Lithium metal battery cell, battery device, and electric device

Abstract

Provided in embodiments of the present application are a lithium metal battery cell, a battery device, and an electric device. The lithium metal battery cell comprises a casing and an electrode assembly accommodated in the casing, and the electrode assembly comprises a negative electrode sheet and an insulating member. The casing is provided with a negative electrode lead-out portion. The negative electrode sheet comprises a negative electrode body and at least one negative tab, and the negative electrode body and the negative tab are arranged in a first direction and connected to each other; in a second direction, the size of the negative tab is smaller than the size of the negative electrode body, and the first direction, the second direction and the thickness direction of the negative electrode body are perpendicular to each other. The negative tab is electrically connected to the negative electrode lead-out portion. At least part of the insulating member is located on one side of the negative electrode body in the thickness direction and attached to the negative electrode body, and the region of the negative electrode body covered by the insulating member is connected to at least one negative tab.

Description

Lithium metal battery cell, battery device, and powered device TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and more particularly, to a lithium metal battery cell, a battery device, and a powered device. BACKGROUND

[0002] Batteries are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes, electric tools, and the like.

[0003] Lithium metal battery cells have a high theoretical energy density, and thus, lithium metal battery cells are expected to be one of the next generation of high energy density storage devices to meet the stringent requirements of emerging industries. How to improve the reliability of lithium metal batteries is a research direction in the technical field of batteries.

[0004] SUMMARY

[0005] The present application provides a lithium metal battery cell, a battery device, and a powered device, which can improve reliability.

[0006] In a first aspect, the embodiments of the present application provide a lithium metal battery cell, comprising a shell and an electrode assembly contained in the shell, the electrode assembly comprising a negative electrode sheet and an insulating piece. The shell is provided with a negative electrode lead-out portion. The negative electrode sheet comprises a negative electrode main body and at least one negative electrode tab, the negative electrode main body and the negative electrode tab are arranged along a first direction and connected; along a second direction, the size of the negative electrode tab is smaller than the size of the negative electrode main body, the first direction, the second direction, and the thickness direction of the negative electrode main body are perpendicular to each other. The negative electrode tab is electrically connected to the negative electrode lead-out portion. At least part of the insulating piece is located on one side of the negative electrode main body along the thickness direction and attached to the negative electrode main body, and the area of the negative electrode main body covered by the insulating piece is connected to the at least one negative electrode tab.

[0007] By reducing the size of the negative electrode tab along the second direction, the risk of short circuit can be reduced, and the connection of the negative electrode sheet with other components can be facilitated. In addition, when an abnormally large current occurs in the lithium metal battery cell, the negative electrode tab can also limit the excessive increase of the current through its own resistance and structural characteristics, thereby playing a certain overcurrent protection role.

[0008] The insulating piece can separate at least part of the area of the negative electrode main body close to the negative electrode tab from the electrolyte, reduce the charge exchange between the area of the negative electrode main body close to the negative electrode tab and the electrolyte, thereby inhibiting the deposition and stripping of lithium occurring in the area of the negative electrode main body close to the negative electrode tab, slowing down the pulverization of lithium, reducing the formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell, and reducing the impedance and slowing down the capacity decay of the lithium metal battery cell.

[0009] In some embodiments, the insulating piece includes a first insulating portion attached to the negative electrode body, and the negative electrode body is covered by the first insulating portion in a region connected to the negative electrode tab. The first insulating portion continuously extends in the second direction, and both ends of the first insulating portion in the second direction are beyond all the negative electrode tabs.

[0010] The first insulating portion extends a large length in the second direction, which can cover the region of the negative electrode body close to the negative electrode tab in the second direction, thereby inhibiting lithium deposition and lithium peeling in the region of the negative electrode body around the negative electrode tab, slowing down lithium pulverization, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell, reducing impedance, and slowing down the capacity attenuation of the lithium metal battery cell.

[0011] In some embodiments, the negative electrode tab includes a plurality of negative electrode tabs arranged at intervals in the second direction. The insulating piece includes a plurality of first insulating portions attached to the negative electrode body, and the plurality of first insulating portions are arranged at intervals in the second direction. In the direction of the negative electrode tab pointing to the negative electrode body, each first insulating portion is located on one side of a corresponding negative electrode tab, and the negative electrode body is covered by the first insulating portion in a region connected to the corresponding negative electrode tab.

[0012] By arranging a plurality of first insulating portions, the region of the negative electrode body close to each negative electrode tab can be covered, thereby inhibiting lithium deposition and lithium peeling in the region of the negative electrode body close to each negative electrode tab, and slowing down lithium pulverization. The plurality of first insulating portions are arranged at intervals, which can reduce the weight and space occupied by the insulating piece as a whole, and reduce the blocking of the region of the negative electrode body where lithium pulverization is less likely to occur by the insulating piece, thereby reducing the impact of the insulating piece on the capacity of the lithium metal battery cell.

[0013] In some embodiments, in the second direction, both ends of the first insulating portion are beyond the corresponding negative electrode tab. The first insulating portion has a large size in the second direction, which can inhibit lithium deposition and lithium peeling in the region of the negative electrode body around the negative electrode tab, slow down lithium pulverization, reduce the risk of short circuit, improve the reliability of the lithium metal battery cell, and slow down the capacity attenuation of the lithium metal battery cell.

[0014] In some embodiments, in the direction of the negative electrode body pointing to the negative electrode tab, the end of the insulating piece protruding from the negative electrode body towards the negative electrode tab. The embodiments of the present application can increase the insulating area and reduce the risk of short circuit.

[0015] In some embodiments, the insulating piece includes a first insulating portion and at least one second insulating portion connected to the first insulating portion. In the direction of the negative electrode body pointing to the negative electrode tab, the second insulating portion is located on one side of the first insulating portion. The first insulating portion is attached to the negative electrode body, and the negative electrode body is covered by the first insulating portion in a region connected to at least one negative electrode tab. The second insulating portion is arranged one-to-one corresponding to the negative electrode tab, and the second insulating portion is attached to the negative electrode tab.

[0016] By setting the second insulation part, the connection area between the insulation piece and the negative tab can be increased, the risk of the insulation piece falling off the negative tab can be reduced, and the insulation effect can be improved. The second insulation part can also support the negative tab, reducing the risk of the negative tab being inserted upside down between the negative main body and the positive tab, thereby reducing the risk of short circuit.

[0017] In some embodiments, the insulation piece further comprises at least one third insulation part; along the direction of the negative main body pointing to the negative tab, at least part of the third insulation part is located on one side of the first insulation part. The third insulation part connects the first insulation part and the second insulation part.

[0018] By setting the third insulation part, the insulation piece can protrude from the end of the negative main body towards the negative tab in the first direction, thereby covering the burrs of the end of the negative main body, reducing the possibility of the burrs piercing the separator and contacting the positive tab, thereby reducing the risk of short circuit and improving the reliability of the lithium metal battery cell. The third insulation part is connected to the second insulation part, so that the insulation piece can protrude from the negative tab in the second direction, thereby covering the burrs at the end of the negative tab along the second direction, reducing the possibility of the burrs piercing the separator and contacting the positive tab, thereby reducing the risk of short circuit and improving the reliability of the lithium metal battery cell.

[0019] In some embodiments, the negative tab comprises a plurality of negative tabs, and the plurality of negative tabs are arranged at intervals along the second direction. The second insulation part is a plurality of second insulation parts, and the plurality of second insulation parts are arranged one-to-one corresponding to the plurality of negative tabs. The third insulation part is a plurality of third insulation parts, and the plurality of third insulation parts and the plurality of second insulation parts are arranged alternately along the second direction. The first insulation part is continuously arranged along the second direction and connected to the plurality of second insulation parts and the plurality of third insulation parts.

[0020] The plurality of third insulation parts connects the plurality of second insulation parts as a whole, which can not only increase the insulation area, but also reduce the risk of the insulation piece falling off the negative tab, thereby improving the insulation reliability. The insulation piece is continuously arranged as a whole, which can constrain the negative tab, reduce the deformation of the negative tab, reduce the possibility of the negative tab being inserted upside down between the positive tab and the negative main body, and reduce the risk of short circuit.

[0021] In some embodiments, the insulation piece comprises a first insulation part and at least one third insulation part, and the third insulation part is connected to the first insulation part. Along the direction of the negative main body pointing to the negative tab, the third insulation part is located on one side of the first insulation part. The first insulation part is attached to the negative main body, and the area of the negative main body covered by the first insulation part is connected to the at least one negative tab. The third insulation part is arranged along the second direction with the negative tab.

[0022] By setting the third insulation part, the insulation piece can protrude from the end of the negative main body toward the negative tab in the first direction, thereby covering burrs of the end of the negative main body, reducing the possibility of the burrs piercing the separator and contacting the positive tab, further reducing the risk of short circuit, and improving the reliability of the lithium metal battery cell.

[0023] In some embodiments, the electrode assembly includes two insulation pieces, and the first insulation parts of the two insulation pieces are respectively arranged on the two sides of the negative main body. The third insulation parts of the two insulation pieces are attached and / or connected.

[0024] After the third insulation parts of the two insulation pieces are attached, the end of the negative main body facing the negative tab can be covered, so that the metal debris remaining at the end of the negative main body is not easy to fall into the electrode assembly, and the risk of short circuit of the lithium metal battery cell can be better reduced.

[0025] In some embodiments, the electrode assembly includes two insulation pieces, and the two insulation pieces are respectively attached to the two sides of the negative main body.

[0026] The two insulation pieces can cover the area of the negative main body close to the negative tab from both sides, thereby inhibiting the deposition and stripping of lithium occurring in the area of the negative main body close to the negative tab, slowing down the pulverization of lithium, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell, and reducing the impedance and slowing down the capacity decay of the lithium metal battery cell.

[0027] In some embodiments, the negative main body includes a current collecting main body, and the current collecting main body and the negative tab are in an integral structure. The insulation piece is attached to the current collecting main body, and the area of the current collecting main body covered by the insulation piece is connected with at least one negative tab.

[0028] The insulation piece can cover the area of the current collecting main body close to the negative tab, thereby inhibiting the deposition and stripping of lithium occurring in the area of the current collecting main body close to the negative tab, slowing down the pulverization of lithium, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell, and reducing the impedance and slowing down the capacity decay of the lithium metal battery cell.

[0029] In some embodiments, the negative main body includes a current collecting main body and a film layer, the film layer is arranged on at least one side of the current collecting main body in the thickness direction, and the negative tab is connected to the current collecting main body. The insulation piece is attached to at least one of the film layer and the current collecting main body; and the insulation piece at least partially covers the area of the current collecting main body adjacent to and connected with the negative tab.

[0030] By setting the film layer, the deposition of lithium metal on the negative main body is facilitated.

[0031] In some embodiments, the current collector body includes a first current collector portion and a second current collector portion arranged along a first direction, the first current collector portion is covered with the film layer, and the second current collector portion is uncovered with the film layer, the second current collector portion is connected to the first current collector portion and the negative tab. Along a second direction, the negative tab has a size smaller than that of the second current collector portion. The insulating member is attached to the second current collector portion, and the second current collector portion is covered by the insulating member in a region connected to the at least one negative tab.

[0032] By reserving the second current collector portion uncovered with the film layer, the area of the film layer covered by the insulating member is reduced, the waste of the film layer is reduced, and the influence of the setting of the insulating member on the capacity of the lithium metal battery cell is reduced. The insulating member can cover the region of the second current collector portion close to the negative tab, thereby inhibiting the deposition and stripping of lithium occurring in the region of the second current collector portion close to the negative tab, slowing down the pulverization of lithium, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell, and reducing the impedance, slowing down the capacity attenuation of the lithium metal battery cell.

[0033] In some embodiments, the end surface of the current collector body facing the negative tab is flush with the end surface of the film layer facing the negative tab. The insulating member is attached to the film layer and covers a portion of the film layer. The insulating member can cover the region of the film layer close to the negative tab, thereby inhibiting the deposition and stripping of lithium occurring in the region of the film layer close to the negative tab, slowing down the pulverization of lithium, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell, and reducing the impedance, slowing down the capacity attenuation of the lithium metal battery cell.

[0034] In some embodiments, the film layer includes metal lithium.

[0035] In some embodiments, the insulating member includes an insulating glue, and the melting temperature of the insulating glue is lower than the melting point of the metal lithium. The embodiments of the present application can reduce the temperature of the metal lithium when the insulating glue is coated, simplify the oxidation rate of the surface layer of the metal lithium, and reduce the side reactions occurring in the metal lithium.

[0036] In some embodiments, the electrode assembly further includes a positive tab including a positive active material layer. Along the direction of the negative body pointing to the negative tab, the end surface of the negative body facing the negative tab exceeds the positive active material layer, and at least part of the insulating member exceeds the positive active material layer. The negative body has a larger size to receive ions released from the positive active material layer, thereby improving the capacity of the lithium metal battery cell.

[0037] In some embodiments, along the direction of the negative body pointing to the negative tab, the insulating member as a whole exceeds the positive active material layer, so as to reduce the ions blocked by the insulating member and reduce the capacity loss.

[0038] In some embodiments, in the first direction, the size of the insulating member covering the negative body is W, and 1mm≤W≤5mm.

[0039] W is defined as greater than or equal to 1 mm, so that the insulating piece covers the area of the negative pole body close to the negative pole lug as much as possible, slows down the pulverization of lithium, reduces the risk of short circuit, improves the reliability of the lithium metal battery cell, and slows down the attenuation of the capacity of the lithium metal battery cell. W is defined as less than or equal to 5 mm, so as to reduce the influence of the insulating piece on the capacity of the lithium metal battery cell.

[0040] In some embodiments, the insulating piece comprises an insulating base layer and a bonding layer, at least part of the bonding layer is bonded between the negative pole body and the insulating base layer.

[0041] The insulating base layer can have a higher structural strength and a lower porosity, which can effectively block ions from passing through and is not easy to be pierced by burrs, thereby facilitating to improve the isolation effect and the insulation effect and to improve the reliability of the lithium metal battery cell. Compared with the bonding layer, the insulating base layer has a high strength and a small deformation in the fitting process of the insulating piece; the bonding layer can stably fix the insulating base layer on the negative pole piece, thereby reducing the risk of falling off of the insulating piece.

[0042] In some embodiments, the electrode assembly comprises a plurality of negative pole pieces and a plurality of insulating pieces, the plurality of negative pole pieces are arranged in a stacking manner along the thickness direction, and each negative pole piece is attached with at least one insulating piece. Optionally, the plurality of negative pole pieces and the plurality of positive pole pieces are arranged alternately.

[0043] In some embodiments, the negative pole body is arranged in a winding manner, the negative pole piece comprises a plurality of negative pole lugs, and the plurality of negative pole lugs are arranged in a stacking manner.

[0044] In some embodiments, the negative pole body is arranged in a folding manner and forms a plurality of negative pole folding sections, the plurality of negative pole folding sections are arranged in a stacking manner, the negative pole piece comprises a plurality of negative pole lugs, and at least two negative pole folding sections are connected with the negative pole lugs.

[0045] In a second aspect, the embodiments of the present application provide a battery device, which comprises a plurality of lithium metal battery cells provided by any one of the embodiments of the first aspect.

[0046] In a third aspect, the embodiments of the present application provide a power utilization device, which comprises the battery device provided by any one of the embodiments of the second aspect, and the battery device is used for providing electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the drawings.

[0048] FIG. 1 is a structural schematic view of a vehicle provided by some embodiments of the present application;

[0049] FIG. 2 is a schematic diagram of a battery device according to some embodiments of the present application;

[0050] FIG. 3 is an exploded schematic diagram of a lithium metal battery cell according to some embodiments of the present application;

[0051] FIG. 4 is a schematic diagram of an electrode assembly according to some embodiments of the present application;

[0052] FIG. 5 is a partial cross-sectional view of FIG. 4 taken along the A-A direction;

[0053] FIG. 6 is a schematic diagram of a negative tab of an electrode assembly in a flattened state according to some embodiments of the present application;

[0054] FIG. 7 is a schematic diagram of the negative tab of FIG. 6 after being connected to an insulating member;

[0055] FIG. 8 is a cross-sectional view of FIG. 7 taken along the B-B direction;

[0056] FIG. 9 is a cross-sectional view of FIG. 7 taken along the C-C direction;

[0057] FIG. 10 is a schematic diagram of an insulating member of an electrode assembly in a flattened state according to some embodiments of the present application;

[0058] FIG. 11 is a schematic diagram of a negative tab and an insulating member of a lithium metal battery cell in an unfolded state according to some other embodiments of the present application;

[0059] FIG. 12 is a schematic diagram of a sub-insulating member of FIG. 11;

[0060] FIG. 13 is a schematic diagram of a negative tab and an insulating member of a lithium metal battery cell in an unfolded state according to some other embodiments of the present application;

[0061] FIG. 14 is a schematic diagram of the negative tab of FIG. 13;

[0062] FIG. 15 is a schematic diagram of a negative tab and an insulating member of a lithium metal battery cell in an unfolded state according to some other embodiments of the present application;

[0063] FIG. 16 is a schematic diagram of the negative tab of FIG. 15;

[0064] FIG. 17 is a cross-sectional schematic diagram of an insulating member of a lithium metal battery cell according to some embodiments of the present application;

[0065] FIG. 18 is a cross-sectional schematic diagram of a negative tab of a lithium metal battery cell according to some embodiments of the present application;

[0066] FIG. 19 is a cross-sectional schematic diagram of an electrode assembly of a lithium metal battery cell according to some embodiments of the present application;

[0067] FIG. 20 is a schematic view of a negative tab and an insulating member of a lithium metal battery cell according to some embodiments of the present application;

[0068] FIG. 21 is a cross-sectional schematic view of an electrode assembly of a lithium metal battery cell according to some embodiments of the present application;

[0069] FIG. 22 is a schematic view of a negative tab and an insulating member of a lithium metal battery cell according to some embodiments of the present application in an unfolded state.

[0070] Reference signs are explained as follows:

[0071] 1, vehicle; 2, battery device; 3, controller; 4, motor; 5, case; 5a, first case; 5b, second case; 6, lithium metal battery cell;

[0072] 10, electrode assembly;

[0073] 11, positive tab; 111, positive current collector; 112, positive active material layer;

[0074] 12, negative tab; 121, negative main body; 1211, current collecting main body; 1211a, first current collecting portion; 1211b, second current collecting portion; 1212, film layer; 1213, negative folding section; 1214, negative bending section; 122, negative tab;

[0075] 13, separator;

[0076] 14, insulating member; 141, first insulating portion; 142, second insulating portion; 143, third insulating portion; 14a, sub insulating member; 14b, insulating base layer; 14c, adhesive layer;

[0077] 20, housing; 21, case; 22, end cap; 30, positive lead-out portion; 40, negative lead-out portion; 50, pressure relief mechanism;

[0078] V, winding direction; V1, width direction; V2, length direction; X, second direction; Y, thickness direction; Z, first direction. DETAILED DESCRIPTION

[0079] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an overly literal sense unless expressly so defined herein.

[0081] Reference throughout this application to "example" means that a particular feature, structure, or characteristic described in connection with the example can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of other embodiments.

[0082] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "attaching" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0083] The term "and / or" in this application is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. In addition, the character " / " in this application generally represents that the front and rear associated objects have an "or" relationship.

[0084] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0085] "Multiple" appearing in this application refers to two or more (including two).

[0086] At present, from the development of market situation, the application of battery is more and more extensive. The battery is not only applied to the energy storage power system of hydropower, thermal power, wind power and solar power station, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric vehicles and electric transportation tools, and aerospace and other fields. With the continuous expansion of the application field of battery, the demand of its market is also increasing.

[0087] The battery device generally refers to a single physical module including a plurality of battery monomers to provide higher voltage and capacity. The battery monomer can be the smallest unit constituting the battery device.

[0088] The lithium metal battery monomer generally includes a shell and an electrode assembly contained in the shell, and the electrode assembly generally includes a positive electrode sheet and a negative electrode sheet.

[0089] During charging, Li + The negative electrode sheet generally includes a negative electrode body and a negative electrode tab, and the negative electrode body is subjected to lithium deposition and lithium stripping, and the negative electrode tab is used for transmitting current. + The process is the lithium stripping process.

[0090] The negative electrode sheet generally includes a negative electrode body and a negative electrode tab, and the negative electrode body is subjected to lithium deposition and lithium stripping, and the negative electrode tab is used for transmitting current.

[0091] In some embodiments, in order to reduce the risk of short circuit and facilitate the connection of the negative electrode sheet and other components, the negative electrode tab generally has a small size; for example, in a wound electrode assembly, the size of the negative electrode tab along the winding direction is generally smaller than the size of the negative electrode body along the winding direction.

[0092] However, during charging and discharging, due to the small size of the negative electrode tab, the charge flux or charge density flowing through the area of the negative electrode body close to the negative electrode tab is greater than that of other areas of the negative electrode body, and high charge density can accelerate lithium deposition and lithium stripping. With the continuation of the cycle, the area of the negative electrode body close to the tab is prone to produce a powdered lithium metal layer. The powdered lithium forms an uneven distribution, causing poor contact between the powdered lithium, increasing the impedance, leading to the attenuation of the reversible capacity of the lithium metal battery monomer. The powdered lithium can also form lithium dendrites, which can pierce the separator of the electrode assembly, causing the risk of direct conduction of the positive electrode sheet and the negative electrode sheet, reducing the reliability of the lithium metal battery monomer.

[0093] In view of this, the embodiments of the present application provide a lithium battery metal monomer, which sets an insulating piece on the negative electrode sheet to separate the area of the negative electrode body close to the negative electrode tab from the electrolyte, block the transmission path of charge exchange, inhibit lithium deposition and lithium stripping of the area of the negative electrode body close to the negative electrode tab, slow down the powdering of lithium, reduce the risk of short circuit, and improve the reliability of the lithium metal battery monomer.

[0094] The lithium metal battery cell described in the embodiments of the present application is suitable for a battery device and a power consumption device using the battery device. The power consumption device can be a device using the battery device as a power source or various energy storage systems using the battery device as an energy storage element. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric automobile toy, an electric ship toy, and an electric aircraft toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0095] The following embodiments are described for convenience of illustration by taking a vehicle as an example of a power consumption device.

[0096] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application.

[0097] As shown in FIG. 1, the vehicle 1 is internally provided with a battery device 2, which can be arranged at the bottom, head or tail of the vehicle 1. The battery device 2 can be used for power supply of the vehicle 1, for example, the battery device 2 can be used as an operating power source of the vehicle 1.

[0098] The vehicle 1 can further include a controller 3 and a motor 4, the controller 3 being used to control the battery device 2 to supply power to the motor 4, for example, for the working power demand of the vehicle 1 during starting, navigation and driving.

[0099] In some embodiments of the present application, the battery device 2 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0100] FIG. 2 is a schematic diagram of a battery device provided by some embodiments of the present application.

[0101] In some embodiments, the battery device 2 can include one or more battery cell assemblies for providing voltage and capacity.

[0102] The battery cell assembly can include a plurality of lithium metal battery cells 6, which are connected in series, in parallel or in a mixed connection through a busbar component. The mixed connection means that there are both series connection and parallel connection among the plurality of lithium metal battery cells 6.

[0103] The lithium metal battery cell 6 can be used continuously by activating the active material through charging after discharging.

[0104] As an example, the lithium metal battery cell 6 can be a prismatic lithium metal battery cell, a pouch lithium metal battery cell, or a lithium metal battery cell of other shapes, including a square lithium metal battery cell, a blade lithium metal battery cell, a multi-prismatic lithium metal battery cell, such as a hexagonal lithium metal battery cell, etc.

[0105] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of lithium metal battery cells 6; as an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of lithium metal battery cells 6 into one independent module. As an example, the battery module can be formed by bundling a plurality of lithium metal battery cells 6 with a cable tie.

[0106] In some embodiments, the battery device 2 can be a battery pack, which includes a box 5 and one or more battery cell assemblies, which are housed in the box 5. As an example, the battery cell assembly can be a battery module, which can be housed in the box by fixing the battery module in the box. As an example, the battery cell assembly can also be housed in the box by fixing a plurality of lithium metal battery cells 6 directly in the box.

[0107] In some embodiments, the box 5 is used to house the lithium metal battery cell 6, and the box 5 can be of various structures.

[0108] In some embodiments, the box 5 can include a first box 5a and a second box 5b. The first box 5a and the second box 5b are fastened so that an enclosed space is formed inside the box 5 to accommodate the battery cell assembly. Here, enclosed means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0109] In some embodiments, the box 5 can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame so that an enclosed space is formed inside the box to accommodate the battery cell assembly. As an example, the frame can include a plurality of side beams.

[0110] In some embodiments, the box 5 can be part of the chassis structure of a vehicle. For example, part of the box 5 can be at least part of the floor of the vehicle, or part of the box 5 can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0111] In some embodiments, the battery device 2 can be an energy storage device.

[0112] The energy storage device can be used in an energy storage power station, a wind power system, a solar power system, a mobile power system, or a temporary power supply system, etc. The energy storage device can store electrical energy as needed and output the electrical energy at an appropriate time. For example, the energy storage device can store electrical energy during a low electricity consumption period and provide electrical energy to relevant users or electrical equipment during a high electricity consumption period.

[0113] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0114] FIG. 3 is an exploded schematic view of a lithium metal battery cell according to some embodiments of the present application.

[0115] Referring to FIG. 3, in some embodiments, the lithium metal battery cell 6 includes a housing 20 and an electrode assembly 10 contained in the housing 20.

[0116] In some embodiments, the housing 20 can be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite shell), an aluminum-plastic film, etc.

[0117] In some embodiments, the housing 20 can be a sealed structure or a non-sealed structure. As an example, when the housing 20 is a non-sealed structure, the housing 20 serves to protect the electrode assembly 10, and a sealing bag is further included between the housing 20 and the electrode assembly 10, which is used to encapsulate the electrode assembly 10 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the housing 20 is a sealed structure, it is used to encapsulate the electrode assembly 10, the electrolyte, etc.

[0118] In some embodiments, the housing 20 includes a shell 21 having an opening and an end cap 22 connected to the shell 21 and covering the opening.

[0119] The shell 21 is a component used to cooperate with the end cap 22 to form an internal cavity of the lithium metal battery cell 6, and the internal cavity formed can be used to contain the electrode assembly 10, the electrolyte, and other components.

[0120] The shell 21 and the end cap 22 can be independent components. As an example, an opening can be provided on the shell 21, and the internal cavity of the lithium metal battery cell 6 can be formed by covering the opening with the end cap 22.

[0121] The shell 21 can be in various shapes and sizes, such as a cuboid. Specifically, the shape of the shell 21 can be determined according to the specific shape and size of the electrode assembly 10. The shell 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0122] The shape of the end cover 22 can be adapted to the shape of the shell 21 to fit the shell 21. The material of the end cover 22 can be the same as or different from the material of the shell 21. Optionally, the end cover 22 can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cover 22 is not easily deformed when subjected to extrusion and collision, and the lithium metal battery cell 6 can have higher structural strength and improved reliability.

[0123] The end cover 22 is connected to the shell 21 by welding, bonding, clamping, or other means.

[0124] The shell 21 can be open at one end or both ends. In some examples, the shell 21 can be a structure open on one side, and the end cover 22 is provided as one and covers the shell 21. In other examples, the shell 21 can also be a structure open on both sides, and the end cover 22 is provided as two, and the two end covers 22 cover the two openings of the shell 21, respectively.

[0125] The electrode assembly 10 is a component in which electrochemical reactions occur in the lithium metal battery cell 6. The shell 21 can contain one or more electrode assemblies 10.

[0126] The electrode assembly 10 includes a positive electrode sheet, a negative electrode sheet, and a separator that separates the positive electrode sheet and the negative electrode sheet.

[0127] During charging and discharging of the lithium metal battery cell 6, active ions (such as lithium ions) are inserted and extracted between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet, which can prevent short circuiting of the positive and negative electrodes, while allowing the active ions to pass through.

[0128] In some embodiments, the lithium metal battery cell 6 further includes an electrolyte, which functions to conduct ions between the positive electrode sheet and the negative electrode sheet.

[0129] In some embodiments, the electrolyte includes an electrolyte salt and a solvent.

[0130] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroboric oxalate, lithium boric oxalate, lithium difluorophosphoric boric oxalate, and lithium tetrafluorophosphoric oxalate.

[0131] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be selected from an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and a crown ether.

[0132] In some embodiments, the electrolyte can also optionally include an additive. For example, the additive can include a negative electrode film-forming additive, a positive electrode film-forming additive, an additive capable of improving certain properties of the lithium metal battery cell, such as an additive capable of improving overcharge / fast charge properties of the lithium metal battery cell, an additive capable of improving high temperature properties of the lithium metal battery cell, an additive capable of improving low temperature properties of the lithium metal battery cell, and the like.

[0133] In some embodiments, the lithium metal battery cell 6 includes a positive electrode lead-out portion 30 and a negative electrode lead-out portion 40. The positive electrode lead-out portion 30 is connected to the positive electrode tab, and the negative electrode lead-out portion 40 is connected to the negative electrode tab.

[0134] The positive electrode lead-out portion 30 and the negative electrode lead-out portion 40 are used to electrically connect with an external circuit to enable charging or discharging of the lithium metal battery cell 6.

[0135] In some embodiments, the positive electrode lead-out portion 30 includes a positive electrode terminal. At least a portion of the positive electrode terminal is exposed to an exterior of the lithium metal battery cell 6 to facilitate connection with a busbar member.

[0136] As an example, the positive electrode terminal can be a separately formed component that is mounted to the housing 20. Alternatively, the positive electrode terminal can also be part of the housing 20.

[0137] In some examples, the positive electrode terminal is directly connected to the positive electrode tab; in other examples, the positive electrode lead-out portion 30 further includes other conductive structures, such as a positive electrode adapter tab, that connect the positive electrode terminal and the positive electrode tab.

[0138] In some embodiments, the positive electrode terminal is connected to the end cap 22 by welding, riveting, clamping, or other means.

[0139] In some embodiments, the negative electrode lead-out portion 40 includes a negative electrode terminal. At least a portion of the negative electrode terminal is exposed to an exterior of the lithium metal battery cell 6 to facilitate connection with a busbar member.

[0140] As an example, the negative terminal can be a separately formed component that is mounted to the housing 20. Alternatively, the negative terminal can also be formed as part of the housing 20.

[0141] In some examples, the negative terminal is directly connected to the negative tab; in other examples, the negative terminal further includes other conductive structures, such as a negative adapter tab, that connects the negative terminal and the negative tab.

[0142] In some embodiments, the negative terminal is connected to the end cap 22 by welding, riveting, clamping, or other means.

[0143] In some embodiments, the lithium metal battery cell 6 further includes a pressure relief mechanism 50. The pressure relief mechanism 50 is configured to release internal gas of the lithium metal battery cell 6.

[0144] As an example, the pressure relief mechanism 50 is actuated to release internal pressure or temperature of the lithium metal battery cell 6 when the internal pressure or temperature reaches a predetermined threshold. When the internal pressure or temperature of the lithium metal battery cell 6 reaches the predetermined threshold, the pressure relief mechanism 50 performs an action or a weak structure provided in the pressure relief mechanism 50 is broken, thereby forming an opening or a passage for the internal pressure or temperature to release. The threshold is designed differently depending on design requirements. The threshold can depend on the material of one or more of the positive tab, the negative tab, the electrolyte, and the separator in the lithium metal battery cell 6.

[0145] As an example, the pressure relief mechanism 50 can be integrally formed with the housing 20.

[0146] As an example, the pressure relief mechanism 50 can also be separately provided from the housing 20 and connected to the housing 20.

[0147] FIG. 4 is a schematic view of an electrode assembly according to some embodiments of the present application; and FIG. 5 is a partial cross-sectional view of FIG. 4 taken along line A-A.

[0148] Referring to FIGS. 4 and 5, in some embodiments, the electrode assembly 10 includes a positive tab 11 and a negative tab 12.

[0149] In some embodiments, the positive tab 11 can include a positive current collector 111 and a positive active material layer 112 provided on at least one surface of the positive current collector 111.

[0150] As an example, the positive current collector 111 has two opposite surfaces in a thickness direction thereof, and the positive active material layer 112 is provided on either one or both of the two opposite surfaces of the positive current collector 111.

[0151] As an example, the positive electrode current collector 111 can employ a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, a nickel alloy, titanium, or silver, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0152] As an example, the positive electrode active material layer 112 includes a positive electrode active material, which can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or two or more can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (which can also be referred to simply as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be referred to simply as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be referred to simply as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be referred to simply as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al0.05 O2) and modified compounds thereof, and the like. The modified compound refers to a substance obtained by modification means such as doping or coating on the basis of the above-mentioned substance.

[0153] In some embodiments, the negative electrode sheet 12 can include a negative electrode current collector.

[0154] As an example, the negative electrode current collector can employ a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, a nickel alloy, titanium, or silver, and the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, a copper alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, and the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, and the like).

[0155] In some embodiments, the negative electrode current collector can be directly used as the negative electrode sheet 12. This type of lithium metal battery cell 6 can also be referred to as a "negative electrode-free battery cell". During charging, lithium ions are deposited on the negative electrode current collector from the positive electrode active material to form lithium metal (i.e., the negative electrode active material is lithium metal). Alternatively, in other embodiments, the negative electrode sheet 12 can further include a film layer disposed on the negative electrode current collector.

[0156] In some embodiments, the material of the positive electrode current collector 111 can be aluminum, and the material of the negative electrode current collector can be copper.

[0157] In some embodiments, the electrode assembly 10 further includes a separator 13 for separating the positive electrode sheet 11 and the negative electrode sheet 12. The separator 13 can reduce the risk of positive and negative short circuits, while allowing active ions to pass through.

[0158] In some embodiments, the separator 13 is a separator film. The separator film of the present application can use any known porous structure separator film with good chemical stability and mechanical stability.

[0159] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different. The separator 13 can be a separate component located between the positive electrode sheet 11 and the negative electrode sheet 12, or can be attached to the surface of the positive electrode sheet 11 or the surface of the negative electrode sheet 12. An inorganic particle coating layer, an organic particle coating layer, or an organic / inorganic composite coating layer can also be applied to the surface of the separator film.

[0160] In some embodiments, the electrode assembly 10 is in a wound structure. Exemplarily, the positive electrode sheet 11 and the negative electrode sheet 12 are both in a strip structure, and the positive electrode sheet 11, the separator 13 and the negative electrode sheet 12 are wound into a wound structure.

[0161] In some embodiments, the electrode assembly 10 is in a stacked structure.

[0162] Exemplarily, a plurality of positive electrode sheets 11 and a plurality of negative electrode sheets 12 are provided respectively, and the plurality of positive electrode sheets 11 and the plurality of negative electrode sheets 12 are alternately and stacked.

[0163] Exemplarily, a plurality of positive electrode sheets 11 are provided, and the negative electrode sheet 12 is folded to form a plurality of folded segments which are stacked, and one positive electrode sheet 11 is clamped between adjacent folded segments.

[0164] Exemplarily, the positive electrode sheet 11 and the negative electrode sheet 12 are both folded to form a plurality of folded segments which are stacked.

[0165] Exemplarily, a plurality of separators 13 are provided, and each of the separators 13 is arranged between any adjacent positive electrode sheet 11 or negative electrode sheet 12.

[0166] Exemplarily, the separators 13 are continuously provided, and are arranged between any adjacent positive electrode sheet 11 or negative electrode sheet 12 by folding or winding.

[0167] In some embodiments, the electrode assembly 10 can be in a cylindrical shape, a flat shape or a multi-prism shape, etc.

[0168] FIG. 6 is a schematic view of a negative electrode sheet of an electrode assembly in a flattened state according to some embodiments of the present application; FIG. 7 is a schematic view of the negative electrode sheet of FIG. 6 after being connected to an insulating member, wherein the portion of the negative electrode sheet covered by the insulating member is shown by a dashed line; FIG. 8 is a cross-sectional view of FIG. 7 taken along the direction of B-B; FIG. 9 is a cross-sectional view of FIG. 7 taken along the direction of C-C; and FIG. 10 is a schematic view of an insulating member of an electrode assembly in a flattened state according to some embodiments of the present application.

[0169] Referring to FIGS. 3 to 10, the present embodiments provide a lithium metal battery cell 6, which includes a housing 20 and an electrode assembly 10 accommodated in the housing 20. The electrode assembly 10 includes a negative electrode sheet 12 and an insulating member 14. The housing 20 is provided with a negative electrode lead-out portion 40.

[0170] The negative electrode sheet 12 includes a negative electrode body 121 and at least one negative electrode tab 122, and the negative electrode body 121 and the negative electrode tab 122 are arranged and connected along a first direction Z. Along a second direction X, the size of the negative electrode tab 122 is smaller than the size of the negative electrode body 121, and the first direction Z, the second direction X and the thickness direction Y of the negative electrode body 121 are perpendicular to each other. The negative electrode tab 122 is electrically connected to the negative electrode lead-out portion 40.

[0171] At least part of the insulating member 14 is located on one side of the negative electrode body 121 in the thickness direction Y and is attached to the negative electrode body 121, and the area of the negative electrode body 121 covered by the insulating member 14 is connected to the at least one negative electrode tab 122.

[0172] The negative electrode sheet 12 can be one or multiple. In some examples, the negative electrode sheet 12 is multiple, and each negative electrode sheet 12 is attached with an insulating member 14.

[0173] The negative electrode lead-out portion 40 can be directly connected to the negative electrode tab 122; for example, the negative electrode lead-out portion 40 is directly welded to the negative electrode tab 122. Alternatively, the negative electrode lead-out portion 40 can be connected to the negative electrode tab 122 through a conductive member (for example, a jumper).

[0174] The first direction Z can refer to a direction perpendicular to the thickness direction Y of the negative electrode body 121; the second direction X can refer to a direction perpendicular to both the thickness direction Y and the first direction Z of the negative electrode body 121.

[0175] In some examples, the electrode assembly 10 is a wound structure, and in the unfolded state of the negative electrode sheet 12, the first direction Z can refer to the width direction V1 of the negative electrode body 121; the second direction X can refer to the length direction V2 of the negative electrode body 121. In the wound state of the negative electrode sheet 12, the second direction X can refer to the winding direction V of the negative electrode sheet 12, and the first direction Z can be parallel to the winding axis of the negative electrode sheet 12.

[0176] In other examples, the electrode assembly 10 is a laminated structure, and one of the first direction Z and the second direction X is the width direction V1 of the negative electrode body 121, and the other is the length direction V2 of the negative electrode body 121.

[0177] The negative electrode tab 122 can be one or multiple. For example, the negative electrode tab 122 is multiple, and the multiple negative electrode tabs 122 can be arranged at intervals along the second direction X.

[0178] For example, the size of the negative electrode body 121 along the second direction X is L1, and the size of the junction between the negative electrode tab 122 and the negative electrode body 121 along the second direction X is L2. The number of negative electrode tabs 122 is n, and n is a positive integer. L1 > n x L2. Optionally, n is 1, 2, 4, 5, 8, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, or 100.

[0179] The insulating member 14 can refer to a component capable of insulation. The insulating member 14 can refer to an integrated structure, or a component that is separately formed in multiple parts and then assembled together.

[0180] The insulating member 14 can be, but is not limited to, an insulating coating, an insulating glue (for example, hot melt glue, etc.), or an insulating adhesive tape.

[0181] The insulating member 14 can be one or multiple.

[0182] The insulating member 14 can be located on one side of the negative body 121 in the thickness direction Y as a whole. Alternatively, the insulating member 14 can also protrude from the negative body 121 in the first direction Z or the second direction X.

[0183] The insulating member 14 can be attached only to the negative body 121 or can be attached to other parts of the negative sheet 12, such as the negative tab 122.

[0184] As an example, “attached” can mean attached and connected. For example, the insulating member 14 is attached to the negative body 121 by adhesion or coating.

[0185] The insulating member 14 covers the negative body 121. As an example, covering can mean that the insulating member 14 covers the negative body 121 in the thickness direction.

[0186] The area of the negative body 121 covered by the insulating member 14 can be covered by the insulating member 14 on one side in the thickness direction or can be covered by the insulating member 14 on both sides in the thickness direction.

[0187] The area of the negative body 121 covered by the insulating member 14 is directly connected to the negative tab 122.

[0188] As an example, the insulating member 14 covers the junction of the negative body 121 and the negative tab 122, and protrudes from the junction of the negative body 121 and the negative tab 122 in the direction of the negative tab 122 pointing to the negative body 121.

[0189] The insulating member 14 can separate at least part of the area of the negative body 121 close to the negative tab 122 from the electrolyte, reduce the exchange of electric charges between the area of the negative body 121 close to the negative tab 122 and the electrolyte, thereby inhibiting the deposition of lithium and the stripping of lithium occurring in the area of the negative body 121 close to the negative tab 122, slowing down the pulverization of lithium, reducing the formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell 6, and reducing the impedance, slowing down the capacity decay of the lithium metal battery cell 6.

[0190] In some embodiments, the electrode assembly 10 is a jelly-roll structure.

[0191] In some embodiments, the negative body 121 is wound, and the negative sheet 12 includes multiple negative tabs 122. The multiple negative tabs 122 are stacked.

[0192] The negative body 121 is wound in the winding direction V, and the multiple negative tabs 122 are arranged at intervals in the winding direction V. After the electrode assembly 10 is wound and formed, the multiple negative tabs 122 are stacked.

[0193] In some embodiments, the insulating member 14 includes a first insulating portion 141 attached to the negative electrode body 121.

[0194] Exemplarily, the first insulating portion 141 can be a portion of the insulating member 14 that overlaps the negative electrode body 121 in the thickness direction Y.

[0195] The first insulating portion 141 covers a portion of the negative electrode body 121.

[0196] The first insulating portion 141 can be one or multiple.

[0197] The first insulating portion 141 can be provided on one side of the negative electrode body 121 in the thickness direction Y, or can be provided on both sides of the negative electrode body 121 in the thickness direction Y.

[0198] In some embodiments, the area of the negative electrode body 121 covered by the first insulating portion 141 is connected to at least one of the negative electrode tabs 122.

[0199] In some examples, there can be multiple negative electrode tabs 122. The area of the negative electrode body 121 covered by the first insulating portion 141 can be connected to all of the negative electrode tabs 122, or can be connected to only some of the negative electrode tabs 122.

[0200] In some embodiments, the first insulating portion 141 continuously extends in the second direction X, and both ends of the first insulating portion 141 in the second direction X are beyond all of the negative electrode tabs 122.

[0201] In some examples, there is one negative electrode tab 122. Both ends of the first insulating portion 141 in the second direction X are beyond the negative electrode tab 122. In some examples, there are multiple negative electrode tabs 122, and among the multiple negative electrode tabs 122, two negative electrode tabs 122 located at the two ends in the second direction X are respectively a first negative electrode tab and a second negative electrode tab. In the second direction X, one end of the first insulating portion 141 is beyond the first negative electrode tab away from the edge of the second negative electrode tab, and the other end of the first insulating portion 141 is beyond the second negative electrode tab away from the edge of the first negative electrode tab.

[0202] The first insulating portion 141 extends a large length in the second direction X, which can cover the area of the negative electrode body 121 close to the negative electrode tab 122 in the second direction X, thereby inhibiting the deposition and stripping of lithium occurring in the area of the negative electrode body 121 around the negative electrode tab 122, slowing down the pulverization of lithium, reducing the formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell 6, and reducing the impedance, slowing down the capacity decay of the lithium metal battery cell 6.

[0203] In some embodiments, the insulating member 14 protrudes from the end of the negative body 121 towards the negative tab 122 in the direction in which the negative body 121 points to the negative tab 122.

[0204] The present application can increase the insulating area and reduce the risk of short circuit.

[0205] In some embodiments, the insulating member 14 comprises a first insulating part 141 and at least one second insulating part 142, and the second insulating part 142 is connected to the first insulating part 141. In the direction in which the negative body 121 points to the negative tab 122, the second insulating part 142 is located on one side of the first insulating part 141.

[0206] The first insulating part 141 is attached to the negative body 121, and the area of the negative body 121 covered by the first insulating part 141 is connected to at least one negative tab 122.

[0207] The second insulating part 142 is arranged one-to-one corresponding to the negative tab 122, and the second insulating part 142 is attached to the negative tab 122.

[0208] For example, the second insulating part 142 can be the part of the insulating member 14 that overlaps the negative tab 122 in the thickness direction of the negative tab 122.

[0209] For example, the second insulating part 142 only covers part of the negative tab 122, so as to facilitate the connection of the negative tab 122 with other conductive structures.

[0210] The number of negative tabs 122 and the number of second insulating parts 142 of the insulating member 14 can be the same. In some examples, there is one second insulating part 142 and one negative tab 122. In other examples, there are multiple second insulating parts 142 and multiple negative tabs 122, and the multiple second insulating parts 142 are arranged one-to-one corresponding to the multiple negative tabs 122.

[0211] By arranging the second insulating part 142, the connection area between the insulating member 14 and the negative tab 12 can be increased, the risk of the insulating member 14 falling off the negative tab 12 can be reduced, and the insulating effect can be improved. The second insulating part 142 can also support the negative tab 122, reduce the risk of the negative tab 122 being inserted upside down between the negative body 121 and the positive tab 11 when the negative tab 122 is bent, and further reduce the risk of short circuit.

[0212] For example, in the lithium metal battery cell 6, in order to save the space occupied by the negative tab 122, the negative tab 122 can be bent; during the bending process, the root of the negative tab 122 can be deformed and inserted upside down between the positive tab 11 and the negative body 121; the second insulating part 142 can support the root of the negative tab 122 close to the negative body 121, and reduce the risk of the negative tab 122 being inserted upside down between the positive tab 11 and the negative body 121 when the negative tab 122 is bent.

[0213] In some embodiments, the negative tab 122 protrudes from the insulating member 14 in a direction pointing from the negative body 121 to the negative tab 122. Exemplarily, the portion of the negative tab 122 protruding from the insulating member 14 can be used to connect with other conductive members.

[0214] In some embodiments, the insulating member 14 further comprises at least one third insulating portion 143; at least a portion of the third insulating portion 143 is located on one side of the first insulating portion 141 in a direction pointing from the negative body 121 to the negative tab 122. The third insulating portion 143 connects the first insulating portion 141 and the second insulating portion 142.

[0215] Exemplarily, in the thickness direction Y of the negative body 121, the third insulating portion 143 does not overlap with the negative body 121; in the thickness direction of the negative tab 122, the third insulating portion 143 does not overlap with the negative tab 122.

[0216] The third insulating portion 143 can be one or multiple.

[0217] By providing the third insulating portion 143, the end of the insulating member 14 protruding from the negative body 121 in the first direction Z towards the negative tab 122 can cover the burrs at the end of the negative body 121, reducing the possibility of the burrs piercing the separator 13 and contacting the positive sheet 11, thereby reducing the risk of short circuit and improving the reliability of the lithium metal battery cell 6. The third insulating portion 143 is connected to the second insulating portion 142, therefore, the insulating member 14 can protrude from the negative tab 122 in the second direction X, thereby covering the burrs at the end of the negative tab 122 along the second direction X, reducing the possibility of the burrs piercing the separator 13 and contacting the positive sheet 11, thereby reducing the risk of short circuit and improving the reliability of the lithium metal battery cell 6.

[0218] In some embodiments, the negative sheet 12 comprises multiple negative tabs 122, and the multiple negative tabs 122 are arranged at intervals along the second direction X. The second insulating portion 142 is multiple, and the multiple second insulating portions 142 are arranged one-to-one corresponding to the multiple negative tabs 122. The third insulating portion 143 is multiple, and the multiple third insulating portions 143 and the multiple second insulating portions 142 are arranged alternately along the second direction X. The first insulating portion 141 is arranged continuously along the second direction X and is connected to the multiple second insulating portions 142 and the multiple third insulating portions 143.

[0219] Exemplarily, two adjacent second insulating portions 142 are connected by one third insulating portion 143.

[0220] The plurality of third insulation portions 143 connect the plurality of second insulation portions 142 into one body, which can increase the insulation area and reduce the risk of the insulation member 14 falling off from the negative tab 12, and improve the insulation reliability. The insulation member 14 is continuously arranged as a whole, which can bind the negative tab 122 and reduce the deformation of the negative tab 122, reduce the possibility of the negative tab 122 being inserted upside down between the positive tab 11 and the negative main body 121, and reduce the risk of short circuit.

[0221] In other examples, the second insulation portion 142 can be omitted.

[0222] Exemplarily, the insulation member 14 includes the first insulation portion 141 and at least one third insulation portion 143, and the third insulation portion 143 is connected to the first insulation portion 141. In the direction of the negative main body 121 pointing to the negative tab 122, the third insulation portion 143 is located on one side of the first insulation portion 141. The first insulation portion 141 is attached to the negative main body 121, and the area of the negative main body 121 covered by the first insulation portion 141 is connected to the at least one negative tab 122. The third insulation portion 143 is arranged along the second direction X with the negative tab 122.

[0223] The third insulation portion 143 can be connected to the negative tab 122 or arranged spaced apart from the negative tab 122.

[0224] In some examples, the negative tab 122 is one, and the third insulation portion 143 is arranged on both sides of the negative tab 122 along the second direction X. In other examples, the negative tab 122 is a plurality, and the third insulation portion 143 is arranged between adjacent negative tabs 122.

[0225] By arranging the third insulation portion 143, the insulation member 14 can protrude from the negative main body 121 in the first direction Z towards the end of the negative tab 122, thereby covering the burrs of the end of the negative main body 121, reducing the possibility of the burrs piercing the separator 13 and contacting the positive tab 11, and further reducing the risk of short circuit, and improving the reliability of the lithium metal battery cell 6.

[0226] In some embodiments, the electrode assembly 10 includes two insulation members 14, and the two insulation members 14 are respectively attached to the two sides of the negative main body 121.

[0227] The two insulation members 14 can cover the area of the negative main body 121 close to the negative tab 122 from both sides, thereby inhibiting the deposition and stripping of lithium occurring in the area of the negative main body 121 close to the negative tab 122, slowing down the pulverization of lithium, reducing the formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell 6, and reducing the impedance and slowing down the capacity decay of the lithium metal battery cell 6.

[0228] In some embodiments, the first insulation part 141 of the two insulation pieces 14 is respectively arranged on both sides of the negative body 121. The first insulation part 141 of the two insulation pieces 14 is respectively attached to the negative body 121.

[0229] The number of the first insulation part 141 of the two insulation pieces 14 can be the same or different. In some examples, the first insulation part 141 of the two insulation pieces 14 is one; in other examples, the first insulation part 141 of the two insulation pieces 14 is multiple. The multiple first insulation parts 141 of the two insulation pieces 14 are arranged one by one.

[0230] In some embodiments, the third insulation part 143 of the two insulation pieces 14 is attached to reduce the risk of burrs extending from between the two third insulation parts 143 and improve reliability.

[0231] The third insulation part 143 of the two insulation pieces 14 can be attached together by pasting, static adsorption or other means.

[0232] After the third insulation part 143 of the two insulation pieces 14 is attached, the end of the negative body 121 facing the negative tab 122 can be covered, so that the metal debris remaining at the end of the negative body 121 is not easy to fall into the electrode assembly 10, which can better reduce the risk of short circuit of the lithium metal battery cell 6.

[0233] In some embodiments, the third insulation part 143 of the two insulation pieces 14 is connected to improve the stability of the insulation piece 14 and reduce the risk of the insulation piece 14 falling off the negative sheet 12.

[0234] In some embodiments, the third insulation part 143 of the two insulation pieces 14 is attached and connected. Optionally, the third insulation part 143 of the two insulation pieces 14 is bonded.

[0235] In some embodiments, the first insulation part 141 is connected to the two third insulation parts 143 at both ends in the second direction X. The insulation piece 14 protrudes from the negative body 121 in the second direction X to cover the burrs at the end of the negative body 121 in the second direction X.

[0236] In some embodiments, the electrode assembly 10 further includes a positive sheet 11 including a positive active material layer 112. In the direction of the negative body 121 pointing to the negative tab 122, the end surface of the negative body 121 towards the negative tab 122 exceeds the positive active material layer 112, and at least part of the insulation piece 14 exceeds the positive active material layer 112.

[0237] The negative body 121 has a large size to receive ions released from the positive active material layer 112, thereby improving the capacity of the lithium metal battery cell 6.

[0238] In some embodiments, the insulating member 14 entirely protrudes from the positive active material layer 112 in a direction pointing from the negative electrode body 121 to the negative electrode tab 122, so as to reduce the ions blocked by the insulating member 14 and reduce the capacity loss.

[0239] In some embodiments, the insulating member 14 covers the negative electrode body 121 in the first direction Z by a dimension W, 1 mm≤W≤5 mm.

[0240] For example, W is 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0241] W is limited to be greater than or equal to 1 mm, so that the insulating member 14 covers the area of the negative electrode body 121 close to the negative electrode tab 122 as much as possible, slows down the pulverization of lithium, reduces the formation of lithium dendrites, reduces the risk of short circuit, improves the reliability of the lithium metal battery cell 6, and reduces the impedance and slows down the capacity attenuation of the lithium metal battery cell 6. W is limited to be less than or equal to 5 mm, so as to reduce the impact of the insulating member 14 on the capacity of the lithium metal battery cell 6.

[0242] In some embodiments, the insulating member 14 protrudes from the negative electrode body 121 in a direction pointing from the negative electrode body 121 to the negative electrode tab 122 by a dimension W1, 1 mm≤W1≤3 mm.

[0243] For example, W1 is 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0244] W1 is limited to be greater than or equal to 1 mm, so that the insulating member 14 can cover the burr and reduce the risk of the burr protruding outside the insulating member 14. W1 is limited to be less than or equal to 3 mm, so as to reduce the space and weight occupied by the insulating member 14 and reduce the impact of setting the insulating member 14 on the energy density of the lithium metal battery cell 6.

[0245] In some embodiments, the negative electrode body 121 comprises a current collecting body 1211, and the current collecting body 1211 is connected to the negative electrode tab 122.

[0246] For example, the dimension of the current collecting body 1211 along the second direction X is equal to the dimension of the negative electrode body 121 along the second direction X.

[0247] In some examples, the current collecting body 1211 and the negative electrode tab 122 are integrally formed. Alternatively, in other examples, the current collecting body 1211 and the negative electrode tab 122 are independently formed and connected by welding, bonding, or other means.

[0248] In some embodiments, the negative electrode body 121 comprises a film layer 1212, and the film layer 1212 is arranged on at least one side of the current collecting body 1211 along the thickness direction Y.

[0249] In some examples, the current collector body 1211 is provided with the film layer 1212 on one side along the thickness direction Y; in other examples, the current collector body 1211 is provided with the film layer 1212 on both sides along the thickness direction Y.

[0250] By providing the film layer 1212, deposition of lithium metal on the negative electrode body 121 is facilitated.

[0251] In some embodiments, the film layer 1212 is a conductive film layer.

[0252] In some embodiments, the film layer 1212 can be provided on at least one surface of the current collector body 1211 by a method such as Physical Vapor Deposition (PVD), spin coating, electroplating, Chemical Vapor Deposition (CVD), or the like.

[0253] In some embodiments, the insulating member 14 is attached to at least one of the film layer 1212 and the current collector body 1211. The area of the current collector body 1211 covered by the insulating member 14 is connected to the at least one negative electrode tab 122.

[0254] In some examples, the insulating member 14 can be directly covered on the current collector body 1211. For example, the area of the current collector body 1211 adjacent to and connected to the negative electrode tab 122 is not covered with the film layer 1212, and the insulating member 14 can be attached to the current collector body 1211 to cover the area of the current collector body 1211 adjacent to and connected to the negative electrode tab 122.

[0255] In other examples, the insulating member 14 can be covered on the current collector body 1211 through the film layer 1212. For example, the area of the current collector body 1211 adjacent to and connected to the negative electrode tab 122 is covered with the film layer 1212. The insulating member 14 can be attached to the film layer 1212 to cover the area of the film layer 1212 close to the negative electrode tab 122 and the area of the current collector body 1211 adjacent to and connected to the negative electrode tab 122.

[0256] In some embodiments, the end surface of the current collector body 1211 toward the negative electrode tab 122 is flush with the end surface of the film layer 1212 toward the negative electrode tab 122. The insulating member 14 is attached to the film layer 1212 and covers a portion of the film layer 1212.

[0257] The insulating member 14 can cover the area of the film layer 1212 close to the negative electrode tab 122, thereby inhibiting deposition and peeling of lithium occurring in the area of the film layer 1212 close to the negative electrode tab 122, slowing down pulverization of lithium, reducing formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell 6, and reducing impedance, slowing down the decay of the capacity of the lithium metal battery cell 6.

[0258] In some embodiments, the film layer 1212 includes lithium metal.

[0259] In some examples, the film layer 1212 can include at least one of lithium metal, a carbon-based material deposited with lithium metal, a composite material containing lithium metal, an alloy material containing lithium metal.

[0260] FIG. 11 is a schematic view of a negative tab and an insulating piece of a metal battery cell in an unfolded state according to some embodiments of the present application, wherein the portion of the negative tab covered by the insulating piece is shown by a dashed line; and FIG. 12 is a schematic view of a sub-insulating piece shown in FIG. 11.

[0261] Referring to FIGS. 11 and 12, in some embodiments, the negative tab 12 includes a plurality of negative tabs 122 spaced apart along the second direction X. The insulating piece 14 includes a plurality of first insulating portions 141 attached to the negative body 121, the plurality of first insulating portions 141 being spaced apart along the second direction X.

[0262] Each first insulating portion 141 is located at one side of a corresponding negative tab 122 in a direction pointing from the negative tab 122 to the negative body 121. The area of the negative body 121 covered by the first insulating portion 141 is connected to the corresponding negative tab 122.

[0263] By providing the plurality of first insulating portions 141, the area of the negative body 121 close to each negative tab 122 can be covered, so as to inhibit lithium deposition and lithium stripping from the area of the negative body 121 close to each negative tab 122, slow down lithium pulverization, and reduce the formation of lithium dendrites. The plurality of first insulating portions 141 are spaced apart, which can reduce the weight and space occupied by the insulating piece 14 as a whole, reduce the blocking of the area of the negative body 121 where lithium pulverization is less likely to occur by the insulating piece 14, and reduce the impact of the insulating piece 14 on the capacity of the lithium metal battery cell 6.

[0264] In some embodiments, along the second direction X, both ends of the first insulating portion 141 extend beyond the corresponding negative tab 122.

[0265] The first insulating portion 141 has a large dimension along the second direction X, which can inhibit lithium deposition and lithium stripping from the area of the negative body 121 around the negative tab 122, slow down lithium pulverization, reduce the formation of lithium dendrites, reduce the risk of short circuit, improve the reliability of the lithium metal battery cell 6, and reduce the impedance and slow down the capacity attenuation of the lithium metal battery cell 6.

[0266] In some embodiments, the insulating piece 14 includes a plurality of sub-insulating pieces 14a spaced apart along the second direction X, the plurality of sub-insulating pieces 14a being arranged one-to-one with the plurality of negative tabs 122.

[0267] Each sub-insulating member 14a includes a first insulating portion 141 and a second insulating portion 142. The second insulating portion 142 is connected to the first insulating portion 141. The second insulating portion 142 is located on one side of the first insulating portion 141 in a direction in which the negative electrode tab 122 points to the negative electrode body 121, and is attached to the negative electrode tab 122.

[0268] The sub-insulating member 14a covers the junction of the corresponding negative electrode tab 122 and the negative electrode body 121.

[0269] In some embodiments, each sub-insulating member 14a includes two third insulating portions 143, which are respectively connected to two ends of the second insulating portion 142 in the second direction X. The third insulating portion 143 is located on one side of the first insulating portion 141 in the direction in which the negative electrode tab 122 points to the negative electrode body 121. The two third insulating portions 143 are connected to the first insulating portion 141.

[0270] In some embodiments, the electrode assembly 10 includes two insulating members 14, which are respectively attached to two sides of the negative electrode body 121. The plurality of sub-insulating members 14a of the two insulating members 14 are arranged one by one in correspondence.

[0271] FIG. 13 is a schematic view of a negative tab and an insulating member of a lithium metal battery cell in an unfolded state according to some embodiments of the present application, wherein the portion of the negative tab covered by the insulating member is shown by a dashed line; and FIG. 14 is a schematic view of the negative tab shown in FIG. 13.

[0272] Referring to FIGS. 13 and 14, in some embodiments, the negative electrode body 121 includes a current collecting body 1211, which is an integral structure with the negative electrode tab 122.

[0273] The insulating member 14 is attached to the current collecting body 1211, and at least partially covers the region of the current collecting body 1211 adjacent to and connected with the negative electrode tab 122.

[0274] The insulating member 14 can cover the region of the current collecting body 1211 close to the negative electrode tab 122, thereby inhibiting the deposition and stripping of lithium occurring in the region of the current collecting body 1211 close to the negative electrode tab 122, slowing down the pulverization of lithium, reducing the formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell 6, and reducing the impedance, slowing down the capacity decay of the lithium metal battery cell 6.

[0275] In some embodiments, the current collecting body 1211 and the negative electrode tab 122 constitute the negative current collector of the negative tab 12.

[0276] In some embodiments, the negative electrode body 121 only includes the current collecting body 1211. The lithium metal battery cell 6 can be a “negative electrode-free battery cell”.

[0277] FIG. 15 is a schematic view of a negative tab and an insulating piece of a lithium metal battery cell in an unfolded state according to some embodiments of the present application, wherein the portion of the negative tab covered by the insulating piece is shown in dashed line; and FIG. 16 is a schematic view of the negative tab shown in FIG. 15.

[0278] Referring to FIGS. 15 and 16, in some embodiments, the current collecting body 1211 includes a first current collecting portion 1211a and a second current collecting portion 1211b arranged along the first direction Z, the first current collecting portion 1211a is covered with the film layer 1212, and the second current collecting portion 1211b is not covered with the film layer 1212, and the second current collecting portion 1211b connects the first current collecting portion 1211a and the negative tab 122. Along the second direction X, the size of the negative tab 122 is smaller than the size of the second current collecting portion 1211b. The insulating piece 14 is attached to the second current collecting portion 1211b, and the area of the second current collecting portion 1211b covered by the insulating piece 14 is connected with the at least one negative tab 122.

[0279] The insulating piece 14 can cover the film layer 1212 or not cover the film layer 1212.

[0280] By reserving the second current collecting portion 1211b not covered with the film layer 1212, the area of the film layer 1212 covered by the insulating piece 14 is reduced, the waste of the film layer 1212 is reduced, and the influence of the setting of the insulating piece 14 on the capacity of the lithium metal battery cell 6 is reduced. The insulating piece 14 can cover the area of the second current collecting portion 1211b close to the negative tab 122, thereby inhibiting the deposition and stripping of lithium occurring in the area of the second current collecting portion 1211b close to the negative tab 122, slowing down the pulverization of lithium, reducing the formation of lithium dendrites, reducing the risk of short circuit, improving the reliability of the lithium metal battery cell 6, and reducing the impedance, slowing down the capacity attenuation of the lithium metal battery cell 6.

[0281] In some embodiments, the insulating piece 14 does not cover the film layer 1212.

[0282] In some embodiments, along the direction of the negative tab 122 pointing to the negative tab 122, one end of the film layer 1212 close to the negative tab 122 exceeds the positive active material layer 112.

[0283] FIG. 17 is a schematic view of a cross section of an insulating piece of a lithium metal battery cell according to some embodiments of the present application.

[0284] Referring to FIGS. 7 and 17, in some embodiments, the insulating piece 14 includes an insulating base layer 14b and an adhesive layer 14c, and at least part of the adhesive layer 14c is adhered between the negative tab 122 and the insulating base layer 14b.

[0285] Exemplarily, the insulating base layer 14b can refer to a main body part of the insulating piece 14 that plays an insulating role, and the adhesive layer 14c can refer to an adhesive layer covering the surface of the insulating base layer 14b. For example, the insulating piece 14 adopts a structure form of a tape.

[0286] Exemplarily, the material of the insulating base layer 14b can include at least one of polyethylene terephthalate (PET), polypropylene, polyethylene, and a block copolymer thereof. The material of the adhesive layer 14c can include at least one of polyacrylate, styrene butadiene rubber, polyisobutylene, or butyl rubber.

[0287] The insulating base layer 14b can have a relatively high structural strength and a relatively low porosity, which can effectively block ions from passing through and is not easy to be pierced by burrs, thereby being beneficial to improving the isolation effect and the insulation effect and improving the reliability of the lithium metal battery cell 6. Compared with the adhesive layer 14c, the insulating base layer 14b has a high strength, and the deformation of the insulating base layer 14b is small during the lamination process of the insulating piece 14; the adhesive layer 14c can stably fix the insulating base layer 14b on the negative electrode sheet 12, thereby reducing the risk of falling off of the insulating piece 14.

[0288] In some embodiments, the insulating piece 14 is a tape. The tape is easy to cover comprehensively, which is beneficial to reducing the risk of incomplete coverage and reducing the risk of internal short circuit of the lithium metal battery cell 6.

[0289] In some embodiments, the layer thickness of the insulating base layer 14b ranges from 3 μm to 20 μm.

[0290] The layer thickness of the insulating base layer 14b is T1, and 3 μm≤T1≤20 μm. The value of T1 can be 3 μm, 20 μm, and any value between 3 μm and 20 μm. Exemplarily, the value of T1 can be, but is not limited to, 3 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 18 μm, or 20 μm.

[0291] The design of T1≥3 μm makes the insulating base layer 14b have a certain thickness, and the insulating base layer 14b can isolate the electrolyte and the area of the negative electrode main body 121 close to the negative electrode tab 122; the design of T1≤20 μm makes the thickness of the insulating base layer 14b not too large, which is beneficial to reducing the volume occupied by the insulating piece 14 and improving the energy density of the lithium metal battery cell 6.

[0292] In some embodiments, the layer thickness of the adhesive layer 14c ranges from 0.3 μm to 6 μm.

[0293] The layer thickness of the bonding layer 14c is T2, and 0.3 μm≤T2≤6 μm. It can be understood that T2 can be 0.3 μm, 6 μm, or any value between 0.3 μm and 6 μm. For example, T2 can be, but is not limited to, 0.3 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, or 6 μm.

[0294] The design of T2≥0.5 μm enables the bonding layer 14c to have a certain thickness, so that the insulating member 14 can be stably bonded to the negative electrode sheet 12, and the reliability of the insulating member 14 is improved. The design of T2≤3 μm enables the thickness of the bonding layer 14c not to be too large, which is conducive to reducing the volume occupied by the insulating member 14 and improving the energy density of the battery cell.

[0295] In some embodiments, the layer thickness of the insulating base layer 14b is in the range of 3 μm-20 μm, and the layer thickness of the bonding layer 14c is in the range of 0.3 μm-6 μm.

[0296] FIG. 18 is a cross-sectional view of a negative electrode sheet of a lithium metal battery cell according to some embodiments of the present application.

[0297] Referring to FIG. 18, in some embodiments, the insulating member 14 includes an insulating glue.

[0298] For example, the molten insulating glue can be coated on both sides of the negative electrode sheet 12 by heating, and the insulating glue forms an insulating glue after solidification.

[0299] For example, the third insulating portions 143 of the two insulating members 14 are integrally formed.

[0300] In some embodiments, the thickness of the insulating glue is less than or equal to 50 μm, and the thickness of the insulating glue is greater than or equal to 3 μm.

[0301] In some embodiments, the negative electrode body 121 includes a film layer 1212, and the film layer 1212 includes metal lithium. The melting temperature of the insulating glue is lower than the melting point of the metal lithium.

[0302] The embodiments of the present application can reduce the temperature of the metal lithium when the insulating glue is coated, simplify the oxidation rate of the surface layer of the metal lithium, and reduce the side reactions of the metal lithium.

[0303] In some embodiments, the melting temperature of the insulating glue is lower than 180 °C.

[0304] FIG. 19 is a cross-sectional view of an electrode assembly of a lithium metal battery cell according to some embodiments of the present application; and FIG. 20 is a schematic view of a negative electrode sheet and an insulating member of a lithium metal battery cell according to some embodiments of the present application.

[0305] Referring to FIGS. 19 and 20, in some embodiments, the electrode assembly 10 is a laminated structure.

[0306] In some embodiments, the electrode assembly 10 includes a plurality of negative electrode sheets 12 and a plurality of insulating pieces 14, the plurality of negative electrode sheets 12 are stacked along the thickness direction Y, and each negative electrode sheet 12 is attached with at least one insulating piece 14.

[0307] For example, the positive electrode sheet 11 can be one or multiple. For example, the positive electrode sheet 11 is one, and the positive electrode sheet 11 is folded to form a plurality of positive electrode folded sections, and one positive electrode folded section is arranged between two adjacent negative electrode sheets 12. For example, the positive electrode sheet 11 is multiple, and the plurality of negative electrode sheets 12 and the plurality of positive electrode sheets 11 are alternately stacked.

[0308] For example, the negative electrode sheet 12 can be provided with one negative electrode tab 122 or multiple negative electrode tabs 122.

[0309] FIG. 21 is a cross-sectional schematic view of an electrode assembly of a lithium metal battery cell according to some embodiments of the present application; and FIG. 22 is a schematic view of a negative electrode sheet and an insulating piece of a lithium metal battery cell according to some embodiments of the present application in an unfolded state.

[0310] Referring to FIGS. 21 and 22, in some embodiments, the negative electrode body 121 is folded to form a plurality of negative electrode folded sections 1213, the plurality of negative electrode folded sections 1213 are stacked, and the negative electrode sheet 12 includes a plurality of negative electrode tabs 122, and at least two negative electrode folded sections 1213 are connected with the negative electrode tabs 122.

[0311] For example, one negative electrode folded section 1213 can be connected with one negative electrode tab 122 or multiple negative electrode tabs 122.

[0312] For example, each negative electrode folded section 1213 can be connected with a negative electrode tab 122, or part of the negative electrode folded sections 1213 are connected with negative electrode tabs 122.

[0313] For example, the second direction can be a continuous folding direction of the negative electrode body 121.

[0314] In some embodiments, the plurality of negative electrode folded sections 1213 and the plurality of negative electrode tabs 122 are arranged one-to-one.

[0315] In some embodiments, the negative electrode body 121 further includes a plurality of negative electrode bending sections 1214, and two adjacent negative electrode folded sections 1213 are connected through the negative electrode bending sections 1214.

[0316] The present application also provides a battery device including a plurality of battery cells according to any one of the above embodiments.

[0317] The application also provides a power consuming device comprising the battery device of any of the above embodiments, the battery device being configured to provide power for the power consuming device. The power consuming device can be an apparatus or a system of any of the above applications.

[0318] Referring to FIGS. 3-10, the embodiments of the application provide a lithium metal battery cell 6 comprising a housing 20 and an electrode assembly 10 accommodated in the housing 20.

[0319] The housing 20 comprises a shell 21 having an opening and an end cap 22 connected to the shell 21 and covering the opening. The lithium metal battery cell 6 further comprises a positive electrode terminal and a negative electrode terminal disposed on the end cap 22.

[0320] The electrode assembly 10 comprises a positive electrode sheet 11, a negative electrode sheet 12, and a separator 13 separating the positive electrode sheet 11 and the negative electrode sheet 12. Exemplarily, the positive electrode sheet 11, the separator 13, and the negative electrode sheet 12 are wound into a wound structure.

[0321] The positive electrode sheet 11 can comprise a positive electrode current collector 111 and a positive electrode active material layer 112 disposed on at least one surface of the positive electrode current collector 111. The positive electrode current collector 111 is electrically connected to the positive electrode terminal.

[0322] The negative electrode sheet 12 comprises a negative electrode body 121 and a plurality of negative electrode tabs 122, the negative electrode body 121 and the negative electrode tabs 122 being arranged and connected along a first direction Z, and the plurality of negative electrode tabs 122 being spaced apart along a second direction X. Along the second direction X, the sum of the sizes of the plurality of negative electrode tabs 122 is less than the size of the negative electrode body 121, and the first direction Z, the second direction X, and a thickness direction Y of the negative electrode body 121 are perpendicular to each other. The negative electrode tabs 122 are electrically connected to the negative electrode terminal.

[0323] The negative electrode body 121 comprises a current collecting body 1211 and a film layer 1212 disposed on at least one side of the current collecting body 1211 along the thickness direction Y. The current collecting body 1211 is connected to the negative electrode tabs 122.

[0324] The electrode assembly 10 further comprises two insulating members 14 attached to both sides of the negative electrode body 121 along the thickness direction Y, respectively.

[0325] The insulating member 14 comprises a first insulating portion 141, a plurality of second insulating portions 142, and a plurality of third insulating portions 143.

[0326] The first insulating portion 141 covers the negative electrode body 121. Along the direction in which the negative electrode body 121 points to the negative electrode tab 122, the plurality of second insulating portions 142 are located on the same side of the first insulating portion 141, the plurality of second insulating portions 142 are located on one side of the first insulating portion 141, the plurality of second insulating portions 142 are arranged one-to-one corresponding to the plurality of negative electrode tabs 122, and the second insulating portion 142 is attached to the negative electrode tab 122.

[0327] Along the direction in which the negative electrode body 121 points to the negative electrode tab 122, at least part of the third insulating portion 143 is located on one side of the first insulating portion 141.

[0328] The plurality of third insulating portions 143 and the plurality of second insulating portions 142 are alternately arranged along the second direction X. The first insulating portion 141 is continuously arranged along the second direction X and connected to the plurality of second insulating portions 142 and the plurality of third insulating portions 143.

[0329] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0330] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A lithium metal battery cell, comprising a housing and an electrode assembly contained in the housing, the electrode assembly comprising a negative electrode tab and an insulating member; the housing is provided with a negative electrode lead-out portion; the negative electrode tab comprises a negative electrode body and at least one negative electrode ear, the negative electrode body and the negative electrode ear are arranged and connected along a first direction, along a second direction, the size of the negative electrode ear is smaller than the size of the negative electrode body, the first direction, the second direction and the thickness direction of the negative electrode body are perpendicular to each other, the negative electrode ear is electrically connected to the negative electrode lead-out portion; At least part of the insulating member is located on one side of the negative electrode body along the thickness direction and is attached to the negative electrode body, and the area of the negative electrode body covered by the insulating member is connected with at least one of the negative electrode ear.

2. The lithium metal battery cell of claim 1, wherein, The insulating member comprises a first insulating portion attached to the negative electrode body, and the area of the negative electrode body covered by the first insulating portion is connected with the negative electrode ear; The first insulating portion continuously extends along the second direction, and both ends of the first insulating portion along the second direction exceed all the negative electrode ears.

3. The lithium metal battery cell of claim 1, wherein, The negative electrode tab comprises a plurality of negative electrode ears, and the plurality of negative electrode ears are arranged at intervals along the second direction; The insulating member comprises a plurality of first insulating portions attached to the negative electrode body, and the plurality of first insulating portions are arranged at intervals along the second direction; Along the direction of the negative electrode ear pointing to the negative electrode body, each first insulating portion is located on one side of the corresponding negative electrode ear, and the area of the negative electrode body covered by the first insulating portion is connected with the corresponding negative electrode ear.

4. The lithium metal battery cell of claim 3, wherein, Along the second direction, both ends of the first insulating portion exceed the corresponding negative electrode ear.

5. The lithium metal battery cell of any one of claims 1-4, wherein, Along the direction of the negative electrode body pointing to the negative electrode ear, the end of the insulating member protruding from the negative electrode body towards the negative electrode ear.

6. The lithium metal battery cell of claim 5, wherein, The insulating member comprises a first insulating portion and at least one second insulating portion, and the second insulating portion is connected to the first insulating portion; Along the direction of the negative electrode body pointing to the negative electrode ear, the second insulating portion is located on one side of the first insulating portion; The first insulating portion is attached to the negative electrode body, and the area of the negative electrode body covered by the first insulating portion is connected with at least one of the negative electrode ear, the second insulating portion is arranged one by one corresponding to the negative electrode ear, and the second insulating portion is attached to the negative electrode ear.

7. The lithium metal battery cell of claim 6, wherein, The insulating member further comprises at least one third insulating portion; Along the direction of the negative electrode body pointing to the negative electrode ear, at least part of the third insulating portion is located on one side of the first insulating portion; The third insulating portion connects the first insulating portion and the second insulating portion.

8. The lithium metal battery cell of claim 7, wherein, The negative electrode tab comprises a plurality of negative electrode ears, and the plurality of negative electrode ears are arranged at intervals along the second direction; There are a plurality of second insulating portions, and the plurality of second insulating portions are arranged one by one corresponding to the plurality of negative electrode ears; There are a plurality of third insulating portions, and the plurality of third insulating portions and the plurality of second insulating portions are arranged alternately along the second direction; The first insulating portion is continuously arranged along the second direction and is connected to the plurality of second insulating portions and the plurality of third insulating portions.

9. The lithium metal battery cell of any one of claims 5-8, wherein, the insulating member comprises a first insulating portion and at least one third insulating portion, the third insulating portion being connected to the first insulating portion; in a direction of the negative tab from the negative body, the third insulating portion is located at one side of the first insulating portion; the first insulating portion is attached to the negative body, and a region of the negative body covered by the first insulating portion is connected to at least one of the negative tabs; the third insulating portion is arranged with the negative tab in the second direction.

10. The lithium metal battery cell of any one of claims 7-9, wherein, the electrode assembly comprises two insulating members, the first insulating portions of the two insulating members are respectively arranged at two sides of the negative body; the third insulating portions of the two insulating members are attached and / or connected.

11. The lithium metal battery cell of any one of claims 1-10, wherein, the electrode assembly comprises two insulating members, the two insulating members are respectively attached to two sides of the negative body.

12. The lithium metal battery cell of any one of claims 1-11, wherein, the negative body comprises a current collecting body, the current collecting body and the negative tab are in an integrated structure; the insulating member is attached to the current collecting body, and a region of the current collecting body covered by the insulating member is connected to at least one of the negative tabs.

13. The lithium metal battery cell of any one of claims 1-12, wherein, the negative body comprises a current collecting body and a film layer, the film layer is arranged on at least one side of the current collecting body in the thickness direction, and the negative tab is connected to the current collecting body; the insulating member is attached to at least one of the film layer and the current collecting body, and a region of the current collecting body covered by the insulating member is connected to at least one of the negative tabs.

14. The lithium metal battery cell of claim 13, wherein, the current collecting body comprises a first current collecting portion and a second current collecting portion arranged in the first direction, the first current collecting portion is covered with the film layer, the second current collecting portion is not covered with the film layer, and the second current collecting portion is connected to the first current collecting portion and the negative tab; in the second direction, the size of the negative tab is smaller than the size of the second current collecting portion; the insulating member is attached to the second current collecting portion, and a region of the second current collecting portion covered by the insulating member is connected to at least one of the negative tabs.

15. The lithium metal battery cell of claim 13, wherein, an end surface of the current collecting body towards the negative tab is flush with an end surface of the film layer towards the negative tab; the insulating member is attached to the film layer and covers a part of the film layer.

16. The lithium metal battery cell of any one of claims 13-15, wherein, the film layer comprises metal lithium.

17. The lithium metal battery cell of claim 16, wherein, the insulating member comprises an insulating glue, and the melting temperature of the insulating glue is lower than the melting point of the metal lithium.

18. The lithium metal battery cell of any one of claims 1-17, wherein, the electrode assembly further comprises a positive sheet, and the positive sheet comprises a positive active material layer; in a direction of the negative tab from the negative body, an end surface of the negative body towards the negative tab exceeds the positive active material layer, and at least part of the insulating member exceeds the positive active material layer.

19. The lithium metal battery cell of claim 18, wherein, in a direction of the negative tab from the negative body, the insulating member as a whole exceeds the positive active material layer.

20. The lithium metal battery cell of any one of claims 1-19, wherein, in the first direction, the size of the insulating member covering the negative body is W, and 1 mm≤W≤5 mm.

21. The lithium metal battery cell of any one of claims 1-16, 18-20, wherein, The insulating member includes an insulating base layer and an adhesive layer, and at least part of the adhesive layer is adhered between the negative electrode body and the insulating base layer.

22. The lithium metal battery cell of any one of claims 1-21, wherein, The electrode assembly includes a plurality of negative electrode sheets and a plurality of the insulating members, the plurality of negative electrode sheets are stacked along the thickness direction, and each of the negative electrode sheets is attached with at least one of the insulating members.

23. The lithium metal battery cell of any one of claims 1-21, wherein, The negative electrode body is wound, the negative electrode sheet includes a plurality of the negative electrode tabs, and the plurality of negative electrode tabs are stacked; or The negative electrode body is folded and forms a plurality of negative electrode folded sections, the plurality of negative electrode folded sections are stacked, the negative electrode sheet includes a plurality of the negative electrode tabs, and at least two of the negative electrode folded sections are connected with the negative electrode tabs.

24. A battery device comprising a plurality of lithium metal battery cells according to any one of claims 1-23.

25. An electrically powered device comprising the battery device according to claim 24, the battery device being configured to provide electrical power.

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