Battery monomer, battery device and electric equipment

Abstract

The utility model provides a battery monomer, a battery device and electric equipment. The battery cell includes an electrode assembly, a housing, an electrode terminal, and a first insulating member. The shell comprises a first end wall, a side wall and a containing cavity, the first end wall is provided with an electrode leading-out hole communicated with the containing cavity, and the side wall is connected to the first end wall. The electrode terminal is arranged in the electrode leading-out hole, and the electrode terminal and the first end wall are arranged in an insulated mode. The electrode assembly is contained in the containing cavity, the side wall surrounds the electrode assembly, the electrode assembly comprises a first electrode lug and a second electrode lug which are opposite in polarity, the first electrode lug is electrically connected to the electrode terminal, and the second electrode lug is electrically connected to the first end wall and the side wall. The first insulating member has a thermal weight loss temperature of 300 DEG C or more. At least part of the first insulating member is arranged between the first end wall and the first tab, and / or at least part of the first insulating member is arranged between the side wall and the first tab.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and more particularly, to a battery cell, a battery device, and an electric equipment. BACKGROUND

[0002] Battery cells 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] In the development of battery technology, how to improve the reliability of battery cells is a research direction in battery technology. SUMMARY

[0004] The present application provides a battery cell, a battery device, and an electric equipment, which can improve the reliability.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising an electrode assembly, a shell, an electrode terminal, and a first insulating member. The shell comprises a first end wall, a side wall, and a receiving cavity, the first end wall is provided with an electrode lead-out hole in communication with the receiving cavity, and the side wall is connected to the first end wall. The electrode terminal is arranged in the electrode lead-out hole, and the electrode terminal is insulated from the first end wall. The electrode assembly is accommodated in the receiving cavity, and the side wall surrounds the electrode assembly. The electrode assembly comprises an electrode main body and first and second electrode tabs led out from the electrode main body, the first and second electrode tabs are opposite in polarity, the first electrode tab is arranged at one end of the electrode assembly facing the first end wall, the first electrode tab is electrically connected to the electrode terminal, and the second electrode tab is electrically connected to the first end wall and the side wall. The thermal weight loss temperature of the first insulating member is greater than or equal to 300°C. At least part of the first insulating member is arranged between the first end wall and the first electrode tab, and / or at least part of the first insulating member is arranged between the side wall and the first electrode tab.

[0006] When the battery cell is in thermal runaway due to internal short circuit or other reasons, the battery cell can maintain a high temperature state for a period of time. The thermal weight loss temperature of the first insulating member is greater than or equal to 300°C, which is not easy to lose weight or loses less weight when the battery cell is in thermal runaway, so that the first insulating member can remain between the shell and the first end wall, and separate the first electrode tab from the first end wall or separate the first electrode tab from the side wall, reducing the risk of the side wall or the first end wall being conducted through the first electrode tab and the electrode terminal. Correspondingly, even if the electrode terminal and the first end wall are electrically connected to other battery cells or an external power source, the first insulating member can inhibit the current between the electrode terminal and the first end wall, reduce the continuous heat generation of the electrode terminal and the first end wall, reduce the thermal impact on the surrounding other battery cells, reduce the risk of thermal runaway of the other battery cells, and improve the reliability.

[0007] In some embodiments, the first insulating member has a thermal weight loss temperature greater than or equal to 350 DEG C, and optionally, the first insulating member has a thermal weight loss temperature greater than or equal to 500 DEG C. The embodiments of the present application can further reduce the weight loss rate of the first insulating member when the battery cell is in thermal runaway, reduce the risk of the side wall or the first end wall being in conduction with the electrode terminal through the first tab, reduce the continuous heat production of the electrode terminal and the first end wall, reduce the thermal impact on the surrounding other battery cells, reduce the risk of the other battery cells being in thermal runaway, and improve the reliability

[0008] In some embodiments, the material of the first insulating member comprises a thermosetting material. The thermosetting material has excellent heat resistance and can maintain good stability at high temperatures without being easily softened, deformed or decomposed. When the battery cell is in thermal runaway, the internal pressure of the shell increases, and the first insulating member containing the thermosetting material is not easily softened at high temperatures, so that the deformation of the first insulating member under the internal pressure can be reduced, the risk of failure of the first insulating member can be reduced, and the insulation performance can be improved.

[0009] In some embodiments, the material of the first insulating member comprises one or more of thermosetting polyimide and derivatives thereof. The thermosetting polyimide has excellent heat resistance. When the battery cell is in thermal runaway, the first insulating member containing the thermosetting polyimide can maintain good performance stability in a high temperature environment, and the weight loss is small, thereby reducing the risk of insulation failure.

[0010] In some embodiments, the material of the first insulating member comprises one or more of bismaleimide, acetylene-terminated polyimide and norbornene dianhydride-terminated polyimide. The bismaleimide, acetylene-terminated polyimide and norbornene dianhydride-terminated polyimide have excellent high temperature resistance, high mechanical strength and strong chemical corrosion resistance.

[0011] In some embodiments, the first insulating member is fixed to at least one of the first end wall, the side wall, the electrode body and the first tab. Fixing the first insulating member to at least one of the first end wall, the side wall, the electrode body and the first tab can improve the stability of the first insulating member, reduce the displacement of the first insulating member in the shell when the battery cell is subjected to external impact, and reduce the risk of insulation failure.

[0012] In some embodiments, the battery cell further comprises an adhesive layer. The adhesive layer adheres the first insulating member to at least one of the first end wall, the side wall, the electrode body and the first tab. The adhesive layer can fix the first insulating member to reduce the risk of displacement of the first insulating member during use of the battery cell.

[0013] In some embodiments, the thickness of the first insulating member is greater than or equal to the thickness of the adhesive layer. The first insulating member can have a greater thickness than the adhesive layer to reduce the risk of the first insulating member being cracked or punctured and to improve insulation reliability.

[0014] In some embodiments, at least a portion of the first insulating member is located between the side wall and the first tab.

[0015] When the battery cell is in thermal runaway, the first insulating member is less likely to lose weight or loses less weight, which can separate the first tab from the side wall and reduce the risk of the electrode terminal being in conduction with the first end wall through the first tab and the side wall. Even if the electrode terminal and the first end wall are electrically connected to other battery cells or an external power source, the first insulating member can inhibit the current between the electrode terminal and the first end wall, reduce the continuous heat generation of the electrode terminal and the first end wall, reduce the thermal impact on the surrounding other battery cells, reduce the risk of thermal runaway of the other battery cells, and improve reliability.

[0016] In some embodiments, the first insulating member is arranged around the first tab to separate the outer peripheral surface of the first tab from the side wall and reduce the risk of the first tab being in conduction with the second tab through the side wall and improve reliability. When the battery cell is in thermal runaway, the first insulating member is less likely to lose weight or loses less weight, which can separate the first tab from the side wall and reduce the risk of the electrode terminal being in conduction with the first end wall through the first tab and the side wall.

[0017] In some embodiments, the first tab has a cylindrical structure, and the first insulating member has an angle of more than 360 degrees around the first tab to improve the insulation effect and reduce the risk of the outer peripheral surface of the first tab being exposed.

[0018] In some embodiments, the outer peripheral surface of the electrode body is closer to the side wall than the outer peripheral surface of the first tab, so that a space for accommodating at least a portion of the first insulating member is formed between the outer peripheral surface of the first tab and the side wall. The present application can reserve a larger space between the outer peripheral surface of the first tab and the side wall, so that the first insulating member can have a greater thickness, reducing the risk of failure of the first insulating member and improving reliability.

[0019] In some embodiments, the first insulating member protrudes from the first tab in a direction pointing to the first end wall, or the end of the first insulating member facing the first end wall is flush with the end of the first tab facing the first end wall. The first insulating member can separate the end of the first tab facing the first end wall from the side wall, thereby reducing the risk of short circuit. When the battery cell is in thermal runaway, the first insulating member can also reduce the risk of the first tab being in conduction with the first end wall.

[0020] In some embodiments, the battery cell further includes a first current collecting member including a tab connecting portion connected to the first tab and a terminal connecting portion connected to the electrode terminal, the tab connecting portion surrounding the terminal connecting portion. The first insulating member protrudes from the tab connecting portion in a direction of the electrode assembly pointing to the first end wall. The tab connecting portion is closer to the side wall than the terminal connecting portion. The first insulating member protruding from the tab connecting portion can separate the tab connecting portion from the side wall, thereby reducing the risk of short circuit. When the battery cell is in thermal runaway, the first insulating member is less likely to lose weight or loses less weight, thereby reducing the risk of the first current collecting member conducting the side wall and the electrode terminal.

[0021] In some embodiments, a portion of the first insulating member is located between the side wall and the electrode body.

[0022] When the battery cell is in thermal runaway, the separator can melt and fail. The embodiments of the present application provide a heat-resistant first insulating member between the side wall and the electrode body, which can reduce the risk of the residual portion of the electrode body conducting the side wall when in thermal runaway, thereby reducing the risk of the first end wall conducting the electrode terminal through the side wall, the residual portion of the electrode body, and the first tab, inhibiting current flow between the electrode terminal and the first end wall, reducing the sustained heat generation of the electrode terminal and the first end wall, reducing the thermal impact on other battery cells in the surrounding, reducing the risk of thermal runaway of other battery cells, and improving reliability.

[0023] In some embodiments, the first insulating member includes a first insulating portion and a second insulating portion connected to the first insulating portion, at least a portion of the first insulating portion being located between the side wall and the first tab, and at least a portion of the second insulating portion being located between the first end wall and the first tab.

[0024] When the battery cell is in thermal runaway, the first insulating member is less likely to lose weight or loses less weight at high temperature, the first insulating portion can separate the first tab from the side wall, and the second insulating portion can separate the first tab from the first end wall, thereby reducing the risk of the side wall conducting the electrode terminal through the first tab and the risk of the first end wall conducting the electrode terminal through the first tab; even if the electrode terminal and the first end wall are electrically connected to other battery cells or an external power source, the first insulating member can inhibit current flow between the electrode terminal and the first end wall, reduce the sustained heat generation of the electrode terminal and the first end wall, reduce the thermal impact on other battery cells in the surrounding, reduce the risk of thermal runaway of other battery cells, and improve reliability.

[0025] In some embodiments, the first insulation part is attached to the inner surface of the side wall, and the second insulation part is attached to the inner surface of the first end wall. The embodiments of the present application can improve the stability of the first insulation member, reduce the displacement of the first insulation part relative to the side wall and the displacement of the second insulation part relative to the side wall when the battery cell is in thermal runaway, improve the insulation effect, and reduce the risk of conduction of the first tab and the first end wall when the battery cell is in thermal runaway.

[0026] In some embodiments, the battery cell further comprises a second insulation member. At least part of the second insulation member surrounds the first tab and is located between the first insulation member and the first tab; and / or, at least part of the second insulation member surrounds the first tab and is located between the side wall and the first insulation member. By providing the first insulation member and the second insulation member, a double-layer insulation structure can be formed between the first tab and the side wall, thereby further improving the insulation effect and reducing the risk of conduction of the first tab and the side wall when the battery cell is in thermal runaway.

[0027] In some embodiments, at least part of the first insulation member is attached to the inner surface of the side wall. At least part of the second insulation member surrounds the first tab and is located between the first insulation member and the first tab. The second insulation member can separate the first tab from the first insulation member, thereby reducing the risk of the first insulation member being cracked or scratched by the first tab during use of the battery cell.

[0028] In some embodiments, the second insulation member has a smaller tensile modulus than the first insulation member. When the second insulation member is wrapped around the outside of the first tab, the second insulation member can stretch and tighten to gather and bind the first tab. The second insulation member has a smaller tensile modulus, which can release stress through tensile deformation and reduce the deformation of the first tab under the binding of the second insulation member. The first insulation member is attached to the side wall, which can have a larger tensile modulus. When the electrode assembly expands, the first insulation member can bind the side wall, reducing the deformation of the side wall and improving the shape of the battery cell.

[0029] In some embodiments, a portion of the second insulation member is arranged between the first tab and the first end wall. The second insulation member can isolate at least part of the first tab from the first end wall, thereby reducing the risk of contact between the first tab and the first end wall, and further reducing the risk of short circuit and improving reliability.

[0030] In some embodiments, the first insulation member has a higher thermal weight loss temperature than the second insulation member. When the battery cell is in thermal runaway, the second insulation member can soften and lose weight under the action of high temperature, thereby adhering to metal particles near the first tab, reducing the impact of the metal particles on the first insulation member, and reducing the risk of failure of the first insulation member.

[0031] In some embodiments, the battery cell further comprises a third insulating member disposed between the electrode body and the side wall. The third insulating member can separate the electrode body and the side wall to reduce the risk of short circuit.

[0032] In some embodiments, the third insulating member is fixed to the outer circumferential surface of the electrode body. The electrode body comprises a separator wound and arranged, and the third insulating member is connected to the outer surface of the separator. The third insulating member can protect the separator from the outside to reduce the risk of the separator being punctured. The third insulating member can also bind the separator to reduce the risk of the separator being scattered. The third insulating member can also constrain the electrode body from the outside to reduce the deformation of the electrode body due to swelling.

[0033] In some embodiments, the thermal weight loss temperature of the third insulating member is greater than or equal to 300℃. When the battery cell is in thermal runaway due to internal short circuit or other reasons, the battery cell may maintain a high temperature for a period of time. The thermal weight loss temperature of the third insulating member is greater than or equal to 300℃, which is not easy to lose weight or loses less weight when the battery cell is in thermal runaway, so that the third insulating member can remain in the shell and separate the residual part of the electrode body from the side wall, reduce the risk of the side wall being conducted through the residual part of the electrode body and the first tab and the electrode terminal, thereby inhibiting the current between the electrode terminal and the first end wall, reducing the continuous heat generation of the electrode terminal and the first end wall, reducing the thermal impact on other battery cells in the surrounding, reducing the risk of thermal runaway of other battery cells, and improving reliability.

[0034] In some embodiments, at least part of the first insulating member is disposed between the side wall and the third insulating member. By arranging the first insulating member and the third insulating member, a double-layer insulation structure can be formed between the electrode body and the side wall, thereby further improving the insulation effect and reducing the risk of the electrode body and the side wall being conducted when the battery cell is in thermal runaway.

[0035] In some embodiments, the first insulating member protrudes from the third insulating member in the direction of the electrode assembly pointing to the first end wall. The first insulating member protrudes from the third insulating member in the direction of the electrode assembly pointing to the first end wall. Both ends of the first insulating member protrude from the third insulating member, and the first insulating member can separate the part of the electrode assembly protruding from the third insulating member from the side wall to reduce the risk of the residual part of the electrode body contacting the side wall when the battery cell is in thermal runaway, thereby improving reliability.

[0036] In some embodiments, the first insulating member is located on one side of the third insulating member in the direction of the electrode assembly pointing to the first end wall. The embodiments of the present application utilize the first insulating member and the third insulating member to achieve insulation together, thereby saving the space and weight occupied by the first insulating member and improving the energy density of the battery cell.

[0037] In some embodiments, a first gap is provided between the first insulating member and the third insulating member in a direction of the electrode assembly pointing to the first end wall. During the operation of the battery cell, the electrode body will swell. By reserving the first gap between the first insulating member and the second insulating member, the risk of the first insulating member and the third insulating member being in contact and being pressed can be reduced when the electrode assembly swells and deforms, and thus the risk of the first insulating member cracking can be reduced, and the insulation reliability can be improved.

[0038] In some embodiments, the size D3 of the first gap in a direction of the electrode assembly pointing to the first end wall is 0.5mm-5mm.

[0039] In the embodiments of the present application, D3 is limited to be greater than or equal to 0.5mm to reduce the risk of the first insulating member and the second insulating member overlapping due to assembly errors. D3 is also limited to be greater than or equal to 0.5mm to reduce the risk of the first insulating member and the third insulating member being in contact and being pressed when the electrode assembly swells and deforms. D3 is limited to be less than or equal to 5mm to reduce the risk of the residual part of the electrode body being in contact with the side wall when the battery cell is in thermal runaway.

[0040] In some embodiments, the second tab is arranged at an end of the electrode assembly away from the first end wall, and at least part of the first insulating member is located between the side wall and the second tab. In a direction of the first end wall pointing to the electrode assembly, the first insulating member protrudes beyond the second tab, or the end of the first insulating member away from the first end wall is flush with the end of the second tab away from the first end wall. The embodiments of the present application can increase the insulation range of the first insulating member to isolate the residual part of the electrode assembly from the side wall after the battery cell is in thermal runaway, and reduce the risk of the residual part of the electrode assembly connecting the side wall to the electrode terminal.

[0041] In some embodiments, at least part of the first insulating member is located between the first end wall and the first tab.

[0042] When the battery cell is in thermal runaway, the first insulating member is less likely to lose weight or loses less weight at high temperature, and the first insulating member can isolate the first tab from the first end wall, thereby reducing the risk of the first end wall being connected to the electrode terminal through the first tab. Even if the electrode terminal and the first end wall are electrically connected to other battery cells or an external power source, the first insulating member can inhibit the current between the electrode terminal and the first end wall, reduce the continuous heat generation of the electrode terminal and the first end wall, reduce the thermal impact on the surrounding other battery cells, reduce the risk of the other battery cells being in thermal runaway, and improve the reliability.

[0043] In some embodiments, the battery cell further comprises a fourth insulating member, and at least part of the fourth insulating member is arranged between the first end wall and the first tab to isolate the first end wall from the first tab and reduce the risk of the first end wall being connected to the first tab, thereby improving the reliability.

[0044] In some embodiments, at least part of the first insulating member is disposed between the first end wall and the fourth insulating member; and / or, at least part of the first insulating member is disposed between the first tab and the fourth insulating member. By disposing the first insulating member and the fourth insulating member, a double-layer insulation structure can be formed between the first tab and the first end wall, thereby further improving the insulation effect and reducing the risk of the first tab and the first end wall being conducted when the battery cell is in thermal runaway.

[0045] In some embodiments, the battery cell further comprises a first current collecting member, the first current collecting member being located between the first end wall and the first tab, the first current collecting member connecting the electrode terminal and the first tab. A part of the first insulating member is disposed between the first current collecting member and the first end wall. When the battery cell is in thermal runaway, the first insulating member can separate the first current collecting member from the first end wall, thereby reducing the risk of the first end wall being conducted through the first current collecting member and the electrode terminal.

[0046] In some embodiments, the shell further comprises a second end wall, the second end wall being disposed opposite to the first end wall, the side wall connecting the first end wall and the second end wall. The second tab is disposed at one end of the electrode assembly facing the second end wall. By disposing the first tab and the second tab at opposite ends of the electrode assembly, the risk of the first tab and the second tab being in contact and short-circuited can be reduced, and more space can be provided for the first tab and the second tab, thereby improving the overcurrent capacity of the first tab and the second tab.

[0047] In some embodiments, the battery cell further comprises a pressure relief mechanism, the pressure relief mechanism being disposed at the second end wall. When the battery cell is in thermal runaway, the pressure relief mechanism can release the temperature and pressure inside the battery cell, thereby reducing the risk of explosion of the battery cell. After the pressure relief mechanism is actuated, the temperature of the shell gradually decreases, thereby shortening the time of the first insulating member in a high-temperature environment, reducing the weight loss of the first insulating member, and reducing the risk of failure of the first insulating member.

[0048] In some embodiments, in a direction from the first end wall to the second end wall, the minimum distance between the first insulating member and the second end wall is D1, and the total size of the electrode body is D2, 0≤D1 / D2≤0.25. When the battery cell is in thermal runaway, at least part of the second tab and a part of the electrode body close to the second end wall will be discharged to the outside of the shell via the pressure relief mechanism under the action of high temperature and high pressure. After the battery cell is relieved, a part of the electrode body close to the first end wall will remain in the shell. By limiting D1 / D2 to be less than or equal to 0.25, the first insulating member can separate the remaining part of the electrode body from the side wall when the battery cell is in thermal runaway, thereby reducing the risk of the remaining part of the electrode body conducting the first tab and the side wall, and improving the reliability.

[0049] In some embodiments, the pressure relief mechanism comprises a pressure relief portion and a weak portion arranged along the outer periphery of the pressure relief portion. The area of the region enclosed by the outer contour of the projection of the second end wall along the thickness direction of the second end wall is S1, and the area of the projection of the pressure relief portion in the thickness direction of the second end wall is S2. 0.1≤S2 / S1≤0.8.

[0050] Limiting S2 / S1 to be greater than or equal to 0.1 can form a larger pressure relief passage for the pressure relief mechanism when the battery cell is in thermal runaway, improve the discharge rate of the internal temperature and pressure of the battery cell, and reduce the risk of explosion of the battery cell. Limiting S2 / S1 to be greater than or equal to 0.1 can also shorten the time of the first insulating member in a high-temperature environment, reduce the weight loss of the first insulating member, reduce the risk of insulation failure, and improve the reliability of the battery cell. Limiting S2 / S1 to be less than or equal to 0.8 can limit the range of the weak portion, reduce the impact of arranging the weak portion on the strength of the second end wall, reduce the risk of the weak portion breaking during normal use of the battery cell, and improve the reliability of the battery cell.

[0051] In some embodiments, 0.3≤S2 / S1≤0.7, which can further improve the reliability of the battery cell.

[0052] In some embodiments, the battery cell is a cylindrical battery cell, and the first end wall and the second end wall are arranged opposite to each other along the axial direction of the cylindrical battery cell. The pressure relief mechanism comprises a pressure relief portion and a weak portion arranged along the outer periphery of the pressure relief portion, and the pressure relief portion is circular. The diameter φ1 of the pressure relief portion and the diameter φ2 of the cylindrical battery cell satisfy the following relationship: 0.35≤φ1 / φ2≤0.85.

[0053] Limiting φ1 / φ2 to be greater than or equal to 0.35 can form a larger pressure relief passage for the pressure relief mechanism when the battery cell is in thermal runaway, improve the discharge rate of the internal temperature and pressure of the battery cell, and reduce the risk of explosion of the battery cell. Limiting φ1 / φ2 to be greater than or equal to 0.35 can also shorten the time of the first insulating member in a high-temperature environment, reduce the weight loss of the first insulating member, reduce the risk of insulation failure, and improve the reliability of the battery cell. Limiting φ1 / φ2 to be less than or equal to 0.85 can limit the range of the weak portion, reduce the impact of arranging the weak portion on the strength of the second end wall, reduce the risk of the weak portion breaking during normal use of the battery cell, and improve the reliability of the battery cell.

[0054] In some embodiments, the thickness of the second end wall is less than the thickness of the first end wall. The first end wall is less deformed than the second end wall, thereby reducing the deformation or displacement of the first tab under the drag of the first end wall and the electrode terminal, reducing the risk of the first tab pressing the first insulating member, thereby reducing the risk of the first insulating member being crushed, improving the insulation effect, and improving the reliability of the battery cell. The second end wall is more likely to deform outwardly than the first end wall, which can increase the gas flow channel on the inner side of the second end wall and improve the gas discharge efficiency.

[0055] In some embodiments, the electrode assembly is provided with a first through hole. The first through hole is arranged between the electrode terminal and the pressure relief mechanism along the extension direction of the first through hole. When the battery cell is in thermal runaway, the gas between the electrode assembly and the first end wall can flow to the pressure relief mechanism through the first through hole, thereby reducing the pressure on the first end wall and the electrode terminal, reducing the deformation or displacement of the first tab under the drag of the electrode terminal, reducing the risk of the first tab pressing the first insulating member, thereby reducing the risk of the first insulating member being crushed, improving the insulation effect, and improving the reliability of the battery cell.

[0056] In some embodiments, the battery cell further comprises a second current collecting member. The second current collecting member connects the second end wall and the second tab, and the second end wall is electrically connected to the side wall; or the second current collecting member connects the side wall and the second tab.

[0057] In some embodiments, the battery cell further comprises a pressure relief mechanism arranged on the second end wall. At least part of the second current collecting member is located between the pressure relief mechanism and the second tab. When the battery cell is in thermal runaway, the high-temperature gas is discharged to the outside of the shell through the pressure relief channel formed by the pressure relief mechanism. At least part of the second current collecting member is opposite to the pressure relief mechanism, and the second current collecting member can be deformed or even melted under the action of the high-temperature gas when the battery cell is in thermal runaway, thereby reducing the risk of the second current collecting member conducting the residual part of the side wall and the electrode body, and improving the reliability of the battery cell.

[0058] In some embodiments, the shell comprises a shell and an end cover, the shell comprises an integrally formed first end wall and a side wall, and the end cover is a second end wall. The end cover is sealingly connected to the side wall. The first insulating member is arranged in a spaced manner with the end cover, so as to reduce the interference of the first insulating member with the connection of the end cover and the shell during the assembly of the shell and the end cover, improve the connection strength of the end cover and the shell, and reduce the risk of the first insulating member being crushed.

[0059] In some embodiments, the electrode terminal includes a terminal body and a first limiting portion, at least part of the terminal body is accommodated in the electrode lead-out hole, the first limiting portion is connected to the terminal body, at least part of the first limiting portion protrudes from the outer peripheral surface of the terminal body. The battery monomer also includes a sealing element, in the thickness direction of the first end wall, the first limiting portion is located on the inner side of the first end wall, and at least part of the sealing element is arranged between the first end wall and the first limiting portion. The thermal weight loss temperature of the sealing element is greater than or equal to 200℃.

[0060] The sealing element is less likely to lose weight or has less weight loss when the battery monomer is in thermal runaway, so that the sealing element can be kept between the first end wall and the electrode terminal, reducing the risk of direct contact between the electrode terminal and the first end wall.

[0061] In some embodiments, the electrode assembly includes a positive electrode sheet, the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, the positive electrode film layer includes a positive electrode active material, and the positive electrode active material includes at least one of a layered transition metal oxide and a modified compound thereof. The layered transition metal oxide has a chemical formula of Li a Ni b Co c M d O e A f , 0.8≤a≤1.2, 0.8≤b≤0.95, 0

[0062] Battery monomers with high nickel content have the advantages of high energy density, good low-temperature performance, and good charge-discharge performance. In addition, the thermal stability of battery monomers with high nickel content is relatively poor, and when it is in thermal runaway, the heat generated is more, and the temperature rise of the battery monomer is higher. The first insulating member with high temperature resistance is arranged in the shell in the embodiments of the application, and the first insulating member can withstand the high temperature generated when the high-nickel battery monomer is in thermal runaway, thereby reducing the risk of electrical connection between the first end wall and the first tab, suppressing the current between the electrode terminal and the first end wall, and reducing the continuous heat generation of the electrode terminal and the first end wall.

[0063] In some embodiments, the battery monomer also includes an electrolyte accommodated in the shell. The electrolyte includes a chain ester solvent, and the mass percentage content of the chain ester solvent in the electrolyte is 25.5wt% to 76.5wt%.

[0064] The mass percentage content of the chain ester solvent in the embodiments of the present application is greater than or equal to 25.5 wt%, so that the conductivity of the electrolyte is relatively high, which is beneficial to improving the liquid-phase transmission capacity of active ions, improving the rapid charging and discharging capacity of the battery cell, and thus improving the rate performance of the battery cell. The mass percentage content of the chain ester solvent is greater than or equal to 25.5 wt%, which can also make the viscosity of the electrolyte system relatively low, and it is easier to flow and infiltrate the electrode assembly, so as to improve the rapid charging and discharging capacity of the battery cell, and thus improve the rate performance of the battery cell.

[0065] The chain ester solvent may face decomposition and gas production problems during the cycle charging and discharging process of the battery cell. In the embodiments of the present application, the mass percentage content of the chain ester solvent is set to be less than or equal to 76.5 wt%, which can limit the internal pressure of the battery cell, reduce the deformation of the shell, reduce the risk of battery cell failure, and improve the reliability.

[0066] In some embodiments, the mass percentage content of the chain ester solvent in the electrolyte is 42.5 wt% to 70 wt%, which can further consider the rate performance and use reliability of the battery cell, and improve the cycle performance of the battery cell.

[0067] In some embodiments, the battery cell is a cylindrical battery cell, and the diameter of the cylindrical battery cell is greater than or equal to 35 mm and less than or equal to 70 mm. Setting the diameter of the cylindrical battery cell to be greater than or equal to 35 mm can improve the capacity and energy density of the cylindrical battery cell. The diameter of the cylindrical battery cell is related to the heat generation when the cylindrical battery cell is in thermal runaway, and the diameter of the cylindrical battery cell is set to be less than or equal to 70 mm to limit the maximum temperature of the cylindrical battery cell when it is in thermal runaway, and reduce the risk of failure of the first insulating member.

[0068] In a second aspect, the embodiments of the present application provide a battery device comprising a plurality of battery cells according to any one of the embodiments of the first aspect.

[0069] In some embodiments, at least two battery cells are connected in parallel. The plurality of battery cells of the battery device forms a multi-parallel and series connection structure. The multi-parallel and series connection structure can improve the reliability, and when a certain battery cell fails due to an accident, the battery cells connected in parallel with the battery cell can still work normally, reducing the risk of complete failure of the entire circuit. When a certain battery cell is in thermal runaway, the normal battery cells connected in parallel with the battery cell in thermal runaway may be respectively electrically connected to the first end wall and the electrode terminal of the battery cell in thermal runaway. The first insulating member can insulate the first tab from the first end wall, inhibit the current between the electrode terminal and the first end wall, reduce the continuous heat generation of the electrode terminal and the first end wall, reduce the thermal impact on the surrounding other battery cells, reduce the risk of thermal runaway of the other battery cells, and improve the reliability.

[0070] Thirdly, embodiments of this application provide an electrical device including a battery device provided in any of the embodiments of the second aspect, the battery device being used to provide electrical energy. Attached Figure Description

[0071] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0072] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0073] Figure 2 Schematic diagram of a battery device provided for some embodiments of this application;

[0074] Figure 3 for Figure 2 The diagram shows the structure of the battery module.

[0075] Figure 4 This is a schematic diagram of the structure of a single battery cell in some embodiments of this application;

[0076] Figure 5 for Figure 4 The diagram shows an exploded battery cell;

[0077] Figure 6 This is a cross-sectional schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application;

[0078] Figure 7 A schematic diagram of the positive electrode sheet of the electrode assembly of a battery cell provided in some embodiments of this application after being unfolded;

[0079] Figure 8 A schematic diagram of the negative electrode sheet of the electrode assembly of a battery cell provided in some embodiments of this application after being unfolded;

[0080] Figure 9 A cross-sectional schematic diagram of a battery cell provided in some embodiments of this application;

[0081] Figure 10 for Figure 9 An enlarged view of box A;

[0082] Figure 11 for Figure 10 Enlarged view of the area within the circle;

[0083] Figure 12 for Figure 9 Enlarged view of point B in the circle;

[0084] Figure 13 is a partial cross-sectional view of a battery cell according to some embodiments of the present application; Figure 9 is an enlarged schematic view at the circle;

[0085] Figure 14 is a partial cross-sectional view of a battery cell according to some embodiments of the present application;

[0086] Figure 15 Figure 14 is an enlarged schematic view at the circle;

[0087] Figure 16 is a partial cross-sectional view of a battery cell according to some embodiments of the present application;

[0088] Figure 17 is a partial cross-sectional view of a battery cell according to some embodiments of the present application; Figure 16 is an enlarged schematic view at the circle;

[0089] Figure 18 is a partial cross-sectional view of a battery cell according to some embodiments of the present application; Figure 16 is an enlarged schematic view at the circle;

[0090] Figure 19 is a schematic view of an electrode assembly, a first insulating member, and a third insulating member of a battery cell according to some embodiments of the present application;

[0091] Figure 20 is a partial cross-sectional view of a battery cell according to some embodiments of the present application;

[0092] Figure 21 is a schematic view of a first insulating member and an adhesive layer of a battery cell according to some embodiments of the present application;

[0093] Figure 22 is an exploded schematic view of a battery cell according to some embodiments of the present application;

[0094] Figure 23 is a simplified schematic view of a battery device according to some embodiments of the present application.

[0095] Explanation of reference numerals is as follows:

[0096] 1 vehicle; 2 battery device; 3 controller; 4 motor; 5 case; 5a first case; 5b second case; 6 battery module; 7 battery cell; 7a battery unit; 8 current-combining member;

[0097] 10, electrode assembly; 10a, first tab; 10b, second tab; 10c, electrode main body; 10d, first through-hole; 10e, first end surface; 10f, second end surface; 10g, outer peripheral surface of first tab; 10i, outer peripheral surface of electrode main body; 11, positive electrode sheet; 111, positive electrode current collector; 1111, positive electrode main body region; 1112, positive electrode blank region; 112, positive electrode film layer; 12, negative electrode sheet; 121, negative electrode current collector; 1211, negative electrode main body region; 1212, negative electrode blank region; 122, negative electrode film layer; 13, separator; 131, winding start end; 132, winding end end;

[0098] 20, housing; 20a, second end wall; 20b, accommodation cavity; 21, casing; 211, first end wall; 2111, electrode lead-out hole; 212, side wall; 2121, protrusion; 2122, second recess; 2123, crimping portion; 212a, first sub-wall; 212b, second sub-wall; 22, end cap;

[0099] 30, electrode terminal; 31, terminal main body; 311, second through-hole; 32, first limiting portion; 33, second limiting portion; 34, terminal recess;

[0100] 40, first insulating member; 40a, leading end; 40b, trailing end; 41, first insulating portion; 42, second insulating portion;

[0101] 50, second insulating member; 51, third insulating portion; 52, fourth insulating portion;

[0102] 60, third insulating member;

[0103] 70, pressure relief mechanism; 71, pressure relief portion; 72, weak portion; 73, first recess; 80, sealing member; 81, first current collecting member; 811, tab connecting portion; 811a, outer peripheral surface of tab connecting portion; 812, terminal connecting portion; 82, cover plate; 83, sealing peg; 84, second current collecting member; 85, fifth insulating member; 86, adhesive layer; 87, sixth insulating member; 88, electrode lead-out portion; 90, fourth insulating member;

[0104] G1, first gap; G2, second gap;

[0105] V, winding direction; Z, thickness direction. DETAILED DESCRIPTION

[0106] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0107] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0108] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiments, nor are they necessarily mutually exclusive or alternative embodiments to each other.

[0109] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium; it can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0110] In the present application, the term "and / or" 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 mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents a "or" relationship between the front and rear associated objects.

[0111] In the embodiments of the present 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 present application shown in the drawings, and the overall thickness, length and width of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0112] In this application, "multiple" means two or more (including two).

[0113] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0114] A battery device typically refers to a single physical module comprising multiple battery cells to provide higher voltage and capacity. A battery cell can be the smallest unit that makes up a battery device.

[0115] A battery cell typically includes a casing, an electrode assembly housed within the casing, and a positive and negative electrode lead disposed on the casing. The electrode assembly typically includes a positive tab and a negative tab, with the positive electrode lead electrically connected to the positive tab and the negative electrode lead electrically connected to the negative tab. The positive and negative electrode leads are used for electrical connection to an external circuit to enable charging or discharging of the battery cell.

[0116] In some embodiments, a single battery cell includes electrode terminals; one of the positive electrode lead and the negative electrode lead includes electrode terminals, and the other includes the shell wall of the outer casing.

[0117] When a battery cell in a battery pack experiences thermal runaway due to an accident (such as an internal short circuit), that cell may remain at a high temperature for a period of time. At this high temperature, the internal insulation components of the casing may fail, and the tabs (positive or negative) may simultaneously connect to both the casing and the electrode terminals. Since the tabs have low resistance, when the casing and electrode terminals are connected via the tabs, current from other battery cells or from an external power source may continuously flow between the electrode terminals and the casing, causing continuous localized heat generation in that battery cell. This can trigger abnormal temperature increases and thermal runaway in other normal battery cells, leading to heat propagation.

[0118] For example, when a conductive path is formed between the electrode terminals and the casing of the battery cell, a closed loop is formed between the battery cell and the battery cells connected in parallel with the battery cell, and current will continuously flow through the battery cell, causing the battery cell to generate heat locally.

[0119] In view of this, the present application provides a battery cell that, by providing an insulating component with a high thermal runaway temperature inside the casing, reduces the risk of the tab simultaneously conducting with the electrode terminals and the casing when the battery cell experiences thermal runaway, reduces the continuous heat generation of the thermally runaway battery cell, reduces the risk of thermal runaway in other battery cells, and improves reliability.

[0120] The battery cells described in this application are applicable to battery devices and electrical equipment using battery devices. Electrical equipment can be devices that use battery devices as a power source or various energy storage systems that use battery devices as energy storage elements. Electrical equipment can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0121] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0122] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0123] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0124] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0125] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0126] Figure 2 A schematic diagram of a battery device provided for some embodiments of this application.

[0127] In some embodiments, the battery device 2 may include one or more battery cell assemblies for providing voltage and capacity.

[0128] A battery cell assembly may include multiple battery cells ( Figure 2 (Not shown), multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0129] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0130] As an example, the battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium-metal battery cell, a sodium-metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0131] As an example, the battery cell can be a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, including a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, etc.

[0132] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module 6, which is formed by arranging and fixing a plurality of battery cells into one independent module. As an example, the battery module 6 can be formed by bundling a plurality of battery cells with a cable tie.

[0133] In some embodiments, the battery device 2 can be a battery pack, which includes a case 5 and one or more battery cell assemblies housed in the case 5. As an example, the battery cell assembly can be a battery module 6, which can be housed in the case by fixing the battery module 6 in the case. As an example, the battery cell assembly can also be housed in the case by fixing a plurality of battery cells directly in the case.

[0134] In some embodiments, the case 5 for housing the battery cells can be of various structures.

[0135] In some embodiments, the case 5 can include a first case 5a and a second case 5b. The first case 5a and the second case 5b are coupled so that an enclosed space is formed inside the case 5 to receive the battery cell assembly. The enclosed here means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0136] In some embodiments, the case 5 can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that an enclosed space is formed inside the case to receive the battery cell assembly. As an example, the frame can include a plurality of side beams.

[0137] In some embodiments, the case 5 can be part of the chassis structure of a vehicle. For example, part of the case 5 can be at least part of the floor of the vehicle, or part of the case 5 can be at least part of the cross beams and the longitudinal beams of the vehicle.

[0138] In some embodiments, the battery device 2 can be an energy storage device.

[0139] 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 electric energy as needed and output the electric energy at an appropriate time. For example, the energy storage device can store electric energy during a low electricity consumption period, and provide electric energy for relevant users or electric equipment during a high electricity consumption period.

[0140] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0141] Figure 3 For Figure 2 a structural diagram of a battery module.

[0142] In some embodiments, as Figure 3 shown, the battery monomer 7 is multiple, and the multiple battery monomers 7 are connected in series or in parallel or in a mixed manner to form a battery module 6. Multiple battery modules 6 are connected in series or in parallel or in a mixed manner to form a whole and are accommodated in a box.

[0143] The multiple battery monomers 7 in the battery module 6 can be electrically connected through a busbar component to realize parallel connection, series connection or mixed connection of the multiple battery monomers 7 in the battery module 6. The busbar component can be one or more, and each busbar component is used to electrically connect at least two battery monomers 7.

[0144] Figure 4 For a structural diagram of a battery monomer in some embodiments of the application; Figure 5 For Figure 4 an exploded schematic diagram of the battery monomer; Figure 6 For a cross-sectional schematic diagram of an electrode assembly of a battery monomer provided by some embodiments of the application; Figure 7 For a schematic diagram of an anode sheet of an electrode assembly of a battery monomer after unfolding provided by some embodiments of the application; Figure 8 For a schematic diagram of a cathode sheet of an electrode assembly of a battery monomer after unfolding provided by some embodiments of the application.

[0145] Referring Figures 4 to 8 , the embodiments of the application provide a battery monomer 7, which includes a shell 20 and an electrode assembly 10 accommodated in the shell 20.

[0146] In some embodiments, the shell 20 can be a steel shell, an aluminum shell or a composite metal shell (such as a copper-aluminum composite shell), etc.

[0147] The shell 20 can be a hollow structure, and an accommodation cavity 20b for accommodating the electrode assembly 10 and the electrolyte is formed inside.

[0148] In some embodiments, the shell 20 of the battery monomer 7 is a cylindrical shell, a square shell, a prismatic shell or a shell of other shapes.

[0149] In some embodiments, the housing 20 includes a shell 21 having an opening and an end cap 22 coupled to the shell 21 and covering the opening.

[0150] The shell 21 is a component for cooperating with the end cap 22 to form an internal cavity of the battery cell 7, which can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0151] The shell 21 and the end cap 22 can be separate components. For example, the shell 21 can be provided with an opening, and the end cap 22 can be coupled to the shell 21 by covering the opening to form the internal cavity of the battery cell 7.

[0152] The shell 21 can be in various shapes and sizes, such as a cuboid or a cylinder. In particular, 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.

[0153] The end cap 22 can be shaped to fit the shell 21. The material of the end cap 22 can be the same as or different from that of the shell 21. Optionally, the end cap 22 can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap 22 is less likely to deform when subjected to extrusion or impact, and the battery cell 7 can have higher structural strength and improved reliability.

[0154] The end cap 22 can be coupled to the shell 21 by welding, bonding, clamping, or other means.

[0155] The shell 21 can be open at one end or both ends. In some examples, the shell 21 can be open at one side, and the end cap 22 can be provided as one and cover the shell 21. In other examples, the shell 21 can be open at both ends, and the end cap 22 can be provided as two and cover the two openings of the shell 21, respectively.

[0156] The electrode assembly 10 is a component in which electrochemical reactions occur in the battery cell 7. The shell 21 can contain one or more electrode assemblies 10.

[0157] In some embodiments, the electrode assembly 10 includes a positive electrode sheet 11, a negative electrode sheet 12, and a separator 13, the positive electrode sheet 11 and the negative electrode sheet 12 being opposite in polarity, and the separator 13 separating the positive electrode sheet 11 and the negative electrode sheet 12.

[0158] At least a portion of the separator 13 is positioned between the positive electrode sheet 11 and the negative electrode sheet 12. During charging and discharging of the battery cell 7, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive electrode sheet 11 and the negative electrode sheet 12. The separator 13, which is provided between the positive electrode sheet 11 and the negative electrode sheet 12, can function to prevent short-circuiting between the positive and negative electrodes while allowing the active ions to pass therethrough.

[0159] In some embodiments, the positive electrode sheet 11 can include a positive electrode current collector 111 and a positive electrode film layer 112 provided on at least one surface of the positive electrode current collector 111.

[0160] As an example, the positive electrode current collector 111 has two surfaces opposite in the thickness direction thereof, and the positive electrode film layer 112 is provided on either one or both of the two opposite surfaces of the positive electrode current collector 111.

[0161] 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 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, 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, a silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0162] As an example, the positive electrode film 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 in combination of two or more. Examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., 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 (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to as NCM 333 ), LiNi 0.5 Co0.2 Mn 0.3 O2(also can be referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2), and modified compounds thereof. The modified compounds refer to substances obtained by modification means such as doping or coating on the basis of the above-mentioned substances.

[0163] In some embodiments, the negative electrode sheet 12 can include a negative electrode current collector 121.

[0164] As an example, the negative electrode current collector 121 can adopt 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, etc. can be adopted. 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, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0165] As an example, the negative electrode sheet 12 can include the negative electrode current collector 121 and a negative electrode film layer 122 provided on at least one surface of the negative electrode current collector 121.

[0166] As an example, the negative electrode current collector 121 has two surfaces opposite in the thickness direction thereof, and the negative electrode film layer 122 is provided on any one or both of the two opposite surfaces of the negative electrode current collector 121.

[0167] As an example, the negative electrode film layer 122 includes a negative electrode active material, which can employ a negative electrode active material for a battery cell as known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0168] In some embodiments, the material of the positive electrode current collector 111 can be aluminum, and the material of the negative electrode current collector 121 can be copper.

[0169] In some embodiments, the separator 13 includes a separator film. The separator film of the present application can employ any known porous structure film having good chemical stability and mechanical stability.

[0170] 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.

[0171] An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can be applied to the surface of the separator film.

[0172] The separator 13 can be a single 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.

[0173] In some embodiments, the separator 13 is a solid electrolyte. The solid electrolyte is provided between the positive electrode sheet 11 and the negative electrode sheet 12, and functions to transport ions and separate the positive electrode and the negative electrode.

[0174] In some embodiments, the battery cell 7 further includes an electrolyte, which functions to conduct ions between the positive electrode sheet 11 and the negative electrode sheet 12. The electrolyte of the present application can be selected as needed. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0175] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0176] 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 difluoro oxalato borate, lithium difluoro dioxalato borate, lithium difluoro dioxalato phosphonate, and lithium tetrafluoro oxalato phosphonate.

[0177] 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.

[0178] In some embodiments, the electrolyte solution 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 performance of the battery cell, such as an additive capable of improving overcharge / fast charge performance of the battery cell, an additive capable of improving high-temperature performance of the battery cell, an additive capable of improving low-temperature performance of the battery cell, etc.

[0179] In some embodiments, the gel-state electrolyte includes a polymer as a backbone network and can be used in combination with an ionic liquid-lithium salt.

[0180] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0181] As an example, the polymer of the polymer solid-state electrolyte can include a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid, cellulose, etc.

[0182] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfur, argyrodite), amorphous sulfide), and a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0183] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0184] In some embodiments, the electrode assembly 10 can be a wound structure, a stacked structure, or a hybrid structure of a wound and a stacked structure.

[0185] In some embodiments, the electrode assembly 10 is a wound structure. The positive electrode sheet 11 and the negative electrode sheet 12 are wound into the wound structure.

[0186] In some embodiments, the electrode assembly 10 is a stacked structure.

[0187] As an example, a plurality of positive electrode sheets 11 and a plurality of negative electrode sheets 12 can be alternately stacked. As an example, a plurality of positive electrode sheets 11 can be provided, and the negative electrode sheet 12 can be folded to form a plurality of folded segments which are stacked. One positive electrode sheet 11 can be interposed between adjacent folded segments.

[0188] As an example, the positive electrode sheet 11 and the negative electrode sheet 12 can be folded to form a plurality of folded segments which are stacked.

[0189] As an example, a plurality of separators 13 can be provided between any adjacent positive electrode sheets 11 or negative electrode sheets 12.

[0190] As an example, the separators 13 can be continuously provided between any adjacent positive electrode sheets 11 or negative electrode sheets 12 by folding or winding.

[0191] In some embodiments, the electrode assembly 10 can have a cylindrical shape, a flat shape, or a polygonal shape.

[0192] In some embodiments, the positive current collector 111 includes a positive main region 1111 and a positive blank region 1112. The positive main region 1111 is covered with the positive electrode film layer 112, and the positive blank region 1112 is not covered with the positive electrode film layer 112.

[0193] In some embodiments, the negative current collector 121 includes a negative main region 1211 and a negative blank region 1212. The negative main region 1211 is covered with the negative electrode film layer 122, and the negative blank region 1212 is not covered with the negative electrode film layer 122.

[0194] In some embodiments, the electrode assembly 10 includes an electrode main body 10c. As an example, the electrode main body 10c includes the positive electrode film layer 112, the positive main region 1111, the negative electrode film layer 122, the negative main region 1211, and the separators 13. At least a portion of the positive blank region 1112 protrudes outside the separators 13, and at least a portion of the negative blank region 1212 protrudes outside the separators 13.

[0195] In some embodiments, the electrode assembly 10 includes a first tab 10a and a second tab 10b drawn out from the electrode body 10c. One of the first tab 10a and the second tab 10b is a positive tab, and the other is a negative tab.

[0196] In some examples, a portion of the positive blank area 1112 protruding to the outside of the separator 13 constitutes a positive tab, and a portion of the negative blank area 1212 protruding to the outside of the separator 13 constitutes a negative tab.

[0197] The first tab 10a and the second tab 10b can be drawn out from the same end of the electrode body 10c, or can be drawn out from opposite ends of the electrode body 10c, respectively.

[0198] In some embodiments, the electrode assembly 10 is in a wound structure. The positive blank area 1112 is wound in multiple turns along the winding direction V. Optionally, the end portion of the positive blank area 1112 is bent by a kneading or smoothing process to form a positive tab. The positive tab has a multi-layer structure stacked in the winding axial direction of the electrode assembly 10. Optionally, the positive tab is in a cylindrical shape.

[0199] In some embodiments, the electrode assembly 10 is in a wound structure. The negative blank area 1212 is wound in multiple turns along the winding direction V. Optionally, the end portion of the negative blank area 1212 is bent by a kneading or smoothing process to form a negative tab. The negative tab has a multi-layer structure stacked in the winding axial direction of the electrode assembly 10. Optionally, the negative tab is in a cylindrical shape.

[0200] Figure 9 A cross-sectional view of a battery cell provided by some embodiments of the present application; Figure 10 A cross-sectional view of a battery cell provided by some embodiments of the present application; Figure 9 An enlarged view at the square frame A; Figure 11 An enlarged view at the square frame A; Figure 10 An enlarged view at the square frame A; Figure 12 An enlarged view at the square frame A; Figure 9 An enlarged view at the square frame A; Figure 13 An enlarged view at the square frame A; Figure 9 An enlarged view at the square frame A.

[0201] Referring to Figures 4 to 13The battery cell 7 includes an electrode assembly 10, a case 20, an electrode terminal 30, and a first insulating member 40. The case 20 includes a first end wall 211 provided with an electrode lead-out hole 2111 communicating with a receiving cavity 20b, and a side wall 212 connected to the first end wall 211. The electrode terminal 30 is provided in the electrode lead-out hole 2111. The electrode terminal 30 is insulated from the first end wall 211. The electrode assembly 10 is received in the receiving cavity 20b. The side wall 212 surrounds the electrode assembly 10. The electrode assembly 10 includes an electrode main body 10c, and a first tab 10a and a second tab 10b led out from the electrode main body 10c, the first tab 10a and the second tab 10b being opposite in polarity, the first tab 10a being provided at an end of the electrode assembly 10 toward the first end wall 211, the first tab 10a being electrically connected to the electrode terminal 30, and the second tab 10b being electrically connected to the first end wall 211 and the side wall 212. The first insulating member 40 has a thermal weight loss temperature greater than or equal to 300°C.

[0202] At least part of the first insulating member 40 is provided between the first end wall 211 and the first tab 10a, and / or at least part of the first insulating member 40 is provided between the side wall 212 and the first tab 10a.

[0203] As an example, the first end wall 211 can be an end cover 22, or a wall of the case 21.

[0204] As an example, at least part of the first insulating member 40 is provided between the first end wall 211 and the first tab 10a in a thickness direction Z of the first end wall 211. As an example, at least part of the first insulating member 40 is provided between the side wall 212 and the first tab 10a in a thickness direction of the side wall 212.

[0205] One of the first tab 10a and the second tab 10b is a positive tab, and the other is a negative tab. The polarity of the electrode terminal 30 corresponds to the polarity of the first tab 10a. In some examples, the first tab 10a is a positive tab, and the electrode terminal 30 is a positive terminal. In other examples, the first tab 10a is a negative tab, and the electrode terminal 30 is a negative terminal.

[0206] The second tab 10b can be provided at an end of the electrode assembly 10 toward the first end wall 211, or at an end of the electrode assembly 10 away from the first end wall 211.

[0207] In some examples, the electrode body 10c includes a first end surface 10e and a second end surface 10f oppositely arranged, the first end surface 10e is located at a side of the electrode body 10c facing the first end wall 211, and the second end surface 10f is located at a side of the electrode body 10c facing away from the first end wall 211. As an example, the two ends of the spacer 13 oppositely form the first end surface 10e and the second end surface 10f.

[0208] The first tab 10a protrudes from the first end surface 10e. Optionally, the second tab 10b protrudes from the first end surface 10e; alternatively, the second tab 10b protrudes from the second end surface 10f.

[0209] The first tab 10a can be directly connected to the electrode terminal 30, or indirectly connected to the electrode terminal 30 through other conductive structures.

[0210] In some examples, the second tab 10b can be directly connected to the first end wall 211, or indirectly connected to the first end wall 211 through other conductive structures.

[0211] In some examples, the second tab 10b can be directly connected to the side wall 212, or indirectly connected to the side wall 212 through other conductive structures.

[0212] In some examples, the second tab 10b can be electrically connected to the first end wall 211 through the side wall 212; in other examples, the second tab 10b can be electrically connected to the side wall 212 through the first end wall 211.

[0213] The electrode lead-out hole 2111 penetrates the first end wall 211. As an example, along the thickness direction Z of the first end wall 211, the electrode lead-out hole 2111 penetrates the first end wall 211, and the projection of the electrode terminal 30 at least partially overlaps the projection of the electrode lead-out hole 2111.

[0214] As an example, the electrode lead-out hole 2111 is a circular hole, a square hole, a racetrack-shaped hole, an oval hole, or a hole of other shapes.

[0215] In some examples, at least part of the electrode terminal 30 is located outside the first end wall 211 and covers the electrode lead-out hole 2111. Optionally, the electrode terminal 30 can be located outside the first end wall 211 as a whole; alternatively, the electrode terminal 30 is arranged in the electrode lead-out hole 2111, part of the electrode terminal 30 is located outside the first end wall 211, and part of the electrode terminal 30 is located inside the first end wall 211.

[0216] The side wall 212 is electrically connected to the first end wall 211.

[0217] In some examples, the side wall 212 and the first end wall 211 can be integrally formed. In other examples, the side wall 212 and the first end wall 211 can also be independently formed and connected as a whole by bonding, clamping, welding or other means.

[0218] In some examples, the battery cell 7 is a cylindrical battery cell, and the side wall 212 can be a cylindrical structure. In other examples, the battery cell 7 is a square battery cell, and the side wall 212 can be a square cylindrical structure.

[0219] For example, the thermal weight loss temperature of the first insulating member 40 can be 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃ or 1000℃.

[0220] For example, the thermal weight loss temperature of the first insulating member 40 can be a 5% thermal weight loss temperature; the 5% thermal weight loss temperature can be the temperature at which the mass of the test sample is lost by 5% relative to the initial mass in thermal gravimetric analysis. The thermal weight loss temperature of the first insulating member 40 can be measured according to GB / T 27761-2011 Thermal Gravimetric Analyzer Test Method for Weight Loss and Residual Quantity.

[0221] In some examples, at least part of the first insulating member 40 is arranged between the first end wall 211 and the first tab 10a. In other examples, at least part of the first insulating member 40 is arranged between the side wall 212 and the first tab 10a. In yet other examples, part of the first insulating member 40 is arranged between the first end wall 211 and the first tab 10a, and another part of the first insulating member 40 is arranged between the side wall 212 and the first tab 10a.

[0222] When the battery cell 7 is working normally, the first insulating member 40 can isolate the first tab 10a from the side wall 212 or isolate the first tab 10a from the first end wall 211, thereby reducing the risk of the first tab 10a being in conduction with the second tab 10b and improving reliability.

[0223] When the battery cell 7 is in thermal runaway due to internal short circuit or other reasons, the battery cell 7 can maintain a high temperature for a period of time. The thermal weight loss temperature of the first insulating member 40 is greater than or equal to 300°C, which is not easy to lose weight or loses less weight when the battery cell 7 is in thermal runaway, so that the first insulating member 40 can remain in the shell 20 and separate the first tab 10a from the first end wall 211 or separate the first tab 10a from the side wall 212, reducing the risk of the side wall 212 or the first end wall 211 being conducted with the electrode terminal 30 through the first tab 10a; Correspondingly, even if the electrode terminal 30 and the first end wall 211 are electrically connected to other battery cells 7 or external power sources, the first insulating member 40 can inhibit the current between the electrode terminal 30 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve the reliability.

[0224] Exemplarily, when the first end wall 211 and the electrode terminal 30 of the normal battery cell 7 are respectively electrically connected to the first end wall 211 and the electrode terminal 30 of the battery cell 7 in thermal runaway, the first insulating member 40 can reduce the risk of electrical conduction between the two battery cells 7, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211 of the battery cell 7 in thermal runaway, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve the reliability.

[0225] The first end wall 211 and the electrode terminal 30 can serve as two electrodes of the battery cell 7 and are located on the same side of the battery cell 7. When a plurality of battery cells 7 are assembled into a group, it is convenient to realize the connection of the bus member with the first end wall 211 or the connection of the bus member with the electrode terminal 30, and simplify the structure of the battery device.

[0226] In some embodiments, the thermal weight loss temperature of the first insulating member 40 is greater than or equal to 350°C, which can further reduce the weight loss rate of the first insulating member 40 when the battery cell 7 is in thermal runaway, reduce the risk of the side wall 212 or the first end wall 211 being conducted with the electrode terminal 30 through the first tab 10a, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve the reliability.

[0227] In some embodiments, the thermal weight loss temperature of the first insulating member 40 is greater than or equal to 500°C. This can further reduce the weight loss rate of the first insulating member 40 when the battery cell 7 is in thermal runaway, reduce the risk of the side wall 212 or the first end wall 211 being in conduction with the electrode terminal 30 through the first tab 10a, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of the other battery cells 7 being in thermal runaway, and improve the reliability.

[0228] In some embodiments, the thermal weight loss temperature of the first insulating member 40 is greater than or equal to 550°C.

[0229] In some embodiments, the material of the first insulating member 40 includes a thermosetting material.

[0230] The thermosetting material has excellent heat resistance and can maintain good stability at high temperatures without being easily softened, deformed, or decomposed. When the battery cell 7 is in thermal runaway, the internal pressure of the housing 20 increases, and the first insulating member 40 containing the thermosetting material is not easily softened at high temperatures. This can reduce the deformation of the first insulating member 40 under the internal pressure and reduce the risk of failure of the first insulating member 40, thereby improving the insulation performance.

[0231] In some embodiments, the thermosetting material can include at least one of thermosetting polyimide, thermosetting phenolic resin, or other high-temperature-resistant thermosetting materials.

[0232] In some embodiments, the material of the first insulating member 40 includes one or more of thermosetting polyimide and derivatives thereof.

[0233] For example, the derivative can refer to a product derived from the substitution of hydrogen atoms or atomic groups in a polymer with other atoms or atomic groups.

[0234] The thermosetting polyimide has excellent heat resistance. When the battery cell 7 is in thermal runaway, the first insulating member 40 containing the thermosetting polyimide can maintain good performance stability in a high-temperature environment, and is not easily lost or has less weight loss, thereby reducing the risk of insulation failure.

[0235] The thermosetting polyimide has high strength. When the battery cell 7 is in thermal runaway, the first insulating member 40 containing the thermosetting polyimide can withstand a large load and is not easily cracked under the internal pressure of the battery cell 7, thereby reducing the risk of insulation failure.

[0236] The thermosetting polyimide has low creep. During the long-term use of the battery cell 7, the first insulating member 40 containing the thermosetting polyimide has less creep, and the size and shape thereof can maintain good stability, thereby reducing the risk of insulation failure.

[0237] The thermosetting polyimide has good corrosion resistance. During use of the battery cell 7, the first insulating member 40 containing the thermosetting polyimide is less likely to be corroded by the electrolyte, thereby reducing the risk of insulation failure.

[0238] In some embodiments, the material of the first insulating member 40 includes one or more of bismaleimide, acetylene-terminated polyimide, and norbornene dianhydride-terminated polyimide.

[0239] The bismaleimide, acetylene-terminated polyimide, and norbornene dianhydride-terminated polyimide have excellent high-temperature resistance, high mechanical strength, and strong chemical corrosion resistance.

[0240] In some embodiments, the material of the first insulating member 40 includes polyimide-siloxane resin. Polyimide itself has high thermal stability, and the introduction of siloxane further enhances this property. Polyimide has high strength and modulus, and the addition of siloxane can adjust the mechanical properties of the material to some extent, making it have better toughness and impact resistance. At the same time, polyimide-siloxane resin also has high elongation at break, which makes the first insulating member 40 able to deform to some extent without breaking when subjected to external force, improving the reliability and service life of the first insulating member 40.

[0241] In some embodiments, the material of the first insulating member 40 includes cyanate resin modified polyimide. Cyanate resin itself has high heat resistance, and the generated triazine ring structure makes it stable at high temperatures. Polyimide is also a high-temperature resistant material, and after combining the two, the heat resistance of the modified material is further improved, and the thermal decomposition temperature is increased, which can still maintain good performance in a high-temperature environment. Polyimide has excellent strength and modulus, which can enhance the mechanical properties of cyanate resin. The modified material has high tensile strength, bending strength, and hardness, etc., while still maintaining good toughness and impact resistance, so it is not easy to be damaged when subjected to external force.

[0242] In some embodiments, the material of the first insulating member 40 includes thermosetting phenolic resin. Thermosetting phenolic resin has good heat resistance, dimensional stability, and corrosion resistance.

[0243] When the battery cell 7 is in thermal runaway, the first insulating member 40 containing thermosetting phenolic resin can maintain good performance stability in a high-temperature environment, and it is less likely to lose weight or lose weight, thereby reducing the risk of insulation failure. The three-dimensional network structure formed after the thermosetting phenolic resin is cured makes it have good dimensional stability, and during long-term use of the battery cell 7, the size and shape of the first insulating member 40 containing the thermosetting polyimide can maintain good stability, thereby reducing the risk of insulation failure.

[0244] In some embodiments, the first insulating member 40 is fixed to at least one of the first end wall 211, the side wall 212, the electrode body 10c, and the first tab 10a.

[0245] As an example, the first insulating member 40 can be fixed to at least one of the first end wall 211, the side wall 212, the electrode body 10c, and the first tab 10a by adhesion, crimping, or other means.

[0246] Fixing the first insulating member 40 to at least one of the first end wall 211, the side wall 212, the electrode body 10c, and the first tab 10a can improve the stability of the first insulating member 40, reduce the risk of insulation failure by reducing the displacement of the first insulating member 40 within the case 20 when the battery cell 7 is subjected to external impact.

[0247] In some embodiments, the first insulating member 40 includes an insulating coating.

[0248] In some embodiments, the first insulating member 40 is adhered to at least one of the first end wall 211, the side wall 212, the electrode body 10c, and the first tab 10a.

[0249] In some examples, the first insulating member 40 is adhered to the side wall 212. The first insulating member 40 can be directly adhered to the side wall 212, for example, an insulating material (e.g., a thermosetting material) having adhesion can be directly applied to the surface of the side wall 212, and the insulating material forms the first insulating member 40 after curing. The first insulating member 40 can be adhered to the side wall 212 by other materials, for example, a gel can be applied to the surface of the first insulating member 40, and then adhered to the side wall 212 through the gel, and the gel forms an adhesive layer after curing.

[0250] In some examples, the first insulating member 40 can be directly adhered to the first end wall 211, or can be adhered to the first end wall 211 through a gel.

[0251] In some examples, the first insulating member 40 can be directly adhered to the electrode body 10c, or can be adhered to the electrode body 10c through a gel.

[0252] In some examples, the first insulating member 40 can be directly adhered to the first tab 10a, or can be adhered to the first tab 10a through a gel.

[0253] In some embodiments, the first insulating member 40 is fixed to at least two of the first end wall 211, the side wall 212, the electrode body 10c, and the first tab 10a.

[0254] For example, the first insulating member 40 is fixed to the first end wall 211 and the side wall 212. Alternatively, the first insulating member 40 is bonded to the first end wall 211 and the side wall 212.

[0255] For example, the first insulating member 40 is fixed to the electrode body 10c and the first tab 10a. Alternatively, the first insulating member 40 is bonded to the electrode body 10c and the first tab 10a.

[0256] Bonding the first insulating member 40 to at least one of the first end wall 211, the side wall 212, the electrode body 10c and the first tab 10a can improve the stability of the first insulating member 40, reduce the displacement of the first insulating member 40 when the battery cell 7 is subjected to external impact, and reduce the risk of insulation failure.

[0257] In some embodiments, at least part of the first insulating member 40 is located between the side wall 212 and the first tab 10a.

[0258] The first insulating member 40 can be provided entirely between the side wall 212 and the first tab 10a, or can be provided only partially between the side wall 212 and the first tab 10a.

[0259] As an example, the first insulating member 40 can be fixed to the side wall 212, or can be fixed to the first tab 10a, or can be provided non-fixedly between the side wall 212 and the first tab 10a.

[0260] When the battery cell 7 is in thermal runaway, the first insulating member 40 is less likely to lose weight or loses less weight, which can separate the first tab 10a from the side wall 212, reducing the risk of the electrode terminal 30 being conducted through the first tab 10a and the side wall 212 to the first end wall 211; even if the electrode terminal 30 and the first end wall 211 are electrically connected to other battery cells 7 or an external power source, the first insulating member 40 can inhibit the current between the electrode terminal 30 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve reliability.

[0261] In some embodiments, the minimum distance between the first tab 10a and the side wall 212 is less than the minimum distance between the first tab 10a and the first end wall 211. The first tab 10a and the first end wall 211 can have a larger distance, thereby reserving installation space for other components. The first tab 10a and the side wall 212 can have a smaller distance, which can allow the first tab 10a to have a larger overcurrent area and improve overcurrent capacity. The first insulating member 40 can separate the first tab 10a from the side wall 212, thereby reducing the risk of short circuit caused by increasing the first tab 10a.

[0262] In some embodiments, the first insulating member 40 is arranged around the first tab 10a to isolate the outer circumferential surface 10g of the first tab from the side wall 212, reducing the risk of the first tab 10a being in conduction with the second tab 10b through the side wall 212, and improving reliability. When the battery cell 7 is in thermal runaway, the first insulating member 40 is less likely to be lost or has a smaller risk of being lost, which can isolate the first tab 10a from the side wall 212, reducing the risk of the electrode terminal 30 being in conduction with the first end wall 211 through the first tab 10a and the side wall 212.

[0263] In some embodiments, the first tab 10a has a cylindrical structure. For example, the battery cell 7 is a cylindrical battery cell, and the electrode body 10c has a cylindrical shape. The surface of the first tab 10a away from the electrode body 10c can be a circular ring surface.

[0264] In some embodiments, the first insulating member 40 can have an angle of wrap greater than or equal to 360°. The first insulating member 40 at least wraps around the first tab 10a once.

[0265] In some embodiments, the outer circumferential surface 10i of the electrode body is closer to the side wall 212 than the outer circumferential surface 10g of the first tab, so that a space for accommodating at least part of the first insulating member 40 is formed between the outer circumferential surface 10g of the first tab and the side wall 212.

[0266] Embodiments of the present application can reserve more space between the outer circumferential surface 10g of the first tab and the side wall 212, so that the first insulating member 40 can have a greater thickness, reducing the risk of failure of the first insulating member 40, and improving reliability.

[0267] In some embodiments, the outer circumferential surface 10i of the electrode body is a cylindrical surface, and the outer circumferential surface 10g of the first tab can be a cylindrical surface. The diameter of the outer circumferential surface 10i of the electrode body is greater than the diameter of the outer circumferential surface 10g of the first tab.

[0268] In some embodiments, the end of the first insulating member 40 towards the first end wall 211 is flush with the end of the first tab 10a towards the first end wall 211. The first insulating member 40 can isolate the end of the first tab 10a towards the first end wall 211 from the side wall 212, thereby reducing the risk of short circuit. When the battery cell 7 is in thermal runaway, the first insulating member 40 can also reduce the risk of the first tab 10a being in conduction with the first end wall 211.

[0269] In some embodiments, the first insulating member 40 protrudes from the first tab 10a in a direction pointing to the first end wall 211 along the electrode assembly 10, and can separate the first tab 10a from the side wall 212 toward the end of the first end wall 211, thereby reducing the risk of short circuit. The first insulating member 40 protruding from the first tab 10a can increase the insulating area, and when thermal runaway occurs, the first insulating member 40 can block metal particles, thereby reducing the risk of the metal particles passing over the first insulating member 40 and conducting the first tab 10a to the side wall 212.

[0270] In some embodiments, the battery cell 7 further includes a first current collecting member 81 connecting the first tab 10a and the electrode terminal 30.

[0271] In some embodiments, the first current collecting member 81 is located on a side of the first tab 10a facing the first end wall 211 and connected to the first tab 10a. The electrode terminal 30 abuts against a surface of the first current collecting member 81 facing the first end wall 211 and is connected. The first current collecting member 81 can act as an adapter to achieve electrical connection between the first tab 10a and the electrode terminal 30.

[0272] In some embodiments, the first current collecting member 81 includes a tab connecting portion 811 connected to the first tab 10a and a terminal connecting portion 812 connected to the electrode terminal 30, and the tab connecting portion 811 surrounds the terminal connecting portion 812.

[0273] As an example, the terminal connecting portion 812 can be a portion of the first current collecting member 81 abutting against the electrode terminal 30.

[0274] In some embodiments, the first insulating member 40 protrudes from the tab connecting portion 811 in a direction pointing to the first end wall 211 along the electrode assembly 10.

[0275] The tab connecting portion 811 is closer to the side wall 212 than the terminal connecting portion 812. The first insulating member 40 protruding from the tab connecting portion 811 can separate the tab connecting portion 811 from the side wall 212, thereby reducing the risk of short circuit. When the battery cell 7 is in thermal runaway, the first insulating member 40 is less likely to lose weight or loses less weight, thereby reducing the risk of the first current collecting member 81 conducting the side wall 212 and the electrode terminal 30.

[0276] In some embodiments, the first tab 10a is welded to the tab connecting portion 811, and the electrode terminal 30 is welded to the terminal connecting portion 812.

[0277] In some embodiments, the electrode terminal 30 is provided with a terminal recess 34. A bottom wall of the terminal recess 34 is welded to the terminal connecting portion 812.

[0278] The terminal recess 34 can be provided on the side of the electrode terminal 30 facing the first current collecting member 81, or on the side of the electrode terminal 30 facing away from the first current collecting member 81.

[0279] By providing the terminal recess 34, the thickness of the bottom wall of the terminal recess 34 can be reduced, the power required for welding the electrode terminal 30 and the terminal connecting portion 812 from the outside can be reduced, the risk of particles generated by welding falling into the case 20 can be reduced, and the reliability of the battery cell 7 can be improved.

[0280] In some embodiments, the side of the electrode terminal 30 facing away from the first current collecting member 81 is provided with the terminal recess 34.

[0281] In some embodiments, the side of the electrode terminal 30 facing the first current collecting member 81 is provided with one terminal recess 34, and the side of the electrode terminal 30 facing away from the first current collecting member 81 is provided with another terminal recess 34; the bottom surfaces of the two terminal recesses 34 are welded to the first current collecting member 81.

[0282] In some embodiments, the bottom wall of the terminal recess 34 is provided with a second through-hole 311, which can be used for injecting electrolyte.

[0283] In some embodiments, the battery cell 7 further includes a cover plate 82 connected to the electrode terminal 30 and used to separate the second through-hole 311 from the external space of the battery cell 7.

[0284] In some embodiments, at least part of the cover plate 82 is accommodated in the terminal recess 34.

[0285] In some embodiments, the first tab 10a is a positive tab, and the positive lead-out portion includes the cover plate 82 and the electrode terminal 30; alternatively, the first tab 10a is a negative tab, and the negative lead-out portion includes the cover plate 82 and the electrode terminal 30.

[0286] In some embodiments, the battery cell 7 further includes a sealing pin 83 inserted into and sealing the second through-hole 311.

[0287] In some embodiments, a portion of the first insulating member 40 is located between the side wall 212 and the electrode body 10c.

[0288] When the battery cell 7 is in thermal runaway, the separator 13 can melt and fail. In the embodiments of the present application, the first insulating member 40 is arranged between the side wall 212 and the electrode body 10c, which can reduce the risk of the residual part of the electrode body 10c being in conduction with the side wall 212 when the battery cell 7 is in thermal runaway, and further reduce the risk of the first end wall 211 being in conduction with the electrode terminal 30 through the side wall 212, the residual part of the electrode body 10c and the first tab 10a, inhibit the current between the electrode terminal 30 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of the other battery cells 7 being in thermal runaway, and improve the reliability.

[0289] In some embodiments, the second tab 10b is arranged at an end of the electrode assembly 10 away from the first end wall 211, and at least part of the first insulating member 40 is located between the side wall 212 and the second tab 10b. In the direction of the first end wall 211 pointing to the electrode assembly 10, the first insulating member 40 protrudes from the second tab 10b; or, the end of the first insulating member 40 away from the first end wall 211 is flush with the end of the second tab 10b away from the first end wall 211.

[0290] The embodiments of the present application can increase the insulation range of the first insulating member 40, so as to separate the residual part of the electrode assembly 10 from the side wall 212 after the battery cell 7 is in thermal runaway, and reduce the risk of the residual part of the electrode assembly 10 connecting the side wall 212 with the electrode terminal 30.

[0291] In some embodiments, the battery cell 7 further comprises a second insulating member 50. At least part of the second insulating member 50 is arranged between the first tab 10a and the side wall 212. The second insulating member 50 can insulate at least part of the first tab 10a from the side wall 212.

[0292] The second insulating member 50 can be arranged between the first tab 10a and the side wall 212 as a whole, or only partially arranged between the first tab 10a and the side wall 212. In some examples, part of the second insulating member 50 is further arranged between the first tab 10a and the first end wall 211.

[0293] The second insulating member 50 can be independently arranged between the first tab 10a and the side wall 212, or fixed to the first tab 10a or the side wall 212.

[0294] The thermal gravimetric temperature of the second insulating member 50 can be higher than, equal to, or lower than the thermal gravimetric temperature of the first insulating member 40.

[0295] The material of the second insulating member 50 can be the same as or different from the material of the first insulating member 40.

[0296] In some examples, the second insulating member 50 can be disposed along an outer periphery of the first tab 10a. For example, the second insulating member 50 can surround the first tab 10a at an angle greater than or equal to 180°.

[0297] In some embodiments, at least a portion of the second insulating member 50 surrounds the first tab 10a to increase an insulating area and improve an insulating effect.

[0298] In some embodiments, at least a portion of the second insulating member 50 surrounds the first tab 10a and is located between the first insulating member 40 and the first tab 10a. In other embodiments, at least a portion of the second insulating member 50 surrounds the first tab 10a and is located between the sidewall 212 and the first insulating member 40. In yet other embodiments, a portion of the second insulating member 50 surrounds the first tab 10a and is located between the first insulating member 40 and the first tab 10a, and a portion of the second insulating member 50 surrounds the first tab 10a and is located between the sidewall 212 and the first insulating member 40.

[0299] By disposing the first insulating member 40 and the second insulating member 50, a double-layer insulating structure can be formed between the first tab 10a and the sidewall 212, thereby further improving an insulating effect and reducing a risk of the first tab 10a and the sidewall 212 being electrically connected when the battery cell 7 is in thermal runaway.

[0300] In some embodiments, at least a portion of the first insulating member 40 is attached to an inner surface of the sidewall 212. For example, the first insulating member 40 can be bonded to the inner surface of the sidewall 212.

[0301] Attaching the first insulating member 40 to the inner surface of the sidewall 212 can improve stability of the first insulating member 40, reduce displacement of the first insulating member 40 relative to the sidewall 212 when the battery cell 7 is in thermal runaway, improve an insulating effect, and reduce a risk of the first tab 10a and the sidewall 212 being electrically connected when the battery cell 7 is in thermal runaway.

[0302] In addition, the sidewall 212 and the first insulating member 40 can be integrally provided during assembly of the battery cell 7, thereby simplifying an assembly process.

[0303] In some embodiments, at least a portion of the second insulating member 50 surrounds the first tab 10a and is located between the first insulating member 40 and the first tab 10a.

[0304] The second insulating member 50 can have a tensile modulus that is less than, greater than, or equal to a tensile modulus of the first insulating member 40.

[0305] The second insulating member 50 can separate the first tab 10a from the first insulating member 40, thereby reducing the risk of the first insulating member 40 being cracked or scratched by the first tab 10a during use of the battery cell 7.

[0306] In some embodiments, the second insulating member 50 has a tensile modulus less than that of the first insulating member 40.

[0307] By way of example, the tensile modulus of the second insulating member 50 and the tensile modulus of the first insulating member 40 can be measured in accordance with GBT 1040.1-2018 Determination of tensile properties of plastics - Part 1: General principles.

[0308] When the second insulating member 50 is wrapped around the outside of the first tab 10a, the second insulating member 50 can be stretched to tighten and bind the first tab 10a. The second insulating member 50 has a small tensile modulus, which can release stress through tensile deformation, reducing excessive deformation of the first tab 10a under the binding of the second insulating member 50. The first insulating member 40 is attached to the side wall 212, which can have a large tensile modulus. When the electrode assembly 10 expands, the first insulating member 40 can bind the side wall 212, reducing the deformation of the side wall 212 and improving the shape of the battery cell 7.

[0309] In some embodiments, the first tab 10a is cylindrical. The wrapping angle of the second insulating member 50 around the first tab 10a is greater than or equal to 360°. Optionally, the wrapping angle of the second insulating member 50 is greater than 360°.

[0310] In some embodiments, the second insulating member 50 can be bonded to the outer circumferential surface 10g of the first tab 10a.

[0311] In some embodiments, a portion of the second insulating member 50 is disposed between the first tab 10a and the first end wall 211.

[0312] The second insulating member 50 can isolate at least part of the first tab 10a from the first end wall 211, thereby reducing the risk of the first tab 10a contacting the first end wall 211, and in turn reducing the risk of short circuit and improving reliability.

[0313] In some embodiments, the second insulating member 50 includes a third insulating portion 51 and a fourth insulating portion 52, the fourth insulating portion 52 being connected to the third insulating portion 51. At least part of the third insulating portion 51 is disposed between the side wall 212 and the first tab 10a, and at least part of the fourth insulating portion 52 is disposed between the first end wall 211 and the first tab 10a.

[0314] In some embodiments, the fourth insulating portion 52 is connected to one end of the third insulating portion 51 towards the first end wall 211 and is bent relative to the third insulating portion 51.

[0315] In some embodiments, a portion of the third insulating portion 51 is located between the sidewall 212 and the electrode body 10c.

[0316] In some embodiments, at least a portion of the tab connecting portion 811 is located between the fourth insulating portion 52 and the first tab 10a. The fourth insulating portion 52 can separate at least a portion of the tab connecting portion 811 from the first end wall 211 to reduce the risk of short circuit.

[0317] In some embodiments, the fourth insulating portion 52 is bonded to the tab connecting portion 811.

[0318] In some embodiments, the third insulating portion 51 can be a cylindrical structure. The fourth insulating portion 52 can be a circular ring structure. As an example, the second insulating member 50 can independently be sleeved on the first tab 10a without the need for the first tab 10a to be bonded.

[0319] In some embodiments, the thermal weight loss temperature of the first insulating member 40 is greater than the thermal weight loss temperature of the second insulating member 50.

[0320] When the battery cell 7 is in thermal runaway, the second insulating member 50 can soften and lose weight under the action of high temperature, thereby adhering to the metal particles near the first tab 10a, reducing the impact of the metal particles on the first insulating member 40, and reducing the risk of failure of the first insulating member 40.

[0321] In some embodiments, the material of the second insulating member 50 includes a thermoplastic material.

[0322] The thermoplastic material has the advantages of easy molding, good flexibility, high chemical stability, excellent electrical insulation, etc. The second insulating member 50 containing the thermoplastic material is easy to mold, and its shape can be adapted to the first tab 10a. The second insulating member 50 containing the thermoplastic material can deform to a certain extent when subjected to external force without being easily broken, has good toughness and impact resistance, and improves the insulation effect.

[0323] In some embodiments, the battery cell 7 further includes a third insulating member 60, which is arranged between the electrode body 10c and the sidewall 212.

[0324] The thermal weight loss temperature of the third insulating member 60 can be higher than, equal to, or lower than the thermal weight loss temperature of the first insulating member 40.

[0325] The material of the third insulating member 60 can be the same as or different from the material of the first insulating member 40.

[0326] The third insulating member 60 can be provided entirely between the electrode body 10c and the side wall 212. Alternatively, a part of the third insulating member 60 can be provided between the electrode body 10c and the side wall 212.

[0327] The third insulating member 60 can overlap the first insulating member 40 in the thickness direction of the third insulating member 60, or can not overlap the first insulating member 40.

[0328] The third insulating member 60 can separate the electrode body 10c from the side wall 212 to reduce the risk of short circuit.

[0329] For example, metal particles can remain inside the case 20 due to a process during the production of the battery cell 7, and the metal particles can pierce the separator 13 of the electrode body 10c, causing a risk of short circuit. The third insulating member 60 can separate the electrode body 10c from the side wall 212 to reduce the risk of short circuit.

[0330] In some embodiments, the third insulating member 60 is provided along the outer periphery of the electrode body 10c. Optionally, the third insulating member 60 surrounds the electrode body 10c at an angle of greater than or equal to 90°.

[0331] In some embodiments, the third insulating member 60 is fixed to the outer peripheral surface 10i of the electrode body to reduce the risk of displacement of the third insulating member 60 and improve the stability of the third insulating member 60 when the battery cell 7 is subjected to external impact.

[0332] As an example, the third insulating member 60 is bonded to the outer peripheral surface 10i of the electrode body.

[0333] In some embodiments, the electrode body 10c includes a separator 13 wound in a roll shape, and the third insulating member 60 is connected to the outer surface of the separator 13.

[0334] The third insulating member 60 can protect the separator 13 from the outside to reduce the risk of the separator 13 being pierced. The third insulating member 60 can also bind the separator 13 to reduce the risk of the separator 13 spreading apart.

[0335] The third insulating member 60 can also constrain the electrode body 10c from the outside to reduce the swelling deformation of the electrode body 10c.

[0336] In some embodiments, the separator 13 has a winding start end 131 and a winding end 132. The third insulating member 60 extends continuously in the winding direction V, and a part of the third insulating member 60 is located on one side of the winding end 132, and a part of the third insulating member 60 is located on the other side of the winding end 132. The third insulating member 60 can cover the winding end 132 of the separator 13 to reduce the risk of the separator 13 spreading apart.

[0337] In some embodiments, the thermal weight loss temperature of the third insulating member 60 is greater than or equal to 300°C.

[0338] For example, the thermal weight loss temperature of the third insulating member 60 can be 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, or 1000°C.

[0339] For example, the thermal weight loss temperature of the third insulating member 60 can be a 5% thermal weight loss temperature; the 5% thermal weight loss temperature can be the temperature at which the mass of the test sample is lost by 5% relative to the initial mass in the thermal gravimetric analysis. The thermal weight loss temperature of the third insulating member 60 can be measured according to GB / T 27761-2011 Thermal Gravimetric Analyzer Test Method for Weight Loss and Residual Quantity.

[0340] When the battery cell 7 is in thermal runaway due to internal short circuit or other reasons, the battery cell 7 can maintain a high temperature state for a period of time. The thermal weight loss temperature of the third insulating member 60 is greater than or equal to 300°C, which is not easy to lose weight or loses less weight when the battery cell 7 is in thermal runaway, so that the third insulating member 60 can remain between the outer shell 20 and the side wall 212, and separate the residual part of the electrode body 10c from the side wall 212, reduce the risk of the side wall 212 being conducted through the residual part of the electrode body 10c and the first tab 10a to the electrode terminal 30, thereby inhibiting the current between the electrode terminal 30 and the first end wall 211, reducing the continuous heat generation of the electrode terminal 30 and the first end wall 211, reducing the thermal impact on other battery cells 7 around, reducing the risk of thermal runaway of other battery cells 7, and improving reliability.

[0341] In some embodiments, at least part of the first insulating member 40 is arranged between the side wall 212 and the third insulating member 60.

[0342] By arranging the first insulating member 40 and the third insulating member 60, a double-layer insulation structure can be formed between the electrode body 10c and the side wall 212, thereby further improving the insulation effect and reducing the risk of conduction between the electrode body 10c and the side wall 212 when the battery cell 7 is in thermal runaway.

[0343] For example, since the first insulating member 40 has high heat resistance, the third insulating member 60 can also be selected to have a lower thermal weight loss temperature.

[0344] In some embodiments, the first insulating member 40 protrudes from the third insulating member 60 in a direction of the electrode assembly 10 pointing to the first end wall 211. The first insulating member 40 protrudes from the third insulating member 60 in a direction of the electrode assembly 10 pointing to the first end wall 211.

[0345] Both ends of the first insulating member 40 protrude from the third insulating member 60, and the first insulating member 40 can separate the portion of the electrode assembly 10 protruding from the third insulating member 60 from the side wall 212, to reduce the risk of the remaining portion of the electrode body 10c contacting the side wall 212 when the battery cell 7 is thermally runaway, and improve reliability.

[0346] In some embodiments, the electrode body 10c protrudes from the third insulating member 60, and the first insulating member 40 protrudes from the electrode body 10c in the direction of the electrode assembly 10 pointing to the first end wall 211. The first end surface 10e of the electrode body 10c is spaced apart from the third insulating member 60.

[0347] In some embodiments, the electrode body 10c protrudes from the third insulating member 60, and the first insulating member 40 protrudes from the electrode body 10c in the direction of the electrode assembly 10 pointing to the first end wall 211. The second end surface 10f of the electrode body 10c is spaced apart from the third insulating member 60.

[0348] In some embodiments, the second insulating member 50 is located on one side of the third insulating member 60 in the direction of the electrode assembly 10 pointing to the first end wall 211.

[0349] In some embodiments, a second gap G2 is provided between the second insulating member 50 and the third insulating member 60 in the direction of the electrode assembly 10 pointing to the first end wall 211, which can reduce the risk of the second insulating member 50 and the third insulating member 60 overlapping. The electrode assembly 10 can swell during operation, and if the third insulating member 60 and the second insulating member 50 overlap in the radial direction of the battery cell 7, it can cause local stress concentration and affect the cycle performance of the electrode assembly 10.

[0350] In some embodiments, the size D4 of the second gap G2 in the direction of the electrode assembly 10 pointing to the first end wall 211 is 0.5mm-10mm.

[0351] Optionally, the size D4 of the second gap G2 in the direction of the electrode assembly 10 pointing to the first end wall 211 is 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm.

[0352] In some embodiments, the first insulating member 40 covers the second gap G2 from the outside to separate the side wall 212 from the electrode body 10c.

[0353] In some embodiments, the housing 20 further comprises a second end wall 20a, which is opposite to the first end wall 211, and the side wall 212 connects the first end wall 211 and the second end wall 20a.

[0354] In some examples, one of the second end wall 20a and the first end wall 211 is integrally formed with the side wall 212, and the other is independently formed with the side wall 212.

[0355] For example, the side wall 212 and the second end wall 20a can be independently formed and connected as a whole by bonding, clamping, welding or other means. The side wall 212 and the second end wall 20a can be electrically connected or insulated.

[0356] In some embodiments, the second tab 10b is arranged at one end of the electrode assembly 10 towards the second end wall 20a. For example, the second tab 10b protrudes from the second end surface 10f of the electrode body 10c.

[0357] Arranging the first tab 10a and the second tab 10b at opposite ends of the electrode assembly 10 can reduce the risk of short circuiting of the first tab 10a and the second tab 10b, and provide more space for the first tab 10a and the second tab 10b, thereby improving the overcurrent capacity of the first tab 10a and the second tab 10b.

[0358] In some embodiments, the battery cell 7 further comprises a pressure relief mechanism 70 arranged in the housing 20.

[0359] The pressure relief mechanism 70 can be arranged in the first end wall 211, the side wall 212 or the second end wall 20a.

[0360] For example, the pressure relief mechanism 70 is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 7 reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 7 reaches the predetermined threshold, the pressure relief mechanism performs an action or a weak structure provided in the pressure relief mechanism is broken, thereby forming an opening or a passage for the internal pressure or temperature to be released. The threshold value is designed differently according to design requirements. The threshold value can depend on the material of one or more of the positive plate, the negative plate, the electrolyte and the separator film in the battery cell.

[0361] "Actuation" as referred to in the present application means that the pressure relief mechanism is activated or actuated to a certain state, so that the internal pressure and temperature of the battery cell can be released. The actuation of the pressure relief mechanism can include, but is not limited to, movement of a component in the pressure relief mechanism to form an exhaust passage, at least a portion of the pressure relief mechanism rupturing, breaking, tearing or opening, etc. When the pressure relief mechanism is actuated, the high temperature and pressure material inside the battery cell is discharged as exhaust from the actuated part. In this way, the battery cell can be depressurized and cooled at a controllable pressure or temperature, so as to avoid a potentially more serious accident.

[0362] When the battery cell 7 is in thermal runaway, the pressure relief mechanism 70 can release the temperature and pressure inside the battery cell 7, so as to reduce the risk of explosion of the battery cell 7.

[0363] After the pressure relief mechanism 70 is actuated, the temperature of the outer shell 20 gradually decreases, so as to shorten the time of the first insulating member 40 in a high temperature environment, reduce the weight loss of the first insulating member 40, and reduce the risk of failure of the first insulating member 40.

[0364] In some embodiments, the pressure relief mechanism 70 is arranged at the second end wall 20a.

[0365] When the battery cell 7 is in thermal runaway, high temperature substances (such as high temperature gas, particles, debris, etc.) can be released outward through the pressure relief passage formed by the pressure relief mechanism 70. Arranging the pressure relief mechanism 70 at the second end wall 20a can reduce the thermal shock received by the first insulating member 40, and reduce the risk of deformation and failure of the first insulating member 40.

[0366] In the process of releasing high temperature gas, the high temperature gas can conduct part of the heat to the second end wall 20a. The second end wall 20a is far away from the first tab 10a, so as to reduce the heat conducted to the part of the first insulating member 40 close to the first tab 10a, and further reduce the thermal weight loss of the first insulating member 40, improve the insulation effect, and improve the reliability of the battery cell 7.

[0367] Arranging the pressure relief mechanism 70 at the second end wall 20a can also reduce the high temperature particles sputtered near the electrode terminal 30, and reduce the risk of insulation failure between the first end wall 211 and the electrode terminal 30.

[0368] In some embodiments, the pressure relief mechanism 70 includes a pressure relief part 71 and a weak part 72 arranged along the outer periphery of the pressure relief part 71.

[0369] The weak part 72 is a part that ruptures, breaks, tears or opens. For example, the strength of the pressure relief mechanism 70 is less than the strength of the part of the pressure relief mechanism 70 close to the weak part 72.

[0370] In some examples, a groove, a notch, a through hole or other structure can be formed in a predetermined region of the pressure relief mechanism 70 to reduce the strength of the pressure relief mechanism 70 in the region, thereby forming the weak portion 72. For example, a thinning process can be performed on the predetermined region of the pressure relief mechanism 70, and the thinned portion of the pressure relief mechanism 70 forms the weak portion 72. In other examples, a material treatment can be performed on the predetermined region of the pressure relief mechanism 70 so that the strength of the region is weaker than that of other regions, in other words, the region is the weak portion 72.

[0371] The weak portion 72 can be ruptured when the internal pressure or temperature of the battery cell 7 reaches a threshold value; the pressure relief portion 71 can be a portion of the pressure relief mechanism 70 that forms a pressure relief passage when the weak portion 72 is ruptured.

[0372] In some examples, the weak portion 72 can surround the pressure relief portion 71. When the battery cell 7 is in thermal runaway, the weak portion 72 is at least partially ruptured; for example, the weak portion 72 is completely ruptured, and the pressure relief portion 71 is separated from the shell 20 to form a pressure relief passage; for example, the weak portion 72 is partially ruptured, and the pressure relief portion 71 is outwardly flipped under the internal pressure of the battery cell 7 to form a pressure relief passage.

[0373] In other examples, the weak portion 72 can also partially surround the pressure relief portion 71. The weak portion 72 and the line connecting the two ends of the weak portion 72 together define the pressure relief portion 71. When the battery cell 7 is in thermal runaway, the weak portion 72 is ruptured, and the pressure relief portion 71 can be outwardly flipped about the line connecting the two ends of the weak portion 72 under the internal pressure of the battery cell 7 to form a pressure relief passage. Optionally, the line connecting one end of the weak portion 72 to the center of the pressure relief portion 71 is L1, the line connecting the other end of the weak portion 72 to the center of the pressure relief portion 71 is L2, the angle α between L1 and L2 is greater than or equal to 180°, and the angle α is opposite to the weak portion 72. Optionally, the angle α is greater than or equal to 270°.

[0374] In some embodiments, the area of the pressure relief portion 71 is greater than the area of the electrode lead-out hole 2111.

[0375] For example, the area of the electrode lead-out hole 2111 can be the area of the smallest cross section of the electrode lead-out hole 2111 perpendicular to the axial direction of the electrode lead-out hole 2111. The area of the pressure relief portion 71 can be the area of the smallest cross section of the pressure relief portion 71 perpendicular to the thickness direction of the pressure relief portion 71.

[0376] Compared with the electrode lead-out hole 2111, the pressure relief portion 71 can have a larger area, so that the internal temperature and pressure of the battery cell 7 can be quickly released when the battery cell 7 is in thermal runaway. Compared with the pressure relief portion 71, the electrode lead-out hole 2111 can have a smaller area, so that the influence of the electrode lead-out hole 2111 on the strength of the first end wall 211 can be reduced, and the deformation of the portion of the first end wall 211 close to the electrode lead-out hole 2111 can be reduced.

[0377] In some embodiments, the pressure relief portion 71 is circular, and a diameter φ1 of the pressure relief portion 71 satisfies: 20 mm ≤ φ1 ≤ 35 mm. Optionally, 22 mm ≤ φ1 ≤ 32 mm.

[0378] In some embodiments, the electrode lead-out hole 2111 is a circular hole, and a diameter φ3 of the electrode lead-out hole 2111 satisfies: 8 mm ≤ φ3 ≤ 25 mm. Optionally, 10 mm ≤ φ3 ≤ 20 mm.

[0379] In some embodiments, an area of a region surrounded by an outer contour of a projection of the second end wall 20a along a thickness direction of the second end wall 20a is S1, and an area of a projection of the pressure relief portion 71 in the thickness direction of the second end wall 20a is S2. 0.1 ≤ S2 / S1 ≤ 0.8.

[0380] For example, S2 / S1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8.

[0381] In the embodiments of the present application, by limiting S2 / S1 to be greater than or equal to 0.1, a larger pressure relief channel can be formed by the pressure relief mechanism 70 when the battery cell 7 is in thermal runaway, the release rate of the internal temperature and pressure of the battery cell 7 can be improved, and the risk of explosion of the battery cell 7 can be reduced. By limiting S2 / S1 to be greater than or equal to 0.1, the time of the first insulating member 40 in a high-temperature environment can be shortened, the weight loss of the first insulating member 40 can be reduced, the risk of insulation failure can be reduced, and the reliability of the battery cell 7 can be improved.

[0382] By limiting S2 / S1 to be less than or equal to 0.8, the range of the weak portion 72 can be limited, the influence of the weak portion 72 on the strength of the second end wall 20a can be reduced, the risk of the weak portion 72 being broken during normal use of the battery cell 7 can be reduced, and the reliability of the battery cell 7 can be improved.

[0383] In some embodiments, 0.3 ≤ S2 / S1 ≤ 0.7, which can further improve the reliability of the battery cell 7.

[0384] In some embodiments, the pressure relief mechanism 70 is formed integrally with the second end wall 20a. For example, the second end wall 20a is provided with a first recess 73, and the weak portion 72 includes a bottom wall of the first recess 73. The first recess 73 is arranged around the pressure relief portion 71.

[0385] In some embodiments, the battery cell 7 is a cylindrical battery cell. The cylindrical battery cell has advantages of mature production process, good consistency, good heat dissipation performance, high group efficiency, etc.

[0386] In some examples, at least part of the first insulating member 40 is arranged between the first tab 10a and the first end wall 211 in the axial direction of the cylindrical battery cell. As an example, the thickness direction Z of the first end wall is parallel to the axial direction of the cylindrical battery cell.

[0387] In some examples, at least part of the first insulating member 40 is arranged between the first tab 10a and the side wall 212 in the radial direction of the cylindrical battery cell.

[0388] In some embodiments, the first end wall 211 and the second end wall 20a are oppositely arranged along the axial direction of the cylindrical battery cell. The pressure relief mechanism 70 includes a pressure relief portion 71 and a weak portion 72 arranged along the outer periphery of the pressure relief portion 71, and the pressure relief portion 71 is circular. The diameter φ1 of the pressure relief portion 71 and the diameter φ2 of the cylindrical battery cell satisfy the following relationship: 0.35 ≤ φ1 / φ2 ≤ 0.85.

[0389] As an example, φ1 / φ2 can be 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, or 0.85.

[0390] In the embodiments of the present application, by limiting φ1 / φ2 to be greater than or equal to 0.35, when the battery cell 7 is in thermal runaway, the pressure relief mechanism 70 can form a larger pressure relief channel, thereby improving the discharge rate of the internal temperature and pressure of the battery cell 7 and reducing the risk of explosion of the battery cell 7. By limiting φ1 / φ2 to be greater than or equal to 0.35, the time of the first insulating member 40 in a high-temperature environment can be shortened, the weight loss of the first insulating member 40 can be reduced, the risk of insulation failure can be reduced, and the reliability of the battery cell 7 can be improved.

[0391] By limiting φ1 / φ2 to be less than or equal to 0.85, the range of the weak portion 72 can be limited, the influence of arranging the weak portion 72 on the strength of the second end wall 20a can be reduced, the risk of the weak portion 72 breaking during normal use of the battery cell 7 can be reduced, and the reliability of the battery cell 7 can be improved.

[0392] In some embodiments, the battery cell 7 is a cylindrical battery cell, and the diameter φ2 of the cylindrical battery cell is greater than or equal to 35 mm and less than or equal to 70 mm.

[0393] As an example, the diameter φ2 of the cylindrical battery cell is 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, or 70 mm.

[0394] The diameter φ2 of the cylindrical battery cell is greater than or equal to 35 mm, which can improve the capacity and energy density of the cylindrical battery cell. The diameter of the cylindrical battery cell is related to the heat generation of the cylindrical battery cell in thermal runaway. The diameter of the cylindrical battery cell is less than or equal to 70 mm to limit the maximum temperature of the cylindrical battery cell in thermal runaway and reduce the risk of failure of the first insulating member 40.

[0395] Optionally, the diameter φ2 of the cylindrical battery cell is 45 mm to 60 mm.

[0396] In some embodiments, the height of the housing 20 is 50 mm to 150 mm. For example, the height of the housing 20 is 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, or 150 mm.

[0397] Optionally, the height of the housing 20 is 60 mm to 100 mm.

[0398] In some embodiments, the height of the housing 20 is 1.3 times to 4 times the diameter of the housing 20. Illustratively, the height of the housing 20 can be the dimension of the housing 20 along the axis of the cylindrical battery cell.

[0399] Optionally, the height of the housing 20 is 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2.0 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times, 2.6 times, 2.7 times, 2.8 times, 2.9 times, 3.0 times, 3.1 times, 3.2 times, 3.3 times, 3.4 times, 3.5 times, 3.6 times, 3.7 times, 3.8 times, 3.9 times, or 4.0 times the diameter of the housing 20.

[0400] When the housing 20 meets the above size requirements, the structural stability of the housing 20 can be high, which can improve the use reliability of the cylindrical battery cell.

[0401] In some embodiments, the height of the housing 20 is 1.5 times to 2.5 times the diameter of the housing 20.

[0402] In some embodiments, the thickness t2 of the second end wall 20a is less than the thickness t1 of the first end wall 211.

[0403] Compared with the second end wall 20a, the first end wall 211 deforms less when the battery cell 7 is in thermal runaway, thereby reducing the deformation or displacement of the first tab 10a under the drag of the first end wall 211 and the electrode terminal 30, reducing the risk of the first tab 10a pressing the first insulating member 40, and further reducing the risk of the first insulating member 40 being cracked, improving the insulation effect, and improving the reliability of the battery cell 7. Compared with the first end wall 211, the second end wall 20a is more likely to deform outward, which can increase the gas flow channel inside the second end wall 20a and improve the gas discharge efficiency.

[0404] In some embodiments, t1 / t2≥1.5.

[0405] In some embodiments, 0.5mm≤t1≤2mm. Optionally, 0.5mm≤t1≤1.5mm. Optionally, t1 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2.0mm.

[0406] In some embodiments, 0.3mm≤t2≤1.8mm. Optionally, 0.4mm≤t2≤1.3mm. Optionally, t2 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, or 1.8mm.

[0407] In some embodiments, the thickness of the side wall 212 is less than the thickness of the first end wall 211. When the battery cell 7 is in thermal runaway, the first end wall 211 with a larger thickness deforms less, thereby reducing the deformation or displacement of the first tab 10a under the drag of the first end wall 211 and the electrode terminal 30, reducing the risk of the first tab 10a pressing the first insulating member 40, and further reducing the risk of the first insulating member 40 being cracked, improving the insulation effect, and improving the reliability of the battery cell 7. When the battery cell 7 is in thermal runaway, the side wall 212 with a smaller thickness can deform outward, which can increase the gap between the side wall 212 and the electrode body 10c, and help gas discharge.

[0408] In some embodiments, the material of the side wall 212 includes steel.

[0409] In some embodiments, the thickness of the side wall 212 is 0.3mm to 1.5mm.

[0410] As an example, the thickness of the side wall 212 is 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.35 mm, 0.38 mm, 0.40 mm, 0.42 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.05 mm, 1.1 mm, 1.15 mm, 1.2 mm, 1.3 mm, 1.35 mm, 1.4 mm, 1.45 mm, or 1.5 mm.

[0411] In embodiments of the present application, the thickness of the first end wall 211, the thickness of the side wall 212, and the thickness of the second end wall are of the meanings known in the art and can be detected using devices and methods known in the art, for example, using a screw micrometer or a vernier caliper.

[0412] As an example, the material of the side wall 212 includes stainless steel.

[0413] In some embodiments, the thickness of the side wall 212 is 0.3 mm to 1.2 mm.

[0414] In some embodiments, the thickness of the side wall 212 is 0.3 mm to 0.9 mm, and optionally 0.3 mm to 0.6 mm.

[0415] In some embodiments, the material of the first end wall 211 is the same as the material of the side wall 212.

[0416] In some embodiments, the center of the electrode assembly 10 is provided with a first through hole 10d.

[0417] In some examples, the electrode assembly 10 is in a wound structure, and the first through hole 10d is formed at the center of the winding of the electrode assembly 10. Optionally, the extension direction of the first through hole 10d is parallel to the winding axis of the electrode assembly 10.

[0418] In some embodiments, along the extension direction of the first through hole 10d, the first through hole 10d is disposed between the electrode terminal 30 and the pressure relief mechanism 70.

[0419] When the battery cell 7 is in thermal runaway, the gas between the electrode assembly 10 and the first end wall 211 can flow to the pressure relief mechanism 70 through the first through hole 10d, thereby reducing the pressure on the first end wall 211 and the electrode terminal 30, reducing the deformation or displacement of the first tab 10a under the action of the electrode terminal 30, reducing the risk of the first tab 10a pressing the first insulating member 40, and further reducing the risk of the first insulating member 40 being cracked, improving the insulation effect, and improving the reliability of the battery cell 7.

[0420] In some embodiments, the extending direction of the first through hole 10d is parallel to the thickness direction Z of the first end wall 211.

[0421] In some embodiments, in a direction of the first end wall 211 pointing to the second end wall 20a, the minimum distance between the first insulating member 40 and the second end wall 20a is D1, and the total size of the electrode body 10c is D2, 0≤D1 / D2≤0.25.

[0422] As an example, D1 / D2 can be 0, 0.01, 0.02, 0.03, 0.05, 0.06, 0.08, 0.1, 0.11, 0.12, 0.13, 0.15, 0.16, 0.18, 0.2, 0.21, 0.22, 0.23, or 0.25.

[0423] When the battery cell 7 is in thermal runaway, at least part of the second tab 10b and part of the electrode body 10c close to the second end wall 20a can be discharged to the outside of the shell 20 via the pressure relief mechanism 70 under high temperature and high pressure. After the battery cell 7 is relieved, part of the electrode body 10c close to the first end wall 211 can remain in the shell 20.

[0424] The embodiments of the present application limit D1 / D2 to be less than or equal to 0.25, which can enable the first insulating member 40 to separate the remaining part of the electrode body 10c from the side wall 212 when the battery cell 7 is in thermal runaway, reduce the risk of the remaining part of the electrode body 10c conducting the first tab 10a and the side wall 212, and improve reliability.

[0425] In some embodiments, D1 / D2 is greater than 0. The first insulating member 40 is spaced apart from the second end wall 20a by a certain distance.

[0426] In the process of discharging high-temperature gas, the high-temperature gas can conduct part of the heat to the second end wall 20a. The second end wall 20a is spaced apart from the first insulating member 40, which can reduce the heat conducted to the first insulating member 40, thereby reducing the thermal weight loss of the first insulating member 40, improving the insulation effect, and improving the reliability of the battery cell 7.

[0427] In some embodiments, 0.01≤D1 / D2≤0.2.

[0428] In some embodiments, the battery cell 7 further includes a second current collecting member 84, the second tab 10b is connected to the second current collecting member 84, and at least one of the side wall 212 and the second end wall 20a is connected to the second current collecting member 84, so that the side wall 212 electrically connects the first end wall 211 and the second current collecting member 84.

[0429] In some embodiments, the second current collecting member 84 connects the second end wall 20a and the second tab 10b, and the second end wall 20a is electrically connected to the side wall 212. The second tab 10b is electrically connected to the first end wall 211 through the second current collecting member 84, the second end wall 20a, and the side wall 212.

[0430] In some embodiments, the battery cell 7 further comprises a pressure relief mechanism 70 disposed on the second end wall 20a. At least part of the second current collecting member 84 is located between the pressure relief mechanism 70 and the second tab 10b.

[0431] When the battery cell 7 is in thermal runaway, high-temperature gas is discharged to the outside of the shell 21 through the pressure relief channel formed by the pressure relief mechanism 70. At least part of the second current collecting member 84 is opposite to the pressure relief mechanism 70, and the second current collecting member 84 can be deformed or even melted under the action of the high-temperature gas when the battery cell 7 is in thermal runaway, thereby reducing the risk of the second current collecting member 84 conducting the side wall 212 and the residual part of the electrode body 10c, and improving the reliability of the battery cell 7.

[0432] In some embodiments, the outer shell 20 comprises a shell 21 and an end cover 22, the shell 21 comprises an integrally formed first end wall 211 and a side wall 212, and the end cover 22 is a second end wall 20a, and the end cover 22 is sealingly connected to the side wall 212.

[0433] The end cover 22 can be insulated from the side wall 212 or electrically connected.

[0434] The shell 21 has an opening at an end away from the first end wall 211, and the end cover 22 covers the opening of the shell 21.

[0435] The first end wall 211 and the side wall 212 are integrally formed, and the connection strength between the first end wall 211 and the side wall 212 is high; when the battery cell 7 is in thermal runaway, the side wall 212 can constrain the first end wall 211, reduce the deformation of the first end wall 211, thereby reducing the deformation or displacement of the first tab 10a under the action of the first end wall 211 and the electrode terminal 30, reducing the risk of the first tab 10a pressing the first insulating member 40, and further reducing the risk of the first insulating member 40 being cracked, improving the insulation effect, and improving the reliability of the battery cell 7.

[0436] In some embodiments, the material of the shell 21 is steel. The material of the electrode terminal 30 is aluminum or aluminum alloy.

[0437] In some embodiments, the material of the end cover 22 is steel.

[0438] In some embodiments, the first insulating member 40 is spaced apart from the end cap 22 to reduce the risk of the first insulating member 40 being crushed during assembly of the housing 21 and the end cap 22, to improve the connection strength of the end cap 22 and the housing 21, and to reduce interference of the first insulating member 40 with the connection of the end cap 22 and the housing 21.

[0439] In some embodiments, the end cap 22 is welded to the side wall 212.

[0440] In some embodiments, the electrode terminal 30 includes a terminal body 31 and a first stopper 32, at least a portion of the terminal body 31 is housed in the electrode lead-out hole 2111, the first stopper 32 is connected to the terminal body 31, and at least a portion of the first stopper 32 protrudes from an outer peripheral surface of the terminal body 31.

[0441] In some examples, the first stopper 32 and the terminal body 31 can be an integrally formed structure. In other examples, the first stopper 32 and the terminal body 31 are separately formed and connected by welding, riveting, adhesion, or other means.

[0442] In some embodiments, the terminal recess 34 is formed in the terminal body 31.

[0443] In some embodiments, in the thickness direction Z of the first end wall 211, the first stopper 32 is located inside the first end wall 211.

[0444] In the thickness direction Z of the first end wall 211, the first stopper 32 at least partially overlaps the first end wall 211.

[0445] The first end wall 211 and the first stopper 32 can be limited to each other in the thickness direction Z to reduce the risk of the electrode terminal 30 being detached from the case 20 via the electrode lead-out hole 2111.

[0446] In some embodiments, the battery cell 7 further includes a seal 80, at least a portion of the seal 80 is disposed between the first end wall 211 and the first stopper 32.

[0447] The first stopper 32 and the first end wall 211 can sandwich the seal 80 in the thickness direction Z to achieve sealing of the electrode lead-out hole 2111.

[0448] In some embodiments, the thermal weight loss temperature of the seal 80 is greater than or equal to 200°C. As an example, the thermal weight loss temperature of the seal 80 can be 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, or 800°C.

[0449] Exemplarily, the heat loss temperature of the sealing member 80 can be a 5% heat loss temperature. The heat loss temperature of the sealing member 80 can be measured according to GB / T 27761-2011 Test Method for Thermogravimetric Analysis of Residual Mass.

[0450] The sealing member 80 is less likely to lose weight or loses less weight when the battery cell 7 is in thermal runaway, so that the sealing member 80 can be kept between the first end wall 211 and the electrode terminal 30, reducing the risk of direct contact between the electrode terminal 30 and the first end wall 211.

[0451] When the battery cell 7 is in thermal runaway, the sealing member 80 and the electrode terminal 30 can limit the displacement of the first tab 10a to maintain a certain distance between the first tab 10a and the first end wall 211, reducing the risk of contact between the first tab 10a and the first end wall 211. Therefore, in some embodiments, the first insulating member 40 can not be provided between the first end wall 211 and the first tab 10a.

[0452] In some embodiments, the sealing member 80 has electrical insulation. Exemplarily, the sealing member 80 is made of an insulating material. After the battery cell 7 is in thermal runaway, the sealing member 80 can inhibit the current between the first limiting portion 32 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the risk of thermal runaway of other battery cells 7, and improve reliability.

[0453] In some embodiments, the heat loss temperature of the sealing member 80 is less than the heat loss temperature of the first insulating member 40. In order to achieve sealing, the sealing member 80 is usually in a compressed state; when the battery cell 7 is in thermal runaway, even if the weight loss rate of the sealing member 80 is greater than that of the first insulating member 40, it can still fill between the first limiting portion 32 and the first end wall 211, reducing the risk of direct contact between the first limiting portion 32 and the first end wall 211.

[0454] In some embodiments, the sealing member 80 comprises a thermosetting material. The sealing member 80 containing a thermosetting material can maintain good stability at high temperatures, which can isolate the first limiting portion 32 from the first end wall 211 when the battery cell 7 is in thermal runaway.

[0455] In some embodiments, the material of the sealing member 80 comprises fluororubber. Optionally, the material of the sealing member 80 comprises thermosetting fluororubber.

[0456] In some embodiments, the electrode terminal 30 further comprises a second limiting portion 33. The second limiting portion 33 is connected to the terminal body 31, and at least part of the second limiting portion 33 protrudes from the outer peripheral surface of the terminal body 31. The second limiting portion 33 is located outside the first end wall 211. In order to improve the stability of the electrode terminal 30, the second limiting portion 33 and the first limiting portion 32 can clamp the first end wall 211 from both sides.

[0457] In some examples, the second limiting portion 33 and the terminal body 31 can be an integrally formed structure. In other examples, the second limiting portion 33 and the terminal body 31 are separately formed, and are connected by welding, riveting, bonding or other means.

[0458] In some embodiments, the battery cell 7 further comprises a fifth insulating member 85, at least a portion of the fifth insulating member 85 being disposed between the second limiting portion 33 and the first end wall 211. Optionally, the thermal degradation temperature of the fifth insulating member 85 is greater than 300°C.

[0459] In some embodiments, the second limiting portion 33 and the terminal body 31 are an integrally formed structure.

[0460] In some embodiments, the electrode terminal 30 is riveted to the first end wall 211.

[0461] In some examples, the second limiting portion 33 is configured to be formed after the electrode terminal 30 passes through the electrode lead-out hole 2111. For example, when assembling the first end wall 211 and the electrode terminal 30, the electrode terminal 30 can be first passed through the electrode lead-out hole 2111, and then the end portion of the electrode terminal 30 is extruded to form a flange structure, which can serve as the second limiting portion 33.

[0462] In other examples, the first limiting portion 32 is configured to be formed after the electrode terminal 30 passes through the electrode lead-out hole 2111.

[0463] In some embodiments, the battery cell 7 comprises a fourth insulating member 90. At least a portion of the fourth insulating member 90 is disposed between the first end wall 211 and the first tab 10a, to separate the first end wall 211 from the first tab 10a, reduce the risk of conduction between the first end wall 211 and the first tab 10a, and improve reliability.

[0464] The thermal degradation temperature of the fourth insulating member 90 can be greater than, less than or equal to the thermal degradation temperature of the first insulating member 40.

[0465] The material of the fourth insulating member 90 can be the same as or different from the material of the first insulating member 40.

[0466] In some embodiments, in the thickness direction Z of the first end wall 211, at least a portion of the fourth insulating member 90 is located between the first limiting portion 32 and the first end wall 211, to reduce the risk of conduction between the first limiting portion 32 and the first end wall 211.

[0467] When the battery cell 7 is in normal operation, the fourth insulating member 90 can separate the first limiting portion 32 from the first end wall 211 to reduce the risk of short circuit of the battery cell 7. When the battery cell 7 is in thermal runaway, even if the fourth insulating member 90 melts at high temperature, the seal 80 can be maintained between the first limiting portion 32 and the first end wall 211 to reduce the risk of contact between the first limiting portion 32 and the first end wall 211, and inhibit the current between the electrode terminal 30 and the first end wall 211.

[0468] In some embodiments, the material of the fourth insulating member 90 includes a thermoplastic material. Optionally, the material of the fourth insulating member 90 is plastic. Optionally, the material of the fourth insulating member 90 can be polypropylene.

[0469] In some embodiments, the fourth insulating member 90 is disposed around the terminal body 31.

[0470] In some embodiments, in a direction away from the terminal body 31, the outer periphery of the fourth insulating member 90 exceeds the first tab 10a.

[0471] In some embodiments, a portion of the first insulating member 40 is located between the side wall 212 and the fourth insulating member 90. The first insulating member 40 can fill the gap between the side wall 212 and the fourth insulating member 90, reduce the risk of metal impurities conducting the first tab 10a to the side wall 212 via the gap, and reduce the risk of metal impurities conducting the first tab 10a to the first end wall 211 via the gap.

[0472] In some embodiments, the electrode assembly 10 includes a positive electrode sheet 11, the positive electrode sheet 11 includes a positive electrode current collector 111 and a positive electrode film layer 112 disposed on at least one side of the positive electrode current collector 111, the positive electrode film layer 112 includes a positive electrode active material, and the positive electrode active material includes a layered transition metal oxide.

[0473] The layered transition metal oxide includes at least one of a compound of a chemical formula Li a Ni b Co c M d O e A f and a modified compound thereof, 0.8≤a≤1.2, 0.8≤b≤0.95, 0

[0474] As an example, b is 0.8, 0.82, 0.84, 0.85, 0.88, 0.9, 0.92, 0.94, or 0.95.

[0475] As an example, examples of the layered transition metal oxide can include, but are not limited to, at least one of LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), LiNi 0.9 Co 0.05 Mn 0.05 O2(also can be referred to as Ni 90 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2), and modified compounds thereof, and the like.

[0476] The battery cell 7 with a high nickel content has the advantages of high energy density, good low-temperature performance, good charge and discharge performance, and the like.

[0477] Specifically, the positive electrode film layer 112 has a high nickel content, which can store more electrical energy, thereby significantly improving the energy density of the battery cell 7. With the increase of the nickel content, the use amount of cobalt, which is a scarce and expensive metal, is relatively reduced, and the use of cobalt can reduce the cost of the battery cell 7. The battery cell 7 with a high nickel content has a high electrical conductivity, which means that the battery cell 7 can operate at a higher power, which can support fast charging and large-current discharging. In a low-temperature environment, the capacity attenuation of the battery cell 7 with a high nickel content is relatively small, which can maintain a high discharge efficiency, so that the electrical equipment can be normally used in a low-temperature environment.

[0478] However, the thermal stability of the battery cell 7 with a high nickel content is relatively poor, and when the battery cell 7 is in thermal runaway, the heat generated is more, and the temperature rise of the battery cell 7 is higher. The first insulating member 40 with high temperature resistance is arranged in the shell 20, and the first insulating member 40 can withstand the high temperature generated when the high-nickel battery cell 7 is in thermal runaway, thereby reducing the risk of electrical connection between the first end wall 211 and the first tab 10a, inhibiting the current between the electrode terminal 30 and the first end wall 211, and reducing the sustained heat generation of the electrode terminal 30 and the first end wall 211.

[0479] In some embodiments, b is less than or equal to 0.95, which can reduce the maximum temperature of the battery cell 7 when the battery cell 7 is in thermal runaway, and reduce the risk of excessive weight loss of the first insulating member 40 due to excessive temperature.

[0480] In some embodiments, 0.8≤b≤0.95, and optionally, 0.85≤b≤0.90.

[0481] In some embodiments, the battery cell 7 further comprises an electrolyte contained in the shell 20. The electrolyte comprises a chain ester solvent, and the mass percentage of the chain ester solvent in the electrolyte is 25.5wt% to 76.5wt%.

[0482] For example, the mass percentage of the chain ester solvent in the electrolyte is 25.5wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 32wt%, 35wt%, 38wt%, 40wt%, 42wt%, 45wt%, 48wt%, 50wt%, 52wt%, 55wt%, 58wt%, 60wt%, 62wt%, 65wt%, 68wt%, 70wt%, 72wt%, 75wt%, 76.5wt%, or a range between any two of the above values.

[0483] In the embodiments of the present application, the mass percentage of the chain ester solvent is greater than or equal to 25.5wt%, so that the conductivity of the electrolyte is relatively high, which is beneficial to improving the liquid-phase transmission capacity of active ions and the rapid charging and discharging capacity of the battery cell 7, thereby improving the rate performance of the battery cell 7. The mass percentage of the chain ester solvent being greater than or equal to 25.5wt% can also make the viscosity of the electrolyte system relatively low, which is more conducive to the infiltration of the electrode assembly 10, thereby improving the rapid charging and discharging capacity of the battery cell 7, and further improving the rate performance of the battery cell 7.

[0484] The chain ester solvent may face the problem of gas generation during the cycle charging and discharging of the battery cell 7. In the embodiments of the present application, the mass percentage of the chain ester solvent is set to be less than or equal to 76.5wt%, which can limit the internal pressure of the battery cell 7, reduce the deformation of the shell 20, reduce the risk of failure of the battery cell 7, and improve the reliability.

[0485] In some embodiments, the mass percentage of the chain ester solvent in the electrolyte is 42.5wt% to 70wt%, which can further take into account the rate performance and use reliability of the battery cell 7, and improve the cycle performance of the battery cell 7.

[0486] In some embodiments, the chain ester solvent comprises at least one of a chain carbonate and a chain carboxylic acid ester.

[0487] In some embodiments, the chain ester solvent comprises a chain carbonate and a chain carboxylic acid ester. The combination of the chain carboxylic acid ester and the chain carbonate can improve the conductivity of the electrolyte, improve the liquid-phase transmission kinetics of the electrolyte, and further improve the rate performance and use reliability of the battery cell 7.

[0488] Figure 14 A partial cross-sectional view of a battery cell provided by another embodiment of the present application;Figure 15 Figure 14 An enlarged schematic view at the block.

[0489] Referring to Figure 14 and Figure 15 In some embodiments, at least part of the first insulating member 40 is located between the first end wall 211 and the first tab 10a.

[0490] Exemplarily, in the thickness direction Z of the first end wall 211, the first insulating member 40 can be located between the first end wall 211 and the first tab 10a as a whole, or can be located between the first end wall 211 and the first tab 10a only partially.

[0491] As an example, the first insulating member 40 can be fixed to the first end wall 211, or can be fixed to the first tab 10a, or can be fixed to the first current collecting member 81, or can be arranged non-fixedly between the side wall 212 and the first tab 10a.

[0492] When the battery cell 7 occurs thermal runaway, the first insulating member 40 is less likely to lose weight or loses weight less at high temperature, and the first insulating member 40 can separate the first tab 10a from the first end wall 211, thereby reducing the risk of the first end wall 211 conducting with the electrode terminal 30 through the first tab 10a; even if the electrode terminal 30 and the first end wall 211 are electrically connected to other battery cells 7 or an external power source, the first insulating member 40 can inhibit the current between the electrode terminal 30 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve the reliability.

[0493] In some embodiments, the battery cell 7 further comprises a fourth insulating member 90; at least part of the fourth insulating member 90 is arranged between the first end wall 211 and the first tab 10a.

[0494] The fourth insulating member 90 can separate at least part of the first tab 10a from the first end wall 211, thereby reducing the risk of short circuit.

[0495] In some embodiments, at least part of the first insulating member 40 is arranged between the first end wall 211 and the fourth insulating member 90.

[0496] The first insulating member 40 can be fixedly connected with the fourth insulating member 90, or can not be fixedly connected with the fourth insulating member 90. Optionally, opposite side surfaces of the first insulating member 40 are connected to the first end wall 211 and the fourth insulating member 90, respectively.

[0497] In some embodiments, the first insulating member 40 is disposed between the first tab 10a and the fourth insulating member 90. Optionally, the first insulating member 40 is fixed to at least one of the first tab 10a, the fourth insulating member 90, and the first current collecting member 81.

[0498] In some embodiments, a portion of the first insulating member 40 is disposed between the first end wall 211 and the fourth insulating member 90, and a portion of the first insulating member 40 is disposed between the first tab 10a and the fourth insulating member 90.

[0499] By disposing the first insulating member 40 and the fourth insulating member 90, a double-layer insulating structure can be formed between the first tab 10a and the first end wall 211, thereby further improving the insulation effect and reducing the risk of the first tab 10a and the first end wall 211 being conducted when the battery cell 7 is in thermal runaway.

[0500] In some embodiments, the battery cell 7 further comprises a first current collecting member 81, the first current collecting member 81 being located between the first end wall 211 and the first tab 10a, the first current collecting member 81 connecting the electrode terminal 30 and the first tab 10a, and a portion of the first insulating member 40 being disposed between the first current collecting member 81 and the first end wall 211.

[0501] When the battery cell 7 is in thermal runaway, the first insulating member 40 can separate the first current collecting member 81 from the first end wall 211, thereby reducing the risk of the first end wall 211 being conducted through the first current collecting member 81 and the electrode terminal 30.

[0502] In some embodiments, a portion of the fourth insulating member 90 is disposed between the first current collecting member 81 and the first end wall 211.

[0503] In some embodiments, a portion of the first insulating member 40 is located between the side wall and the first current collecting member 81.

[0504] In some embodiments, at least a portion of the first insulating member 40 is located between the tab connecting portion 811 and the first end wall 211 in the thickness direction Z of the first end wall 211.

[0505] In some embodiments, the outer circumferential surface 10g of the first tab is closer to the side wall 212 than the outer circumferential surface 811a of the tab connecting portion.

[0506] Illustratively, the first tab 10a is cylindrical, and in the radial direction of the first tab 10a, the first tab 10a protrudes from the tab connecting portion 811. The first insulating member 40 separates the portion of the first tab 10a protruding from the tab connecting portion 811 from the first end wall 211.

[0507] In some embodiments, the first insulating member 40 separates the tab connecting portion 811 from the first end wall 211 in the thickness direction Z of the first end wall 211. A projection of the tab connecting portion 811 is located within a projection of the first insulating member 40 in the thickness direction Z of the first end wall 211.

[0508] In some embodiments, a portion of the first insulating member 40 is located between the first limiting portion 32 and the first end wall 211 in the thickness direction Z of the first end wall 211. Optionally, the first insulating member 40 at least partially overlaps the seal 80 in the thickness direction Z of the first end wall 211, and the first insulating member 40 and the seal 80 collectively separate the first limiting portion 32 from the first end wall 211.

[0509] In some embodiments, at least a portion of the first insulating member 40 is bonded to an inner surface of the first end wall 211.

[0510] In some embodiments, at least a portion of the fourth insulating portion 52 is disposed between the fourth insulating member 90 and the first current collecting member 81.

[0511] Between the first end wall 211 and the first tab 10a, the first insulating member 40, the fourth insulating member 90, and the second insulating member 50 form a three-layer insulating structure.

[0512] In some embodiments, the fourth insulating portion 52 is bonded to the first current collecting member 81.

[0513] In some embodiments, the second insulating member 50 covers the outer peripheral surface 10g of the first tab, the outer peripheral surface 811a of the tab connecting portion, and the outer peripheral surface 10i of the electrode main body in the thickness direction Z of the first end wall 211.

[0514] In some embodiments, the first insulating member 40 includes a first insulating portion 41 and a second insulating portion 42 connected to the first insulating portion 41, at least a portion of the first insulating portion 41 is located between the side wall 212 and the first tab 10a, and at least a portion of the second insulating portion 42 is located between the first end wall 211 and the first tab 10a.

[0515] When the battery cell 7 is in thermal runaway, the first insulating member 40 is less likely to lose weight or lose less weight at high temperature, the first insulating part 41 can separate the first tab 10a from the side wall 212, and the second insulating part 42 can separate the first tab 10a from the first end wall 211, thereby reducing the risk of the side wall 212 being conducted with the electrode terminal 30 through the first tab 10a and the risk of the first end wall 211 being conducted with the electrode terminal 30 through the first tab 10a; even if the electrode terminal 30 and the first end wall 211 are electrically connected to other battery cells 7 or external power sources, the first insulating member 40 can inhibit the current between the electrode terminal 30 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve the reliability.

[0516] In some embodiments, the first insulating part 41 can be fixed to at least one of the side wall 212, the electrode body 10c, and the first tab 10a.

[0517] In some embodiments, the second insulating part 42 is fixed to at least one of the first end wall 211, the fourth insulating member 90, the first current collecting member 81, and the first tab 10a.

[0518] In some embodiments, at least part of the third insulating part 51 is arranged between the first tab 10a and the first insulating part 41, and at least part of the fourth insulating part 52 is arranged between the second insulating part 42 and the first tab 10a. In other embodiments, at least part of the third insulating part 51 is arranged between the side wall 212 and the first insulating part 41, and at least part of the fourth insulating part 52 is arranged between the second insulating part 42 and the first end wall 211.

[0519] In some embodiments, the first insulating part 41 is attached to the inner surface of the side wall 212, and the second insulating part 42 is attached to the inner surface of the first end wall 211. For example, the first insulating part 41 is bonded to the inner surface of the side wall 212, and the second insulating part 42 is bonded to the inner surface of the first end wall 211.

[0520] The embodiments of the present application can improve the stability of the first insulating member 40, reduce the displacement of the first insulating part 41 relative to the side wall 212 when the battery cell 7 is in thermal runaway and the displacement of the second insulating part 42 relative to the side wall 212 when the battery cell 7 is in thermal runaway, improve the insulation effect, and reduce the risk of the first tab 10a and the first end wall 211 being conducted when the battery cell 7 is in thermal runaway.

[0521] In some embodiments, at least part of the fourth insulating member 90 is arranged between the second insulating part 42 and the fourth insulating part 52 in the thickness direction Z of the first end wall 211.

[0522] In some embodiments, a portion of the first insulation portion 41 is disposed between the sidewall 212 and the electrode body 10c. In a direction pointing from the first end wall 211 to the electrode assembly 10, the first insulation portion 41 protrudes from the electrode body 10c; in a direction pointing from the electrode assembly 10 to the first end wall 211, the first insulation portion 41 protrudes from the electrode body 10c.

[0523] Figure 16 A partial cross-sectional view of a battery cell is provided for some embodiments of the present application; Figure 17 A partial cross-sectional view of a battery cell is provided for some embodiments of the present application; Figure 16 An enlarged view of the circle is provided; Figure 18 A partial cross-sectional view of a battery cell is provided for some embodiments of the present application; Figure 16 An enlarged view of the circle is provided; Figure 19 A schematic view of an electrode assembly, a first insulation member, and a third insulation member of a battery cell is provided for some embodiments of the present application.

[0524] Referring to Figures 16 to 19 In some embodiments, the first tab 10a is a cylindrical structure, and the first insulation member 40 is used to wrap and bind the first tab 10a. For example, the first insulation member 40 is wrapped around the first tab 10a at least once.

[0525] In some embodiments, the first tab 10a is a cylindrical structure, and the first insulation member 40 is wrapped around the first tab 10a at an angle greater than 360 degrees to improve the insulation effect and reduce the risk of exposing the outer surface 10g of the first tab.

[0526] In some examples, the first insulation member 40 has a leading end 40a and a trailing end 40b. In a winding direction of the first insulation member 40, the trailing end 40b of the first insulation member 40 is beyond the leading end 40a, so that the first insulation member 40 covers a portion of the leading end 40a. For example, in some embodiments, the first insulation member 40 is wrapped around the first tab 10a at least once. Figure 19 In some examples, the leading end 40a is covered, and the covered leading end 40a is shown by a dashed line.

[0527] In some embodiments, the second insulation member can be omitted. Alternatively, the second insulation member can also be attached to the housing 20, for example, the third insulation portion can be attached to the inner surface of the sidewall 212, and the fourth insulation portion can be attached to the inner surface of the first end wall 211.

[0528] In some embodiments, the first insulation portion 41 can also not protrude from the electrode body 10c in a direction pointing from the first end wall 211 to the electrode assembly 10.

[0529] In some embodiments, the portion of the first insulation member 40 between the sidewall 212 and the electrode body 10c in a direction pointing from the first end wall 211 to the second end wall 20a has a size D5, and the total size of the electrode body 10c is D2. 0.01≤D5 / D2≤0.25.

[0530] The embodiments of the present application can save the space and weight occupied by the first insulating member 40, and improve the energy density of the battery monomer 7.

[0531] In some embodiments, the first insulating member 40 is located on one side of the third insulating member 60 in the direction of the electrode assembly 10 pointing to the first end wall 211.

[0532] For example, in the radial direction of the battery monomer 7, the first insulating member 40 can overlap or not overlap with the third insulating member 60.

[0533] The embodiments of the present application use the first insulating member 40 and the third insulating member 60 to jointly realize insulation, thereby saving the space and weight occupied by the first insulating member 40 and improving the energy density of the battery monomer 7.

[0534] In some embodiments, the thermal gravimetric temperature of the third insulating member 60 is greater than or equal to 300°C. Optionally, the first insulating member 40 and the third insulating member 60 are made of the same material.

[0535] In some embodiments, a first gap G1 is provided between the first insulating member 40 and the third insulating member 60 in the direction of the electrode assembly 10 pointing to the first end wall 211.

[0536] During the working process of the battery monomer 7, the electrode body 10c will swell. By reserving the first gap G1 between the first insulating member 40 and the second insulating member 50, the risk of contact and extrusion between the first insulating member 40 and the third insulating member 60 can be reduced when the electrode assembly 10 swells and deforms, thereby reducing the risk of cracking of the first insulating member 40 and improving the insulation reliability.

[0537] In some embodiments, the size D3 of the first gap G1 in the direction of the electrode assembly 10 pointing to the first end wall 211 is 0.5mm-5mm.

[0538] For example, D3 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm, 3.2mm, 3.5mm, 3.8mm, 4.0mm, 4.2mm, 4.5mm, 4.8mm or 5.0mm.

[0539] The embodiment of the present application limits D3 to be greater than or equal to 0.5 mm, so as to reduce the risk of the first insulating member 40 and the second insulating member 50 overlapping due to assembly errors. Limiting D3 to be greater than or equal to 0.5 mm can also reduce the risk of the first insulating member 40 and the third insulating member 60 contacting and extruding when the electrode assembly 10 swells and deforms. Limiting D3 to be less than or equal to 5 mm can reduce the risk of the residual part of the electrode body 10c and the side wall 212 being in conduction when the battery cell 7 is in thermal runaway.

[0540] In some embodiments, 1 mm≤D3≤3 mm.

[0541] In some embodiments, the first gap G1 is formed between the first insulating part 41 and the third insulating member 60.

[0542] In some embodiments, the second insulating part 42 is arranged around the electrode terminal 30. Optionally, in the radial direction of the electrode terminal 30, the second insulating part 42 is arranged in a spaced manner with the first limiting part 32.

[0543] In some embodiments, at least part of the second insulating part 42 is located between the fourth insulating member 90 and the first current collecting member 81. Optionally, the second insulating part 42 is bonded to the first current collecting member 81.

[0544] Figure 20 A partial cross-sectional view of a battery cell is provided for another embodiment of the present application.

[0545] Referring to Figure 20 In some embodiments, the second current collecting member 84 connects the side wall 212 and the second tab 10b.

[0546] In some embodiments, the second current collecting member 84 is directly connected to the side wall 212. For example, the second current collecting member 84 is welded to the side wall 212.

[0547] In some embodiments, the side wall 212 is provided with a protruding part 2121 protruding inwardly. In the thickness direction of the end cover 22, at least part of the protruding part 2121 is located between the end cover 22 and the second tab 10b.

[0548] Exemplarily, the thickness direction of the end cover 22 is parallel to the thickness direction Z of the first end wall.

[0549] Exemplarily, the protruding part 2121 can be a solid structure or a hollow structure.

[0550] The protruding part 2121 overlaps with the second tab 10b in the thickness direction of the end cover 22, which can limit the movement of the second tab 10b along the thickness direction of the end cover 22 when the battery cell 7 is subjected to external impact, and reduce the risk of the second tab 10b failing to connect with the second current collecting member 84.

[0551] In some embodiments, the second current collecting member 84 is connected to the protrusion 2121. As an example, the second current collecting member 84 can be welded to the protrusion 2121; alternatively, the second current collecting member 84 can also be crimped to the protrusion 2121.

[0552] As an example, the second current collecting member 84 is connected to the side of the protrusion 2121 facing the second tab 10b, or to the side of the protrusion 2121 facing the end cover 22.

[0553] Connecting the second current collecting member 84 to the protrusion 2121 can shorten the conductive path between the second tab 10b and the first end wall 211, reduce the resistance, reduce the heat generation, and improve the cycle performance of the battery cell 7.

[0554] In some embodiments, a portion of the second current collecting member 84 is located on the side of the protrusion 2121 facing the end cover 22 and is connected to the protrusion 2121. The second current collecting member 84 is connected to the protrusion 2121 from the outside of the protrusion 2121, which can reduce the assembly difficulty.

[0555] In some embodiments, the second current collecting member 84 is welded to the protrusion 2121.

[0556] In some embodiments, the outer side of the side wall 212 is provided with a second recess 2122, which is in position correspondence with the protrusion 2121. As an example, after the electrode assembly 10 is installed into the housing 21, the protrusion 2121 is formed by extruding the side wall 212 from the outside.

[0557] In some embodiments, the side wall 212 further includes a crimping portion 2123, which extends from one end of the protrusion 2121 away from the first end wall 211 and is arranged around the end cover 22.

[0558] A portion of the crimping portion 2123 is arranged in a bent manner and forms a flange structure, and a portion of the end cover 22 is located between the flange structure and the protrusion 2121 in the thickness direction of the end cover 22. The protrusion 2121 and the flange structure can limit the end cover 22 to achieve the fixation of the end cover 22 in the thickness direction Z.

[0559] In some embodiments, the battery cell 7 further includes a sixth insulating member 87, which is arranged between the side wall 212 and the end cover 22 and insulates the end cover 22 from the side wall 212.

[0560] In some embodiments, a portion of the sixth insulating member 87 is located between the second current collecting member 84 and the end cover 22 to insulate the second current collecting member 84 from the end cover 22.

[0561] In some embodiments, the end cover 22 can be integrally used as a pressure relief mechanism. When the battery cell 7 is in thermal runaway, under the internal pressure of the battery cell 7, the crimping portion 2123 is turned outward to detach the end cover 22 from the side wall 212, forming a pressure relief channel.

[0562] In some embodiments, the first insulating member 40 is spaced apart from the protrusion 2121 in a direction pointing to the end cover 22 along the electrode assembly 10.

[0563] Figure 21 A schematic view of the first insulating member and the adhesive layer of the battery cell is provided for some embodiments of the present application.

[0564] Referring to Figures 10 to 18 and Figure 21 In some embodiments, the battery cell 7 further comprises an adhesive layer 86. The adhesive layer 86 adheres the first insulating member 40 to at least one of the first end wall 211, the side wall 212, the electrode body 10c, and the first tab 10a.

[0565] The adhesive layer 86 can fix the first insulating member 40 to reduce the risk of the first insulating member 40 being offset during use of the battery cell 7.

[0566] In some embodiments, the thickness t3 of the first insulating member 40 is greater than or equal to the thickness t4 of the adhesive layer 86.

[0567] Compared with the adhesive layer 86, the first insulating member 40 can have a greater thickness to reduce the risk of the first insulating member 40 being cracked or punctured and improve insulation reliability.

[0568] In some embodiments, the ratio of the thickness t3 of the first insulating member 40 to the thickness t4 of the adhesive layer 86 is 1-5. As an example, t3 / t4 can be 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5.

[0569] In the embodiments of the present application, t3 / t4 is limited to be greater than or equal to 1, so that the first insulating member 40 can have a greater thickness to reduce the risk of the first insulating member 40 being cracked or punctured and improve insulation reliability. t3 / t4 is limited to be less than or equal to 5, so that the adhesive layer 86 has a higher adhesive strength and reduces the risk of the first insulating member 40 falling off.

[0570] In some embodiments, 5 μm≤t3≤100 μm. Optionally, t3 is 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, or 100 μm.

[0571] In some embodiments, 20 pm < t3 < 60 pm. Optionally, 25 pm < t3 < 50 pm.

[0572] In some embodiments, 3 pm < t4 < 80 pm. Optionally, t4 is 3 pm, 5 pm, 10 pm, 15 pm, 20 pm, 25 pm, 30 pm, 35 pm, 40 pm, 45 pm, 50 pm, 55 pm, 60 pm, 65 pm, 70 pm, 75 pm, or 80 pm.

[0573] In some embodiments, 15 pm < t4 < 50 pm.

[0574] In some embodiments, the adhesive layer 86 comprises a thermosetting material. Optionally, the adhesive layer 86 comprises a thermosetting phenolic resin.

[0575] Figure 22 An exploded view of a battery cell provided for some embodiments of the present application.

[0576] Referring to Figure 22 In some embodiments, the battery cell 7 is a prismatic battery cell. Illustratively, the sidewall 212 is a prismatic cylinder.

[0577] In some embodiments, the outer shell 20 comprises a housing 21 and an end cap 22, the housing 21 comprises an integrally formed second end wall 20a and a sidewall 212, and the end cap 22 is the first end wall 211, the end cap 22 is sealingly connected to the sidewall 212.

[0578] In some embodiments, the battery cell 7 can comprise an electrode lead-out portion 88 disposed on the end cap 22, the electrode lead-out portion 88 is electrically connected to the second tab 10b and the end cap 22. The electrode lead-out portion 88 and the electrode terminal 30 can serve as two electrodes of the battery cell 7.

[0579] In some embodiments, the second tab 10b can be a positive tab, the end cap 22 can be made of aluminum or an aluminum alloy, and the housing 21 can be made of aluminum or an aluminum alloy. By electrically connecting the second tab 10b to the end cap 22, the end cap 22 and the housing 21 can be at a high potential, reducing the risk of corrosion of the end cap 22 by the electrolyte.

[0580] In other embodiments, the second tab 10b can be a negative tab, the end cap 22 can be made of steel, and the housing 21 can be made of steel.

[0581] In some embodiments, the first insulating member 40 can be attached to an inner surface of the sidewall 212.

[0582] In some embodiments, the first insulating member 40 can comprise an insulating coating.

[0583] In some embodiments, the side wall 212 includes two first sub-walls 212a and two second sub-walls 212b, which are arranged alternately along the circumference of the electrode assembly 10. Optionally, at least part of the first insulating member 40 can be arranged on the inner surface of the first sub-wall 212a. Optionally, part of the first insulating member 40 is arranged on the inner surface of the first sub-wall 212a, and another part of the first insulating member 40 is arranged on the inner surface of the second sub-wall 212b.

[0584] In some embodiments, the area of the first sub-wall 212a is larger than the area of the second sub-wall 212b.

[0585] Figure 23 A simplified schematic diagram of a battery device provided for another embodiment of the present application.

[0586] With reference to Figure 23 The present application also provides a battery device 2 including a plurality of the battery cell 7 of any one of the above embodiments.

[0587] In some embodiments, the battery device 2 further includes a plurality of busbar components 8, which electrically connect the plurality of battery cells 7.

[0588] In some embodiments, at least two battery cells 7 are connected in parallel.

[0589] For example, at least two battery cells 7 are connected in parallel and form a battery unit 7a, and a plurality of battery units 7a are connected in series. The plurality of battery cells 7 of the battery device 2 form a multi-parallel and series connection structure. The multi-parallel and series connection structure can improve reliability. When a certain battery cell 7 fails due to an accident (e.g., thermal runaway), the battery cells 7 connected in parallel with the battery cell 7 can still work normally, reducing the risk of complete failure of the entire circuit.

[0590] When a certain battery cell 7 experiences thermal runaway, the normal battery cells 7 connected in parallel with the battery cell 7 experiencing thermal runaway can be respectively electrically connected to the first end wall 211 and the electrode terminal 30 of the battery cell 7 experiencing thermal runaway. The first insulating member 40 can insulate the first tab 10a from the first end wall 211, inhibit the current between the electrode terminal 30 and the first end wall 211, reduce the continuous heat generation of the electrode terminal 30 and the first end wall 211, reduce the thermal impact on the surrounding other battery cells 7, reduce the risk of thermal runaway of the other battery cells 7, and improve reliability.

[0591] According to some embodiments of the present application, the present application also provides a power-consuming device including the battery cell of any one of the above embodiments, which is used to provide power for the power-consuming device. The power-consuming device can be the device or system of any one of the above applications of the battery cell.

[0592] With reference to Figures 4 to 13The cylindrical battery cell provided by the embodiments of the present application includes an electrode assembly 10, a housing 20, an electrode terminal 30, a first insulating member 40, a second insulating member 50, a third insulating member 60, a first current collecting member 81, a second current collecting member 84, and a pressure relief mechanism 70.

[0593] The housing 20 includes a shell 21 and an end cover 22, the shell 21 includes a first end wall 211 and a side wall 212 formed integrally, and the end cover 22 is sealingly connected to the side wall 212 and forms a containing cavity 20b together with the shell 21.

[0594] The first end wall 211 is provided with an electrode lead-out hole 2111 in communication with the containing cavity 20b, and the electrode terminal 30 is arranged in the electrode lead-out hole 2111 and is insulated from the first end wall 211.

[0595] The electrode assembly 10 includes an electrode main body 10c and first and second electrode tabs 10a and 10b led out from the electrode main body 10c, the first and second electrode tabs 10a and 10b are opposite in polarity, the first electrode tab 10a is arranged at one end of the electrode assembly 10 facing the first end wall 211, and the second electrode tab 10b is arranged at one end of the electrode assembly 10 facing the end cover 22.

[0596] The first current collecting member 81 connects the electrode terminal 30 and the first electrode tab 10a, and the second current collecting member 84 connects the end cover 22 and the second electrode tab 10b. The end cover 22 is electrically connected to the side wall 212.

[0597] The first insulating member 40 is attached to the inner surface of the side wall 212 and arranged around the electrode assembly 10. A part of the first insulating member 40 is arranged between the side wall 212 and the first electrode tab 10a, and another part of the first insulating member 40 is arranged between the side wall 212 and the electrode main body 10c.

[0598] The second insulating member 50 is arranged around the first electrode tab 10a. A part of the second insulating member 50 is located between the first electrode tab 10a and the first insulating member 40, and another part of the second insulating member 50 is located between the first electrode tab 10a and the first end wall 211.

[0599] The third insulating member 60 is arranged around the electrode main body 10c and attached to the outer circumferential surface 10i of the electrode main body. In the axial direction of the cylindrical battery cell, the third insulating member 60 is arranged spaced apart from the second insulating member 50.

[0600] The thermal weight loss temperature of the first insulating member 40 is greater than or equal to 300℃. Optionally, the material of the first insulating member 40 includes polyimide.

[0601] 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.

[0602] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements 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 battery cell, characterized by, The application includes: a housing including a first end wall, a side wall, and a receiving cavity, the first end wall being provided with an electrode lead-out hole communicating with the receiving cavity, the side wall being connected to the first end wall; an electrode terminal provided in the electrode lead-out hole, the electrode terminal being provided in insulation from the first end wall; an electrode assembly received in the receiving cavity, the side wall surrounding the electrode assembly, the electrode assembly including an electrode body and first and second electrode tabs led out from the electrode body, the first and second electrode tabs being opposite in polarity, the first electrode tab being provided at an end of the electrode assembly facing the first end wall, the first electrode tab being electrically connected to the electrode terminal, the second electrode tab being electrically connected to the first end wall and the side wall; a first insulating member, the first insulating member having a thermal weight loss temperature greater than or equal to 300℃, at least a portion of the first insulating member being provided between the first end wall and the first electrode tab, and / or at least a portion of the first insulating member being provided between the side wall and the first electrode tab.

2. The battery cell of claim 1, wherein, The first insulating member has a thermal weight loss temperature greater than or equal to 350℃.

3. The battery cell of claim 2, wherein, The first insulating member has a thermal weight loss temperature greater than or equal to 500℃.

4. The battery cell of claim 1, wherein, The material of the first insulating member includes a thermosetting material.

5. The battery cell of claim 1, wherein, The material of the first insulating member includes one of a thermosetting polyimide and a derivative thereof.

6. The battery cell of claim 5, wherein, The material of the first insulating member includes one of a bismaleimide, an ethynyl-terminated polyimide, and a norbornene diacid anhydride-terminated polyimide.

7. The battery cell of claim 1, wherein, The first insulating member is fixed to at least one of the first end wall, the side wall, the electrode body, and the first electrode tab.

8. The battery cell of claim 7, wherein, Further including an adhesive layer, the adhesive layer bonding the first insulating member to at least one of the first end wall, the side wall, the electrode body, and the first electrode tab.

9. The battery cell of claim 8, wherein, The thickness of the first insulating member is greater than or equal to the thickness of the adhesive layer.

10. The battery cell of any one of claims 1-9, wherein, At least a portion of the first insulating member is located between the side wall and the first electrode tab.

11. The battery cell of claim 10, wherein, The first insulating member is provided around the first electrode tab.

12. The battery cell of claim 11, wherein, The first electrode tab has a cylindrical structure, and the first insulating member has an angle of wrap greater than 360 degrees.

13. The battery cell of claim 10, wherein, The outer periphery of the electrode body is closer to the side wall than the outer periphery of the first electrode tab, so that a space for receiving at least a portion of the first insulating member is formed between the outer periphery of the first electrode tab and the side wall.

14. The battery cell of claim 10, wherein, In a direction of the electrode assembly pointing toward the first end wall, the first insulating member protrudes from the first electrode tab; or An end of the first insulating member facing the first end wall is flush with an end of the first electrode tab facing the first end wall.

15. The battery cell of claim 14, wherein, Further including a first current collecting member, the first current collecting member including a tab connecting portion connected to the first electrode tab and a terminal connecting portion connected to the electrode terminal, the tab connecting portion surrounding the terminal connecting portion; In a direction of the electrode assembly pointing toward the first end wall, the first insulating member protrudes from the tab connecting portion.

16. The battery cell of claim 10, wherein, A portion of the first insulating member is located between the side wall and the electrode body.

17. The battery cell of claim 10, wherein, The first insulating member includes a first insulating portion and a second insulating portion connected to the first insulating portion, at least a portion of the first insulating portion is located between the side wall and the first tab, and at least a portion of the second insulating portion is located between the first end wall and the first tab.

18. The battery cell of claim 17, wherein, The first insulating portion is attached to the inner surface of the side wall, and the second insulating portion is attached to the inner surface of the first end wall.

19. The battery cell of claim 10, wherein, Further comprising a second insulating member; At least a portion of the second insulating member surrounds the first tab and is located between the first insulating member and the first tab; and / or, at least a portion of the second insulating member surrounds the first tab and is located between the side wall and the first insulating member.

20. The battery cell of claim 19, wherein, At least a portion of the first insulating member is attached to the inner surface of the side wall. At least a portion of the second insulating member surrounds the first tab and is located between the first insulating member and the first tab.

21. The battery cell of claim 20, wherein, The tensile modulus of the second insulating member is less than the tensile modulus of the first insulating member.

22. The battery cell of claim 19, wherein, A portion of the second insulating member is disposed between the first tab and the first end wall.

23. The battery cell of any one of claims 19-22, wherein, The thermal weight loss temperature of the first insulating member is greater than the thermal weight loss temperature of the second insulating member.

24. The battery cell of claim 1, wherein, Further comprising a third insulating member disposed between the electrode body and the side wall.

25. The battery cell of claim 24, wherein, The third insulating member is fixed to the outer peripheral surface of the electrode body. The electrode body includes a separator disposed in a roll shape, and the third insulating member is connected to the outer surface of the separator.

26. The battery cell of claim 24, wherein, The thermal weight loss temperature of the third insulating member is greater than or equal to 300°C.

27. The battery cell of any one of claims 24-26, wherein, At least a portion of the first insulating member is disposed between the side wall and the third insulating member.

28. The battery cell of claim 27, wherein, In a direction of the first end wall pointing to the electrode assembly, the first insulating member protrudes from the third insulating member. In a direction of the electrode assembly pointing to the first end wall, the first insulating member protrudes from the third insulating member.

29. The battery cell of any one of claims 24-26, wherein, In a direction of the electrode assembly pointing to the first end wall, the first insulating member is located on one side of the third insulating member.

30. The battery cell of claim 29, wherein, In a direction of the electrode assembly pointing to the first end wall, a first gap is provided between the first insulating member and the third insulating member.

31. The battery cell of claim 30, wherein, In a direction of the electrode assembly pointing to the first end wall, the size of the first gap is 0.5mm-5mm.

32. The battery cell of claim 1, wherein, The second tab is disposed at an end of the electrode assembly away from the first end wall, and at least a portion of the first insulating member is located between the side wall and the second tab. In a direction of the first end wall pointing to the electrode assembly, the first insulating member protrudes from the second tab; or, an end of the first insulating member away from the first end wall is flush with an end of the second tab away from the first end wall.

33. The battery cell of claim 1, wherein, At least a portion of the first insulating member is located between the first end wall and the first tab.

34. The battery cell of claim 33, wherein, Further comprising a fourth insulating member; at least a portion of the fourth insulating member is disposed between the first end wall and the first tab.

35. The battery cell of claim 34, wherein, At least a portion of the first insulating member is disposed between the first end wall and the fourth insulating member; and / or At least part of the first insulating member is arranged between the first tab and the fourth insulating member.

36. The battery cell of any one of claims 33-35, wherein, A first current collecting member is further included, which is located between the first end wall and the first tab, and connects the electrode terminal and the first tab. Part of the first insulating member is arranged between the first current collecting member and the first end wall.

37. The battery cell of claim 1, wherein, The shell further includes a second end wall, which is arranged opposite to the first end wall, and the side wall connects the first end wall and the second end wall. The second tab is arranged at one end of the electrode assembly towards the second end wall.

38. The battery cell of claim 37, wherein, A pressure relief mechanism is further included, which is arranged at the second end wall.

39. The battery cell of claim 38, wherein, In the direction of the first end wall pointing to the second end wall, the minimum distance between the first insulating member and the second end wall is D1, and the total size of the electrode body is D2, 0≤D1 / D2≤0.

25.

40. The battery cell of claim 38, wherein, The pressure relief mechanism includes a pressure relief portion and a weak portion arranged along the outer periphery of the pressure relief portion. The area of the region surrounded by the outer contour of the projection of the second end wall in the thickness direction thereof is S1, and the area of the projection of the pressure relief portion in the thickness direction of the second end wall is S2. 0.1≤S2 / S1≤0.

8.

41. The battery cell of claim 40, wherein, 0.3≤S2 / S1≤0.

7.

42. The battery cell of claim 38, wherein, The battery cell is a cylindrical battery cell, and the first end wall and the second end wall are arranged opposite in the axial direction of the cylindrical battery cell. The pressure relief mechanism includes a pressure relief portion and a weak portion arranged along the outer periphery of the pressure relief portion, and the pressure relief portion is circular. The diameter φ1 of the pressure relief portion and the diameter φ2 of the cylindrical battery cell satisfy the following relationship: 0.35≤φ1 / φ2≤0.

85.

43. The battery cell of claim 38, wherein, The thickness of the second end wall is smaller than the thickness of the first end wall.

44. The battery cell of claim 38, wherein, The center of the electrode assembly is provided with a first through hole. In the extension direction of the first through hole, the first through hole is arranged between the electrode terminal and the pressure relief mechanism.

45. The battery cell of claim 37, wherein, A second current collecting member is further included. The second current collecting member connects the second end wall and the second tab, and the second end wall is electrically connected to the side wall; or the second current collecting member connects the side wall and the second tab.

46. The battery cell of claim 45, wherein, A pressure relief mechanism is further included, which is arranged at the second end wall. At least part of the second current collecting member is located between the pressure relief mechanism and the second tab.

47. The battery cell of claim 37, wherein, The shell includes a shell body and an end cover, the shell body includes the first end wall and the side wall which are integrally formed, and the end cover is the second end wall, which is sealingly connected to the side wall. The first insulating member is arranged spaced apart from the end cover.

48. The battery cell of claim 1, wherein, The electrode terminal includes a terminal body and a first limiting portion, at least part of the terminal body is accommodated in the electrode lead-out hole, the first limiting portion is connected to the terminal body, and at least part of the first limiting portion protrudes from the outer peripheral surface of the terminal body. The battery cell further includes a sealing member, in the thickness direction of the first end wall, the first limiting portion is located on the inner side of the first end wall, and at least part of the sealing member is arranged between the first end wall and the first limiting portion. The sealing member has a thermal gravimetric temperature greater than or equal to 200 DEG C.

49. The battery cell of claim 1, wherein, The electrode assembly comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, the positive electrode film layer comprises a positive electrode active material, and the positive electrode active material comprises a layered transition metal oxide. The layered transition metal oxide includes a compound of the formula Li a Ni b Co c M d O e A f one of a compound of the formula Li 0.8≤a≤1.2, 0.8≤b≤0.95, 0 M includes one of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, and A includes one of N, F, S, and Cl.

50. The battery cell of claim 1, wherein, The battery cell is a cylindrical battery cell, and the diameter of the cylindrical battery cell is greater than or equal to 35 mm and less than or equal to 70 mm.

51. A battery device, comprising: The battery device comprises a plurality of battery cells according to any one of claims 1-50.

52. The battery device of claim 51, wherein, At least two battery cells are connected in parallel.

53. An electrical device, comprising: The battery device according to claim 51 or 52 is used for providing electric energy.

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