ADAPTING MEMBER, BATTERY CELL, BATTERY, AND ELECTRIC APPARATUS

Provided are an adapting member, a battery cell, a battery, and an electric apparatus, so as to improve performance of the battery cell. An adapter includes a first connecting portion, a second connecting portion, and an overload protection portion. The first connecting portion is configured to be electrically connected to an electrode terminal, the second connecting portion is configured to be electrically connected to a tab, the overload protection portion is disposed between the first connecting portion and the second connecting portion, and the second connecting portion includes a tab connecting surface for connecting the tab. The blocking member is disposed on a side of the adapter having the tab connecting surface and covers at least a portion of the overload protection portion, and the blocking member is configured to insulate and block direct electrical connection between the tab and the first connecting portion.

TECHNICAL FIELD

This application relates to the field of battery technologies, and more specifically, to an adapting member, a battery cell, a battery, and an electric apparatus.

BACKGROUND

With the development of new energy technologies, rechargeable batteries are increasingly widely used in electronic devices such as mobile phones, notebook computers, electric bicycles, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools. In addition, as a part of people's daily life, most electronic devices have high requirements for battery life and safety.

In the existing battery technologies, a structural member for electrical connection in a battery cell occupies internal space. Therefore, how the internal space of the battery cell occupied by the structural member is reduced while ensuring safe current transmission is an urgent technical problem to be solved in battery technologies.

SUMMARY

This application provides an adapting member, a battery cell, a battery, and an electric apparatus, so as to reduce internal space of the battery cell occupied by a structural member while ensuring safe current transmission, thereby improving performance of the battery cell.

According to a first aspect, an embodiment of this application provides an adapting member applied to a battery cell and including an adapter and a blocking member. The adapter includes a first connecting portion, a second connecting portion, and an overload protection portion, where the first connecting portion is configured to be electrically connected to an electrode terminal of the battery cell, the second connecting portion is configured to be electrically connected to a tab of the battery cell, the overload protection portion is disposed between the first connecting portion and the second connecting portion, and the second connecting portion includes a tab connecting surface for connecting the tab. The blocking member is disposed on a side of the adapter having the tab connecting surface and covers at least a portion of the overload protection portion, and the blocking member extends from the overload protection portion toward two sides in a first direction such that the blocking member extends beyond edges of the overload protection portion on two sides in the first direction. The blocking member is configured to insulate and block direct electrical connection between the tab and the first connecting portion. The first direction is a direction along which the first connecting portion and the overload protection portion are disposed side by side.

In the foregoing technical solution, the blocking member is disposed on the side of the adapter having the tab connecting surface, which greatly reduces the probability of direct electrical connection formed after the tab crosses the overload protection portion to come into direct contact with the first connecting portion, and in turn avoids functional failure of the overload protection portion on the adapter, improving reliability of the adapting member and improving safety of the battery cell. In addition, the blocking member is disposed only on the side of the adapter having the tab connecting surface, which reduces the internal space occupied by the blocking member, further increasing energy density of the battery cell.

In some embodiments, a distance by which the blocking member extends beyond the edges of the overload protection portion on two sides in the first direction is D1, D1satisfying 0.5 mm to 5 mm. The first direction is the direction along which the first connecting portion and the overload protection portion are disposed side by side.

A greater distance by which the edge of the blocking member extends beyond the overload protection portion means larger space and weight occupied by the blocking member, resulting in higher material costs. A smaller distance by which the edge of the blocking member extends beyond the overload protection portion means lower reliability of the blocking member completely covering the overload protection portion due to the risk of misalignment during actual assembly. If the distance by which the edge of the blocking member extends beyond the overload protection portion is excessively small, the blocking member does not completely cover the overload protection portion, and the tab crosses the overload protection portion toward the first connecting portion due to misalignment, resulting in failure of the overload protection portion. In the foregoing technical solution, the distance by which the edge of the blocking member extends beyond the overload protection portion is limited to 0.5 mm to 5 mm, so as to ensure that the blocking member covers the overload protection portion, controlling overall manufacturing costs and space occupation of the adapting member while avoiding the failure of the overload protection portion.

In some embodiments, in a thickness direction of the blocking member, a projection of the blocking member is located within a projection of the adapter, and in a direction perpendicular to the first direction, a distance D2between edges of a projection of the blocking member on two sides and edges of a projection of the adapter on two sides is 0 mm to 0.2 mm.

The foregoing technical solution can prevent the blocking member from extending out of the adapter, reduce the assembly space occupied by the blocking member, and improve space utilization of other components. Moreover, when the blocking member is adhered to the adapter, D2being controlled to be 0 mm to 0.2 mm can reduce the risk of adhesive overflow of the blocking member. In addition, a size of edge regions of the overload protection portion and the first connecting portion that are not covered by the blocking member is controlled to be 0 mm to 0.2 mm, which can ensure that the tab is supported by the blocking member with a certain thickness even if the tab crosses the overload protection portion, such that in the thickness direction of the blocking member, there is a gap between the tab and the overload protection portion as well as between the tab and the first connecting portion, further reducing the risk of the tab crossing the overload protection portion to be directly electrically connected to the first connecting portion.

In some embodiments, the adapter has an electrode terminal connecting surface in its thickness direction, the electrode terminal connecting surface and the tab connecting surface being located on a same side of the adapter or on two sides facing away from each other of the adapter respectively; and the blocking member is disposed on the side of the adapter having the tab connecting surface and covers the overload protection portion and at least a portion of the first connecting portion.

In the foregoing technical solution, the blocking member covers at least a portion of the first connecting portion, which can improve the reliability of the blocking member, further reducing the probability of direct contact between the tab and the first connecting portion caused by misalignment or excessive length of the tab.

In some embodiments, the first connecting portion includes an electrode terminal connecting portion, where in the thickness direction, the electrode terminal connecting portion protrudes in a direction approaching the electrode terminal, the electrode terminal connecting surface is a surface of the electrode terminal connecting portion facing the electrode terminal, and the overload protection portion and the electrode terminal connecting portion are spaced apart.

In the foregoing technical solution, the electrode terminal connecting portion allows for better connection between the electrode terminal connecting surface and the electrode terminal, further reducing the rate of poor welding and improving the reliability of connection between the adapter and the electrode terminal. In addition, when the electrode terminal is laser-welded to the adapter, laser reflected can be blocked by grooves formed in the foregoing solution, which reduces the probability of the laser reflected causing damage to other components in the battery cell, improving the safety of the battery cell.

In some embodiments, a minimum distance between the overload protection portion and the electrode terminal connecting portion is 1 mm to 50 mm.

If the distance between the overload protection portion and the electrode terminal connecting portion is excessively small, the blocking member covers an opening formed after the electrode terminal connecting portion protrudes when covering the overload protection portion. The electrode terminal connecting portion and the electrode terminal are welded through the opening of the electrode terminal connecting portion, but interference between the blocking member and the opening affects the yield rate of welding. In addition, the laser scattered during welding also irradiates the blocking member, which causes damage to the blocking member, reducing the reliability of the blocking member. A greater distance between the overload protection portion and the electrode terminal connecting portion means a longer length of the blocking member in the first direction, which in turn means higher material costs required for the blocking member. In the foregoing technical solution, the distance between the overload protection portion and the electrode terminal connecting portion is limited to 1 mm to 50 mm, so as to avoid interference between the overload protection portion and the opening of the electrode terminal connecting portion. In addition, the material costs of the blocking member are reduced.

In some embodiments, the overload protection portion includes a through hole and a fusing portion, where the fusing portion and the through hole are successively distributed along a second direction, and the first direction intersects with the second direction.

In the foregoing technical solution, in the overload protection portion formed by the through hole and the fusing portion, the through hole has a simple manufacturing process, thereby reducing process difficulty of the overload protection portion.

In some embodiments, the overload protection portion has a thinned portion, where the thinned portion extends along a second direction, and the first direction intersects with the second direction.

In the foregoing technical solution, the fusing portion and thinned portion in the overload protection portion jointly provide overload protection. When a sum of cross-sectional areas of the fusing portion and the thinned portion is smaller than that of the first connecting portion and also smaller than that of the second connecting portion, and the current that the fusing portion and the thinned portion can withstand exceeds a threshold, the fusing portion and the thinned portion break, and the current cannot be transferred from the second connecting portion to the first connecting portion. In the foregoing solution, the threshold of the overload protection portion can be adjusted more flexibly by adjusting shape and thickness of the thinned portion.

A greater thickness of the thinned portion means higher strength of the adapter, higher working current that can pass through the thinned portion, and more heat that the thinned portion can withstand. However, because the thinned portion is a portion of the overload protection portion, the heat that the thinned portion can withstand needs to be reduced, so that the thinned portion can break when the current exceeding a given threshold flows through the thinned portion. In the foregoing technical solution, the thickness H1of the thinned portion is limited to satisfying 0 mm<H1≤0.5 mm, which can ensure overall strength of the adapter without functional failure of the overload protection portion. In some embodiments, the blocking member has an avoidance hole, where the avoidance hole is configured to avoid the electrode terminal connecting portion and is disposed corresponding to the electrode terminal connecting portion.

In the foregoing technical solution, the avoidance hole on the blocking member reduces interference in the connection between the electrode terminal connecting portion and the electrode terminal, and protects the overload protection portion on the adapter to the greatest extent, reducing the risk of direct contact between the tab and the electrode terminal connecting portion.

In some embodiments, the overload protection portion is provided in two, where the two overload protection portions are located on two sides of the first connecting portion in the first direction and are connected to the two second connecting portions respectively.

The foregoing technical solution can ensure that there are overload protection portions on both sides of the first connecting portion. In a case that the battery cell includes a plurality of electrode assemblies, when any one of the electrode assemblies experiences a short circuit, the plurality of overload protection portions can disconnect electrical connection of that electrode assembly in a timely manner, improving the safety performance of the battery cell.

In some embodiments, the blocking member is an integral structure, and an orthographic projection of the blocking member on the adapter covers at least the two overload protection portions.

In the foregoing technical solution, the blocking member is the integral structure, which can simplify the assembly of the blocking member, improving assembly efficiency.

In some embodiments, the blocking member is a segmented structure, and the blocking member includes a first sub-portion and a second sub-portion, the first sub-portion and the second sub-portion covering the two overload protection portions respectively.

In the foregoing technical solution, when the blocking member is assembled, the electrode terminal connecting portion has certain requirements for the assembly of the blocking member. The blocking member is divided into two portions, and the two portions do not affect each other, so as to reduce the assembly requirements and the probability of misalignment of the blocking member.

In some embodiments, the adapter further includes a limiting portion, the limiting portion extending along a second direction.

The foregoing technical solution can ensure accurate mounting of the blocking member and the adapter, alleviating the problem of blocking capability failure of the blocking member caused by position offset of the blocking member.

In some embodiments, the blocking member covers at least a portion of a surface of the limiting portion facing the tab connecting surface, and the blocking member does not extend beyond an outer edge of the limiting portion.

The foregoing technical solution can reduce the probability of adhesive overflow and interference with other components caused by the blocking member extending beyond the edge of the adapter.

In some embodiments, the blocking member includes an adhesive layer and a blocking layer that are stacked in a thickness direction of the blocking member, the blocking layer being adhered to the adapter through the adhesive layer.

The foregoing technical solution can effectively enhance connection strength between the blocking member and the adapter, reducing the risk of separation between the blocking member and the adapter.

In some embodiments, thickness of the blocking member is 1 μm to 500 μm.

A greater thickness of the blocking member means higher material costs and larger internal space of the battery cell occupied by the blocking member. A smaller thickness of the blocking member means higher process difficulty and higher manufacturing costs. In the foregoing technical solution, the thickness of the blocking member is limited to 1 μm to 500 μm, so as to balance the process requirements and the cost requirements and further reduce the internal space of the battery cell occupied by the blocking member, further increasing the energy density of the battery cell.

In some embodiments, a thickness ratio of the blocking member to the adapter is 1/10 to 4/5.

The space reserved for the adapting member in the battery cell is relatively fixed. Therefore, if the blocking member is thicker, the adapter is thinner, which reduces overall strength of the adapter. If the blocking member is thinner, the adapter is thicker, which reduces overall strength of the blocking member. In this technical solution, the thickness ratio of the blocking member to the adapter is limited to 1/10 to 4/5, so as to prevent the adapting member from occupying the space of the folded tab structure while balancing the respective strengths of the blocking member and the adapter.

In some embodiments, in a thickness direction of the blocking member, a projection area ratio of the blocking member to the adapter is 1/5 to 4/5.

A larger coverage area of the blocking member on the adapter means higher material costs required for the blocking member. A smaller coverage area of the blocking member on the adapter means poorer blocking effect of the blocking member. In addition, when the blocking member is adhered to the adapter, a smaller area of the blocking member means lower adhesion strength of the blocking member. In the foregoing technical solution, the area ratio of the blocking member to the adapter is limited to 1/5 to 4/5, so as to balance the material costs and the blocking effect of the blocking member.

According to a second aspect, an embodiment of this application provides a battery cell including: a housing provided with an accommodating cavity; an electrode terminal disposed on the housing; an electrode assembly accommodated in the accommodating cavity, the electrode assembly including a body portion and a tab led out of the body portion; and an adapting member, where the adapting member is the adapting member according to any one of the embodiments in the first aspect, the first connecting portion of the adapter is electrically connected to the electrode terminal, and the second connecting portion is electrically connected to the tab.

In some embodiments, the tab connecting surface is located on a surface of the second connecting portion facing the electrode assembly.

In the foregoing technical solution, the blocking member and the tab are both located on a side facing away from the electrode terminal, which is conducive to further reducing the internal space of the battery cell occupied by the blocking member, increasing the energy density of the battery cell.

According to a third aspect, an embodiment of this application provides a battery including a plurality of battery cells according to any one of the embodiments in the second aspect.

According to a fourth aspect, an embodiment of this application provides an electric apparatus including a plurality of battery cells according to any one of the embodiments in the second aspect, where the battery cell is configured to supply electric energy.

This application provides the foregoing adapting member, battery cell, battery, and electric apparatus, so as to reduce internal space of the battery cell occupied by a structural member while ensuring safe current transmission, thereby improving performance of the battery cell.

The foregoing description is merely an overview of the technical solution of this application. For a better understanding of the technical means in this application such that they can be implemented according to the content of the specification, and to make the above and other objectives, features, and advantages of this application more obvious and easier to understand, the following describes specific embodiments of this application.

The accompanying drawings are not drawn to scale.

DESCRIPTION OF EMBODIMENTS

Unless otherwise defined, all technical and scientific terms used in this application shall have the same meanings as commonly understood by persons skilled in the art to which this application relates. The terms used in the specification of this application are intended to merely describe the specific embodiments rather than to limit this application. The terms “include”, “comprise”, and any variations thereof in the specification, claims, and brief description of drawings of this application are intended to cover non-exclusive inclusions. In the specification, claims, or accompanying drawings of this application, the terms “first”, “second”, and the like are intended to distinguish between different objects rather than to describe a particular order or a primary-secondary relationship.

In this application, reference to “embodiment” means that specific features, structures, or characteristics described with reference to the embodiment may be incorporated in at least one embodiment of this application. The word “embodiment” appearing in various places in this specification does not necessarily refer to the same embodiment or an independent or alternative embodiment that is exclusive of other embodiments.

The term “and/or” in this application is only an associative relationship for describing associated objects, indicating that three relationships may be present. For example, A and/or B may indicate the following three cases: presence of only A; presence of both A and B; and presence of only B. In addition, the character “/” in this application generally indicates an “or” relationship between the contextually associated objects.

In the embodiments of this application, the same reference signs denote the same components. For brevity, in different embodiments, detailed descriptions of the same components are not repeated. It should be understood that as shown in the accompanying drawings, sizes such as thickness, length, and width of various components and sizes such as thickness, length, and width of integrated devices in the embodiments of this application are merely for illustrative purposes and should not constitute any limitations on this application.

In this application, “a plurality of” means more than two (inclusive).

In this application, a battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, or the like. This is not limited in the embodiments of this application. The battery cell may be cylindrical, flat, cuboid, or of other shapes. This is not limited in the embodiments of this application either. Battery cells are typically categorized into three types by packaging method: cylindrical battery cell, prismatic battery cell, and pouch battery cell. This is not limited in the embodiments of this application either.

The battery mentioned in the embodiments of this application is a single physical module that includes one or more battery cells for providing a higher voltage and capacity. A battery typically includes a box configured to enclose one or more battery cells. The box can prevent a liquid or another foreign matter from affecting charging or discharging of the battery cells.

The battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly relies on migration of metal ions between the positive electrode plate and the negative electrode plate to work. The positive electrode plate includes a positive electrode current collector and a positive electrode active substance layer. The positive electrode active substance layer is applied on a surface of the positive electrode current collector. The positive electrode current collector includes a positive electrode coated region and a positive tab connected to the positive electrode coated region. The positive electrode coated region is coated with the positive electrode active substance layer, and the positive tab is coated with no positive electrode active substance layer. A lithium-ion battery cell is used as an example, for which, the positive electrode current collector may be made of aluminum, the positive electrode active substance layer includes a positive electrode active substance, and the positive electrode active substance may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganate oxide, or the like. The negative electrode plate includes a negative electrode current collector and a negative electrode active substance layer. The negative electrode active substance layer is applied on a surface of the negative electrode current collector. The negative electrode current collector includes a negative electrode coated region and a negative tab connected to the negative electrode coated region. The negative electrode coated region is coated with the negative electrode active substance layer, and the negative tab is coated with no negative electrode active substance layer. The negative electrode current collector may be made of copper, the negative electrode active substance layer includes a negative electrode active substance, and the negative electrode active substance may be carbon, silicon, or the like. The separator may be made of polypropylene (polypropylene, PP), polyethylene (polyethylene, PE), or the like.

The battery cell further includes a housing, an electrode terminal, and an adapting member, where an accommodating cavity for accommodating the electrode assembly is formed inside the housing, and the electrode terminal is mounted on the housing. The housing can protect the electrode assembly from the outside to prevent external foreign matters from affecting charging or discharging of the electrode assembly. The electrode terminal is configured to be electrically connected to a tab of the electrode assembly to lead out electric energy generated by the electrode assembly. The adapting member is configured to connect the electrode terminal and the tab to electrically connect the electrode terminal and the tab.

In the related art, when the adapting member connects the electrode terminal and the tab, an overload protection portion needs to be provided in the adapting member, where the overload protection portion is disposed between a region connected to the tab and a region connected to the electrode terminal. When the battery cell experiences excessive current flow, the overload protection portion disconnects electrical connection between the tab connecting region and the electrode terminal connecting region, thereby reducing the risk of thermal runaway caused by short circuit inside the battery, reducing safety hazards of the battery. To ensure proper functioning of the overload protection portion, that is, to avoid electrical connection formed after the tab directly crosses the overload protection portion to come into direct contact with the region connected to the electrode terminal caused by misalignment or excessive length of the tab, the overload protection portion is typically surrounded by an insulating material on the adapting member.

The inventors have found that an insulating member such as lower plastics for insulation is disposed between the housing and the adapting member of the battery cell. To be specific, there is no need to dispose a blocking member on a surface of an adapter facing the electrode terminal, and the tab is typically welded to the surface of the adapter facing the electrode assembly, so the risk of the tab crossing the overload protection portion generally occurs on the surface of the adapter facing the electrode assembly.

In view of this, the embodiments of this application provide a technical solution. In this technical solution, an adapting member is applied to a battery cell, where the adapting member includes an adapter and a blocking member. The adapter includes a first connecting portion, a second connecting portion, and an overload protection portion. The first connecting portion is configured to be electrically connected to an electrode terminal of the battery cell, the second connecting portion is configured to be electrically connected to a tab of the battery cell, the overload protection portion is disposed between the first connecting portion and the second connecting portion, and the second connecting portion includes a tab connecting surface for connecting the tab. The blocking member is disposed on a side of the adapter having the tab connecting surface and covers at least a portion of the overload protection portion, and the blocking member extends from the overload protection portion toward two sides in a first direction such that the blocking member extends beyond edges of the overload protection portion on two sides in the first direction. The blocking member is configured to insulate and block direct electrical connection between the tab and the first connecting portion. The first direction is a direction along which the first connecting portion and the overload protection portion are disposed side by side. In the embodiments of this application, the blocking member is disposed on the side of the adapter having the tab connecting surface, which reduces the risk of direct electrical connection formed after the tab crosses the overload protection portion to come into direct contact with the first connecting portion, and in turn reduces the probability of functional failure of the overload protection portion on the adapter, improving safety of the adapting member. In addition, the blocking member is located on a side of the adapter, so as to reduce internal space of the battery cell occupied by the blocking member, thereby increasing energy density of the battery cell.

The technical solution described in the embodiments of this application is applicable to batteries and electric apparatuses using a battery.

The electric apparatus may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, or the like. The vehicle may be a fossil fuel vehicle, a natural gas vehicle, or a new energy vehicle. The new energy vehicle may be a battery electric vehicle, a hybrid electric vehicle, a range-extended electric vehicle, or the like. The spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, and the like. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric toy car, an electric toy ship, and an electric toy airplane. The electric tool includes an electric metal cutting tool, an electric grinding tool, an electric assembly tool, and an electric railway-specific tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an electric impact drill, a concrete vibrator, and an electric planer. The embodiments of this application impose no special limitation on the foregoing electric apparatus.

For ease of description, the electric apparatus being a vehicle is used as an example for description of the following embodiments.

FIG.1is a schematic structural diagram of a vehicle according to some embodiments of this application.

As shown inFIG.1, the vehicle1000is provided with a battery100inside, where the battery100may be disposed at the bottom, front, or rear of the vehicle1000. The battery100may be configured to supply power to the vehicle1000. For example, the battery100may be used as an operational power source for the vehicle1000.

The vehicle1000may further include a controller200and a motor300, where the controller200is configured to control the battery100to supply power to the motor300, for example, to satisfy power needs of start, navigation, and driving of the vehicle1000.

In some embodiments of this application, the battery100can be used as not only the operational power source for the vehicle1000but also a driving power source for the vehicle1000, replacing or partially replacing fossil fuel or natural gas to provide driving traction for the vehicle1000.

FIG.2is a schematic exploded view of a battery according to some embodiments of this application.

As shown inFIG.2, the battery100includes a box400and a battery cell1(not shown), where the battery cell1is accommodated in the box400.

The box400is configured to accommodate the battery cell1, and the box400may be a variety of structures. In some embodiments, the box400may include a first box portion401and a second box portion402. The first box portion401and the second box portion402fit together to jointly define an accommodating space for accommodating the battery cells1. The second box portion402may be a hollow structure with an opening at one end, the first box portion401is a plate-shaped structure, and the first box portion401covers the opening side of the second box portion402so as to form the box having the accommodating space. Alternatively, both the first box portion401and the second box portion402may be hollow structures with an opening at one side, and the opening side of the first box portion401is engaged with the opening side of the second box portion402so as to form the box having the accommodating space. Certainly, the first box portion401and the second box portion402may be of various shapes, such as cylinder or cuboid.

In order to improve airtightness after connection of the first box portion401and the second box portion402, a sealing member, such as sealing gum and sealing ring, may further be disposed between the first box portion401and the second box portion402.

Assuming that the first box portion401fits on the top of the second box portion402, the first box portion401may also be referred to as an upper box part and the second box portion402may also be referred to as a lower box part.

In the battery100, one or more battery cells1may be provided. If a plurality of battery cells1are provided, the plurality of battery cells1may be connected in series, parallel, or series-parallel, where being connected in series-parallel means that the plurality of battery cells1are connected in both series and parallel. The plurality of battery cells1may be directly connected in series, parallel, or series-parallel, and then an entirety of the plurality of battery cells1is accommodated in the box400; or certainly, the plurality of battery cells1may be connected in series, parallel, or series-parallel first to form a battery module500, and then a plurality of battery modules500are connected in series, parallel, or series-parallel to form an entirety which is accommodated in the box400.

FIG.3is a schematic structural diagram of the battery module shown inFIG.2.FIG.4is a schematic exploded view of an adapting member according to some embodiments of this application.FIG.5is a schematic structural diagram of the adapting member shown inFIG.4.FIG.6is a schematic structural diagram of a cross section along A-A inFIG.5.FIG.7is an enlarged view of a structure of region Q shown inFIG.6.FIG.8is an enlarged view of a structure of region R shown inFIG.6.FIG.9is a schematic exploded view of another adapting member according to some embodiments of this application.

As shown inFIG.3toFIG.9, an adapting member40in the embodiments of this application is applied to the battery cell1, where the adapting member40includes an adapter41and a blocking member42. The adapter41includes a first connecting portion411, a second connecting portion412, and an overload protection portion413. The first connecting portion411is configured to be electrically connected to an electrode terminal20of the battery cell1, the second connecting portion412is configured to be electrically connected to a tab32of the battery cell1, the overload protection portion413is disposed between the first connecting portion411and the second connecting portion412, and the second connecting portion412includes a tab connecting surface412afor connecting the tab32. The blocking member42is disposed on a side of the adapter41having the tab connecting surface412aand covers at least a portion of the overload protection portion413, and the blocking member42extends from the overload protection portion413toward two sides in a first direction X such that the blocking member42extends beyond edges of the overload protection portion413on two sides in the first direction X. The blocking member42is configured to insulate and block direct electrical connection between the tab32and the first connecting portion411. The first direction X is a direction along which the first connecting portion411and the overload protection portion413are disposed side by side.

The tab32is a portion protruding out of a body portion31in the electrode assembly30. For example, the electrode assembly30includes a positive tab and a negative tab, where the positive tab may be a portion of a positive electrode plate that is coated with no active substance layer, the negative tab may be a portion of a negative electrode plate that is coated with no active substance layer, and the positive tab and the negative tab lead out electric energy generated by the body portion31. The positive tab and the negative tab may both be located at one end of the body portion31or be located at two opposite ends of the body portion31respectively. The adapting member40can be configured to connect the positive tab and the electrode terminal20, and can also be configured to connect the negative tab and the electrode terminal20.

At least a portion of the electrode terminal20is exposed to the outside of the battery cell1for ease of connection to other members (for example, a busbar), so as to lead out electric energy generated by the electrode assembly30.

The electrode terminal20may be a portion of the housing10or an independent member mounted on the housing10.

In some examples of these embodiments, the blocking member42in the adapting member40is adhered to the side of the adapter41having the tab connecting surface412a,and the blocking member42covers the overload protection portion413. In some other examples of these embodiments, the blocking member42is connected to the adapter41by snap-fitting or in another non-welding manner.

The adapter41includes a conductive material, so that current can flow through the adapter41. The adapter41may be made of metal such as aluminum or copper. The overload protection portion413in the adapter41includes a conductive material. In some embodiments, the current can flow through the adapter41via the overload protection portion413. When the current flows through the adapter41, the overload protection portion413can generate heat and warm up. When the current exceeds a given threshold, the overload protection portion413breaks, so as to disconnect electrical connection between the first connecting portion411and the second connecting portion412.

The blocking member42has electrical insulation, so the blocking member42can effectively insulate the current, making it impossible for the tab32to be in direct contact with the overload protection portion413and the first connecting portion411. In some embodiments, the blocking member42has high-temperature resistance, so the blocking member42can effectively withstand heat generated by the overload protection portion413, alleviating melting and deformation of the blocking member42during use. In some examples, the blocking member42is made of polyethylene glycol terephthalate (polyethylene glycol terephthalate, PET), PE, or PP.

The blocking member42is disposed on the side of the adapter41having the tab connecting surface412a,and no blocking member42is disposed on a side of the adapter41provided with no tab connecting surface412a,so as to reduce space occupied by the blocking member42, and in turn reduce space occupied by the adapting member40in the battery cell1, increasing energy density of the battery cell1.

In the first direction X, the overload protection portion413has edges on two opposite sides, and the blocking member42also has edges on two opposite sides. In a stacking direction of the adapter41and the blocking member42, a projection of the blocking member42covers at least a portion of the overload protection portion413, and the edges of the overload protection portion413on two sides in the first direction X are located between the edges of the blocking member42on two sides. The first direction X is the direction along which the first connecting portion411and the overload protection portion413are disposed side by side. To be specific, in the adapter41, the first connecting portion411and the overload protection portion413are located in a same plane, and the first direction X is the direction along which the first connecting portion411and the overload protection portion413are disposed side by side in this plane. Therefore, there is enough space between an edge of the overload protection portion413on a side close to the first connecting portion411in the first direction X and the first connecting portion411, so that the blocking member42covers the adapter41. It should be noted that the first connecting portion411and the overload protection portion413being disposed side by side in the adapter41does not mean that the first connecting portion411and the overload protection portion413are stacked.

In the embodiments of this application, the blocking member42is disposed on the side of the adapter41having the tab connecting surface412a,which greatly reduces the probability of direct electrical connection formed after the tab32crosses the overload protection portion413to come into direct contact with the first connecting portion411, and in turn avoids functional failure of the overload protection portion413on the adapter41, improving reliability of the adapting member40. In addition, the blocking member42is located on a side of the adapter41, so as to reduce the internal space of the battery cell1occupied by the blocking member42, thereby increasing the energy density of the battery cell1.

In some embodiments, as shown inFIG.6andFIG.7, a distance by which the blocking member42extends beyond the edges of the overload protection portion413on two sides in the first direction X is 0.5 mm to 5 mm, where the first direction X is the direction along which the first connecting portion411and the overload protection portion413are disposed side by side.

In the first direction X, a distance by which the blocking member42extends from the overload protection portion413toward two sides is 0.5 mm to 5 mm. For example, the distance by which the edge of the blocking member42extends is D1, where the value of D1is 0.5 mm, 0.6 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, or 5 mm.

A greater distance by which the edge of the blocking member42extends beyond the overload protection portion413means larger space and weight occupied by the blocking member42, resulting in higher material costs. A smaller distance by which the edge of the blocking member42extends beyond the overload protection portion413means lower reliability of the blocking member42completely covering the overload protection portion413due to the risk of misalignment during actual assembly. If the distance by which the edge of the blocking member42extends beyond the overload protection portion413is excessively small, the blocking member42does not completely cover the overload protection portion413, and the tab32crosses the overload protection portion413toward the first connecting portion411due to misalignment, resulting in failure of the overload protection portion413. In these embodiments, the distance by which the edge of the blocking member42extends beyond the overload protection portion413is limited to 0.5 mm to 5 mm, so as to ensure that the blocking member42covers the overload protection portion413, controlling overall manufacturing costs and space occupation of the adapting member40while avoiding the failure of the overload protection portion413.

In some embodiments, the blocking member42is adhered to the adapter41, and the distance by which the edge of the blocking member42extends beyond the overload protection portion413is limited to 0.5 mm to 5 mm, so that there is an enough connecting area between the blocking member42and the adapter41, thereby reducing the risk of falling-off of the blocking member42.

In some embodiments, still referring toFIG.5, in a thickness direction of the blocking member42, a projection of the blocking member42is located within a projection of the adapter41, and in a direction perpendicular to the first direction X, a distance D2between edges of a projection of the blocking member42on two sides and edges of a projection of the adapter41on two sides is 0 mm to 0.2 mm.

For example, the value of the distance D2between the edges of the projection of the blocking member42on two sides and the edges of the projection of the adapter41on two sides is 0 mm, 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, or 0.2 mm.

In the thickness direction of the blocking member42, the overall structure of the blocking member42covers the adapter41within a preset region, and any portion of the blocking member42does not extend beyond edges of the adapter41, which can prevent the blocking member42from occupying space of other components, reducing influence on other components in the battery cell1.

In some embodiments of this application, in the direction perpendicular to the first direction X, the distance D2between the edges of the projection of the blocking member42on two sides and the edges of the projection of the adapter41on two sides is 0 mm to 0.2 mm. Such a size range can prevent the blocking member42from extending out of the adapter41, reduce the assembly space occupied by the blocking member42, and reduce the risk of adhesive overflow of the blocking member42when the blocking member42is adhered to the adapter41. In addition, a size of edge regions of the overload protection portion413and the first connecting portion411that are not covered by the blocking member42is controlled to be 0 mm to 0.2 mm, which can ensure that the tab32is supported by the blocking member42with a certain thickness even if the tab32crosses the overload protection portion413, such that in the thickness direction of the blocking member42, there is a gap between the tab32and the overload protection portion413as well as between the tab32and the first connecting portion411, further reducing the risk of the tab32crossing the overload protection portion413to be directly electrically connected to the first connecting portion411.

In some embodiments, still referring toFIG.6, the adapter41has an electrode terminal connecting surface411ain its thickness direction, the electrode terminal connecting surface411aand the tab connecting surface412abeing located on a same side of the adapter41or on two sides facing away from each other of the adapter41respectively; and the blocking member42is disposed on the side of the adapter41having the tab connecting surface412aand covers the overload protection portion413and at least a portion of the first connecting portion411.

In some embodiments, the electrode terminal connecting surface411aand the tab connecting surface412aare located on a same side of the adapter41, and the blocking member42covers the overload protection portion413and also a portion of the electrode terminal connecting surface411a.In some other examples, the electrode terminal connecting surface411aand the tab connecting surface412aare located on two sides facing away from each other of the adapter41respectively, and the blocking member42covers the overload protection portion413and a portion of the first connecting portion411.

In some embodiments of this application, the blocking member42covers at least a portion of the first connecting portion411, which can improve the reliability of the blocking member42, further reducing the probability of direct contact between the tab32and the first connecting portion411caused by misalignment or excessive length of the tab32.

In some embodiments, the first connecting portion411includes an electrode terminal connecting portion411b,where in the thickness direction, the electrode terminal connecting portion411bprotrudes in a direction approaching the electrode terminal20, the electrode terminal connecting surface411ais a surface of the electrode terminal connecting portion411bfacing the electrode terminal20, and the overload protection portion413and the electrode terminal connecting portion411bare spaced apart.

In some cases, length of the electrode terminal20used is similar to thickness of an end cover12, and the electrode terminal connecting portion411bneeds to protrude in the direction approaching the electrode terminal20, such that a side of the electrode terminal connecting portion411bfacing the electrode terminal20abuts against the electrode terminal20. A side of the electrode terminal connecting portion411bfacing away from the electrode terminal20and the electrode terminal20are provided with a plurality of grooves for preventing mirror reflection of welding laser during welding, so as to prevent laser reflected during welding from burning other components.

In some embodiments of this application, the electrode terminal connecting portion411ballows for better connection between the electrode terminal connecting surface411aand the electrode terminal20, further reducing the rate of poor welding and improving the reliability of connection between the adapter41and the electrode terminal20. In addition, when the electrode terminal20is laser-welded to the adapter41, the laser reflected can be blocked by the grooves formed, which reduces the probability of the laser reflected causing damage to other components in the battery cell1, improving safety of the battery cell1.

If the distance between the overload protection portion413and the electrode terminal connecting portion411bis excessively small, the blocking member42covers an opening formed after the electrode terminal connecting portion411bprotrudes when covering the overload protection portion413. The electrode terminal connecting portion411band the electrode terminal20are welded through the opening of the electrode terminal connecting portion411b,but interference between the blocking member42and the opening affects the yield rate of welding. In addition, the laser scattered during welding also irradiates the blocking member42, which causes damage to the blocking member42, reducing the reliability of the blocking member42. A greater distance between the overload protection portion413and the electrode terminal connecting portion411bmeans a longer length of the blocking member42in the first direction X, which in turn means higher material costs required for the blocking member42. In these embodiments, the distance between the overload protection portion413and the electrode terminal connecting portion411bis defined as D3, and the value of D3is 1 mm to 50 mm, so as to avoid interference between the overload protection portion413and the opening of the electrode terminal connecting portion411b.In addition, the material costs of the blocking member42are reduced.

In some embodiments, as shown inFIG.7andFIG.9, the overload protection portion413includes a through hole414aand a fusing portion415, where the fusing portion415and the through hole414aare successively distributed along a second direction Y. The first direction X intersects with the second direction Y. In some examples, the fusing portion415is a region from an edge of the through hole414ato an edge of the adapter41in the second direction Y. No current passes through the through hole414a,and the current passes through only the fusing portion415. In other words, a cross-sectional area of the fusing portion415in the thickness direction is smaller than those of other portions (for example, the first connecting portion411), and a maximum threshold that the fusing portion415can withstand is positively correlated with a distance between the edge of the through hole414aand the edge of the adapter41.

In these embodiments, in the overload protection portion413formed by the through hole414aand the fusing portion415, the through hole414ahas a simple manufacturing process, thereby reducing process difficulty of the overload protection portion413.

In some embodiments, as shown inFIG.8andFIG.9, the overload protection portion413has a thinned portion414, where the thinned portion414extends along a second direction Y, and the first direction X intersects with the second direction Y.

In some embodiments, the thinned portion414has a residual thickness, and the fusing portion415includes the thinned portion414and a region from the thinned portion414to the edge of the adapter41in the second direction Y. The maximum threshold that the fusing portion415can withstand is not only affected by the distance from the thinned portion414to the edge of the adapter41, but also positively correlated with the thickness of the thinned portion414.

In these embodiments, the fusing portion415and thinned portion414in the overload protection portion413jointly provide overload protection. When a sum of cross-sectional areas of the fusing portion415and the thinned portion414is smaller than that of the first connecting portion411and also smaller than that of the second connecting portion412, and the current that the fusing portion415and the thinned portion414can withstand exceeds the threshold, the fusing portion415and the thinned portion414break, and the current cannot be transferred from the second connecting portion412to the first connecting portion411. In the foregoing solution, the threshold of the overload protection portion413can be adjusted more flexibly by adjusting the shape and thickness of the thinned portion414.

In some other embodiments, the thinned portion414extends to an edge of the overload protection portion413along the second direction Y, and the fusing portion415is the thinned portion414.

In the foregoing solution, the threshold of the overload protection portion413can be adjusted more flexibly by adjusting the thickness of the thinned portion414.

In some embodiments, to improve current flow capacity of the adapter41, the thinned portion414has a certain thickness, thereby improving current flow capacity at the thinned region.

A greater thickness of the thinned portion414means higher working current that can pass through the thinned portion414and more heat that the thinned portion414can withstand. However, because the thinned portion414is a portion of the overload protection portion413, the heat that the thinned portion414can withstand needs to be reduced, so that the thinned portion414can burn out when the current exceeding a given threshold flows through the thinned portion414. In these embodiments, the thickness H1of the thinned portion414is limited to satisfying 0 mm<H1≤0.5 mm, which can ensure overall strength of the adapter41without functional failure of the overload protection portion413.

In some embodiments, as shown inFIG.9, the blocking member42includes an avoidance hole42a,where the avoidance hole42ais configured to avoid the electrode terminal connecting portion411band is disposed corresponding to the electrode terminal connecting portion411b.

The electrode terminal connecting portion411bis generally welded to the electrode terminal20, and the avoidance hole42ais disposed corresponding to the electrode terminal connecting portion411b,so as to reduce the risk of the blocking member42being melted by laser or interfering with welding.

The avoidance hole42aon the blocking member42reduces interference in the connection between the electrode terminal connecting portion411band the electrode terminal20, and protects the overload protection portion413on the adapter41to the greatest extent, reducing the risk of direct contact between the tab32and the electrode terminal connecting portion411b.

In some embodiments, as shown inFIG.9, the overload protection portion413is provided in two, where the two overload protection portions413are located on two sides of the first connecting portion411in the first direction X and are connected to the two second connecting portions412respectively.

In some examples of these embodiments, the battery cell1may include a plurality of electrode assemblies30, and the overload protection portion413is disposed on both sides of the first connecting portion411. When any one of the electrode assemblies30experiences a short circuit, the plurality of overload protection portions413can disconnect electrical connection of that electrode assembly30in a timely manner, improving the safety performance of the battery cell1.

In some embodiments, the blocking member42is an integral structure, and an orthographic projection of the blocking member42on the adapter41covers at least the two overload protection portions413. The integral structure can simplify the assembly of the blocking member42, improving the assembly efficiency.

FIG.10is a schematic exploded view of still another adapting member according to some embodiments of this application.FIG.11is a schematic structural diagram of the adapting member shown inFIG.10.FIG.12is a schematic structural diagram of a cross section along B-B inFIG.11.

In some embodiments, referring toFIG.10toFIG.12, the blocking member42is a segmented structure, and the blocking member42includes a first sub-portion42band a second sub-portion42c,the first sub-portion42band the second sub-portion42ccovering the two overload protection portions413respectively.

In these embodiments, the assembly requirements for assembling the blocking member42onto the adapter41can be reduced. The blocking member42is divided into the first sub-portion42band the second sub-portion42c,with the first sub-portion42bcovering one overload protection portion413and the second sub-portion42ccovering one overload protection portion413. Similarly, in some other examples of these embodiments, there may further be a third sub-portion, a fourth sub-portion, and the like, where the third sub-portion covers one overload protection portion413, the fourth sub-portion covers one overload protection portion413, and the sub-portions do not affect each other. This expands the application range of the blocking member42and reduces the need for specialized manufacturing, making the blocking member42become a general-purpose structure.

In some embodiments, as shown inFIG.11, the adapter41further includes a limiting portion416, the limiting portion416extending along a second direction Y.

In these embodiments, the limiting portion416disposed on the adapting member40allows the blocking member42to be more accurately mounted in the preset region when the blocking member42is assembled onto the adapter41, and reduces the defective rate of the assembly of the blocking member42and the adapter41in automated production and manual production.

In some embodiments, the blocking member42covers at least a portion of a surface of the limiting portion416facing the tab connecting surface412a,and the blocking member42does not extend beyond an outer edge of the limiting portion416.

In some examples of these embodiments, the outer edge of the limiting portion416on the adapter41extends beyond an outer edge of the blocking member42by 0 mm to 0.2 mm, which reduces the assembly difficulty of the adapter41and the blocking member42, reducing the probability of the edge of the blocking member42extending beyond the edge of the adapter41to interfere with other components. In addition, the blocking member42can be assembled with the adapter41through adhesion, and the space reserved can prevent the problem of adhesive overflow of the blocking member42during mounting.

In some embodiments, as shown inFIG.11, a fool-proofing structure417is disposed on a side of the adapter41in the first direction X.

In these embodiments, the fool-proofing structure417is configured to avoid the problem of incorrect mounting direction of the adapter41when the adapter41is mounted between the electrode assembly30and the electrode terminal20.

In some embodiments, as shown inFIG.11, an edge of the blocking member42adjacent to the fool-proofing structure417in the first direction X is distributed at a preset distance from the fool-proofing structure417, where the preset distance is 0 mm to 0.2 mm.

In these embodiments, the fool-proofing structure417is disposed in a region of the adapter41that is not connected to the tab32and the electrode terminal20, reducing influence of the fool-proofing structure417on the adapting function of the adapter41. The preset distance between the edge of the blocking member42adjacent to the fool-proofing structure417in the first direction X and the fool-proofing structure417is used to prevent the edge of the blocking member42from extending beyond the adapter41along the stacking direction of the blocking member42and the adapter41, avoiding interference between the blocking member42and other components. In these embodiments, the preset distance is D4, and the value of D4is 0 mm to 0.2 mm.

In some embodiments, still referring toFIG.7, the blocking member42includes an adhesive layer421and a blocking layer422that are stacked in a thickness direction of the blocking member42, the blocking layer422being adhered to the adapter41through the adhesive layer421.

In some examples of these embodiments, the adhesive layer421is made of a material with good insulation, thereby further improving the blocking characteristic of the blocking member42. In addition, the adhesive layer421allows for sufficient connection strength between the blocking member42and the adapter41, avoiding separation between the blocking member42and the adapter41.

A greater thickness of the blocking member42means higher material costs and larger internal space of the battery cell occupied by the blocking member42. A smaller thickness of the blocking member42means higher process difficulty and higher manufacturing costs. In these embodiments, the thickness of the blocking member42is defined as H, and the value of H is 1 μm to 500 μm, so as to balance the process requirements and the cost requirements and further reduce the internal space of the battery cell1occupied by the blocking member42, further increasing the energy density of the battery cell1.

In some embodiments, a thickness ratio of the blocking member42to the adapter41is 1/10 to 4/5. For example, the thickness ratio of the blocking member42to the adapter41is 1/10, 1/5, 3/10, 2/5, 1/2, 3/5, 7/10, or 4/5.

The space occupied by the adapting member40mounted in the battery cell1is relatively fixed. Therefore, if the blocking member42is thicker, the adapter41is thinner, which reduces the overall strength of the adapter41. If the blocking member42is thinner, the adapter41is thicker, which reduces the overall strength of the blocking member42. In this technical solution, the thickness ratio of the blocking member42to the adapter41is limited to 1/10 to 4/5, so as to prevent the adapting member40from occupying the space of the folded tab structure while balancing the respective strengths of the blocking member42and the adapter41.

In some embodiments, in a thickness direction of the blocking member42, a projection area ratio of the blocking member42to the adapter41is 1/5 to 4/5. For example, the projection area ratio of the blocking member42to the adapter41is 1/5, 2/5, 3/5, or 4/5.

A larger coverage area of the blocking member42on the adapter41means higher material costs required for the blocking member42. A smaller coverage area of the blocking member42on the adapter41means poorer blocking effect of the blocking member42. In addition, when the blocking member42is adhered to the adapter41, a smaller area of the blocking member42means lower adhesion strength of the blocking member42. In these embodiments, the area ratio of the blocking member42to the adapter41is limited to 1/5 to 4/5, so as to balance the material costs and the blocking effect of the blocking member42.

In some embodiments, this application further provides a battery cell1including: a housing10provided with an accommodating cavity; an electrode terminal20disposed on the housing10; an electrode assembly30accommodated in the accommodating cavity, the electrode assembly30including a body portion31and a tab32led out of the body portion31; and an adapting member40, where the adapting member40is the adapting member40according to any one of the foregoing embodiments, the first connecting portion411of the adapter41is electrically connected to the electrode terminal20, and the second connecting portion412is electrically connected to the tab32.

The housing10is a component for accommodating the electrode assembly30. The housing10may be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The housing10may be of various shapes, such as cylinder or cuboid. For example, in the figure, the housing10is a cuboid.

The housing10includes a housing body11and an end cover12, where the housing body11has an opening, and the end cover12covers the opening.

The housing body11may be a structure with an opening at one side, and the end cover12is designed to cover the opening of the housing body11. Alternatively, the housing body11may be a structure with openings at two sides, and the end cover12is provided in two, where the two end covers12cover the two openings of the housing body11respectively.

For example, the end cover12is connected to the housing body11through welding, adhesion, snap-fitting, or in another manner.

The electrode assembly30is a component in which electrochemical reactions take place in the battery cell1. The electrode assembly30may be a wound structure formed by a positive electrode plate, a separator, and a negative electrode plate through winding. The electrode assembly30may alternatively be a laminated structure formed by a positive electrode plate, a separator, and a negative electrode plate through lamination.

The body portion31may include a portion of the positive electrode plate coated with an active substance layer, a portion of the negative electrode plate coated with an active substance layer, and the separator. Active substances in the active substance layers are used for electrochemical reactions with the electrolyte and the like to produce charging and discharging processes.

In some embodiments, the tab connecting surface412ais located on a surface of the second connecting portion412facing the electrode assembly30.

In these embodiments, the blocking member42and the tab32are both located on a side facing away from the electrode terminal20, which is conducive to further reducing the internal space of the battery cell1occupied by the blocking member42, increasing the energy density of the battery cell1.

In some embodiments, this application further provides a battery including a plurality of battery cells1according to any one of the foregoing embodiments.

In some embodiments, this application further provides an electric apparatus including a plurality of battery cells1according to any one of the foregoing embodiments, where the battery cell1is configured to supply electric energy.

In some embodiments, referring toFIG.4toFIG.9, this application provides an adapting member40applied to a battery cell, where the adapting member40includes an adapter41and a blocking member42. The adapter41includes a first connecting portion411, a second connecting portion412, an overload protection portion413, a limiting portion416, and a fool-proofing structure417. The first connecting portion411is configured to be electrically connected to an electrode terminal20of the battery cell1, the second connecting portion412is configured to be electrically connected to a tab32of the battery cell1, the overload protection portion413is disposed between the first connecting portion411and the second connecting portion412, and the second connecting portion412includes a tab connecting surface412afor connecting the tab32. The blocking member42is disposed on a side of the adapter41having the tab connecting surface412aand covers at least a portion of the overload protection portion413. The tab connecting surface412ais located on a surface of the second connecting portion412facing the electrode assembly30.

The blocking member42extends from the overload protection portion413toward two sides in a first direction X, such that a distance by which the blocking member42extends beyond edges of the overload protection portion413on two sides in the first direction X is 0.5 mm to 5 mm. In a direction perpendicular to the first direction X, a distance D2between an outer contour of a projection of the blocking member42and an outer contour of a projection of the adapter41is 0 mm to 0.2 mm. The first connecting portion411includes an electrode terminal connecting portion411b,and the electrode terminal connecting portion411bprotrudes in a direction approaching the electrode terminal20. The overload protection portion413includes a through hole414aand a fusing portion415. The blocking member42includes an avoidance hole42a,and the avoidance hole42ais disposed corresponding to the electrode terminal connecting portion411b.The limiting portion416extends along a second direction Y.

It should be noted that in absence of conflicts, the embodiments and features in the embodiments in this application may be combined with each other.