity, or vibration, the welded joints are prone to electrochemical corrosion, leading to increased contact resistance.

[0062] In view of this, this application provides a fuse in which the electrical connector is made of elemental aluminum with a purity greater than 99%. The aluminum electrical connector has lower hardness and better ductility, allowing it to be integrally formed into a thin-walled structure using ordinary stamping processes, thereby helping to reduce the forming cost of the electrical connector. Furthermore, because the aluminum electrical connector is lightweight, its weight can be effectively reduced, contributing to a reduction in the overall weight of the fuse.

[0063] The following detailed description of the fuse provided in the embodiments of this application is based on the accompanying drawings. The drawings show a first direction and a second direction, where the first direction is the X direction and the second direction is the Y direction.

[0064] In a first aspect, embodiments of this application provide a fuse, which includes a device body 100 and an electrical connector 200.

[0065] Please see Figures 1 to 4The device body 100 includes a fusible molten element 110. An electrical connector 200 is electrically connected to the end of the molten element 110, and the electrical connector 200 is also configured to be electrically connected to an external circuit. The material of the electrical connector 200 includes elemental aluminum with a purity greater than 99%.

[0066] The fuse 110 in the device body 100 is the core component of the fuse to realize the overcurrent protection function. When the circuit is overloaded, short-circuited or other abnormal conditions, the heat generated by the current in the fuse 110 increases rapidly, the temperature of the fuse 110 rises rapidly to its own melting point, and the fuse 110 melts and breaks, thereby cutting off the entire circuit path and preventing damage to the external circuit due to continuous overcurrent.

[0067] Electrical connector 200 electrically connects the external circuit and fuse 110 to protect the external circuit.

[0068] Compared to electrical connectors 200 made of copper, copper alloys, or zinc-aluminum alloys, high-purity aluminum electrical connectors 200 have lower hardness and better ductility. This allows the electrical connectors 200 to be integrally formed into thin-walled structures using ordinary stamping processes, eliminating the need for high-pressure die-casting processes and complex forming procedures. Furthermore, the material cost of aluminum is significantly lower than that of copper, thus helping to reduce the production cost of the electrical connectors 200.

[0069] Because the electrical connector 200 in this embodiment uses high-purity aluminum, when the external circuit is an aluminum circuit such as an aluminum busbar or aluminum core, the electrical connector 200 and the components of the external circuit are made of the same metal. The electrode potentials of the electrical connector 200 and the external circuit are similar, making electrochemical corrosion less likely at their connection points, thus helping to reduce the contact resistance at the connection points. Simultaneously, the thermal expansion coefficients of the electrical connector 200 and the external circuit are similar, making stress concentration less likely at their connection points during temperature rises and falls, helping to reduce cracking, desoldering, and other problems, thereby improving the connection stability between the electrical connector 200 and the external circuit.

[0070] In addition, aluminum has a lower density than copper, copper alloys and zinc-aluminum alloys, which can effectively reduce the weight of electrical connector 200, thereby reducing the weight of the fuse, which in turn helps to reduce the overall weight of the battery pack and improve the driving range of electric vehicles.

[0071] Therefore, in this embodiment, the electrical connector 200 is made of elemental aluminum with a purity greater than 99%, which reduces the production cost and weight of the electrical connector 200, thereby reducing the production cost and overall weight of the fuse. In this embodiment, the purity of the elemental aluminum can be 99%, 99.2%, 99.4%, 99.6%, 99.8%, 99.9%, 99.99%, 100%, or any range between two of these values. No specific limitation is made on the aluminum purity of the electrical connector 200.

[0072] In some alternative embodiments, please refer to Figure 2 and Figure 4 The device body 100 also includes a housing 120 and a metal adapter 130. The molten material 110 is disposed within the housing 120. An electrical connector 200 and the metal adapter 130 are located at the ends of the housing 120 in the first direction X, corresponding to the ends of the molten material 110. The metal adapter 130 is located between the housing 120 and the electrical connector 200 to connect them. The electrical connector 200 is electrically connected to the end of the molten material 110 via the metal adapter 130.

[0073] The housing 120 serves as the basic support and protective carrier for the device body 100, resisting external mechanical impacts and preventing damage to the housing from exposing the molten metal 110 inside. The housing 120 has an internal cavity, within which the molten metal 110 and arc-extinguishing material 140 are disposed. The molten metal 110 penetrates the cavity inside the housing 120, allowing its end to connect to the metal adapter 130. The arc-extinguishing material 140 is used to quickly extinguish the arc when the molten metal 110 melts, preventing continuous arc discharge. Furthermore, the arc-extinguishing material 140 transfers heat from the molten metal 110 to the outside of the housing 120, preventing excessive heat accumulation inside the device body 100.

[0074] The metal adapter 130 serves as a connector between the housing 120 and the electrical connector 200, securing them together. One end of the metal adapter 130 connects to the electrical connector 200, and the other end connects to the molten element 110, enabling an electrical connection between them. It is understood that the materials at both ends of the metal adapter 130 can be matched to the materials of the electrical connector 200 and the molten element 110, respectively. This avoids abrupt changes in contact resistance between the molten element 110 and the metal adapter 130, and between the metal adapter 130 and the electrical connector 200, due to material differences, thus ensuring impedance stability during current transmission.

[0075] For example, the housing 120 may be cylindrical, box-shaped, or tubular, with openings at both ends. The housing 120 may be made of a material that is heat-resistant and has excellent insulation properties, such as ceramic or resin.

[0076] In some embodiments, welding the ends of the metal adapter 130 and the melt 110 helps to improve the connection stability between the two and ensure stable current transmission.

[0077] Please continue reading. Figure 2 and Figure 4 The housing 120 and the electrical connector 200 are respectively interference-fitted with the metal adapter 130. That is to say, the metal adapter 130 does not need to be connected to the housing 120 and the electrical connector 200 by fasteners or welding, but is fixedly installed by the interference fit of its own structure, which helps to reduce installation costs. At the same time, if the metal adapter 130 and the housing 120, and the metal adapter 130 and the electrical connector 200 are made of different metal materials, since the above three do not need to be welded, the contact resistance at the connection point is avoided due to welding of different materials, which helps to stabilize current transmission.

[0078] The metal adapter 130 and the housing 120, and the metal adapter 130 and the electrical connector 200, can be interference-fitted through a shaft hole structure. The metal adapter 130 and the housing 120 and the electrical connector 200 are fastened at their connection points based on the radial friction of the shaft hole structure.

[0079] For example, in some embodiments, the metal adapter 130 is provided with convex shafts at both ends, and the housing 120 and the electrical connector 200 are provided with concave holes at the ends facing the metal adapter 130. There is a certain interference between the convex shafts and the concave holes so that the metal adapter 130 is interference-fitted with the housing 120 and the electrical connector 200.

[0080] In some alternative embodiments, please continue to refer to Figure 2 and Figure 4 The electrical connector 200 includes a first mounting portion 210 and a first connecting portion 220. The first mounting portion 210 is interference-fitted with the metal adapter 130. The first connecting portion 220 is located on the side of the first mounting portion 210 opposite to the metal adapter 130 and is configured to be electrically connected to an external circuit.

[0081] The electrical connector 200 is connected to the metal adapter 130 via the first assembly part 210 and to an external circuit via the first connection part 220, thus connecting the external circuit to the metal adapter 130 and allowing current from the external circuit to flow into the fuse element 110. The first assembly part 210 can be a recessed hole structure or a convex shaft structure. The metal adapter 130 has a corresponding convex shaft structure or recessed hole structure on its end facing the first assembly part 210. In this way, the metal adapter 130 and the first assembly part 210 achieve an interference fit through the convex shaft structure and the recessed hole structure, eliminating the need for bolts, rivets, or other fasteners. The tight fit surface formed by the interference fit can prevent impurities such as air, moisture, and dust from entering through the connection gap between the electrical connector 200 and the metal adapter 130, helping to improve the overall sealing performance of the fuse.

[0082] The first connecting portion 220 of the electrical connector 200 is structurally adapted to the external circuit connection portion to ensure a stable connection between the electrical connector 200 and the external circuit. For example, the plate-shaped first connecting portion 220 is welded to the aluminum busbar inside the battery pack, forming a large conductive contact area between the first connecting portion 220 and the aluminum busbar. Current from the external circuit flows into the pure aluminum material of the first connecting portion 220 through this contact area. Due to the high conductivity of pure aluminum, the current can be evenly distributed inside the first connecting portion 220. Subsequently, the current is smoothly transmitted to the first assembly portion 210 through the integrated structure of the first connecting portion 220 and the first assembly portion 210, and then enters the metal adapter 130 and the molten metal 110 to complete the current introduction.

[0083] In some alternative embodiments, please continue to refer to Figure 5 and Figure 8 The device body 100 also includes a housing 120, with at least a portion of the molten material 110 disposed within the housing 120; an electrical connector 200 is disposed at the end of the housing 120 in the first direction X and is welded to the end of the molten material 110.

[0084] In this embodiment, the device body 100 does not include the metal adapter 130. The device body 100 is directly connected to the electrical connector 200 through the housing 120, which helps to simplify the fuse structure, improve the compactness of the fuse, and reduce the weight of the fuse. The first direction X of the housing 120 can be the length direction of the housing 120.

[0085] The molten element 110 is disposed within the housing 120, and the portion of the molten element 110 located within the internal cavity of the housing 120 is encased in arc-quenching material 140. The molten element 110 also extends at least partially beyond the end of the housing 120 in the first direction X. An electrical connector 200 is welded to the portion of the molten element 110 extending beyond the housing 120, achieving a robust mechanical connection between the electrical connector 200 and the molten element 110. Thus, the electrical connector 200 is directly electrically connected to the molten element 110, allowing current from the external circuit to be directly transmitted to the molten element 110, which provides overcurrent protection for the current circuit.

[0086] In some alternative embodiments, please continue to refer to Figure 6 and Figure 8 The electrical connector 200 includes a second assembly part 230 and a second connection part 240. The second assembly part 230 is detachably connected to the housing 120, and the end of the molten metal 110 is welded to the second assembly part 230.

[0087] The electrical connector 200 is detachably fixed to the housing 120 via the second assembly part 230 and stably welded to the fusible link 110, thereby achieving the assembly of the electrical connector 200. The second assembly part 230 and the housing 120 can be detachably connected by riveting, threaded connection, snap-fit ​​connection, etc., which facilitates the later maintenance of the fuse and reduces maintenance costs. For example, the second assembly part 230 and the housing 120 are fastened together by screws and rivets.

[0088] The second connection part 240 is located on the side of the second assembly part 230 away from the housing 120. The second connection part 240 is configured to be electrically connected to an external circuit, which can be a battery cell or an aluminum busbar in the battery pack.

[0089] The second connecting part 240 is similar to the first connecting part 220 mentioned above. The second connecting part 240 matches the connecting part structure of the melt 110 so that the two have a certain welding area, ensuring that the second connecting part 240 and the melt 110 are firmly connected.

[0090] In some alternative embodiments, please continue to refer to Figure 9 and Figure 10 The melt 110 includes a fusing portion 111 and a non-fusing portion 112. Along the extension direction of the melt 110, the fusing portion 111 and the non-fusing portion 112 are alternately arranged, and a portion of the non-fusing portion 112 forms the end of the melt 110. The non-fusing portion 112 is an aluminum melt portion, which includes elemental aluminum with a purity greater than or equal to 99.95%. The fusing portion 111 is a metallic structure, and the melting point of the metallic structure is higher than that of the metallic aluminum melt portion.

[0091] The non-fusible section 112 serves as the main channel for current transmission. Since the non-fusible section 112 is made of molten aluminum, which has a low resistivity, it ensures minimal energy loss during current transmission within the molten element 110, preventing additional temperature rise due to excessive resistance and guaranteeing the overall conductivity of the fuse. Simultaneously, because both the non-fusible section 112 at the end of the molten element 110 and the electrical connector 200 are made of aluminum, electrochemical corrosion caused by welding dissimilar metals is avoided, effectively reducing the contact resistance at the welded joint.

[0092] The fusible part 111 has the characteristic of being easier to fuse than the non-fusible part 112, that is, the fusible part 111 can fuse before the non-fusible part 112, so that it can fuse quickly when the melt 110 flows through.

[0093] Under high current and high voltage conditions, since the metal structure of the fuse part 111 includes metals with a melting point higher than that of the aluminum melt, the fuse part 111 can maintain structural stability under normal high current conditions, thereby adapting to high current and high voltage conditions.

[0094] It is understood that the fusible part 111 can be structured in such a way that it melts before the non-fusible part 112. For example, the cross-sectional area of ​​the fusible part 111 is smaller than that of the non-fusible part 112, so that the impedance of the fusible part 111 is greater than that of the non-fusible part 112, and the heat generation rate of the fusible part 111 is higher than that of the non-fusible part 112, thereby causing the fusible part 111 to melt first.

[0095] In some alternative embodiments, the metal structure is a silver melt portion comprising elemental silver with a purity greater than or equal to 99.95%.

[0096] The resistivity of the silver melt at 20°C is approximately 1.59 × 10⁻⁻⁻⁻⁶. 8 With a melting point of approximately 961.78°C (Ω·m), silver has a higher melting point than the aluminum melt (660°C). Furthermore, the silver melt's vapor easily condenses after melting, making it less prone to forming a sustained electric arc and helping to prevent heat dissipation. Therefore, due to its inherent properties, the silver melt exhibits excellent electrical conductivity and resistance to arc erosion, making it suitable for high-current, high-voltage applications.

[0097] In some alternative embodiments, please continue to refer to Figure 9 and Figure 10 The fuse element 111 has several perforated structures to increase its impedance. These perforated structures effectively reduce the conductive cross-sectional area, thus increasing its impedance. When an overload current passes through the fusible element 110, the heat in the fuse element 111 rises rapidly, facilitating rapid melting of the fuse element 111 under overload current and protecting the circuit. For example, the perforated structures can be circular, square, or oblong holes.

[0098] The molten element 110 can be made of different materials depending on actual usage and cost requirements. For example, the molten element 110 can be made of non-aluminum materials, such as copper, silver, or copper-silver composites. However, when the electrical connector 200 is made of pure aluminum, welding the electrical connector 200 to the molten element 110 can easily result in excessive contact resistance at the weld joint. Excessive contact resistance increases the total impedance of the circuit, slowing down the heat accumulation rate of the molten element 110 during overcurrent and delaying the melting response time. The following detailed explanation addresses these issues with reference to embodiments.

[0099] In some alternative embodiments, please refer to Figure 11 and Figure 12 When the material of the melt 110 does not include aluminum, a copper-clad layer 231 is formed on the second assembly part 230, and the end of the melt 110 is welded to the copper-clad layer 231.

[0100] In this embodiment, the electrical connector 200 is made of aluminum with a purity greater than 99%. The second assembly part 230 of the electrical connector 200 is connected to the molten material 110, which does not contain aluminum, through a copper-clad layer 231. This avoids the aluminum substrate of the electrical connector 200 being directly connected to the molten material 110, which does not contain aluminum, thereby avoiding defects caused by welding dissimilar metals.

[0101] Specifically, when the material at the end where the molten material 110 connects to the copper-clad layer 231 is silver, the potential difference between silver and copper is small, and their coefficients of thermal expansion are similar. This results in a low contact resistance at the weld joint between the molten material 110 and the copper-clad layer 231, significantly reducing the degree of electrochemical corrosion. Therefore, copper and silver have excellent welding characteristics, enabling the formation of a stable weld joint.

[0102] The copper clad layer 231 can be combined with the pure aluminum substrate through an electroplating process, so that the second assembly part 230 of the electrical connector 200 has a copper clad layer 231.

[0103] In some optional embodiments, the aforementioned aluminum-containing melt 110 also includes a fusing portion 111 and a non-fusing portion 112. Along the extending direction of the melt 110, the fusing portion 111 and the non-fusing portion 112 are alternately arranged, with a portion of the non-fusing portion 112 forming an end of the melt 110. It is understood that, relative to the non-fusing portion 112, the fusing portion 111 can melt first when the melt 110 is overloaded.

[0104] The extension direction of the melt 110 can be its length direction, and the length direction of the melt 110 is the same as the length direction of the shell 120.

[0105] In some optional embodiments, both the fused portion 111 and the non-fused portion 112 include a silver melt portion, which contains elemental silver with a purity greater than or equal to 99.95%.

[0106] In this embodiment, the fuse 110 can be made of pure silver. Compared to copper, silver has an overall impedance of less than 0.3mΩ, and its energy loss is reduced by 30% compared to pure copper fuse 110. This makes it suitable for scenarios with extremely high requirements for low loss, such as new energy commercial vehicles and large-scale energy storage. Furthermore, silver has good breaking capacity and can melt and break in a very short time when the current is overloaded, which helps to improve the protection performance of the fuse.

[0107] Among them, the non-fusible part 112 at the end of the fusible part 110 is welded to the copper-clad layer 231 through the silver fusible part, which can form a stable welded connection structure and realize the conductive function of the fuse.

[0108] For example, the purity of elemental silver in the silver melt portion is 99.95%, 99.96%, 99.97%, 99.98%, 99.99%, 100%, or any two of these ranges, without any specific limitation.

[0109] In some optional embodiments, both the fused portion 111 and the non-fused portion 112 include a copper melt portion, which contains elemental copper with a purity greater than or equal to 99.95%.

[0110] In this embodiment, the melt 110 is made of pure copper. Copper is cheaper than silver, thus effectively reducing the production cost of the melt 110. At the same time, the non-melting portion 112 at the end of the melt 110 is welded to the copper cladding layer 231 through the copper melt portion. Since both are made of the same material, the welding difficulty is low.

[0111] For example, the purity of elemental copper in the copper melt is within the range of 99.95%, 99.96%, 99.97%, 99.98%, 99.99%, 100%, or any two of these ranges, without any specific limitation.

[0112] In some optional embodiments, the fused portion 111 is a silver melt portion and the non-fused portion 112 is a copper melt portion. The silver melt portion includes elemental silver with a purity greater than or equal to 99.95%, and the copper melt portion includes elemental copper with a purity greater than or equal to 99.95%.

[0113] In this embodiment, the silver melt section and the copper melt section are alternately arranged along the length of the melt 110 to form the melt 110. The copper melt section ensures that the melt 110 has a certain structural strength and tensile strength, while the silver melt section has high breaking capacity, ensuring that the melt 110 can achieve a rapid melting response. Thus, the melt 110 in this embodiment can achieve both high performance and economy through the silver melt section and the copper melt section.

[0114] In some alternative embodiments, please refer to Figure 11 , Figure 13 and Figure 14 The copper clad layer 231 is located on the side of the second assembly part 230 away from the housing 120. The end of the melt 110 is bent to the side of the second assembly part 230 where the copper clad layer 231 is located and welded to the copper clad layer 231.

[0115] The end of the molten material 110 is bent and extends to the side of the second assembly portion 230 away from the housing 120, so that it can be welded to the copper-clad layer 231 on the second assembly portion 230. In this way, the welding area between the molten material 110 and the copper-clad layer 231 is located on the side of the second assembly portion 230 away from the housing 120, providing more operating space for welding operations and avoiding spatial interference of the housing 120 during welding, thereby reducing the welding difficulty between the molten material 110 and the electrical connector 200.

[0116] The end of the melt 110 can be in the form of a thin sheet, which gives it good bending performance and reduces the difficulty of bending and forming.

[0117] In some alternative embodiments, please refer to Figure 12 , Figure 15 and Figure 16 Along the second direction Y of the housing 120, the copper clad layer 231 is located on at least one side wall of the second assembly part 230, and the end of the melt 110 is bent to the side of the second assembly part 230 where the copper clad layer 231 is disposed, and is welded to the copper clad layer 231; the second direction Y intersects with the first direction X.

[0118] By placing the copper-clad layer 231 on the side wall of the second assembly part 230 in the second direction Y, the extension distance of the end of the melt 110 can be shortened, so that the end of the melt 110 can be welded to the copper-clad layer 231 on this side wall without extending to the side of the second assembly part 230 away from the housing 120.

[0119] Therefore, by designing the position of the copper cladding layer 231, this embodiment can effectively reduce the length of the end of the fuse 110, thereby reducing the material used in the fuse 110, saving fuse costs and reducing fuse weight.

[0120] In some alternative embodiments, the copper-clad layer 231 and the second assembly 230 have a copper-aluminum alloy layer on their contacting sides, which is not shown in the figure.

[0121] The copper-aluminum alloy layer is located between the copper-clad layer 231 and the substrate of the second assembly part 230, which can improve the bonding strength between the copper-clad layer 231 and the second assembly part 230, and improve the peel resistance of the copper-clad layer 231. In addition, the coefficient of thermal expansion of the copper-aluminum alloy layer is between that of copper and aluminum, which can buffer the thermal stress during welding and prevent the copper-clad layer 231 from cracking due to thermal stress; at the same time, the plasticity of the copper-aluminum alloy layer can absorb the energy during vibration and reduce the stress concentration of the weld joint.

[0122] In addition, the copper-aluminum alloy layer makes the copper and aluminum between the copper-clad layer 231 and the aluminum substrate have a gradient composition distribution, which makes the current transmission from the copper-clad layer 231 to the pure aluminum substrate smoother and makes its overall transmission impedance stable.

[0123] In some optional embodiments, the thickness of the copper cladding layer 231 is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0124] When the thickness of the copper clad layer 231 is less than 0.5 mm, the current density is prone to exceed the safety value under high current conditions, causing local overheating or even softening and deformation. If the thickness of the copper clad layer 231 exceeds 2 mm, it will increase the weight and deviate from the lightweight design. At the same time, it is difficult to form a uniform copper-aluminum alloy layer during diffusion annealing, affecting the bonding strength and reliability. In this embodiment, the thickness of the copper clad layer 231 is limited to between 0.5 and 2 mm, which can ensure the safety of high current carrying capacity, control weight and process risks, and ensure contact resistance stability and current distribution uniformity after bonding with the copper-aluminum alloy layer.

[0125] In some alternative embodiments, the number of melts 110 is one or more, and the two or more melts 110 are spaced apart within the housing 120.

[0126] The number of fuse elements 110 in a fuse can be determined based on the application scenario and usage requirements. For example, a fuse with a single fuse element 110 can be used in mainstream medium to high current scenarios such as home energy storage and new energy passenger vehicles, with a simple structure and controllable cost. Fuses with two or more fuse elements 110 can be used in ultra-high current scenarios such as large industrial equipment and ultra-high voltage energy storage converters.

[0127] In this embodiment, the number of fuses can be 1, 2, 3, 4, etc., and there is no specific limitation on this.

[0128] In some alternative embodiments, the electrical connector 200 is a stamped part. The electrical connector 200 is manufactured by stamping, which can achieve standardized mass production through molds, with high processing precision, ensuring accurate docking with the melt 110 and the copper cladding layer 231; at the same time, the stamping process can form complex structures in one step, saving multiple machining processes, which is conducive to improving the production efficiency of the electrical connector 200.

[0129] Secondly, embodiments of this application also provide a battery pack, including a battery cell, an aluminum busbar, and a fuse of any of the above embodiments, wherein the electrical connector 200 of the fuse is electrically connected to the battery cell or the aluminum busbar.

[0130] Thirdly, embodiments of this application also provide an electrical device, including a device body and the aforementioned battery pack, wherein the device body has an installation compartment and the battery pack is disposed within the installation compartment.

[0131] It is understood that the battery pack structure and electrical equipment provided in this application embodiment both include the fuse of any of the above embodiments. Therefore, the battery pack and electrical equipment also possess the beneficial effects of the fuse of any of the above embodiments. That is, because the battery pack and electrical equipment have the above-mentioned fuse, the production cost of the battery pack is reduced, the weight of the battery pack is reduced, and the connection stability of the circuit within the battery pack is improved, thereby reducing the manufacturing cost and weight of the electrical equipment.

[0132] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0133] In the description of this invention, it should be understood that the terms “comprising” and “having” as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0134] Unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuse, characterized in that, include: Device body (100), the device body (100) includes a fusible melt (110). An electrical connector (200) is electrically connected to the end of the melt (110), the electrical connector (200) is configured to also be electrically connected to an external circuit, and the material of the electrical connector (200) includes elemental aluminum with a purity greater than 99%. The electrical connector (200) includes a second assembly portion (230) and a second connection portion (240). The device body (100) also includes a housing (120). The second assembly portion (230) is detachably connected to the housing (120). The end of the molten metal (110) is welded to the second assembly portion (230). The second connection portion (240) is located on the side of the second assembly portion (230) away from the housing (120). The second connection portion (240) is configured to be electrically connected to the external circuit. A copper-clad layer (231) is formed on the second assembly part (230), and the end of the melt (110) is welded to the copper-clad layer (231); The materials used to make the melt (110) do not include aluminum. The copper clad layer (231) is located on the side of the second assembly part (230) away from the housing (120). The end of the melt (110) is bent and extended to the side of the second assembly part (230) away from the housing (120) and welded to the copper clad layer (231). The welding area of ​​the melt (110) and the copper clad layer (231) is located on the side of the second assembly part (230) away from the housing (120).

2. The fuse according to claim 1, characterized in that, At least a portion of the melt (110) is disposed within the housing (120); the electrical connector (200) is disposed at the end of the housing (120) in a first direction and is welded to the melt (110).

3. The fuse according to claim 1, characterized in that, The melt (110) includes a fused portion (111) and a non-fused portion (112). Along the extension direction of the melt (110), the fused portion (111) and the non-fused portion (112) are alternately arranged, and part of the non-fused portion (112) forms the end of the melt (110).

4. The fuse according to claim 3, characterized in that, Both the fused section (111) and the non-fused section (112) include a silver melt section, which contains elemental silver with a purity greater than or equal to 99.95%. Alternatively, both the fused section (111) and the non-fused section (112) include a copper melt section, wherein the copper melt section includes elemental copper with a purity greater than or equal to 99.95%; Alternatively, the fused portion (111) may be a silver melt portion, and the non-fused portion (112) may be a copper melt portion, wherein the silver melt portion contains silver with a purity greater than or equal to 99.95%, and the copper melt portion contains copper with a purity greater than or equal to 99.95%.

5. The fuse according to any one of claims 1-4, characterized in that, The copper-clad layer (231) and the second assembly part (230) have a copper-aluminum alloy layer on the side that is in contact with each other; And / or, the thickness of the copper cladding layer (231) is greater than or equal to 0.5 mm and less than or equal to 2 mm.

6. A battery pack, characterized in that, include: Battery cells and aluminum busbars; The fuse as described in any one of claims 1-5, wherein the electrical connector (200) of the fuse is electrically connected to the external circuit.

7. An electrical appliance, characterized in that, include: The device body, which includes an installation compartment, The battery pack of claim 6, wherein the battery pack is disposed within the mounting compartment.

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