Electrochemical device, battery module and electronic device

Abstract

The present application relates to an electrochemical device, comprising a housing, an electrode assembly, a first pole ear and a first conductive member. The housing is provided with a first cavity and a first hole, the first hole is connected to the first cavity, the electrode assembly is provided in the first cavity, the first end of the first pole ear is electrically connected to the electrode assembly, the first conductive member is provided in the first hole, the first conductive member is provided with a second cavity, the second end of the first pole ear is provided in the second cavity, and the second end of the first pole ear is electrically connected to the first conductive member. The present application also relates to a battery module and an electronic device. Through the above method, the present application can save the internal space of the electrochemical device and improve the energy density.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of energy storage technology, and in particular to an electrochemical device, a battery module, and an electronic device. Background Art

[0002] An electrochemical device is a device that converts external energy into electrical energy and stores it inside to power external electronic devices (such as portable electronic devices, etc.) when needed. Electrochemical devices are widely used in daily life, providing great convenience and richness to people's daily lives.

[0003] During the process of realizing the present application, the inventors of the present application found that there is still a great demand in the field of energy storage technology for improving the energy density of electrochemical devices. Summary of the invention

[0004] In view of the above problems, the embodiments of the present application provide an electrochemical device, a battery module and an electronic device, which can improve the energy density of the electrochemical device and other problems.

[0005] According to one aspect of an embodiment of the present application, an electrochemical device is provided, comprising: a housing, an electrode assembly, a first pole ear and a first conductive member. The housing is provided with a first cavity and a first hole, and the first hole is connected to the first cavity, the electrode assembly is provided in the first cavity, the first end of the first pole ear is electrically connected to the electrode assembly, and the first conductive member is provided in the first hole, the first conductive member is provided with a second cavity, the second end of the first pole ear is provided in the second cavity, and the second end of the first pole ear is electrically connected to the first conductive member. The second cavity of the first conductive member is used to accommodate and fix the second end of the first pole ear, thereby reducing the occupation of the internal space of the electrochemical device.

[0006] In an optional manner, the first conductive member is provided with a first protrusion toward the second cavity, and the second end of the first pole lug is fixedly connected to the first protrusion. The first protrusion is used to increase the connection area between the first conductive member and the first pole lug.

[0007] In an optional manner, the cross-section of the second cavity includes a first end and a second end, the first end is located at one end away from the electrode assembly, the second end is located at the other end close to the electrode assembly, and the area of ​​the cross-section close to the first end is smaller than the area of ​​the cross-section close to the second end, wherein the cross-section of the second cavity is a cross-section of the second cavity along the second direction.

[0008] In an optional manner, along the first direction, the area of ​​the cross section of the second cavity gradually increases. The first direction is the direction from the second end of the first conductive member to the first end of the first conductive member, and the second direction is perpendicular to the first direction.

[0009] In an optional manner, the cross-section of the first conductive member includes a third end and a fourth end, the third end is located at one end away from the electrode assembly, and the fourth end is located at the other end close to the electrode assembly, the area enclosed by the outer contour of the cross-section close to the third end is smaller than the area enclosed by the outer contour of the cross-section close to the fourth end, and the cross-section of the first conductive member is a cross-section of the first conductive member along the second direction.

[0010] In an optional manner, along the first direction, the area enclosed by the outer contour of the cross section of the first conductive member gradually increases. The cross section of the first conductive member is the cross section of the first conductive member along the second direction, the first direction is the direction from the second end of the first conductive member to the first end of the first conductive member, and the second direction is perpendicular to the first direction. The area enclosed by the outer contour of the cross section of the first conductive member gradually increases, and such an arrangement facilitates the connection and sealing between the first conductive member and the first cover.

[0011] In an optional manner, the first electrode tab is provided with at least one first recess, and the at least one first recess forms a first channel. The first channel facilitates the electrolyte to flow into the first cavity, and can facilitate the first electrode tab to be arranged in the second cavity.

[0012] In an optional manner, the first electrode tab is provided with at least one second recess, and the at least one second recess forms a second channel, wherein the direction in which the first channel extends and the direction in which the second channel extends have a predetermined angle. The second channel is arranged to communicate with the first channel, so that the electrolyte flows into the first cavity, and the first electrode tab can be arranged in the second cavity.

[0013] In an optional manner, the electrode assembly includes a first pole piece, the first pole piece includes a first current collector, and one end of the first current collector extends to form a first pole ear.

[0014] In an optional manner, the first electrode tab includes a plurality of first sub-electrode tabs connected to the first current collector.

[0015] In an optional manner, along the extension direction of the first current collector, the ratio of the length of the first electrode tab to the length of the first current collector is in a range of 0.7 to 1.0.

[0016] In an optional manner, the electrochemical device further comprises a first structural member, which is disposed between the outer wall surface of the first conductive member and the inner wall surface of the first hole. The first structural member can seal the connection between the first conductive member and the housing.

[0017] In an optional manner, the first structural member includes insulating material.

[0018] In an optional manner, the first conductive member protrudes from the outer surface of the housing.

[0019] In an optional manner, the electrochemical device further includes a second pole ear and a second conductive member, the housing is provided with a second hole connected to the cavity, the second conductive member is installed in the second hole, and the second conductive member is provided with a third cavity. The first end of the second pole ear is connected to the electrode assembly, the second end of the second pole ear is provided in the third cavity, and the second end of the second pole ear is electrically connected to the second conductive member. The second end of the second pole ear is accommodated and fixed by the third cavity of the second conductive member, thereby reducing the occupation of the internal space of the electrochemical device.

[0020] In an optional manner, the electrochemical device further comprises a second structural member, which is disposed between the outer wall of the second conductive member and the inner wall of the second hole. The second structural member can seal the connection between the second conductive member and the housing.

[0021] In an optional embodiment, the outer shell includes a shell, a first cover body and a second cover body, the first cover body and the second cover body are respectively covered on both ends of the shell, the shell, the first cover body and the second cover body together enclose a first cavity, the first hole is located in the first cover body, and the second hole is located in the second cover body.

[0022] In an optional manner, the first conductive member is connected to the first cover body, and the first cover body is insulated from the shell.

[0023] In an optional manner, the housing is cylindrical or square.

[0024] According to another aspect of an embodiment of the present application, a battery module is provided, comprising the electrochemical device as described above.

[0025] According to another aspect of an embodiment of the present application, an electronic device is provided, comprising the battery module as described above.

[0026] The beneficial effects of the present application include: different from the prior art, the embodiment of the present application is provided with a housing, an electrode assembly, a first pole ear and a first conductive member. Among them, the housing is provided with a first cavity and a first hole, the first hole is connected to the first cavity, the electrode assembly is provided in the first cavity, the first conductive member is provided in the first hole, the first conductive member is provided with a second cavity, the first end of the first pole ear is electrically connected to the electrode assembly, the second end of the first pole ear is provided in the second cavity, and the second end of the first pole ear is electrically connected to the first conductive member. In this way, the second end of the first pole ear is provided in the second cavity and electrically connected to the first conductive member, which saves the internal space of the electrochemical device and reduces the impact on the energy density of the electrochemical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0028] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the electrochemical device of the present application;

[0029] Figure 2 yes Figure 1 Middle AA section cutaway view;

[0030] Figure 3 yes Figure 2 Exploded schematic diagram of a part of the structure in a cross-sectional view;

[0031] Figure 4 It is a schematic diagram of the overall structure of an embodiment of the electrochemical device of the present application;

[0032] Figure 5 yes Figure 4 Sectional view at BB in the middle;

[0033] Figure 6 is a side view schematic diagram of an electrode assembly of an embodiment of the electrochemical device of the present application;

[0034] Figure 7 is a schematic diagram of the expansion of the first pole piece of the electrochemical device of the embodiment of the present application;

[0035] Figure 8 is a schematic diagram of an expanded first electrode sheet of another embodiment of the electrochemical device of the present application;

[0036] Fig. 9 is a schematic vertical cross-sectional view of a first conductive member of an electrochemical device according to an embodiment of the present application;

[0037] Fig.10 is a vertical cross-sectional schematic diagram of a first conductive member of another embodiment of the electrochemical device of the present application;

[0038] Fig.11 is a vertical cross-sectional schematic diagram of a first conductive member of another embodiment of the electrochemical device of the present application;

[0039] Fig.12 is a vertical cross-sectional schematic diagram of a first conductive member of another embodiment of the electrochemical device of the present application;

[0040] Fig.13 is a schematic cross-sectional view of a first conductive member of an electrochemical device according to an embodiment of the present application;

[0041] Fig.14is a cross-sectional schematic diagram of a first conductive member of another embodiment of the electrochemical device of the present application;

[0042] Fig.15 is a cross-sectional schematic diagram of a first conductive member of another embodiment of the electrochemical device of the present application;

[0043] Fig.16 is a cross-sectional schematic diagram of a first conductive member of another embodiment of the electrochemical device of the present application;

[0044] Fig.17 is a schematic diagram of an expanded first electrode sheet of an embodiment of the electrochemical device of the present application;

[0045] Fig.18 is a vertical cross-sectional schematic diagram of another embodiment of the electrochemical device of the present application;

[0046] Fig.19 yes Fig.18 Cross-sectional view of the first pole ear in the middle CC section;

[0047] Fig. 20 is a schematic diagram of an expanded first electrode sheet of another embodiment of the electrochemical device of the present application;

[0048] Fig.21 is a schematic cross-sectional view of a first electrode tab of another embodiment of the electrochemical device of the present application;

[0049] Fig. 22 is a vertical cross-sectional schematic diagram of another embodiment of the electrochemical device of the present application;

[0050] Fig.23 It is a schematic diagram of a vertical cross-section structure explosion of another embodiment of the electrochemical device of the present application;

[0051] Fig.24 is a vertical cross-sectional schematic diagram of another embodiment of the electrochemical device of the present application;

[0052] Fig.25 It is a schematic diagram of the overall structure of an electrode assembly of an embodiment of the electrochemical device of the present application;

[0053] Fig.26 It is a schematic diagram of the overall structure of an electrode assembly of another embodiment of the electrochemical device of the present application. DETAILED DESCRIPTION

[0054] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are for illustrative purposes only.

[0055] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0056] In order to better illustrate the structure of the electrochemical device, the structure of the electrochemical device will be described in conjunction with the X, Y, and Z coordinate axes, wherein the X, Y, and Z coordinate axes are perpendicular to each other, the first direction is the positive direction of the X axis, the second direction is the positive direction of the Y axis, and the third direction is the positive direction of the Z axis.

[0057] See also Figure 1 and Figure 2 The electrochemical device 01 includes a housing 10, an electrode assembly 20, a first pole ear 30, a first conductive member 50 and a first structural member 70. The electrode assembly 20 is disposed in the housing 10, one end of the first pole ear 30 is electrically connected to the electrode assembly 20, the other end of the first pole ear 30 is electrically connected to the first conductive member 50, the first conductive member 50 is disposed on the housing 10, and the first conductive member 50 is partially located in the housing 10, and the first structural member 70 is disposed at the connection between the housing 10 and the first conductive member 50. The first conductive member 50 can be used to electrically connect an external device to realize charging and discharging of the electrochemical device. Optionally, the first conductive member 50 includes a metal material, such as copper.

[0058] Specifically, for the above-mentioned housing 10, please refer to Figure 3 The housing 10 is provided with a first cavity 10a and a first hole 10b, the first hole 10b is connected to the first cavity 10a, the first cavity 10a is used to accommodate the electrode assembly 20, and the first hole 10b is used to install the first conductive member 50. In this embodiment, the housing 10 is at least partially a metal shell, and the metal shell is electrically connected to the electrode assembly 20; it can be understood that in other embodiments of the present application, the housing 10 is an aluminum-plastic film.

[0059] For the electrode assembly 20, Figure 3As shown, the electrode assembly 20 is disposed in the first cavity 10a, and the electrode assembly 20 includes a first electrode 201, a second electrode 202, and a separation membrane 203 disposed between the first electrode 201 and the second electrode 202. The first electrode 210 and the second electrode 220 have opposite polarities, one of which is a positive electrode and the other is a negative electrode. It can be understood that the number of the first electrode 201 and the second electrode 202 is not limited and can be adaptively adjusted according to actual conditions. The electrode assembly 20 can be a winding structure or a laminated structure, such as Figure 4 and Figure 5 As shown, the wound structure electrode assembly includes a first pole piece 201, a second pole piece 202 and a separator 203 disposed therebetween, the first pole piece includes a first current collector and a first active material layer disposed on the first current collector, and at least one pole ear extends from one side of the first current collector. Figure 6 As shown, the stacked electrode assembly includes a plurality of first pole pieces 201, a plurality of second pole pieces 202, and a plurality of diaphragms 203 disposed between the first pole pieces 201 and the second pole pieces 202. The first pole pieces 201 and the second pole pieces 202 are alternately stacked. In some embodiments, each pole piece extends a pole ear. Different structural types of the electrode assembly 20 are applicable to this case and are not specifically limited here.

[0060] In some embodiments, Figure 7 As shown, the first pole piece 201 is unfolded along the third direction Z, and the first pole piece 201 includes a first current collector 2011. One end of the first current collector 2011 extends in a direction opposite to the first direction to form a first pole ear 30, and the first pole ear 30 and the first current collector 2011 are integrally formed. Optionally, along the extension direction of the first current collector 2011, the ratio of the length D of the first pole ear 30 to the length H of the first current collector 2011 is in the range of 0.7 to 1.0. It can be understood that within this ratio range, the first pole ear 30 is easier to be arranged in the first conductive member 50. On the other hand, the larger the size of the first pole ear 30 along the extension direction of the first current collector 2011, the stronger the current flow capacity, the better the rate performance, and the better the heat dissipation performance. For the above-mentioned first conductive member 50, as shown in FIG. Figure 2 and Figure 3 As shown, the first conductive member 50 is disposed in the first hole 10b, wherein the first conductive member 50 is used to connect with the first electrode tab 30 and serve as an electrode of the electrochemical device. It should be noted that the polarity of the first conductive member 50 is not specifically limited, and its polarity is related to the polarity of the connected electrode tab.

[0061] In some embodiments, the first conductive member 50 is provided with a second cavity 50a, and the second cavity 50a is used to receive one end of the first electrode tab 30. It can be understood that Fig. 9 and Fig.10As shown, the shape of the second cavity 50a can be set according to actual needs, and the shape of the second cavity 50a can be rectangular, trapezoidal, etc.

[0062] In some embodiments, Fig.10 As shown, the cross-section of the second cavity includes a first end 50aa and a second end 50ab, the first end is located at one end away from the electrode assembly 20, and the second end is located at the other end close to the electrode assembly 20, and the area of ​​the cross-section close to the first end is smaller than the area of ​​the cross-section close to the second end, wherein the cross-section of the second cavity 50a is the cross-section of the second cavity 50a along the second direction Y.

[0063] In some embodiments, along a first direction X, such as Fig.10 As shown, the cross-sectional area of ​​the second cavity 50a gradually increases. In this way, the second cavity 50a is convenient for accommodating one end of the first electrode tab 30. It can be understood that the cross-sectional area of ​​the second cavity 50a gradually increases along the first direction X, and the shape of the cross section (vertical section) of the second cavity 50a along the first direction X can be a trapezoid.

[0064] In some embodiments, Fig.11 As shown, the cross-section of the first conductive member 50 includes a third end 50b and a fourth end 50c, the third end is located at one end away from the electrode assembly 20, and the fourth end is located at the other end close to the electrode assembly 20, and the area enclosed by the outer contour of the cross-section close to the third end is smaller than the area enclosed by the outer contour of the cross-section close to the fourth end, wherein the cross-section of the first conductive member 50 is a cross-section of the first conductive member 50 along the second direction Y.

[0065] In some embodiments, along a first direction X, such as Fig.11 As shown in FIG. 1 , the area enclosed by the outer contour of the cross section of the first conductive member 50 gradually increases. This arrangement facilitates the connection and sealing between the first conductive member 50 and the first cover 102. It can be understood that the connection between the first conductive member 50 and the first cover 102 can be, but is not limited to, welding, screwing, etc. Fig.12 As shown, the overall outer contour of the first conductive member 50 can be a convex shape, etc.

[0066] In some embodiments, Figure 13-Figure 16 As shown, the shape of the cross section (cross section) of the second cavity 50a along the second direction Y can be circular, rectangular, etc.

[0067] It should be noted that the first direction X is a direction from the second end of the first conductive element 50 to the first end of the first conductive element 50 , and the second direction Y is perpendicular to the first direction X.

[0068] In some embodiments, the first conductive member 50 is provided with a first protrusion 501 toward the second cavity 50a, and the second end of the first pole tab 30 is fixedly connected to the first protrusion 501, and the first protrusion 501 is used to increase the connection area with the first pole tab 30. It can be understood that the connection method between the first protrusion 501 and the first pole tab 30 can be, but is not limited to, a fixing method such as welding.

[0069] For the first electrode tab 30, Figure 2 As shown, the first end of the first electrode tab 30 is electrically connected to a pole piece of the electrode assembly 20 , and the second end of the first electrode tab 30 is disposed in the second cavity 50 a and electrically connected to the first conductive member 50 .

[0070] In some embodiments, Figure 17-Figure 19 As shown, for the first pole ear 30 that is directly formed on the first current collector 2011 without die-cutting, when the first pole ear 30 is arranged in the second cavity 50a and connected to the first conductive member 50, there is a situation where it is difficult for the electrolyte to penetrate into the electrode assembly 20. Therefore, in some embodiments, the first pole ear 30 is provided with at least one first recess 30a, and the at least one first recess forms a first channel 301, and the first channel 301 facilitates the electrolyte to flow into the first cavity 10a and penetrate the electrode assembly 20.

[0071] In some embodiments, Figure 20-21 As shown, the first electrode tab 30 is provided with at least one second recess, and the at least one second recess forms a second channel 302, and the second channel 302 facilitates the electrolyte to flow into the first cavity 10a, wherein the direction in which the first channel 301 extends and the direction in which the second channel 302 extends have a predetermined angle. The predetermined angle can be set according to actual needs and is not specifically limited, and the predetermined angle can be 90°, etc.

[0072] In some embodiments, the first electrode tab 30 is formed by extending from one end of the first current collector 2011 , and the first electrode tab 30 further includes a plurality of first sub-electrode tabs 31 connected to the first current collector 2011 .

[0073] For the first structural member 70, Figure 2 As shown, the first structural member 70 is disposed between the outer wall surface of the first conductive member 50 and the inner wall surface of the first hole 10 b , and the first structural member 70 can seal the connection between the first conductive member 50 and the housing 10 .

[0074] It can be understood that in the above-mentioned embodiments of the present application, the electrochemical device only includes the first pole ear 30, but in other embodiments of the present application, the electrochemical device may also include two or more pole ears, wherein the pole ear connected to the first pole piece of the two pole ears is defined as the first pole ear, and the pole ear connected to the second pole piece of the two pole ears is defined as the second pole ear. Next, the specific structure of the electrochemical device including the first pole ear and the second pole ear of the embodiment of the present application is explained.

[0075] like Fig. 22 and Fig.23 As shown, the electrochemical device further includes a second electrode tab 40, a second conductive member 60, and a second structural member 80. One end of the second electrode tab 40 is electrically connected to the electrode assembly 20, and the other end of the second electrode tab 40 is electrically connected to the second conductive member 60. The second conductive member 60 is disposed on the housing 10, and a portion of the second conductive member 60 is located inside the housing 10. The second structural member 80 is disposed at the connection between the housing 10 and the second conductive member 60.

[0076] In some embodiments, Fig.24 As shown, the housing 10 includes a shell 101, a first cover 102 and a second cover 103, the first cover 102 and the second cover 103 are respectively covered at both ends of the shell 101, the shell 101, the first cover 102 and the second cover 103 together enclose a first cavity 10a, the first hole 10b is located in the first cover 102, the second hole 10c is located in the second cover 103, the first conductive member 50 is connected to the first cover 102, and the second conductive member 60 is connected to the second cover 103. Optionally, the first cover 102 is insulated from the shell 101. In some embodiments, the shell 10 is cylindrical or square.

[0077] In some embodiments, Fig.24 As shown, the first structural member 70 is disposed at the connection between the first cover 102 and the housing 101, and the first structural member 70 can play a sealing role. Optionally, the first structural member 70 includes an insulating material.

[0078] In some embodiments, the housing 10 is further provided with a second hole 10 c , the second hole 10 c is connected to the first cavity 10 a , and the second hole 10 c is used to install the second conductive member 60 .

[0079] For the second electrode tab 40, Fig. 22 As shown, the first end of the second pole tab 40 is electrically connected to another pole piece of the electrode assembly 20 , and the second end of the second pole tab 40 is disposed in the third cavity 60 a and electrically connected to the second conductive member 60 .

[0080] It should be noted that the positions of the first electrode tab 30 and the second electrode tab 40 are not specifically limited. Fig.25As shown, the first pole tab 30 and the second pole tab 40 may be located on the same side, or, as shown in FIG. Fig.26 As shown, the first electrode tab 30 and the second electrode tab 40 may be located on opposite sides.

[0081] In some embodiments, a first end of the second electrode tab 40 is connected to the electrode assembly 20 , a second end of the second electrode tab 40 is connected to the housing 10 , and a portion of the housing 10 connected to the second electrode tab 40 is made of metal.

[0082] For the second conductive member 60, Fig. 22 and Fig.23 As shown, the second conductive member 60 is disposed in the second hole 10c, and the second conductive member 60 is used to connect with the second electrode tab 40 and serve as another electrode of the electrochemical device. It should be noted that the polarity of the first conductive member 50 and the second conductive member 60 is not specifically limited, as long as the polarity between the first conductive member 50 and the second conductive member 60 is opposite, and the polarity is related to the polarity of the connected electrode tab.

[0083] In some embodiments, the second conductive member 60 is provided with a third cavity 60 a, and the third cavity 60 a is used to accommodate one end of the second electrode tab 40 .

[0084] The specific structure and function of the second conductive element 60 may refer to the first conductive element 50 .

[0085] In some embodiments, the cross-section of the third cavity includes a fifth end and a sixth end, the fifth end is located at one end away from the electrode assembly, the sixth end is located at the other end close to the electrode assembly, and the area of ​​the cross-section close to the fifth end is smaller than the area of ​​the cross-section close to the sixth end.

[0086] In some embodiments, the area of ​​the cross section of the third cavity 60a gradually increases along the direction opposite to the first direction X. In this way, the third cavity 60a is convenient for accommodating one end of the second pole tab 40, wherein the cross section of the third cavity 60a is the cross section of the third cavity 60a along the second direction Y. It can be understood that the area of ​​the cross section of the third cavity 60a gradually increases along the direction opposite to the first direction X, and the shape of the cross section (vertical cross section) of the second cavity 50a along the direction opposite to the first direction X can be a trapezoid.

[0087] In some embodiments, the shape of the cross section (cross section) of the third cavity 60a along the second direction Y may be circular, rectangular, or the like.

[0088] In some embodiments, the cross-section of the second conductive member includes a seventh end and an eighth end, the seventh end is located at one end away from the electrode assembly, the eighth end is located at the other end close to the electrode assembly, and the area enclosed by the outer contour of the cross-section near the seventh end is smaller than the area enclosed by the outer contour of the cross-section near the eighth end.

[0089] In some embodiments, along the direction opposite to the first direction X, the area enclosed by the outer contour of the cross section of the second conductive member 60 gradually increases, wherein the cross section of the second conductive member 60 is the cross section of the second conductive member 60 along the second direction Y. This arrangement facilitates the connection and sealing between the second conductive member 60 and the second cover 103. It can be understood that the connection between the second conductive member 60 and the second cover 103 can be, but is not limited to, welding and the like, and the overall outer contour of the second conductive member 60 can be a trapezoid, a convex shape, and the like.

[0090] In some embodiments, the second conductive member 60 is provided with a second protrusion toward the third cavity 60a, and the second end of the second pole tab 40 is fixedly connected to the second protrusion, and the second protrusion is used to increase the connection area with the second pole tab 40. It can be understood that the connection method between the second protrusion and the second pole tab 40 can be, but is not limited to, a fixing method such as welding.

[0091] For the second structural member 80, Fig. 22 As shown, the second structural member 80 is disposed between the outer wall surface of the second conductive member 60 and the inner wall surface of the second hole 10c. The second structural member 80 can seal the connection between the second conductive member 60 and the housing 10.

[0092] In some embodiments, the second structural member 80 is disposed at the connection between the second cover 103 and the housing 101, and the second structural member 80 can play a sealing role. Optionally, the second structural member 80 includes an insulating material.

[0093] In the embodiment of the present application, a shell 10, an electrode assembly 20, a first pole ear 30 and a first conductive member 50 are provided, the shell 10 is provided with a first cavity 10a and a first hole 10b, the first hole 10b is connected to the first cavity 10a, the electrode assembly 20 is provided in the first cavity 10a, the first conductive member 50 is provided in the first hole 10b, the first conductive member 50 is provided with a second cavity 50a, the first end of the first pole ear 30 is electrically connected to the electrode assembly 20, the second end of the first pole ear 30 is provided in the second cavity 50a, and the second end of the first pole ear 30 is electrically connected to the first conductive member 50. In this way, the second end of the first pole ear 30 is provided in the second cavity 50a and is electrically connected to the first conductive member 50, which saves the internal space of the electrochemical device and reduces the impact on the energy density of the electrochemical device.

[0094] The embodiment of the present application also provides an embodiment of a battery module, the battery module includes the electrochemical device as described above, the function and structure of the electrochemical device can be referred to the above embodiment, and will not be described one by one here.

[0095] The present application also provides an example of an electronic device, which includes the battery module described above. The function and structure of the battery module can be referred to in the above embodiments, and will not be described in detail here. It is understandable that the electronic device can be an energy storage product, a mobile phone, a tablet, a drone, a one-wheeled or two-wheeled electric vehicle, or an electric cleaning tool, etc.

[0096] It should be noted that the preferred embodiments of the present application are given in the specification and drawings of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described in the specification. These embodiments are not used as additional limitations on the content of the present application. The purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all regarded as the scope of the description of the present application; further, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should belong to the scope of protection of the claims attached to the present application.

Claims

1. An electrochemical device, comprising a housing, an electrode assembly and at least two first tabs, wherein the housing is provided with a first cavity and a first hole, the first hole is connected to the first cavity, the electrode assembly is arranged in the first cavity, and the first ends of at least two first tabs are electrically connected to the electrode assembly, characterized in that: The electrochemical device further includes a first conductive member, which is disposed in the first hole and has a second cavity. The second ends of at least two of the first pole tabs are stacked and disposed in the second cavity, and the second ends of at least two of the first pole tabs are electrically connected to the first conductive member.

2. The electrochemical device according to claim 1, characterized in that The first conductive member is provided with a first protrusion toward the second cavity, and the second end of the first electrode tab is fixedly connected to the first protrusion.

3. The electrochemical device according to claim 1, characterized in that The cross-section of the second cavity includes a first end and a second end, the first end is located at one end away from the electrode assembly, and the second end is located at the other end close to the electrode assembly, and the area of ​​the cross-section close to the first end is smaller than the area of ​​the cross-section close to the second end, wherein the cross-section of the second cavity is a cross-section of the second cavity along the second direction.

4. The electrochemical device according to claim 3, characterized in that The cross-sectional area of ​​the second cavity gradually increases along a first direction, the first direction is a direction from the second end of the first conductive member to the first end of the first conductive member, and the second direction is perpendicular to the first direction.

5. The electrochemical device according to claim 1, characterized in that The cross-section of the first conductive member includes a third end and a fourth end, the third end is located at one end away from the electrode assembly, and the fourth end is located at the other end close to the electrode assembly, the area enclosed by the outer contour of the cross-section close to the third end is smaller than the area enclosed by the outer contour of the cross-section close to the fourth end, and the cross-section of the first conductive member is a cross-section of the first conductive member along the second direction.

6. The electrochemical device according to claim 5, characterized in that Along a first direction, an area enclosed by an outer contour of a cross section of the first conductive member gradually increases, wherein the first direction is a direction from the second end of the first conductive member to the first end of the first conductive member, and the second direction is perpendicular to the first direction.

7. The electrochemical device according to claim 1, characterized in that The first electrode tab is provided with at least one first recess, and the at least one first recess forms a first channel.

8. The electrochemical device according to claim 7, characterized in that The first electrode tab is further provided with at least one second recess, and the at least one second recess forms a second channel, wherein a direction in which the first channel extends and a direction in which the second channel extends have a predetermined angle.

9. The electrochemical device according to claim 1, characterized in that The electrode assembly includes a first pole piece, the first pole piece includes a first current collector, and one end of the first current collector extends to form the first pole ear.

10. The electrochemical device according to claim 9, characterized in that The first electrode tab includes a plurality of first sub-electrode tabs connected to the first current collector.

11. The electrochemical device according to claim 9, characterized in that Along the extension direction of the first current collector, a ratio of the length of the first electrode tab to the length of the first current collector is in a range of 0.7 to 1.

0.

12. The electrochemical device according to claim 1, characterized in that The electrochemical device further includes a first structural member disposed between an outer wall surface of the first conductive member and an inner wall surface of the first hole.

13. The electrochemical device according to claim 12, characterized in that The first structural member includes insulating material.

14. The electrochemical device according to claim 1, characterized in that The first conductive member protrudes from the outer surface of the housing.

15. The electrochemical device according to claim 1, characterized in that It also includes a second pole lug, wherein a first end of the second pole lug is connected to the electrode assembly, and a second end of the second pole lug is connected to the housing.

16. The electrochemical device according to claim 1, characterized in that It also includes a second pole ear and a second conductive member, the housing is provided with a second hole communicating with the cavity, the second conductive member is installed in the second hole, and the second conductive member is provided with a third cavity; The first end of the second pole tab is connected to the electrode assembly, the second end of the second pole tab is disposed in the third cavity, and the second end of the second pole tab is electrically connected to the second conductive member.

17. The electrochemical device according to claim 16, characterized in that The electrochemical device further includes a second structural member disposed between an outer wall of the second conductive member and an inner wall surface of the second hole.

18. The electrochemical device according to claim 16, characterized in that The shell includes a shell, a first cover body and a second cover body, the first cover body and the second cover body are respectively covered at two ends of the shell, the shell, the first cover body and the second cover body together enclose the first cavity, the first hole is located in the first cover body, and the second hole is located in the second cover body.

19. The electrochemical device according to claim 18, characterized in that The first conductive member is connected to the first cover, and the first cover is insulated from the shell.

20. The electrochemical device according to claim 1, characterized in that The shell is cylindrical or square.

21. A battery module, characterized in that: An electrochemical device comprising any one of claims 1 to 20.

22. An electronic device, characterized in that: Comprising the battery module as claimed in claim 21.

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