Battery cell and electric device

Abstract

The present application provides a battery cell and an electric device. The battery cell comprises an electrode assembly. The electrode assembly has a laminated structure. The electrode assembly comprises multiple first electrode sheets, multiple second electrode sheets, and multiple separators. Each first electrode sheet comprises a first uncoated region, each second electrode sheet comprises a first notch, and in a first direction, at least a portion of the first uncoated region is exposed to the first notch; the first notch comprises a first edge and a second edge connected to each other, and in a second direction, the first uncoated region extends beyond the first edge; and each separator comprises a first protruding portion extending beyond a corresponding second edge in a third direction, first protruding portions of the multiple separators are connected to each other, and when viewed in the first direction, the first protruding portions are located in the first notches. The insulation between the first uncoated regions and the second electrode sheets can be achieved, and when the battery cell is subjected to external force or falls, the possibility of a short circuit resulting from contact between the first uncoated regions and the second electrode sheets is relatively low, thereby making the battery cell safer, and generating less impact on the energy density of the battery cell.

Description

Battery cell and electric device Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. CN202410840359.3, filed on June 26, 2024, entitled “Battery cell and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery cell and an electric device. BACKGROUND

[0003] With the rapid development of electronic information technology, various electronic devices are also developing towards intelligence and multifunction, and the safety requirements for batteries are also becoming higher and higher.

[0004] At present, the tab of the battery cell is generally insulated from the polar plate of opposite polarity by attaching adhesive paper. However, the overlap of the adhesive paper and the active material layer of the battery cell increases the thickness of the battery cell, affecting the energy density of the battery cell. SUMMARY

[0005] The present application provides a battery cell and an electric device, which can improve the energy density of the battery cell.

[0006] In a first aspect, the present application provides a battery cell, the battery cell comprising an electrode assembly, the electrode assembly being a stacked plate structure, the electrode assembly comprising a plurality of first polar plates, a plurality of second polar plates and a plurality of separators, the first polar plates and the second polar plates being of opposite polarity, the plurality of first polar plates and the plurality of second polar plates being stacked in a first direction, and the plurality of separators being arranged between the first polar plates and the second polar plates; each first polar plate has a first empty foil area, and each second polar plate has a first notch, at least part of the first empty foil area being exposed to the first notch in the first direction; the first notch has a first edge and a second edge, the first edge being connected to the second edge, and the first empty foil area exceeding the first edge in a second direction; the separator has a first overhanging portion exceeding the second edge in a third direction, and the first overhanging portions of the plurality of separators are connected; the first overhanging portion is located in the first notch when viewed in the first direction; the first direction is the thickness direction of the electrode assembly, and the first direction, the second direction and the third direction are perpendicular to each other.

[0007] In the technical solution, each first pole piece has a first foil-exposed region, each second pole piece has a first gap, and at least part of the first foil-exposed region is exposed to the first gap in the first direction, which can reduce the volume of the first foil-exposed region protruding from the electrode assembly, so that the spacing space reserved between the electrode assembly and the shell for accommodating the first foil-exposed region is smaller, which is beneficial to improve the energy density of the battery cell, and when the battery cell is subjected to an external force, the electrode assembly is less likely to shake relative to the shell, and the first foil-exposed region is less likely to be in contact with the second pole piece to cause a short circuit, which can reduce the risk of thermal runaway of the battery cell; the separator has a first overhanging portion that extends beyond the second edge in the third direction, and the first overhanging portions of the plurality of separators are connected, so that the first overhanging portions of the plurality of separators can achieve insulation between the first foil-exposed region and the second pole piece, and when the battery cell is subjected to an external force or falls, the first foil-exposed region is less likely to be in contact with the second pole piece to cause a short circuit, so that the safety of the battery cell is higher, and the first overhanging portion does not increase the thickness of the electrode assembly, and the first overhanging portion located in the first gap does not extend beyond the edges of the electrode assembly in the length direction or the width direction, which has little effect on the energy density of the battery cell.

[0008] In some embodiments of the present application, the electrode assembly has a first side and a second side opposite in the first direction; in the first direction, the first overhanging portions of the plurality of separators are gathered towards the first side and connected.

[0009] In the technical solution, by gathering the first overhanging portions of the plurality of separators towards the first side and connecting them in the first direction, the connection mode of the first overhanging portions of the plurality of separators is simple and easy to operate.

[0010] In some embodiments of the present application, the plurality of separators includes a first separator located at the second side, the first overhanging portion of the first separator has a width W1 in the third direction, and the thickness H1 of the electrode assembly satisfies W1≥H1.

[0011] In the technical solution, by making the width W1 of the first overhanging portion of the first separator in the third direction and the thickness H1 of the electrode assembly satisfy W1≥H1, the first overhanging portion of the first separator can extend to the second side of the electrode assembly, so that the first overhanging portions of the plurality of separators can be connected at the first side of the electrode assembly, thereby facilitating the preparation of the battery cell.

[0012] In some embodiments of the present application, the plurality of separators includes a first separator located at the second side, the first overhanging portion of the first separator has a width W1 in the third direction, and the thickness H1 of the electrode assembly satisfies W1≥H1.

[0013] In the technical solution, by making the width W1 of the first overhanging portion of the first separator in the third direction satisfy W1≥2mm, the first overhanging portion of the first separator can extend to the first side of the electrode assembly, so that the first overhanging portions of the plurality of separators can be connected at the first side of the electrode assembly.

[0014] In some embodiments of the present application, the plurality of diaphragms includes a second diaphragm located at the first side, and a first overhanging portion of the second diaphragm has a width W2 along the third direction, satisfying W2≥0.2mm.

[0015] In the above technical solution, by making the width W2 of the first overhanging portion of the second diaphragm along the third direction satisfy W2≥0.2mm, the first overhanging portion of the second diaphragm can be connected with the first overhanging portion of the other diaphragm, so that the connection area is larger and the connection reliability is higher.

[0016] In some embodiments of the present application, the first overhanging portions of the plurality of diaphragms are connected to form a connection portion, and the connection portion has a gap with the first empty foil area when viewed along the third direction.

[0017] In the above technical solution, by making the connection portion have a gap with the first empty foil area when viewed along the third direction, the possibility of interference between the connection portion and the first empty foil area can be reduced, which facilitates subsequent processing of the first empty foil area, and the possibility of separation of the first overhanging portions of the plurality of diaphragms due to interference between the connection portion and other components can be reduced, thereby further reducing the possibility of contact short circuit between the first empty foil area and the second pole piece, so that the safety of the battery cell is higher.

[0018] In some embodiments of the present application, the first overhanging portions of the plurality of diaphragms are gathered to the middle in the first direction and connected.

[0019] In the above technical solution, by making the first overhanging portions of the plurality of diaphragms gathered to the middle in the first direction and connected, the connection mode of the first overhanging portions of the plurality of diaphragms can be simpler and easier to operate, and the width of the first overhanging portion of the first diaphragm located at the second side and the first overhanging portion of the second diaphragm located at the first side can be smaller, so that the possibility of interference between the first overhanging portions of the plurality of diaphragms and the first empty foil area when connected is smaller, further facilitating the connection of the first overhanging portions of the plurality of diaphragms.

[0020] In some embodiments of the present application, the first overhanging portions of the plurality of diaphragms are hot melt bonded.

[0021] In the above technical solution, by making the first overhanging portions of the plurality of diaphragms hot melt bonded, the possibility of separation of the first overhanging portions of the plurality of diaphragms after being soaked in electrolyte is smaller, so that the first overhanging portions of the plurality of diaphragms can maintain insulation to the first empty foil area and the second pole piece, further reducing the possibility of contact short circuit between the first empty foil area and the second pole piece, so that the safety of the battery cell is higher.

[0022] In some embodiments of the present application, the first empty foil area is located at a first corner position of the first pole piece, and the first notch is located at a second corner position of the second pole piece.

[0023] In the technical solution, the first foil-free area is located at the first corner of the first pole piece, and the first notch is located at the second corner of the second pole piece, so that the first notch and the first foil-free area are easy to manufacture, and the first foil-free area is easy to lead out.

[0024] In some embodiments of the present application, the second pole piece has a second foil-free area located at a third corner, the first pole piece has a second notch located at a fourth corner, and along the first direction, the second foil-free area at least partially overlaps the second notch; the second notch has a third edge and a fourth edge, the third edge is connected with the fourth edge, and along the second direction, the second foil-free area exceeds the third edge; the diaphragm has a second excess portion exceeding the fourth edge along the third direction, and the second excess portions of the plurality of diaphragms are connected.

[0025] In the technical solution, along the first direction, the second foil-free area at least partially overlaps the second notch, so that the volume of the second foil-free area protruding from the electrode assembly is reduced, the spacing space reserved between the electrode assembly and the shell for accommodating the second foil-free area is small, which is conducive to improving the energy density of the battery cell, and when the battery cell is subjected to an external force, the possibility of the electrode assembly shaking relative to the shell is small, and the possibility of the second foil-free area contacting the first pole piece and short-circuiting is also small, which can reduce the risk of thermal runaway of the battery cell; the second foil-free area is located at the third corner of the second pole piece, and the second notch is located at the fourth corner of the first pole piece, so that the second notch and the second foil-free area are easy to manufacture, and the second foil-free area is easy to lead out; the diaphragm has a second excess portion exceeding the fourth edge along the third direction, and the second excess portions of the plurality of diaphragms are connected, so that the second excess portions of the plurality of diaphragms can realize insulation between the second foil-free area and the first pole piece, the possibility of the second foil-free area contacting the first pole piece and short-circuiting when the battery cell is subjected to an external force or falls is low, the safety of the battery cell is high, and the second excess portion does not increase the thickness of the electrode assembly, which is conducive to improving the energy density of the battery cell.

[0026] In some embodiments of the present application, the first notch has a fifth edge, the fifth edge is spaced apart from the second edge along the third direction, and the first edge connects the second edge and the fifth edge; the diaphragm has a third excess portion exceeding the fifth edge along the third direction, and the third excess portions of the plurality of diaphragms are connected.

[0027] In the technical solution, the diaphragm has a third excess portion exceeding the fifth edge along the third direction, and the third excess portions of the plurality of diaphragms are connected, so that the third excess portions of the plurality of diaphragms can realize insulation between the first foil-free area and the second pole piece, the possibility of the first foil-free area contacting the second pole piece and short-circuiting when the battery cell is subjected to an external force or falls is low, the safety of the battery cell is high, and the third excess portion does not increase the thickness of the electrode assembly, which is conducive to improving the energy density of the battery cell.

[0028] In a second aspect, the present application provides a power-using device comprising the battery cell as described above, and the battery cell is configured to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. Other related drawings can also be obtained by those skilled in the art according to these drawings.

[0030] Fig. 1 is a perspective structural schematic view of a battery cell provided by some embodiments of the present application;

[0031] Fig. 2 is a perspective schematic view of a partial structure of a battery cell provided by some embodiments of the present application;

[0032] Fig. 3 is an exploded schematic view of a partial structure of a battery cell provided by some embodiments of the present application;

[0033] Fig. 4 is a structural schematic view of a first pole piece of a battery cell provided by some embodiments of the present application;

[0034] Fig. 5 is a structural schematic view of a second pole piece of a battery cell provided by some embodiments of the present application;

[0035] Fig. 6 is a schematic view of a partial structure of a battery cell provided by some embodiments of the present application in a state before a first overhanging portion is folded;

[0036] Fig. 7 is a schematic view of a partial structure of a battery cell provided by some embodiments of the present application in a state after a first overhanging portion is folded;

[0037] Fig. 8 is a partial enlarged structural schematic view of a battery cell at position A in Fig. 6;

[0038] Fig. 9 is a partial enlarged structural schematic view of a battery cell at position B in Fig. 2;

[0039] Fig. 10 is a partial enlarged structural schematic view of a battery cell at position C in Fig. 6;

[0040] Fig. 11 is a structural schematic view of a separator of a battery cell provided by some embodiments of the present application;

[0041] Fig. 12 is a schematic view of a partial structure of a battery cell provided by some other embodiments of the present application;

[0042] Fig. 13 is a structural schematic view of a second pole piece of a battery cell provided by some other embodiments of the present application.

[0043] Icon: 10 - cell; 100 - electrode assembly; 110 - first tab; 111 - first empty foil area; 112 - second notch; 1121 - third edge; 1122 - fourth edge; 120 - second tab; 121 - first notch; 1211 - first edge; 1212 - second edge; 1213 - fifth edge; 122 - second empty foil area; 130 - separator; 130a first separator; 130b - second separator; 131 - first overhang; 132 - second overhang; 133 - third notch; 134 - fourth notch; 135 - third overhang; 200 - housing; 310 - first electrical connector; 320 - second electrical connector; 330 - first seal; 340 - second seal; X - first direction; Y - second direction; Z - third direction. DETAILED DESCRIPTION

[0044] For the purpose of the present application, the technical solutions and advantages will be more clearly described below, the technical solutions in the embodiments of the present application will be clearly described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of 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" in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0046] The terms "first", "second", etc. in the specification and claims of the present application or in the above description of drawings are used to distinguish different objects, rather than to describe a specific order or primary and secondary relationship.

[0047] In the present application, "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0048] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0049] The battery has the advantages of high energy density, small environmental pollution, large power density, long service life, wide application range, small self-discharge coefficient and the like, and is an important part of the development of new energy. With the development of the new energy industry, the battery gradually develops towards high energy density and high power density. However, the volume of the battery compartment for accommodating the battery cell is limited, so that the way of increasing the energy density of the battery cell by increasing the volume of the battery cell is limited. Therefore, it is more feasible to improve the energy density of the battery cell by changing the structure of the battery cell itself.

[0050] At present, the tab of the battery cell is generally insulated from the pole piece with opposite polarity by attaching adhesive paper. However, in order to make the adhesive paper more firmly attached, the adhesive area of the adhesive paper needs to be larger. Therefore, part of the adhesive paper for tab insulation is attached to the active material layer of the pole piece, that is, the adhesive paper overlaps the active material layer of the battery cell in the thickness direction of the battery cell, which increases the thickness of the battery cell and affects the energy density of the battery cell.

[0051] In order to improve the energy density of the battery cell, the present application provides a battery cell, which comprises an electrode assembly, the electrode assembly is a laminated structure, the electrode assembly comprises a plurality of first pole pieces, a plurality of second pole pieces and a plurality of separators, the first pole pieces and the second pole pieces are opposite in polarity, the plurality of first pole pieces and the plurality of second pole pieces are stacked in a first direction, and the plurality of separators are arranged between the first pole pieces and the second pole pieces; each first pole piece has a first empty foil area, each second pole piece has a first notch, at least part of the first empty foil area is exposed to the first notch in the first direction; the first notch has a first edge and a second edge, the first edge is connected with the second edge, and the first empty foil area exceeds the first edge in a second direction; the separator has a first overhanging part which exceeds the second edge in a third direction, and the first overhanging parts of the plurality of separators are connected; the first overhanging part is located in the first notch when viewed in the first direction; the first direction is the thickness direction of the electrode assembly, and the first direction, the second direction and the third direction are perpendicular to each other.

[0052] In the battery cell with the structure, each first tab has a first empty foil area, each second tab has a first notch, at least part of the first empty foil area is exposed to the first notch along the first direction, the volume of the first empty foil area protruding from the electrode assembly can be reduced, the spacing space reserved between the electrode assembly and the shell for accommodating the first empty foil area is smaller, which is conducive to improving the energy density of the battery cell, and the possibility of the electrode assembly shaking relative to the shell when the battery cell is subjected to an external force is smaller, the possibility of the first empty foil area contacting the second tab and short circuiting is also smaller, which can reduce the risk of thermal runaway of the battery cell; the separator has a first overhanging part beyond the second edge along the third direction, the first overhanging parts of the plurality of separators are connected, so that the first empty foil area and the second tab can be insulated, and the possibility of the first empty foil area contacting the second tab and short circuiting when the battery cell is subjected to an external force or falls is lower, so that the safety of the battery cell is higher, and the first overhanging part does not increase the thickness of the electrode assembly, and the first overhanging part located in the first notch does not exceed the edges of the electrode assembly in the length direction or the width direction, and has little effect on the energy density of the battery cell.

[0053] The battery cell provided by the embodiments of the present application can be a secondary battery or a primary battery, for example, can be a lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., and the embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc., and the embodiments of the present application are not limited thereto.

[0054] The embodiments of the present application provide a power consumption device using the battery cell as a power supply, which can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric car, an electric vehicle, a ship, a spacecraft, etc.

[0055] Referring to FIGS. 1-3, FIG. 1 is a perspective structural schematic diagram of a battery cell according to some embodiments of the present application; FIG. 2 is a perspective schematic diagram of a partial structure of the battery cell according to some embodiments of the present application; and FIG. 3 is an exploded schematic diagram of a partial structure of the battery cell according to some embodiments of the present application.

[0056] Some embodiments of the present application provide a battery cell 10, which includes an electrode assembly 100, the electrode assembly 100 is a laminated structure, the electrode assembly 100 includes a plurality of first tabs 110, a plurality of second tabs 120 and a plurality of separators 130, the first tabs 110 and the second tabs 120 are opposite in polarity, the plurality of first tabs 110 and the plurality of second tabs 120 are arranged in a stack along a first direction X, and the plurality of separators 130 are arranged between the first tabs 110 and the second tabs 120.

[0057] Referring to FIGS. 4 and 5, FIG. 4 is a structural schematic diagram of a first tab of a battery cell according to some embodiments of the present application; and FIG. 5 is a structural schematic diagram of a second tab of a battery cell according to some embodiments of the present application.

[0058] In some embodiments, each first tab 110 has a first foil empty area 111, and each second tab 120 has a first notch 121, at least part of the first foil empty area 111 is exposed to the first notch 121 along the first direction X.

[0059] By making each first tab 110 have a first foil empty area 111, and each second tab 120 have a first notch 121, at least part of the first foil empty area 111 is exposed to the first notch 121 along the first direction X, the volume of the first foil empty area 111 protruding out of the electrode assembly 100 can be reduced, so that the spacing space reserved between the electrode assembly 100 and the shell for accommodating the first foil empty area 111 is smaller, which is conducive to improving the energy density of the battery cell 10, and when the battery cell 10 is subjected to external force, the possibility of the electrode assembly 100 shaking relative to the shell is smaller, and the possibility of the first foil empty area 111 contacting the second tab 120 and short-circuiting is also smaller, which can reduce the risk of thermal runaway of the battery cell 10.

[0060] In some embodiments, the battery cell 10 is arranged in a rectangular cuboid, and the top corner is arranged in a rounded corner, which can better adapt to the rounded battery compartment in the electrical equipment.

[0061] In other embodiments, the top corner of the battery cell 10 can also be arranged in a square corner.

[0062] Referring to FIGS. 6-9, FIG. 6 is a schematic view of a part of the structure of the battery cell in a state before the first overhanging part is folded in accordance with some embodiments of the present application; FIG. 7 is a schematic view of a part of the structure of the battery cell in a state after the first overhanging part is folded in accordance with some embodiments of the present application; FIG. 8 is a schematic view of a part of the structure of the battery cell in a state before the first overhanging part is folded in accordance with some embodiments of the present application; and FIG. 9 is a schematic view of a part of the structure of the battery cell in a state after the first overhanging part is folded in accordance with some embodiments of the present application.

[0063] In some embodiments, the first notch 121 has a first edge 1211 and a second edge 1212, the first edge 1211 is connected with the second edge 1212, and the first foil empty area 111 protrudes beyond the first edge 1211 along the second direction Y. The separator 130 has a first overhanging part 131 protruding beyond the second edge 1212 along the third direction Z, and the first overhanging parts 131 of the plurality of separators 130 are connected. The first direction X is the thickness direction of the electrode assembly 100, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. When viewed along the first direction X, the first overhanging part 131 is located within the first notch 121, and the first notch 121 refers to the area enclosed by the extension lines of the edges of the battery cell in the second direction Y and the third direction Z and the first edge 1211 and the second edge 1212. The first overhanging part 131 located within the first notch 121 will not protrude beyond the edges in the length direction or the width direction of the battery cell, and will not affect the energy density of the battery cell.

[0064] By making the diaphragm 130 have the first overhang 131 beyond the second edge 1212 along the third direction Z, the first overhangs 131 of the plurality of diaphragms 130 are connected, so that the first overhangs 131 of the plurality of diaphragms 130 can realize the insulation between the first empty foil area 111 and the second tab 120, and can make the possibility of the first empty foil area 111 and the second tab 120 being in contact and short-circuiting when the battery cell 10 is subjected to external force or falling lower, so that the safety of the battery cell 10 is higher, and the first overhang 131 will not increase the thickness of the electrode assembly 100, which is beneficial to improve the energy density of the battery cell 10.

[0065] In some embodiments, the electrode assembly 100 has a first side and a second side opposite along the first direction X. Along the first direction X, the first overhangs 131 of the plurality of diaphragms 130 are gathered and connected towards the first side.

[0066] By making the first overhangs 131 of the plurality of diaphragms 130 be gathered and connected towards the first side along the first direction X, the connection mode of the first overhangs 131 of the plurality of diaphragms 130 can be simple and easy to operate.

[0067] In some embodiments, the plurality of diaphragms 130 includes a first diaphragm 130a located at the second side, the width of the first overhang 131 of the first diaphragm 130a along the third direction Z is W1, the thickness of the electrode assembly 100 is H1, and W1≥H1 is satisfied. For example, W1 can be H1, 1.1*H1 or 1.3*H1, etc.

[0068] Wherein, the width of the first overhang 131 along the third direction Z is the width of the first overhang 131 in the unfolded state (i.e. before gathering).

[0069] By making the width W1 of the first overhang 131 of the first diaphragm 130a along the third direction Z and the thickness H1 of the electrode assembly 100 satisfy W1≥H1, the first overhang 131 of the first diaphragm 130a can extend to the first side of the electrode assembly 100, so that the first overhangs 131 of the plurality of diaphragms 130 can be connected at the first side of the electrode assembly 100, thereby facilitating the preparation of the battery cell 10.

[0070] In some embodiments, the width of the first overhang 131 of the diaphragm 130 along the third direction Z is greater than or equal to the distance of the diaphragm 130 to the first side along the first direction X. For example, the width of the first overhang 131 of the diaphragm 130 located at the middle of the electrode assembly along the first direction X along the third direction Z is greater than or equal to H1 / 2.

[0071] By making the width of the first overhang 131 of the separator 130 along the third direction Z greater than or equal to the distance of the separator 130 along the first direction X to the first side, the first overhang 131 of each of the plurality of separators 130 can extend to the first side of the electrode assembly 100, so that the first overhang 131 of each of the plurality of separators 130 can be connected at the first side of the electrode assembly 100, thereby facilitating the preparation of the battery cell 10.

[0072] In some embodiments, the plurality of separators 130 includes a first separator 130a located at the second side, and the width of the first overhang 131 of the first separator 130a along the third direction Z is W1, which satisfies W1≥2 mm. For example, W1 can be 2 mm, 2.1 mm, or 2.3 mm, etc.

[0073] By making the width W1 of the first overhang 131 of the first separator 130a along the third direction Z satisfy W1≥2 mm, the first overhang 131 of the first separator 130a can extend to the first side of the electrode assembly 100, so that the first overhang 131 of each of the plurality of separators 130 can be connected at the first side of the electrode assembly 100.

[0074] In some embodiments, the plurality of separators 130 includes a second separator 130b located at the first side, and the width of the first overhang 131 of the second separator 130b along the third direction Z is W2, which satisfies W2≥0.2 mm. For example, W2 can be 0.2 mm, 0.25 mm, or 0.3 mm, etc.

[0075] By making the width W2 of the first overhang 131 of the second separator 130b along the third direction Z satisfy W2≥0.2 mm, the first overhang 131 of the second separator 130b can be connected with the first overhang 131 of the other separators 130, so that the connection area is larger and the connection reliability is higher.

[0076] In some embodiments, the distance of the separator 130 along the first direction X to the first side is S, and the width of the first overhang 131 of the separator 130 along the third direction Z is greater than or equal to S+0.2 mm. For example, the width of the first overhang 131 of the separator 130 along the third direction Z is S+0.2 mm, S+0.25 mm, or S+0.3 mm, etc.

[0077] By making the width of the first overhang 131 of the separator 130 along the third direction Z greater than or equal to S+0.2 mm, the first overhang 131 of each of the plurality of separators 130 can extend to the first side of the electrode assembly 100, and the first overhang 131 of each of the plurality of separators 130 can be connected at the first side of the electrode assembly 100, thereby facilitating the preparation of the battery cell 10.

[0078] In some embodiments, the first overhanging portions 131 of the plurality of separators 130 are connected to form a connection portion, and the connection portion has a gap with the first empty foil area 111 when viewed along the third direction Z.

[0079] By making the connection portion have a gap with the first empty foil area 111 when viewed along the third direction Z, the possibility of interference between the connection portion and the first empty foil area 111 can be reduced, facilitating subsequent processing of the first empty foil area 111, and the possibility of separation of the first overhanging portions 131 of the plurality of separators 130 due to interference between the connection portion and other components can be reduced, thereby further reducing the possibility of contact short circuit between the first empty foil area 111 and the second pole piece 120, so that the safety of the battery cell 10 is higher.

[0080] In some embodiments, the first overhanging portions 131 of the plurality of separators 130 are gathered towards the middle in the first direction X and connected.

[0081] The gathering of the first overhanging portions 131 of the present application refers to pressing the first overhanging portions 131 together along the first direction X.

[0082] By making the first overhanging portions 131 of the plurality of separators 130 gathered towards the middle in the first direction X and connected, the connection method of the first overhanging portions 131 of the plurality of separators 130 can be made simpler and easier to operate, and the width of the first overhanging portion 131 of the first separator 130a on the second side and the first overhanging portion 131 of the second separator 130b on the first side can be made smaller, so that the possibility of interference between the first overhanging portions 131 of the plurality of separators 130 and the first empty foil area 111 when connected can be reduced, further facilitating the connection of the first overhanging portions 131 of the plurality of separators 130.

[0083] In some embodiments, the first overhanging portions 131 of the plurality of separators 130 are hot melt bonded.

[0084] Currently, in a battery cell in which a tab is insulated by adhesive tape, the adhesive tape is stacked with the tab along the first direction, and by attaching two pieces of adhesive tape on both sides of the tab along the first direction, the two pieces of adhesive tape are bonded on both sides of the tab along the third direction, which can achieve tab covering, thereby insulating the tab from the pole piece. However, after the adhesive tape is soaked in electrolyte, the adhesion decreases, which can easily cause the bonded part of the two pieces of adhesive tape to separate, resulting in exposure of the tab, and a high risk of contact short circuit between the tab and the pole piece.

[0085] In the present application, by heat-welding the first overhanging portions 131 of the plurality of diaphragms 130, the first overhanging portions 131 of the plurality of diaphragms 130 are formed in one piece, which can reduce the possibility of the first overhanging portions 131 of the plurality of diaphragms 130 separating after being soaked in electrolyte, so that the first overhanging portions 131 of the plurality of diaphragms 130 can maintain insulation of the first hollow foil area 111 and the second tab 120, further reducing the possibility of the first hollow foil area 111 contacting the second tab 120 and short-circuiting, so that the safety of the battery cell 10 is higher.

[0086] In some embodiments, when the diaphragm 130 is prepared, the width of the first overhanging portion 131 of the diaphragm 130 can be set to be larger, for example, the width of the first overhanging portion 131 of each diaphragm 130 is greater than the thickness of the electrode assembly 100, after the first overhanging portions 131 of the plurality of diaphragms 130 are gathered and heat-welded, a connecting portion is formed, and the connecting portion is cut, so that there is a gap between the connecting portion and the first hollow foil area 111 along the third direction Z.

[0087] In other embodiments, the diaphragm 130 can also be prepared according to the required width of the first overhanging portion 131 of each layer 130 diaphragm when the diaphragm 130 is prepared, for example, for the first diaphragm 130a located on the second side of the electrode assembly 100, the width of the first overhanging portion 131 of the first diaphragm 130a is greater than or equal to the thickness of the electrode assembly 100, and for the second diaphragm 130b located on the first side of the electrode assembly 100, the width of the first overhanging portion 131 of the second diaphragm 130b is less than the spacing distance between the first hollow foil area 111 and the second tab 120 along the third direction Z, so that after the first overhanging portions 131 of the plurality of diaphragms 130 are gathered and heat-welded, a connecting portion is formed, so that there is a gap between the connecting portion and the first hollow foil area 111 along the third direction Z.

[0088] In some embodiments, the first hollow foil area 111 is located at a first corner position of the first tab 110, and the first notch 121 is located at a second corner position of the second tab 120.

[0089] By locating the first hollow foil area 111 at the first corner position of the first tab 110 and locating the first notch 121 at the second corner position of the second tab 120, the preparation of the first notch 121 and the first hollow foil area 111 can be facilitated, and the leading out of the first hollow foil area 111 can be facilitated.

[0090] The corner position in the present application refers to the position at the top corner of the tab. For example, the first corner position is the position formed by the edge of the first tab 110 along the second direction Y and the edge along the third direction X.

[0091] In some embodiments, the first corner position and the second corner position are two adjacent corner positions of the first tab 110.

[0092] By making the first corner position and the second corner position two adjacent corner positions of the first tab 110, the first empty foil area 111 and the second empty foil area 122 can be led out from the same end of the electrode assembly 100, which facilitates the electrical connection between the battery cell 10 and the external device through the first empty foil area 111 and the second empty foil area 122.

[0093] In other embodiments, the first corner position and the second corner position can be two opposite corner positions of the first tab 110. This can be applicable to the structure in which the first empty foil area 111 and the second empty foil area 122 are led out from opposite ends of the battery cell 10.

[0094] Referring to FIGS. 4 to 6 and 10, FIG. 10 is a partial enlarged structure schematic view of the battery cell at C in FIG. 6.

[0095] In some embodiments, the second tab 120 has a second empty foil area 122 at a third corner position, and the first tab 110 has a second notch 112 at a fourth corner position, and the second empty foil area 122 at least partially overlaps the second notch 112 along the first direction X.

[0096] By making the second empty foil area 122 at least partially overlap the second notch 112 along the first direction X, the volume of the second empty foil area 122 protruding from the electrode assembly 100 can be reduced, so that the spacing space reserved between the electrode assembly 100 and the shell for accommodating the second empty foil area 122 is smaller, which is beneficial to improve the energy density of the battery cell 10, and when the battery cell 10 is subjected to an external force, the electrode assembly 100 is less likely to shake relative to the shell, and the second empty foil area 122 is less likely to contact the first tab 110 and short circuit, which can reduce the risk of thermal runaway of the battery cell 10.

[0097] By making the second empty foil area 122 at the third corner position of the second tab 120 and the second notch 112 at the fourth corner position of the first tab 110, the preparation of the second notch 112 and the second empty foil area 122 can be facilitated, and the leading out of the second empty foil area 122 can be facilitated.

[0098] In some embodiments, the second notch 112 has a third edge 1121 and a fourth edge 1122, the third edge 1121 is connected with the fourth edge 1122, and the second empty foil area 122 exceeds the third edge 1121 along the second direction Y. The separator 130 has a second overhanging portion 132 exceeding the fourth edge 1122 along a third direction Z, and the second overhanging portions 132 of the plurality of separators 130 are connected.

[0099] By making the diaphragm 130 have a second overhang 132 beyond the fourth edge 1122 along the third direction Z, the second overhangs 132 of the plurality of diaphragms 130 are connected, so that the second overhangs 132 of the plurality of diaphragms 130 can realize the insulation between the second empty foil area 122 and the first tab 110, and can make the possibility of the second empty foil area 122 and the first tab 110 being in contact and short-circuiting when the battery cell 10 is subjected to external force or falling lower, so that the safety of the battery cell 10 is higher, and the second overhang 132 will not increase the thickness of the electrode assembly 100, which is beneficial to improve the energy density of the battery cell 10.

[0100] Referring to FIG. 3 and FIG. 11, FIG. 11 is a structural schematic diagram of a diaphragm of a battery cell provided in some embodiments of the present application.

[0101] In some embodiments, the diaphragm 130 has a third notch 133 and a fourth notch 134, and along the first direction X, the first empty foil area 111 at least partially overlaps the third notch 133, and the second empty foil area 122 at least partially overlaps the fourth notch 134.

[0102] By making the diaphragm 130 have a third notch 133 and a fourth notch 134, and along the first direction X, the first empty foil area 111 at least partially overlaps the third notch 133, and the second empty foil area 122 at least partially overlaps the fourth notch 134, so that the third notch 133 can be used to accommodate the first empty foil area 111, and the fourth notch 134 can be used to accommodate the second empty foil area 122, which can facilitate the connection of the plurality of first empty foil areas 111 and the plurality of second empty foil areas 122, respectively.

[0103] In some embodiments, the first notch 121 and the second empty foil area 122 are located at one end of the second tab 120 along the second direction Y, and the first notch 121 and the second empty foil area 122 are spaced apart along the third direction Z.

[0104] By making the first notch 121 and the second empty foil area 122 located at one end of the second tab 120 along the second direction Y, the first empty foil area 111 and the second empty foil area 122 can be led out from one end of the electrode assembly 110 along the second direction Y, which facilitates the electrical connection between the battery cell 10 and the external device through the first empty foil area 111 and the second empty foil area 122. The first notch 121 and the second empty foil area 122 are spaced apart along the third direction Z, which can reduce the possibility of the first empty foil area 111 and the second tab 120, and the second empty foil area 122 and the first tab 110 being in contact and short-circuiting, thereby reducing the possibility of thermal runaway of the battery cell 10 and improving the safety of the battery cell 10.

[0105] In some embodiments, the third angle and the fourth angle are two adjacent angles of the second tab 120.

[0106] By making the third corner and the fourth corner two adjacent corners of the second tab 120, the first empty foil area 111 and the second empty foil area 122 can be led out from the same end of the electrode assembly 100, which facilitates the electrical connection between the battery cell 10 and the external device through the first empty foil area 111 and the second empty foil area 122.

[0107] In other embodiments, the third corner and the fourth corner can be two opposite corners of the second tab 120. This can be applicable to the structure in which the first empty foil area 111 and the second empty foil area 122 are led out from opposite ends of the battery cell 10.

[0108] In some embodiments, the first tab 110 is a positive electrode tab, and the second tab 120 is a negative electrode tab.

[0109] Referring to FIGS. 12 and 13, FIG. 12 is a schematic view of one perspective of a partial structure of a battery cell according to other embodiments of the present application, and FIG. 13 is a schematic view of a structure of a second tab of a battery cell according to other embodiments of the present application.

[0110] In other embodiments, the first notch 121 has a fifth edge 1213 spaced apart from the second edge 1212 along the third direction Z, and the first edge 1211 connects the second edge 1212 and the fifth edge 1213. The separator 130 has a third overhanging portion 135 overhanging the fifth edge 1213 along the third direction Z, and the third overhanging portions 135 of the plurality of separators 130 are connected.

[0111] By making the separator 130 have the third overhanging portion 135 overhanging the fifth edge 1213 along the third direction Z, and the third overhanging portions 135 of the plurality of separators 130 are connected, the third overhanging portions 135 of the plurality of separators 130 can achieve insulation between the first empty foil area 111 and the second tab 120, and can reduce the possibility of short circuit between the first empty foil area 111 and the second tab 120 when the battery cell 10 is subjected to an external force or falls, thereby improving the safety of the battery cell 10. In addition, the third overhanging portion 135 does not increase the thickness of the electrode assembly 100, which is conducive to improving the energy density of the battery cell 10.

[0112] Referring to FIGS. 1 and 2, in some embodiments, the battery cell 10 includes a housing 200 provided with a receiving space, and the electrode assembly 100 is arranged in the receiving space.

[0113] In some embodiments, the housing 200 is a packaging bag, so that the housing 200 is simple to install with the electrode assembly 100.

[0114] In some embodiments, the shell 200 can be made of a material with high strength, such as a metal material, for example, steel, aluminum alloy, etc., so that the shell 200 has high strength and is not easy to deform or break due to stress or environmental changes, thereby improving the reliability of the battery cell 10. The shell 200 can also be made of a non-metallic material with high strength, such as carbon fiber or hard plastic.

[0115] The battery cell includes an electrode assembly 100, a shell 200, and an electrolyte. The shell 200 is used to accommodate the electrode assembly 100 and the electrolyte. The electrode assembly 100 is composed of a positive electrode tab, a negative electrode tab, and a separator 130. The battery cell 10 mainly relies on the movement of metal ions between the positive electrode tab and the negative electrode tab to work. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector. The part of the positive electrode current collector without the positive electrode active material layer serves as a positive electrode tab to realize the input or output of electric energy of the positive electrode tab through the positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary material, or lithium manganate, etc. The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector. The part of the negative electrode current collector without the negative electrode active material layer serves as a negative electrode tab to realize the input or output of electric energy of the negative electrode tab through the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be a carbon material or a silicon material, etc. The material of the separator can be polypropylene (PP) or polyethylene (PE), etc. The electrolyte can include an organic solvent, an electrolyte lithium salt, etc.

[0116] In some embodiments, the battery cell 10 further includes a first electrical connector 310, the first electrical connector 310 is connected with the first empty foil area 111, and the first electrical connector 310 extends out of the shell 200.

[0117] By connecting the first electrical connector 310 with the first empty foil area 111 and extending the first electrical connector 310 out of the shell 200, it is convenient for external equipment to be electrically connected with the electrode assembly 100 through the first electrical connector 310.

[0118] In some embodiments, the battery cell 10 further includes a second electrical connector 320, the second electrical connector 320 is connected with the second empty foil area 122, and the second electrical connector 320 extends out of the shell 200.

[0119] By connecting the second electrical connector 320 with the second empty foil area 122 and extending the second electrical connector 320 out of the shell 200, it is convenient for external equipment to be electrically connected with the electrode assembly 100 through the second electrical connector 320.

[0120] In some embodiments, the battery cell 10 further comprises a first sealing member 330, which is arranged between the first electrical connecting member 310 and the shell 200.

[0121] By arranging the first sealing member 330 between the first electrical connecting member 310 and the shell 200, the sealing between the first electrical connecting member 310 and the shell 200 is better, and the sealing of the battery cell 10 is better.

[0122] In some embodiments, the battery cell 10 further comprises a second sealing member 340, which is arranged between the second electrical connecting member 320 and the shell 200.

[0123] By arranging the second sealing member 340 between the second electrical connecting member 320 and the shell 200, the sealing between the second electrical connecting member 320 and the shell 200 is better, and the sealing of the battery cell 10 is better.

[0124] The embodiments of the present application provide a kind of electric equipment, including the battery cell 10 of any one of the above scheme, and the battery cell 10 is used to provide electric energy for electric equipment.

[0125] The electric equipment can be the device or system of any one of the above application battery cell 10.

[0126] It should be explained that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0127] The above is only the preferred embodiment of the present application, and is not used to limit the present application, and the present application can have various changes and changes for the person skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An electric cell, characterized by, The electrode assembly includes a plurality of first electrode plates, a plurality of second electrode plates, and a plurality of separators, the first electrode plates and the second electrode plates being opposite in polarity, the plurality of first electrode plates and the plurality of second electrode plates being stacked in a first direction, and the plurality of separators being disposed between the first electrode plates and the second electrode plates, respectively. Each of the first electrode plates has a first empty foil area, and each of the second electrode plates has a first notch, at least part of the first empty foil area being exposed to the first notch in the first direction. The first notch has a first edge and a second edge, the first edge being connected to the second edge, and the first empty foil area exceeding the first edge in a second direction. The separator has a first excess portion exceeding the second edge in a third direction, and the first excess portions of the plurality of separators are connected, the first excess portions being located within the first notch as viewed in the first direction. The first direction is a thickness direction of the electrode assembly, and the first direction, the second direction, and the third direction are perpendicular to each other.

2. The electric cell of claim 1, wherein, The electrode assembly has a first side and a second side opposite to each other in the first direction. The first excess portions of the plurality of separators are gathered toward the first side and connected in the first direction.

3. The electric cell of claim 2, wherein, The plurality of separators includes a first separator located at the second side, a width of the first excess portion of the first separator in the third direction being W1, and a thickness of the electrode assembly being H1, W1≥H1 being satisfied.

4. The electric cell of claim 2, wherein, The plurality of separators includes a first separator located at the second side, a width of the first excess portion of the first separator in the third direction being W1, W1≥2mm being satisfied.

5. The electric cell of claim 2, wherein, The plurality of separators includes a second separator located at the first side, a width of the first excess portion of the second separator in the third direction being W2, W2≥0.2mm being satisfied.

6. The electric cell of claim 1, wherein, The first excess portions of the plurality of separators are connected to form a connection portion, and a gap is formed between the connection portion and the first empty foil area as viewed in the third direction.

7. The electric cell of claim 1, wherein, The first excess portions of the plurality of separators are gathered toward the middle and connected in the first direction.

8. The electric cell of claim 1, wherein, The first excess portions of the plurality of separators are hot melt bonded.

9. The electric cell of claim 1, wherein, The first empty foil area is located at a first corner position of the first electrode plate, and the first notch is located at a second corner position of the second electrode plate.

10. The electric cell of claim 9, wherein, The second electrode plate has a second empty foil area located at a third corner position, and the first electrode plate has a second notch located at a fourth corner position, the second empty foil area and the second notch at least partially overlapping each other in the first direction. The second notch has a third edge and a fourth edge, the third edge being connected to the fourth edge, and the second empty foil area exceeding the third edge in the second direction. The separator has a second excess portion exceeding the fourth edge in the third direction, and the second excess portions of the plurality of separators are connected.

11. The electric cell of claim 1, wherein, The first notch has a fifth edge, the fifth edge being spaced apart from the second edge in the third direction, and the first edge connecting the second edge and the fifth edge. The separators have third overhangs beyond the fifth edges in the third direction, the third overhangs of the plurality of separators being connected.

12. An electrical device, characterized by An electric power source including the electric cell as claimed in any one of claims 1 to 11 is provided.

Images