Connecting piece, energy storage equipment and electric equipment

Abstract

The utility model discloses a connecting piece, energy storage equipment and electric equipment, and relates to the technical field of battery connection of the energy storage equipment. The connecting piece comprises a body and a fusing gap. The body comprises a tab connecting area, a pole connecting area and a fusing area, the tab connecting area is used for connecting tabs of single batteries, the pole connecting area is used for connecting poles of the single batteries, and the fusing area is located between the tab connecting area and the pole connecting area; the body is also provided with a fusing gap, and the fusing gap is located in the fusing area. By forming the fusing gap in the fusing area, the width of the narrowest channel can be reduced, so that the fusing time is shortened, the safety of the single battery is improved, the influence of the fusing gap on the internal resistance of the battery is relatively small, the energy efficiency of the single battery is ensured, and the balance between the safety and the energy efficiency can be realized.

Description

Technical Field

[0001] This application relates to the field of battery connection technology for energy storage devices, and in particular to a connector, an energy storage device, and an electrical device. Background Technology

[0002] Energy storage devices are generally composed of multiple battery cells. The design of the cell structure is crucial to the cell's energy efficiency and safety. Safety hazards during use, especially the enormous current and heat generated during a short circuit, can potentially cause the battery to catch fire or explode, leading to a safety accident. Connectors act as an internal safety measure, terminating the internal circuit in the event of a battery runaway, preventing escalation and ensuring the safety of the individual cells. However, the internal resistance of the connectors cannot be too high, as excessive internal resistance will affect the cell's energy efficiency. Achieving a balance between safety and energy efficiency in connectors is a problem that urgently needs to be solved. Summary of the Invention

[0003] The embodiments of this application provide a connecting piece, an energy storage device, and an electrical device. By opening a fusing gap in the region with the lowest current density in the fusing zone of the connecting piece body, the fusing time is reduced while the impact on internal resistance is also reduced, thereby achieving a balance between safety and energy efficiency.

[0004] The connecting piece in this embodiment includes a body and a fuse notch. The body includes a tab connection area, a terminal connection area, and a fuse notch. The tab connection area is used to connect the tabs of the battery cell, the terminal connection area is used to connect the terminals of the battery cell, and the fuse notch is located between the tab connection area and the terminal connection area. The body also has a fuse notch located in the fuse notch.

[0005] In some embodiments, the connecting piece is U-shaped or V-shaped.

[0006] In some embodiments, the fusible region is in the body, and the extension direction of the fusible notch is perpendicular to the extension direction of the connecting piece.

[0007] In some embodiments, the width of the narrowest channel of the connecting piece at the fusible gap is determined based on the current carrying capacity and thickness of the connecting piece, the fusible gap including a first end and a second end opposite each other, the second end being located on one side of the edge in the width direction of the connecting piece, and the narrowest channel being determined based on the first end and the position of the connecting piece that is closest to the first end.

[0008] In some embodiments, the width of the narrowest channel of the connecting piece at the fusion gap is in the range [12 mm, 14 mm].

[0009] In some embodiments, the angle between the extension direction of the narrowest channel of the connecting piece and the extension direction of the connecting piece is located in a preset angle range [60 degrees, 120 degrees].

[0010] In some embodiments, the angle between the extension direction of the narrowest channel and the extension direction of the connecting piece is 90 degrees.

[0011] In some embodiments, the fusion gap is elongated, and the elongated shape includes a straight strip, an arc-shaped strip, or a wavy strip.

[0012] In some embodiments, the thickness of the connecting piece is in the range [0.8 mm, 1 mm].

[0013] In some embodiments, the tab connection area has an isolation notch, the tab connection area includes a first tab connection area and a second tab connection area, and the isolation notch is located between the first tab connection area and the second tab connection area; the fusible region includes a first fusible region and a second fusible region, the first fusible region is located between the first tab connection area and the pole connection area, the second fusible region is located between the second tab connection area and the pole connection area, and the fusible notch includes at least one of the first fusible notch and the second fusible notch, the first fusible notch is located in the first fusible region, and the second fusible notch is located in the second fusible region.

[0014] In some embodiments, each of the first and second fusible gaps includes two such gaps. Along a direction perpendicular to the extension direction of the connecting piece, the two first fusible gaps are located on opposite sides of the first fusible area, and the two second fusible gaps are located on opposite sides of the second fusible area.

[0015] The energy storage device of this application includes a connecting piece, a battery cell, and a battery casing according to any of the above embodiments. The battery cell includes a cell body, a terminal post, and a tab. The cell body is located inside the battery casing, and the tab is connected to the cell body. The connecting piece is used to connect the terminal post and the tab. The battery casing includes a top plate and a positioning member. The positioning member is disposed on the surface of the top plate opposite to the cell body. The connecting member is disposed on the positioning member. The surface of the positioning member opposite to the cell body is provided with a positioning protrusion. The shape of the positioning protrusion matches the shape of the fusible gap, and the positioning protrusion is located within the fusible gap. The terminal post passes through the top plate and the positioning member and is connected to the surface of the connecting piece opposite to the top plate. The tab is connected to the surface of the connecting piece opposite to the cell body.

[0016] The electrical equipment in this application includes the energy storage device of any of the above embodiments.

[0017] In the connecting piece, energy storage device, and electrical device of this application embodiment, the connecting piece can connect the tab and terminal of the battery cell to realize the electrical connection of the battery cell. Between the tab connection area and the terminal connection area is the current flow channel (i.e., the fuse zone) of the battery cell. The narrower the width of the narrowest channel, the shorter the melting time. By opening a melting notch in the melting zone, the width of the narrowest channel can be reduced, thereby reducing the melting time and improving the safety of the battery cell. Since the melting notch is located in the area with the lowest current density in the melting zone, the melting notch has a smaller impact on the battery internal resistance, thereby ensuring the energy efficiency of the battery cell and achieving a balance between safety and energy efficiency.

[0018] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the embodiments of this application will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0020] Figure 1 This is a first structural schematic diagram of a V-shaped connecting piece according to certain embodiments of this application.

[0021] Figure 2 This is a second structural schematic diagram of a V-shaped connecting piece according to certain embodiments of this application.

[0022] Figure 3 This is a schematic diagram of the connection between a battery cell and a connecting piece in some embodiments of this application.

[0023] Figure 4 This is a third structural schematic diagram of the V-shaped connecting piece in some embodiments of this application.

[0024] Figure 5 This is a first structural schematic diagram of a U-shaped connecting piece according to certain embodiments of this application.

[0025] Figure 6 This is a second structural schematic diagram of the U-shaped connecting piece according to certain embodiments of this application.

[0026] Figure 7 This is a schematic diagram of the current density distribution of the U-shaped connecting piece in some embodiments of this application.

[0027] Figure 8 This is a schematic diagram showing the location of the fusion notch in the U-shaped connecting piece according to certain embodiments of this application.

[0028] Figure 9 This is a schematic diagram of the current density distribution of the V-shaped connector in some embodiments of this application.

[0029] Figure 10 This is a schematic diagram showing the location of the fusion notch in the V-shaped connecting piece according to certain embodiments of this application.

[0030] Figure 11 This is a schematic diagram of the structure of an energy storage device according to certain embodiments of this application.

[0031] Figure 12 This is a schematic diagram of the structure of a battery cell according to certain embodiments of this application.

[0032] Figure 13 This is a schematic diagram of the structure of an electrical device according to certain embodiments of this application. Detailed Implementation

[0033] The embodiments of this application will be further described below with reference to the accompanying drawings. The same or similar reference numerals in the drawings denote the same or similar elements or elements having the same or similar functions throughout.

[0034] Furthermore, the embodiments of this application described below in conjunction with the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting this application.

[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] To facilitate understanding of the solution in this application, the technical terms involved in this application will be explained below:

[0037] (1) Thermal runaway: This refers to the phenomenon where an uncontrolled exothermic reaction occurs inside a battery under specific conditions, leading to a rapid rise in temperature. Thermal runaway is usually caused by an uncontrolled chemical reaction inside the battery, generating a large amount of heat that cannot be dissipated in time, thus triggering a series of chain reactions. This situation is particularly common in lithium-ion batteries, but it can also occur in other types of batteries.

[0038] a. Causes of thermal runaway:

[0039] Overcharging or over-discharging: When a battery is overcharged or over-discharged, the internal chemical reactions become unstable, leading to an increase in temperature.

[0040] Internal short circuit: When a short circuit occurs inside the battery, the current will bypass the normal path and flow directly through it, generating a lot of heat.

[0041] External short circuit: When the positive and negative terminals of the battery are in direct contact, an external short circuit will occur, causing the current to increase sharply and generating a lot of heat.

[0042] Mechanical damage: Impacts, compressions, and other mechanical damage to the battery may cause internal structural damage and lead to a short circuit.

[0043] High-temperature environment: When exposed to high-temperature environments for extended periods, the chemical substances inside the battery may decompose more rapidly, generating heat.

[0044] Manufacturing defects: Defects in the battery manufacturing process, such as separator rupture and electrolyte leakage, may also lead to thermal runaway.

[0045] b. The process of thermal runaway: The process of thermal runaway can generally be divided into the following stages.

[0046] Initial temperature rise: For some reason, the battery begins to heat up.

[0047] Accelerated internal reactions: As the temperature rises, the rate of chemical reactions inside the battery increases, generating more heat.

[0048] Thermal runaway triggering: When the temperature reaches a critical value, the positive feedback cycle inside the battery begins, generating a large amount of heat energy, causing the temperature to rise rapidly.

[0049] Gas release: The electrolyte inside the battery begins to decompose, releasing gases (such as hydrogen, oxygen, etc.).

[0050] Fire and explosion: In extreme cases, the battery may catch fire or even explode.

[0051] c. Consequences of thermal runaway

[0052] Thermal runaway not only severely impacts the performance of the battery itself, but can also pose serious safety hazards:

[0053] Performance degradation: Battery lifespan is significantly shortened, and performance degrades.

[0054] Fire risk: Thermal runaway could cause the battery to catch fire, resulting in property damage.

[0055] Explosion hazard: In extreme cases, the battery may explode, endangering personal safety.

[0056] d. If signs of thermal runaway are detected in the battery, the following emergency measures can be taken:

[0057] Power outage: Immediately disconnect the power supply to prevent current from continuing to flow through the battery.

[0058] Isolation: Isolate the affected battery to prevent it from affecting other batteries.

[0059] Cooling: Use water or other coolants to cool the battery and lower its temperature.

[0060] Therefore, timely power cut-off can reduce the further expansion of thermal runaway and minimize the losses caused by it.

[0061] (2) Battery connector: Used to connect the tabs and terminals of the battery cell. The connector can reliably connect the tabs and terminals together. Since the tabs and terminals may be made of different materials (e.g., the tabs may be aluminum and the terminals may be copper), or their shapes and sizes may not be perfectly matched, the connector can serve as a transition and adaptation.

[0062] In terms of conductivity, the connector ensures that current can be smoothly transferred from the tab to the terminal. In a battery pack, multiple battery cells are connected in series or parallel via connectors, and the good conductivity of the connectors is crucial to the performance of the entire battery pack. For example, in a lithium-ion battery pack for an electric vehicle, the tab and terminal of each battery cell are connected by connectors. If the connectors malfunction (such as becoming loose or corroded), it will affect the output power and stability of the battery pack.

[0063] Alternatively, there are various ways to connect the connecting piece to the tab and the pole, such as welding, riveting, and crimping. Welding can provide good electrical connection and mechanical stability. Laser welding, for example, can achieve high-precision connections, forming a strong bond between the connecting piece and the tab and pole.

[0064] To ensure reliable connections, the connectors need to possess good conductivity, suitable mechanical strength, and corrosion resistance. This is because batteries are exposed to various factors during use, such as vibration, temperature changes, and humidity. For example, in some outdoor energy storage battery systems, the connectors need to withstand rain erosion and drastic temperature fluctuations to ensure stable connections over extended periods.

[0065] (3) Fusing of the connector: When the circuit containing the battery experiences a short circuit or overload due to thermal runaway, the current increases dramatically. Connectors typically have a certain current-carrying capacity. Exceeding this limit, due to Joule's law (where is heat, is current, is resistance, and is time), the heat generated on the connector will accumulate rapidly. For example, in a simple battery-powered circuit, if the load suddenly short-circuits, the normally functioning connector will instantly carry a current many times greater than its rated current, causing the connector temperature to rise sharply. This overcurrent situation may cause the temperature of the connector's fusible area to rise to its melting point in a very short time, resulting in melting.

[0066] According to the current national standard, batteries must not smoke or leak during external short-circuit testing. The internal connecting pieces must melt and break the circuit as soon as possible when subjected to a large short-circuit current. This means that the designed connecting pieces should be as narrow as possible to meet the overcurrent requirements. However, if the connecting pieces are too narrow, although they are easy to melt during short-circuit testing, the internal resistance of the connecting pieces will increase, affecting the energy efficiency of the cell, thus making it impossible to achieve a balance between safety and energy efficiency.

[0067] Please see Figure 1 The connecting piece 10 in this embodiment includes a body 11 and a fusible notch 12. The body 11 includes a tab connection area 111, a terminal connection area 112, and a fusible area 113. The tab connection area 111 is used to connect the tabs 222 of the battery cell 20, the terminal connection area 112 is used to connect the terminals 223 of the battery cell 20, and the fusible area 113 is located between the tab connection area 111 and the terminal connection area 112. The fusible notch 12 formed in the body 11 is located in the fusible area 113.

[0068] The connecting piece 10 in this embodiment can connect the tab 222 and the terminal 223 of the battery cell 20 to realize the electrical connection of the battery cell 20. Between the tab connection area 111 connecting the tab 222 and the terminal connection area 112 connecting the terminal 223, there is a current flow channel (i.e., a fuse area 113) for the battery cell 20. The narrower the width of the narrowest channel, the shorter the melting time. By opening a melting notch 12 in the melting area 113, the width of the narrowest channel can be reduced, thereby reducing the melting time and improving the safety of the battery cell 20. Since the melting notch 12 is located in the melting area 113, the melting notch 12 has a smaller impact on the battery internal resistance, thereby ensuring the energy efficiency of the battery cell 20 and achieving a balance between safety and energy efficiency.

[0069] Please see Figures 1 to 3 The connecting piece 10 of the embodiments of this application will now be described in detail.

[0070] The connecting piece 10 includes a body 11 and a fusible notch 12, with the fusible notch 12 located on the body 11 (i.e., the body 11 has a fusible notch 12).

[0071] The body 11 includes a tab connection area 111, a pole connection area 112, and a fuse area 113. The fuse area 113 is located between the tab connection area 111 and the pole connection area 112.

[0072] The tab connection area 111 is used to connect the tab 222 of the battery cell 20. The tab connection area 111 can be fixedly connected to the tab 222, such as by welding the tab connection area 111 to the tab 222. This achieves electrical connection between the connecting piece 10 and the tab 222, while also fixing the battery cell 20.

[0073] The tab 222 is a thin metal sheet or strip extending from the electrodes inside the battery. Inside the battery, the electrodes (such as positive and negative electrode materials) transmit the generated current outward through the tab 222. For example, in a pouch lithium battery, the tab 222 is usually located on the top or side of the battery, serving as a "bridge" connecting the internal electrodes to the external circuitry.

[0074] In some embodiments, the tab connection area 111 has an isolation notch 1113, the tab connection area 111 includes a first tab connection area 1111 and a second tab connection area 1112, and the isolation notch 1113 is located between the first tab connection area 1111 and the second tab connection area 1112.

[0075] Optionally, each pole post 223 may be connected to one or more tabs 222. For example... Figure 3 As shown, the positive terminal 223 of the battery is connected to two tabs 222, and the negative terminal 223 is also connected to two tabs 222. The first tab connection area 1111 and the second tab connection area 1112 of the connecting piece 10 ensure that both tabs 222 are connected to their corresponding terminals.

[0076] It is understandable that the number of tabs 222 connected to each terminal 223 varies depending on the type and design of the battery. For ordinary cylindrical batteries, there is generally one positive tab and one negative tab. Tabs are metallic conductors led out from the current collectors at the positive and negative terminals of the battery, mainly used to connect the positive and negative terminals of the battery to external circuits or the battery management system. They are usually quite flexible, facilitating connection and soldering. However, some specially designed batteries or pouch batteries may have multiple tabs. For example, to improve the battery's charge / discharge performance and current carrying capacity, some pouch batteries employ a multiple tab design. High-capacity pouch lithium batteries, for instance, may have two or more positive and negative tabs connected in parallel. This reduces the battery's internal resistance, making the battery more stable during high-rate charge / discharge and reducing heat generation issues.

[0077] In this way, the internal resistance of the battery cell 20 can be reduced by the multi-tab design, thereby improving the energy efficiency of the battery cell and reducing heat generation.

[0078] The connecting piece 10 enables electrical connection from the tab 222 to the post 223. To avoid separating the two tabs 222, an isolation gap 1113 is provided between the first tab connection area 1111 and the second tab connection area 1112 to separate the first tab connection area 1111 and the second tab connection area 1112, thereby enabling electrical connection from the post 223 to multiple tabs 222.

[0079] The terminal connection area 112 is used to connect the terminal 223 of the battery cell 20. The terminal connection area 112 can be fixedly connected to the terminal 223, such as by welding the terminal connection area 112 to the terminal 223. This achieves electrical connection between the connecting piece 10 and the terminal 223, while also fixing the battery cell 20.

[0080] The terminal 223 is a protruding part on the battery casing used for external connection, and it generally has a more robust structure. As the battery interface, it allows for easy connection to external devices (such as battery management systems, electrical appliances, etc.). For example, in a cylindrical battery, the positive and negative terminals 223 are located at opposite ends of the battery.

[0081] The fusible link 113 serves as a current flow path between the tab connection area 111 and the terminal connection area 112. When current flows between the tab 222 and the terminal 223, it passes through this current flow path. Therefore, when the battery cell 20 short-circuits due to thermal runaway or other reasons, the current flow path increases dramatically, causing the temperature of the fusible link 113 to rise rapidly. This causes the fusible link 113 to melt, thus breaking the connection between the tab 222 and the terminal 223 and cutting off the conductive circuit of the battery cell 20.

[0082] Among them, the direction of current flow in the current flow channel (e.g. Figure 3 The direction S1) is the direction from the tab 222 to the post 223 (for the positive electrode of the battery cell 20) or the direction from the post 223 to the tab 222 (for the negative electrode of the battery cell 20). Specifically, it can be the direction from the center of the tab 222 to the center of the post 223, or the direction from the center of the post 223 to the center of the tab 222.

[0083] Optionally, the extension direction of the fuse notch 12 is perpendicular to the extension direction of the connecting piece 10. The extension direction of the connecting piece is parallel to the direction from the tab connection area 111 to the pole connection area 112.

[0084] Thus, by reasonably setting the extension direction of the fuse gap 12, compared with the extension direction of the connecting piece 10, the length of the fuse gap 12 can be set to be shorter, thereby reducing the impact of the opening of the fuse gap 12 on the internal resistance of the connecting piece.

[0085] Optionally, the fusing area 113 is the area with the smallest width along the width direction in the body 11, and the width direction is perpendicular to the extension direction of the connecting piece.

[0086] Thus, since the melting zone 113 is the area with the smallest width along the width direction in the body 11, the narrowest channel 114 at the melting gap 12 in the melting zone 113 is the narrowest channel opening along the width direction. When thermal melting is detected, the narrowest channel 114 will melt first, thereby minimizing the melting time and ensuring the safety of the battery cell 20.

[0087] Optionally, the width of the narrowest channel 114 of the connecting piece 10 at the fusion notch 12 is determined based on the current carrying capacity and thickness of the connecting piece 10.

[0088] The current carrying capacity is the maximum current value that the connecting piece 10 can safely carry, and the unit is ampere-hour (Ah).

[0089] For example, the width of the narrowest channel 114 is positively correlated with the current carrying capacity of the connecting piece 10. Alternatively, the width of the narrowest channel 114 is negatively correlated with the thickness of the connecting piece 10.

[0090] Optionally, the width x of the narrowest channel 114 is determined based on the following formula:

[0091] x = C / 2kay, where a is a constant (e.g., between 0.8 and 1); C is the current carrying capacity; k is the preset overcurrent coefficient, which is determined based on parameters such as the temperature, material, and current of the connecting piece 10, such as a preset overcurrent coefficient of 12.5 amps / square millimeter (A / mm2).

[0092] Optionally, the thickness (in millimeters) of the connecting piece 10 is in the range [0.8mm, 1.2mm], such as the thickness of the connecting piece 10 being approximately 1mm.

[0093] Optionally, the width of the narrowest channel 114 is located in the range [12 mm, 14 mm].

[0094] Thus, by reasonably setting the width of the narrowest channel 114, while ensuring that the connecting piece 10 meets the overcurrent capacity requirements of the battery cell 20, the width of the narrowest channel 114 is reduced as much as possible, thereby minimizing the melting time and ensuring the safety of the battery cell 20.

[0095] Optionally, the thickness of the connecting piece 10 is in the range [0.8 mm, 1 mm].

[0096] In this way, by reasonably setting the thickness of the connecting piece 10, while ensuring that the connecting piece 10 meets the current carrying capacity requirements of the battery cell 20, the thickness of the narrowest channel 114 is reduced as much as possible, thereby minimizing the melting time and ensuring the safety of the battery cell 20.

[0097] Please see Figure 1Optionally, the location of the fuse gap 12 is determined based on the simulation results of the current density before the fuse gap is opened in the fuse zone. The simulation results of the current density include the current density of different areas of the fuse zone.

[0098] When selecting the location for opening the fuse notch 12, the current density of the fuse zone 113 before opening the fuse notch 12 can be simulated based on the shape of the connecting piece 10, thereby obtaining the simulation results of the current density of the fuse zone 113.

[0099] It is understandable that once the shape of the connecting piece 10, the size and position of the tab and post, and the material of the connecting piece are determined, the density distribution of the current flowing between the tab and post conforms to objective laws. Through professional simulation software, the current density simulation result of the fuse zone 113 can be accurately simulated, thereby obtaining the current density of different areas of the fuse zone 113.

[0100] Thus, by determining the current density in different areas of the fuse zone 113 before opening the fuse gap 12, the location of the fuse gap 12 that has the least impact on the internal resistance of the connecting piece 10 can be determined.

[0101] Optionally, the opening location is located in the area of ​​minimum current density in the fuse zone 113.

[0102] It is understandable that the smaller the current density at the location where the fuse notch 12 is opened, the smaller the resistance to the current when the width of the current channel at the notch is the same, thus minimizing the impact on the internal resistance of the connecting piece 10 and minimizing the increase in internal resistance after the fuse notch 12 is opened.

[0103] Alternatively, the opening location can also be located in the fuse zone 113, in a region where the current density is less than a preset current density. In this way, the selection of the opening location of the fuse notch 12 is more flexible while reducing the impact of the fuse notch 12 opening on the internal resistance.

[0104] Optionally, the fusing region 113 includes a first fusing region 1131 and a second fusing region 1132. The first fusing region 1131 is located between the first tab connection region 1111 and the pole connection region 112, and the second fusing region 1132 is located between the second tab connection region 1112 and the pole connection region 112. The fusing gap 12 includes at least one of a first fusing gap 121 and a second fusing gap 122. The first fusing gap 121 is disposed in the first fusing region 1131, and the second fusing gap 122 is disposed in the second fusing region 1132.

[0105] It can be understood that the positive and negative tabs 222 correspond to the first tab connection area 1111 and the second tab connection area 1112, respectively. A current flow channel is formed between the first tab connection area 1111 and the pole connection area 112 (corresponding to the first fuse area 1131), and a current flow channel is also formed between the second tab connection area 1112 and the pole connection area 112 (corresponding to the second fuse area 1132).

[0106] The fusible gap 12 can be provided in at least one of the first fusible zone 1131 and the second fusible zone 1132.

[0107] For example, the fusing gap 12 may include a first fusing gap 121 or a second fusing gap 122, with the first fusing gap 121 located in the first fusing zone 1131 and the second fusing gap 122 located in the second fusing zone 1132. When the first fusing gap 121 or the second fusing gap 122 is opened, the conductive circuit is broken, thus achieving fusing.

[0108] For example, the fusing gap 12 may include a first fusing gap 121 and a second fusing gap 122, which are symmetrically arranged relative to the center of the connecting piece 10. In this way, the internal resistance distribution of the first fusing region 1131 and the second fusing region 1132 can be more balanced while achieving stable fusing.

[0109] Please see Figure 4 Optionally, each of the first fusing notch 121 and the second fusing notch 122 includes two such notches. Along the direction perpendicular to the extension of the connecting piece 10, the two first fusing notches 121 are located on opposite sides of the first fusing region 1131, and the two second fusing notches 122 are located on opposite sides of the second fusing region 1132. The two first fusing notches 121 at one end form the narrowest current flow channel 114, and the two second fusing notches 122 at one end form the narrowest current flow channel 114 of the other.

[0110] The fuse notch 12 is opened in the fuse zone 113, which is the current flow channel. By opening the fuse notch 12 in the fuse zone 113, the narrowest channel width of the current flow channel can be reduced, thereby reducing the fuse time and improving the safety of the battery cell 20.

[0111] Please refer to it again. Figure 1 The fusible notch 12 includes a first end and a second end opposite to each other. The first end is away from the edge of the connecting piece 10 (such as the edge of the fusible region 113), and the second end is located on one side of the edge of the connecting piece 10 in the width direction. That is to say, along the width direction of the connecting piece 10 (i.e., the direction perpendicular to the extension direction of the connecting piece 10), the fusible notch 12 is formed by cutting from the edge of the connecting piece 10 toward the center of the connecting piece 10, and the second end is closer to the edge of the connecting piece 10 than the first end.

[0112] Optionally, the fuse notch 12 is located in the region of lowest current density within the fuse zone 113. This minimizes the impact of the fuse notch 12 on current flow, thereby reducing the influence of the fuse notch 12 on the internal resistance of the connecting piece 10. The increase in internal resistance is small, which improves the safety of the battery cell 20 while ensuring the energy efficiency of the battery cell 20.

[0113] Optionally, the current density distribution of the connecting piece 10 can be determined based on the parameters of the connecting piece 10. For example, the current density distribution of the connecting piece 10 can be simulated based on its shape, material, etc., to obtain a current density distribution map corresponding to the connecting piece 10. Based on the current density distribution map, the region with the minimum current density in the fuse zone 113 can be quickly determined.

[0114] For example, for a connector 10 with a complex shape, a numerical calculation method can be used to determine the current density distribution using the shape and material of the connector 10, such as finite element analysis.

[0115] Optionally, the current density distribution of the connecting piece 10 can also be obtained by actual measurement and calibration of the connecting piece 10. For example, by magnetic field measurement method, micro-resistance measurement method, etc.

[0116] Optionally, the extension direction of the fusible notch 12 is perpendicular to the extension direction of the connecting piece.

[0117] It is understandable that when making the fuse gap 12, the connecting piece 10 can be cut along the width direction of the extension direction of the connecting piece. This can reduce the width of the narrowest channel 114 of the fuse zone 113, reduce the fuse time, and also reduce the length of the fuse gap 12 along the extension direction of the connecting piece. This can reduce the time of obstruction of the current in the battery flow channel, thereby reducing the impact of the fuse gap 12 on the internal resistance of the battery cell 20.

[0118] In some embodiments, the extension direction of the narrowest channel 114 of the connecting piece 10 (e.g.) Figure 3 The angle between S2 and the extending direction of the connecting piece 10 (e.g., the angle between S2 and the extending direction of the connecting piece 10). Figure 3 The angle α in the middle is located in the preset angle range [60 degrees, 120 degrees]. The narrowest channel 114 is determined based on the first end of the fuse gap 12 and the position of the connecting piece 10 that is closest to the first end.

[0119] The current flow path of the fusing zone 113 includes two sides. The fusing notch 12 extends from one side of the current flow path to the other side. The line connecting the first end of the fusing notch 12 on the side furthest from the current flow path to the shortest distance on the other side of the current flow path forms the narrowest channel 114. The direction of extension of the narrowest channel 114 is the direction of this connecting line. The narrower the width of the narrowest channel 114, the shorter the fusing time.

[0120] It can be understood that the closer the angle between the narrowest channel 114 and the extension direction of the connecting piece is to 90 degrees (i.e., the extension direction of the narrowest channel 114), the shorter the length of the narrowest channel 114 in the extension direction of the connecting piece. The current can pass through the narrowest channel 114 more quickly, and the resistance to current flow is smaller. Therefore, by reasonably setting the angle between the extension direction of the narrowest channel 114 and the extension direction of the connecting piece to a preset angle range [60 degrees, 120 degrees], the influence of the setting of the fuse notch 12 on the internal resistance can be reduced, thereby ensuring energy efficiency.

[0121] Optionally, the angle between the extension direction of the narrowest channel 114 and the extension direction of the connecting piece is 90 degrees. In this way, the impact of the fuse notch 12 on the internal resistance can be minimized, thereby improving energy efficiency.

[0122] Please see Figure 1 and Figure 2 It can be understood that the fuse notch 12 is elongated, including straight, arc-shaped, or wavy shapes. This can meet different requirements for the shape of the fuse notch 12. For example, the fuse notch 12 can be matched with the shape of the positioning structure of the battery cell 20 to limit the connection piece 10, such as limiting it in the width direction or the extension direction of the connection piece.

[0123] Optionally, the overcurrent cross-sectional area of ​​the fuse gap 12 is determined based on the battery capacity connected to the connecting piece 10, the preset charge / discharge rate, and the preset overcurrent coefficient of the connecting piece 10.

[0124] The current-passing cross-sectional area of ​​the fuse gap 12 refers to the effective cross-sectional area of ​​the connecting piece 10 that allows current to pass through.

[0125] It is understandable that the cross-sectional area of ​​the fuse gap 12 needs to be adaptively designed in order to meet the current carrying capacity requirements of the battery cell 20.

[0126] For example, the overcurrent cross-sectional area is calculated using the battery capacity connected by connector 10, the preset charge / discharge rate, and the preset overcurrent coefficient of connector 10. Assuming the battery capacity is aAh (ampere-hours), the maximum charge / discharge rate of the battery design is bC, and the overcurrent coefficient of the material used is c (for large-capacity cells, aluminum is typically taken as 7.5A / mm²). 2 (A / mm²), for copper it is generally taken as 11.25A / mm².2 Therefore, the cross-sectional area for the narrowest point at the positive electrode is ab / 2c mm. 2 .

[0127] Please combine Figure 5 and Figure 6 In some embodiments, the connecting piece 10 is U-shaped or V-shaped.

[0128] Among them, for the U-shaped connecting piece 10, the narrowest point of the current flow (i.e. the narrowest channel 114) appears on both sides. During the short circuit test, the melting time is short, and the circuit can be broken quickly.

[0129] In contrast, the narrowest point of the V-shaped connector 10 for overcurrent also appears on both sides, with a uniform current density distribution and relatively low internal resistance, which is beneficial to improving battery energy efficiency.

[0130] Taking the cross-sectional area of ​​the narrowest part of the U-shaped connecting piece 10 as 0.8*16mm and the cross-sectional area of ​​the narrowest part of the V-shaped connecting piece 10 as 1.0*25.0mm as examples, the internal resistance and fusing time are shown in the table below:

[0131] Internal resistance (mΩ) Circuit breaker time (seconds) U-shaped connecting piece 10 0.025 22 V-shaped connecting piece 10 0.015 105

[0132] Please see Figure 7 and Figure 8 , Figure 7 The current density distribution diagram of the U-shaped connector 10 is shown in the simulation diagram. It can be seen that in the fusing region 113, the current density concentrates at the corners, while the density is lowest at the outer corners on both sides of the terminal connection region 112. Therefore, when cutting the fusing notch 12 in the U-shaped connector 10, the corners can be avoided, and the current density distribution can be minimized in the areas with the lowest current density (such as...). Figure 8 As shown, at the outer corners on both sides of the pole connection area 112, as Figure 5 (The location of the fuse gap 12 shown) is where the fuse gap 12 is opened.

[0133] Please see Figure 9 and Figure 10 , Figure 9 The current density distribution diagram of the V-shaped connector 10 is shown in the simulation diagram. It can be seen from the current density distribution diagram of the V-shaped connector 10 that, in the fusing region 113, the current density is lower in the area between the terminal connection region 112 and the tab connection region 111. Therefore, when cutting the fusing notch 12 in the V-shaped connector 10, the terminal connection region 112 and the tab connection region 111 can be avoided, and the current density distribution can be minimized in the region with the lowest current density (such as in...). Figure 10 The locations with lower current density distribution on both sides of the intermediate electrode connection region 112, such as... Figure 1A fusing notch 12 is made at the location shown. After the fusing notch 12 is made in the V-shaped connecting piece 10, the internal resistance becomes 0.22mΩ and the fusing time becomes 25s. Thus, with a slight increase in internal resistance, the fusing time is greatly reduced, thereby achieving a balance between safety and energy efficiency.

[0134] Please see Figure 11 This application provides an energy storage device 100, which includes a cover 30, a housing 40, and a battery module 50. The cover 30 is disposed on the housing 40, and the housing 40 and the cover 30 enclose a receiving space, within which the battery module 50 is disposed.

[0135] The cover 30 is used to seal the containment space to isolate it from the outside world and prevent dust, conductive substances, etc. from entering the containment space, so as to ensure the safety and lifespan of the battery module 50.

[0136] Optionally, the cover 30 is fixedly installed on the housing 40; or the cover 30 is detachably installed on the housing 40 to facilitate subsequent maintenance of the battery module 50.

[0137] In some embodiments, there may be one or more battery modules 50, and multiple battery modules 50 may be disposed within the housing 40, and the multiple battery modules 50 may be combined with the housing 40 to form a battery pack.

[0138] Please combine Figure 3 Optionally, the battery module 50 includes multiple battery cells 20. These multiple battery cells 20 are combined in series, parallel, or a combination of series and parallel connections. The battery pack is a product that is further packaged and integrated based on the battery module 50.

[0139] The battery module 50 forms a power supply circuit with the external load through a total positive and a total negative connection, thereby providing power. The battery module 50 is the core component of the energy storage device 100, used for energy storage and power supply.

[0140] Alternatively, the energy storage device 100 may be a battery pack, a battery module 50, or a battery cell 20.

[0141] Optionally, please combine Figure 3 and Figure 12 The battery cell 20 includes a battery casing 21, a battery cell 22, and an explosion-proof valve 23. The battery cell 22 is disposed inside the battery casing 21, and the explosion-proof valve 23 is disposed inside the battery casing 21.

[0142] The battery cell 22 includes a cell body 221, a tab 222, and a terminal 223. The cell body 221 is located inside the battery casing 21, the tab 222 is connected to the cell body 221, the terminal 223 passes through the battery casing 21, and the tab 222 and the terminal 223 are connected together by a connecting piece 10.

[0143] Optionally, the battery casing 21 includes a top plate 211, a bottom plate 212, a side plate 213, and a positioning member 214. The top plate 211 and the bottom plate 212 are connected by the side plate 213. The positioning member 214 is disposed on the surface of the top plate 211 opposite to the cell body 221. The connecting member 10 is disposed on the positioning member 214. The surface of the positioning member 214 opposite to the cell body 221 is provided with a positioning protrusion 215. The shape of the positioning protrusion 215 matches the shape of the fuse notch 12 (for example, the shape of the positioning protrusion 212 can be rectangular, arc-shaped, wavy, etc.) and the positioning protrusion is located within the fuse notch.

[0144] The pole post 223 passes through the top plate 211 and the positioning member 214, and is connected to the surface of the connecting piece 10 opposite to the top plate 211. The pole tab 222 is connected to the surface of the connecting piece 10 opposite to the cell body 221.

[0145] Alternatively, the positioning element 215 can be a plastic sheet. This is less expensive, lighter, and has flame-retardant properties.

[0146] Thus, the fuse notch 12 can be set based on the shape of the positioning protrusion 212. While reducing the fuse time, it can also cooperate with the positioning protrusion 212 to fix the connecting piece 10 in a fixed position. This makes the tab connection area 111 of the connecting piece 10 opposite to the tab 222 of the battery cell 22, and the post connection area 112 opposite to the post 223 of the battery cell 22. This makes it convenient to connect the tab 222 and post 223 of the battery cell 22 together with the connecting piece 10.

[0147] In some embodiments, there may be one or more battery packs, and one or more battery packs may form a battery cluster. The energy storage device 100 may include one or more battery clusters.

[0148] In some embodiments, the energy storage device 100 may be an energy storage cabinet, which is a large device for storing electrical energy. The energy storage cabinet may be equipped with one or more battery packs or one or more battery clusters, and is equipped with a complete power conversion, monitoring, and management system.

[0149] Please see Figure 13 The electrical device 1000 of this application includes the energy storage device 100 of any of the above embodiments. The energy storage device 100 is used to provide electrical energy to the electrical device 100.

[0150] Among them, electrical equipment 1000 refers to equipment that consumes electrical energy to perform various functions. For example, electrical equipment may include, but is not limited to: mobile electronic devices, electric vehicles, uninterruptible power supply (UPS) equipment, etc.

[0151] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0152] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one feature. In the description of this application, "multiple" means at least two, such as two or three, unless otherwise explicitly specified.

[0153] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A tab, characterized in that include: The body includes a tab connection area, a terminal connection area, and a fuse area. The tab connection area is used to connect the tabs of the battery cell, the terminal connection area is used to connect the terminal of the battery cell, and the fuse area is located between the tab connection area and the terminal connection area. The body also has a fusing notch, which is located in the fusing zone.

2. The tab of claim 1, wherein The connecting piece is U-shaped or V-shaped.

3. The tab of claim 1, wherein The extension direction of the fusion notch is perpendicular to the extension direction of the connecting piece, and the extension direction of the connecting piece is parallel to the direction from the tab connection area to the pole connection area.

4. The tab of claim 1, wherein The width of the narrowest channel of the connecting piece at the fusible gap is determined based on the current carrying capacity and thickness of the connecting piece. The fusible gap includes a first end and a second end opposite to each other. The second end is located on one side of the edge in the width direction of the connecting piece. The narrowest channel is determined based on the first end and the position of the connecting piece that is closest to the first end.

5. The tab of claim 4, wherein, The width of the narrowest channel of the connecting piece at the fusion gap is in the range [12 mm, 14 mm].

6. The tab of claim 4, wherein The angle between the extension direction of the narrowest channel of the connecting piece and the extension direction of the connecting piece is within a preset angle range [60 degrees, 120 degrees].

7. The tab of claim 4, wherein The angle between the extension direction of the narrowest channel and the extension direction of the connecting piece is 90 degrees.

8. The tab according to any one of claims 1-7, characterized in that The fuse gap is elongated, and the elongated shape includes straight strips, arc-shaped strips, or wavy strips.

9. The tab of claim 1, wherein The thickness of the connecting piece is in the range [0.8 mm, 1 mm].

10. The tab of claim 1, wherein The tab connection area has an isolation notch, and the tab connection area includes a first tab connection area and a second tab connection area. The isolation notch is located between the first tab connection area and the second tab connection area. The fusible region includes a first fusible region and a second fusible region. The first fusible region is located between the first tab connection area and the pole connection area, and the second fusible region is located between the second tab connection area and the pole connection area. The fusible notch includes at least one of the first fusible notch and the second fusible notch. The first fusible notch is located in the first fusible region, and the second fusible notch is located in the second fusible region.

11. The tab of claim 10, wherein The first and second fusible gaps each include two, and along the direction perpendicular to the extension direction of the connecting piece, the two first fusible gaps are located on opposite sides of the first fusible area, and the two second fusible gaps are located on opposite sides of the second fusible area.

12. An energy storage device, characterized by, include: The connecting piece according to any one of claims 1-11; Battery casing; and A battery cell, comprising a cell body, terminals, and tabs, wherein the cell body is located inside the battery casing, the tabs are connected to the cell body, and the connecting piece is used to connect the terminals and tabs; The battery casing includes a top plate and a positioning member. The positioning member is disposed on the surface of the top plate opposite to the cell body. The connecting member is disposed on the positioning member. The surface of the positioning member opposite to the cell body is provided with a positioning protrusion. The shape of the positioning protrusion matches the shape of the fuse notch and the positioning protrusion is located within the fuse notch. The terminal post passes through the top plate and the positioning member and is connected to the surface of the connecting piece opposite to the top plate. The electrode tab is connected to the surface of the connecting piece opposite to the cell body.

13. An electrical device, characterized by The electrical equipment includes the energy storage device as described in claim 12.

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