Battery cell, single battery, battery pack and electric equipment

Abstract

The utility model discloses a battery cell, a single battery, a battery pack and electric equipment, and belongs to the technical field of batteries. The battery cell comprises a plurality of pole pieces which are sequentially arranged in a stacked mode, each pole piece comprises a first sub-pole piece and a second sub-pole piece, and the first sub-pole pieces and the second sub-pole pieces are connected in an insulating mode. According to the invention, the integrated pole piece is divided into the first sub-pole piece and the second sub-pole piece which are separated from each other, so that the current flowing path is reduced from the current flowing path, and the original unidirectional transmission current is changed into bidirectional transmission current, thereby improving the charging and discharging speed of the battery cell; on the other hand, the length of a single pole piece is reduced, so that the internal resistance of the battery cell is reduced, and the use performance of the battery cell is further improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a battery cell, a single battery, a battery pack and an electrical device. Background Art

[0002] With the increasing shortage of energy and the increasingly prominent environmental problems, lithium-ion batteries have gradually become the current mainstream energy source. Due to their advantages such as light weight, small size, large capacity and fast charging speed, they are widely used in various mobile phones, mobile devices, new energy vehicles and other equipment.

[0003] In the related art, the battery cell includes a positive electrode sheet, a negative electrode sheet, and a separator layer disposed between the positive electrode sheet and the negative electrode sheet. The ends of the positive electrode sheet and the negative electrode sheet are provided with tabs, and the current inside the battery cell is transmitted unidirectionally to the tabs through the metal foil in the electrode sheet. However, for the battery cell with this structure, the transmission impedance of the current in the metal foil is relatively high, which affects the performance of the battery cell. Utility Model Content

[0004] The present application aims to provide a battery cell, a single battery, a battery pack and an electrical device, which can solve the problem in the related art that the current can only be transmitted in one direction, resulting in slow battery charging and discharging speeds, and the ohmic impedance of the metal coating in the battery is relatively high.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application proposes a battery cell, comprising a plurality of pole pieces stacked in sequence, wherein the pole pieces include a first sub-pole piece and a second sub-pole piece, and the first sub-pole piece and the second sub-pole piece are insulated and connected to each other.

[0007] Optionally, the pole piece includes a substrate, and a metal layer provided on at least one side of the substrate along a first direction, and the first direction is a stacking direction of a plurality of the pole pieces;

[0008] The metal layer includes a first metal layer and a second metal layer spaced apart along a second direction, the second direction being perpendicular to the first direction, the first metal layer and the corresponding substrate forming the first sub-pole piece, and the second metal layer and the corresponding substrate forming the second sub-pole piece.

[0009] Optionally, an active material layer is provided on the side of the first metal layer and the second metal layer facing away from the substrate.

[0010] Optionally, one end of the first metal layer away from the second metal layer is at least partially exposed to the active material layer to form a tab; and / or one end of the second metal layer away from the first metal layer is at least partially exposed to the active material layer to form a tab.

[0011] Optionally, a gap is formed between the first metal layer and the second metal layer, and an insulating layer is provided in the gap.

[0012] Optionally, along the second direction, the size of the gap is: 1mm-5mm.

[0013] Optionally, along the first direction, the thickness of the insulating layer is equal to the sum of the thicknesses of the metal layer and the active material layer.

[0014] Optionally, along the first direction, the thickness of the metal layer is 1 μm-10 μm;

[0015] and / or, along the first direction, the thickness of the active material layer is 100 μm-500 μm;

[0016] And / or, along the first direction, the thickness of the insulating layer is 100 μm-500 μm.

[0017] Optionally, a first pole lug is provided at one end of the first sub-pole piece away from the second sub-pole piece, and a second pole lug is provided at one end of the second sub-pole piece away from the first sub-pole piece;

[0018] Along the direction of the center line connecting the first sub-pole piece and the second sub-pole piece, the orthographic projection of the first pole lug and the orthographic projection of the second pole lug at least partially overlap.

[0019] Optionally, a first pole lug is provided at one end of the first sub-pole piece away from the second sub-pole piece, and a second pole lug is provided at one end of the second sub-pole piece away from the first sub-pole piece;

[0020] Along the direction of the center line connecting the first sub-pole piece and the second sub-pole piece, the orthographic projection of the first pole ear and the orthographic projection of the second pole ear are staggered with each other.

[0021] Optionally, among two adjacent electrode sheets, one electrode sheet is a positive electrode sheet and the other electrode sheet is a negative electrode sheet, the first electrode tab in the positive electrode sheet and the first electrode tab in the negative electrode sheet are staggered with each other, and the second electrode tab in the positive electrode sheet and the second electrode tab in the negative electrode sheet are staggered with each other.

[0022] In a second aspect, an embodiment of the present application provides a single battery, comprising a shell, and a battery cell as described in any one of the above items, wherein the battery cell is disposed in the shell.

[0023] In a third aspect, an embodiment of the present application proposes a battery pack, comprising a battery pack support structure, and a plurality of single cells, wherein the plurality of single cells are disposed in the battery pack support structure.

[0024] In a fourth aspect, an embodiment of the present application proposes an electrical device, comprising a device body, and the battery cell described in any one of the above items, or the battery pack described above, wherein the battery cell or the battery pack is used to provide electrical energy to the device body.

[0025] In the embodiment of the present application, the battery cell includes pole pieces stacked in sequence, the pole pieces include a first sub-pole piece and a second sub-pole piece, and the first sub-pole piece and the second sub-pole piece are insulated and connected. In this way, the integrated pole piece is divided into two spaced first sub-pole pieces and a second sub-pole piece, which reduces the distance of the current flow in the current flow path, and changes the original unidirectional transmission current into a bidirectional transmission current, thereby improving the charging and discharging speed of the battery cell; on the other hand, the length of a single pole piece is reduced, thereby reducing the internal resistance of the battery cell, and further improving the performance of the battery cell.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0029] Figure 2 is a schematic diagram of a single pole piece according to an embodiment of the present application;

[0030] Figure 3 is a schematic structural diagram of a metal layer and a substrate combined according to an embodiment of the present application;

[0031] Figure 4 According to the embodiment of the present application Figure 2 Sectional view along line AA;

[0032] Figure 5 is a schematic diagram of a pole piece according to an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of another pole piece according to an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of positive and negative electrode sheets according to an embodiment of the present application;

[0035] Figure 8 is a schematic diagram of a battery pack according to an embodiment of the present application;

[0036] Fig. 9 is a schematic diagram of another battery pack according to an embodiment of the present application.

[0037] Reference numerals:

[0038] 10: battery cell; 11: positive electrode sheet; 12: negative electrode sheet; 20: positive terminal; 30: negative terminal; 40: battery cell shell; 100: electrode sheet; 101: substrate; 102: metal layer; 103: active material layer; 104: insulating layer; 110: first sub-electrode sheet; 111: first pole lug; 112: first metal layer; 120: second sub-electrode sheet; 121: second pole lug; 122: second metal layer; W: gap width; X: first direction; Y: second direction. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0040] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0041] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0042] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] In the following, in conjunction with the accompanying drawings, a battery cell, a single battery, a battery pack and an electrical device provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0044] like Figure 1 As shown, the battery cell 10 according to some embodiments of the present application includes a plurality of pole pieces 100 stacked in sequence, and a diaphragm arranged between two adjacent pole pieces 100, the pole piece 100 includes a first sub-pole piece 110 and a second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected.

[0045] In the embodiment of the present application, the battery cell 10 includes a plurality of pole pieces 100 stacked in sequence, and the pole piece 100 includes a first sub-pole piece 110 and a second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected. In this way, the integrated pole piece 100 is separated into two spaced first sub-pole pieces 110 and second sub-pole pieces 120, which reduces the distance of the current flow in the current flow path, and changes the original unidirectional transmission current into a bidirectional transmission current, thereby improving the charging and discharging speed of the battery cell; on the other hand, the length of a single pole piece is reduced, thereby reducing the internal resistance of the battery cell, and further improving the performance of the battery cell.

[0046] It can be understood that in a specific application, when a plurality of pole pieces 100 are stacked in sequence, a diaphragm is also provided between two adjacent pole pieces 100, and the diaphragm is used to separate the positive pole piece from the negative pole piece to prevent short circuit inside the battery cell. The diaphragm includes: any one of a polyethylene (PE) diaphragm, a polypropylene (PP) diaphragm, and a PE and PP composite multi-layer microporous membrane. Those skilled in the art can select according to actual needs, and the embodiments of the present application do not limit this.

[0047] Specifically, refer to Figure 1In the manufacturing process of the battery, the pole pieces 100 and the separators (not shown in the figure) disposed between two adjacent pole pieces 100 are stacked and arranged in sequence to form a battery cell 10. It can be understood that the battery cell 10 can be a laminated structure formed by stacking a plurality of pole pieces 100 and separators, or the battery cell 10 can be a wound structure formed by winding a plurality of pole pieces 100 and separators. Those skilled in the art can select according to actual needs, and the embodiments of the present application are not limited to this.

[0048] Specifically, Figure 4 As shown, the pole piece 100 includes a first sub-pole piece 110 and a second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected. Thus, a pole piece contains the first sub-pole piece 110 and the second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected, so that the integrated pole piece 100 is divided into two spaced first sub-pole pieces 110 and second sub-pole pieces 120, which reduces the distance of the current flow from the current flow path, and changes the original unidirectional transmission current into bidirectional transmission.

[0049] It can be understood that in the related art, electrons flow from the end of the pole piece away from the pole ear to the pole ear, and need to flow through the entire length of the pole piece. In the embodiment of the present application, electrons flow from the ends of the two sub-pole pieces away from the pole ear to the pole ear, that is, electrons flow from the end of the pole piece 100 between the two sub-pole pieces to the pole ears of the two sub-pole pieces, turning the original unidirectional transmission current into a bidirectional transmission current, thereby increasing the charging and discharging speed of the battery cell.

[0050] In some embodiments of the present application, the first sub-pole piece 110 and the second sub-pole piece 120 are independently processed pole pieces, and the first sub-pole piece 110 and the second sub-pole piece 120 are connected by an insulating structure to form a pole piece 100. Thus, in the same pole piece, there are two independent first sub-pole pieces 110 and second sub-pole pieces 120, thereby forming two different current directions. In this way, while ensuring a certain pole piece structural strength, it is more convenient to process.

[0051] In other embodiments of the present application, refer to Figure 2 The pole piece 100 includes an insulating member, and a first sub-pole piece 110 and a second sub-pole piece 120 are arranged on the same insulating member to form two independent first sub-pole pieces 110 and second sub-pole pieces 120, thereby forming two different current directions. Therefore, the pole piece 100 formed based on the same insulating member has higher structural strength and stability.

[0052] Optionally, refer to Figure 3 and Figure 4The pole piece 100 includes a substrate 101, and a metal layer 102 arranged on at least one side of the substrate 101 along a first direction X, the first direction X is the stacking direction of a plurality of pole pieces 100; the metal layer 102 includes a first metal layer 112 and a second metal layer 122 arranged at intervals along a second direction Y, the second direction Y is perpendicular to the first direction X, the first metal layer 112 and the corresponding substrate 101 form a first sub-pole piece 110, and the second metal layer 122 and the corresponding substrate 101 form a second sub-pole piece 122.

[0053] Specifically, the pole piece 100 includes a substrate 101 and a metal layer 102 disposed on at least one side of the substrate 101 along the first direction X. It can be understood that the metal layer 102 can be disposed on any side of the substrate 101 along the first direction X, or the metal layer 102 can be disposed on both sides of the substrate 101 along the first direction X. Of course, under the actual production and processing and subsequent operation requirements, preferably, the metal layer 102 is disposed on both sides of the substrate 101 along the first direction X, so as to facilitate the subsequent die-cutting and welding operations of the metal layer 102.

[0054] Among them, the substrate 101 includes any one of polyethylene glycolterephthalate (PET), polypropylene (PP), and polyimide (PI). Those skilled in the art can select it according to actual needs, and the embodiments of the present application are not limited to this.

[0055] It can be understood that the electrode sheet 100 in the battery cell 10 includes a positive electrode sheet and a negative electrode sheet; wherein the metal layer 102 in the positive electrode sheet is generally an aluminum layer, which can be plated onto the substrate 101 by a vacuum evaporation surface treatment process; the metal layer 102 in the negative electrode sheet is generally a copper layer, which can be plated onto the substrate 101 by an electroplating surface treatment process. Both copper and aluminum materials have good conductivity, are relatively soft and easy to bond, are relatively common and cheap, and both can form a layer of oxide protective film on their surfaces.

[0056] Specifically, refer to Figure 3 and Figure 4 The metal layer 102 includes a first metal layer 112 and a second metal layer 122 spaced apart along the second direction Y. The first metal layer 112 and the corresponding substrate 101 form a first sub-electrode sheet 110, and the second metal layer 122 and the corresponding substrate 101 form a second sub-electrode sheet 122. The first sub-electrode sheet 110 and the second sub-electrode sheet 120 respectively formed form a current path. Compared with the related art, the circuit path is shorter, which improves the charging and discharging speed of the battery cell.

[0057] In some embodiments of the present application, the first sub-pole piece 110 includes a substrate, on which a first metal layer 112 is applied; similarly, the second sub-pole piece 120 includes a substrate, on which a second metal layer 122 is applied; the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected through an insulating member to form the pole piece 100. In this way, the pole piece 100 can be processed and produced more conveniently while satisfying the mechanical strength of the pole piece 100.

[0058] In some embodiments of the present application, reference Figure 3 , a first metal layer 112 and a second metal layer 122 are arranged on the substrate 101 along the second direction Y, the first metal layer 112 and the corresponding substrate 101 form a first sub-pole piece 110, and the second metal layer 122 and the corresponding substrate 101 form a second sub-pole piece 122. That is, the first sub-pole piece 110 and the second sub-pole piece 122 use the same substrate 101, so that the processing method is more concise, and the specific processing efficiency is improved. At the same time, the same substrate 101 makes the structure of the pole piece 100 more stable.

[0059] Optionally, refer to Figure 4 An active material layer 103 is disposed on the side of the first metal layer 112 and the side of the second metal layer 122 facing away from the substrate 101 .

[0060] Specifically, refer to Figure 4 , the first metal layer 112 and the second metal layer 122 are both provided with an active material layer 103 on the side facing away from the substrate 101. It can be understood that the active material layer 103 is divided into a positive electrode active material layer and a negative electrode active material layer according to the different polarities of the electrode sheets. In a specific application, a coating process is used to apply the positive electrode active material layer to the metal layer of the positive electrode sheet, and the negative electrode active material layer to the metal layer of the negative electrode sheet, thereby producing a positive electrode sheet and a negative electrode sheet.

[0061] Among them, the coating process can specifically adopt any specific coating method of gravure coating, reverse roller coating, knife roller coating, metering rod coating, slot die coating, dipping, curtain coating, and air knife coating. Technical personnel in this field can select according to actual needs, and the embodiments of the present application do not limit this.

[0062] Among them, the positive electrode active material layer includes: any one of ternary materials, lithium iron phosphate, lithium cobalt oxide, and lithium manganese oxide; the negative electrode active material layer includes: any one of silicon-based negative electrode materials, artificial graphite materials, and natural graphite materials; technical personnel in this field can choose according to actual needs, and the embodiments of this application do not limit this.

[0063] In the embodiment of the present application, the first metal layer 112 and the second metal layer 122 are both provided with an active material layer 103 on the side facing away from the substrate 101, so that when the battery is in a discharge state, the oxide in the positive electrode active material layer loses oxygen atoms, thereby releasing electrons. At the same time, the negative electrode active material layer accepts these electrons and undergoes a reduction reaction. This chemical reaction generates a potential difference, converting chemical energy into electrical energy.

[0064] Optionally, refer to Figure 4 A gap W is formed between the first metal layer 112 and the second metal layer 122 , and an insulating layer 104 is disposed in the gap W.

[0065] Specifically, refer to Figure 4 The first metal layer 112, the substrate 101 disposed on one side of the first metal layer 112, and the active material 103 disposed on the side of the first metal layer 112 away from the substrate 101 form the first sub-pole sheet 110; the second metal layer 122, the substrate 101 disposed between the second metal layers 122, and the active material 103 disposed on the side of the second metal layer 122 away from the substrate 101 form the second sub-pole sheet 120. When the battery cell 10 works normally, the first sub-pole sheet 110 and the second sub-pole sheet 120 work as independent positive or negative electrodes, respectively. By setting a gap W between the first metal layer 112 and the second metal layer 122, the first sub-pole sheet 110 and the second sub-pole sheet 120 can be insulated, and the insulating layer 104 disposed in the gap W can further improve the insulation between the first sub-pole sheet 110 and the second sub-pole sheet 120.

[0066] In specific applications, the insulating layer 104 can be a ceramic layer or an insulating rubber layer, wherein the ceramic layer is any one of aluminum oxide (aluminum oxide, Al2O3) or aluminum hydroxide; the rubber layer is any one of polyvinylidene difluoride (polyvinylidene difluoride, PVDF), styrene butadiene rubber (Polymerized Styrene Butadiene Rubber, SBR), lithium battery adhesive (CMC), polyacrylic acid (Polyacrylic acid, PAA) or a mixed rubber layer; technicians in this field can choose according to actual needs, and the embodiments of the present application are not limited to this.

[0067] Optionally, refer to Figure 2 , one end of the first metal layer 112 away from the second metal layer 122 is at least partially exposed to the active material layer 103 to form a pole ear; and / or, one end of the second metal layer 122 away from the first metal layer 112 is at least partially exposed to the active material layer 103 to form a pole ear.

[0068] Specifically, one end of the first metal layer 112 away from the second metal layer 122 is at least partially exposed to the active material layer 103 to form a pole ear; it can be understood that in specific applications, the first sub-pole piece 110 works as an independent pole piece, and when electrons are transmitted outward through the first sub-pole piece 110, they need to flow through the pole ear and the external connection terminal of the battery. The original part of the first metal layer 112 that is not covered by the active material layer 103 is directly used as the pole ear, and no additional pole ear processing is required, thereby further improving the operating efficiency; at the same time, the strength of the pole ear is also higher.

[0069] Similarly, one end of the second metal layer 122 away from the first metal layer 112 is at least partially exposed from the active material layer 103 to form a pole ear, and the pole ear serves as a pole ear of the second sub-pole sheet 120 .

[0070] Optionally, along the second direction Y, the size of the gap W is: 1mm-5mm.

[0071] Specifically, along the direction of the center line connecting the first sub-pole piece 110 and the second sub-pole piece 120, i.e., the second direction Y, the size of the gap W can be set to any value such as 1mm, 2mm, 3mm, 4mm, 5mm, or a range between any two values. While ensuring that the first metal layer 112 and the second metal layer 122 cannot be directly connected and a certain insulation isolation is performed, the size of the gap W cannot be too large to avoid occupying too much internal space, thereby reducing the length of the metal layer 102 along the direction in which the first sub-pole piece 110 and the second sub-pole piece 120 are connected.

[0072] Preferably, along the first direction X, the thickness of the insulating layer 104 is equal to the sum of the thicknesses of the metal layer 102 and the active material layer 103 .

[0073] Specifically, along the stacking direction of the electrode 100 and the diaphragm, that is, the first direction X, the thickness of the insulating layer 104 is equal to the sum of the thicknesses of the metal layer 102 and the active material layer 103. Figure 4 The thickness of the insulating layer 104 along the stacking direction of the pole piece 100 is equal to the sum of the thicknesses of the metal layer 102 and the active material layer 103, so as to avoid the influence of the insulating layer 104 on the adjacent pole pieces 100 when several pole pieces 100 are stacked in sequence, so that the size of the battery cell 10 is larger in the first direction; at the same time, the insulating layer 104 is consistent with the sum of the thicknesses of the metal layer 102 and the active material layer 103, so that the first sub-pole piece 110, the second sub-pole piece 120 and the insulating layer 104 have similar thicknesses, and at the same time, the overall rigidity of the pole piece 100 is not greatly affected by the gap W, and it is not easy to bend, twist, etc. in the subsequent installation operation.

[0074] It should be noted that, in the stacking direction of the electrode 100 and the diaphragm, ie, the first direction X, the thickness of the insulating layer 104 may be less than or greater than the sum of the thicknesses of the metal layer 102 and the active material layer 103 , and may be flexibly set according to actual needs, which is not limited here.

[0075] Optionally, refer to Figure 4 , along the first direction X, the thickness of the metal layer 102 is 1 μm-10 μm.

[0076] Specifically, refer to Figure 4 , along the stacking direction of the pole piece 100 and the diaphragm, the thickness of the metal layer 102 can be set to: 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm and any other values ​​or a range between any two values. It can be understood that when the metal layer 102 is plated on the substrate 101, as a path for the flow of electrons in the pole piece 100, its conductivity must first be ensured. Considering the specific implementation conditions such as process conditions, the minimum thickness of the metal layer 102 can be set to 1μm. At the same time, when the thickness of the metal layer 102 exceeds 10μm, it affects the thickness of the pole piece 100, so that the number of pole pieces 100 in the battery cell 10 cannot be increased without increasing the width of the battery cell 10 in the first direction.

[0077] Optionally, refer to Figure 4 , along the first direction X, the thickness of the active material layer 103 is 100 μm-500 μm.

[0078] Specifically, along the stacking direction of the pole piece 100 and the diaphragm, the thickness of the active material layer 103 can be set to: 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, etc., any value or a range between any two values. It can be understood that when the battery is working normally, on the one hand, the ions in the electrolyte are transmitted in the pores of the pole piece and the diaphragm, and are also transmitted in the solid-phase electrode material particles; on the other hand, the electrons are transmitted through the solid phase connected by the active material layer of the electrode itself and the conductive agent. Therefore, when the thickness of the active material layer 103 is less than 100μm, the cycle life and coulomb efficiency of the active material layer 103 are affected, and while ensuring the energy density of the pole piece 100, in order to reduce the weight of the pole piece, the thickness of the active material layer 103 cannot be greater than 500μm.

[0079] Optionally, along the first direction X, the thickness of the insulating layer 104 is 100 μm-500 μm.

[0080] Specifically, in order to ensure that the first sub-electrode sheet 110 or the second sub-electrode sheet 120 formed by the metal layer 102 and the active material layer 103 has a thickness similar to that of the insulating layer 104, the thickness of the insulating layer 104 can be set to: 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, or any other value or a range between any two values. Specifically, after selecting the thickness of the active material layer 103, the thickness of the insulating layer 104 can be selected accordingly.

[0081] In the embodiment of the present application, by setting the thickness of the metal layer 102 and the active material layer 103, and the width and thickness of the insulating layer 104, the overall rigidity of the electrode piece 100 is guaranteed to a certain extent on the basis of ensuring the electrical performance of the electrode piece 100; at the same time, by setting the thickness of the metal layer 102 and the active material layer 103, the energy density that the battery cell 10 can accommodate after the electrode piece 100 finally forms the battery cell 10 is guaranteed.

[0082] Optionally, refer to Figure 5 A first pole ear 111 is provided at one end of the first sub-pole piece 110 away from the second sub-pole piece 120, and a second pole ear 121 is provided at one end of the second sub-pole piece 120 away from the first sub-pole piece 110; along the direction of the center line connecting the first sub-pole piece 110 and the second sub-pole piece 120, the orthographic projection of the first pole ear 111 and the orthographic projection of the second pole ear 121 at least partially overlap.

[0083] Specifically, the first sub-pole piece 110 and the second sub-pole piece 120 both work as independent pole pieces. In specific applications, the sub-pole pieces of the same polarity need to be connected. Therefore, a first pole ear 111 is provided at the end of the first sub-pole piece 110 away from the second sub-pole piece 120, and a second pole ear 121 is provided at the end of the second sub-pole piece 120 away from the first sub-pole piece 110, so as to facilitate the connection between the sub-pole pieces of the same polarity.

[0084] It can be understood that the first pole tab 111 and the second pole tab 121 are formed by cutting the end of the first metal layer 112 in the first pole sub-piece 110 that does not cover the active material layer 103 through a die-cutting process after the pole piece is rolled; similarly, the second pole tab 121 is cut from the end of the second metal layer 122 in the second pole sub-piece 120 that does not cover the active material layer 103. Thus, the pole piece 100 is die-cut and formed at one time, thereby improving production efficiency.

[0085] In some embodiments of the present application, the first pole tab 111 and the second pole tab 121 can be welded to the ends of the first metal layer 112 and the second metal layer 122 away from the insulating layer 104 by welding, thereby reducing mold opening costs and making processing more convenient.

[0086] Specifically, refer to Figure 5 Along the center line direction of the first sub-pole sheet 110 and the second sub-pole sheet 120, the orthographic projection of the first pole ear 111 and the orthographic projection of the second pole ear 121 at least partially overlap, so as to flexibly arrange the pole ear positions in the same pole sheet 100 and facilitate subsequent pole ear welding operations.

[0087] Optionally, refer to Figure 6 A first pole ear 111 is provided at one end of the first sub-pole piece 110 away from the second sub-pole piece 120, and a second pole ear 121 is provided at one end of the second sub-pole piece 120 away from the first sub-pole piece 110; along the direction of the center line connecting the first sub-pole piece 110 and the second sub-pole piece 120, the orthographic projection of the first pole ear 111 and the orthographic projection of the second pole ear 121 are staggered with each other.

[0088] Specifically, refer to Figure 6 Along the center line direction of the first sub-pole sheet 110 and the second sub-pole sheet 120, the orthographic projection of the first pole ear 111 and the orthographic projection of the second pole ear 121 are staggered with each other, so as to flexibly arrange the pole ear positions in the same pole sheet 100 and facilitate the subsequent pole ear welding operation.

[0089] Optionally, refer to Figure 7 In two adjacent electrode sheets 100, one electrode sheet is a positive electrode sheet 11, and the other electrode sheet is a negative electrode sheet 12. The first electrode ear 111 in the positive electrode sheet 11 and the first electrode ear 111 in the negative electrode sheet 12 are staggered with each other, and the second electrode ear 121 in the positive electrode sheet 11 and the second electrode ear 121 in the negative electrode sheet 12 are staggered with each other.

[0090] In a specific application, the positive electrode sheet 11 and the negative electrode sheet 12 are arranged in an alternate stack in the battery cell 10, so that an electrochemical reaction occurs between the positive electrode sheet 11 and the negative electrode sheet 12 to generate electric energy. The first pole ear 111 in the positive electrode sheet 11 and the first pole ear 111 in the negative electrode sheet 12 are staggered, and the second pole ear 121 in the positive electrode sheet 11 and the second pole ear 121 in the negative electrode sheet 12 are staggered. Thus, welding between pole sheets of the same polarity is facilitated in subsequent processing.

[0091] In some embodiments of the present application, along the center line direction of the first sub-pole sheet 110 and the second sub-pole sheet 120, the length of the first sub-pole sheet 110 or the second sub-pole sheet 120 can be set to any value such as 100mm, 200mm, 300mm, 400mm, 500mm, 600mm, 700mm, etc. or a range between any two values. The length of a single pole piece 100 can be set to any value such as 500mm, 600mm, 700mm, 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, etc. or a range between any two values. It can be understood that after the length of the pole piece 100 is designed, the length of the sub-pole piece is selected accordingly; so that the pole piece 100 has more specifications to adapt to different battery packs.

[0092] In an embodiment of the present application, a first pole ear 111 is provided at one end of the first sub-pole sheet 110 away from the second sub-pole sheet 120, and a second pole ear 121 is provided at one end of the second sub-pole sheet 120 away from the first sub-pole sheet 110, so that the connection between sub-pole sheets of the same polarity is more convenient; at the same time, the first pole ear 111 in the positive electrode sheet 11 and the first pole ear 111 in the negative electrode sheet 12 are staggered with each other, and the second pole ear 121 in the positive electrode sheet 11 and the second pole ear 121 in the negative electrode sheet 12 are staggered with each other, which facilitates welding between pole sheets of the same polarity in subsequent processing.

[0093] In some embodiments of the present application, reference Figure 8 and Fig. 9 The battery cell 10 includes: a battery cell housing 40 and a positive terminal 20 and a negative terminal 30 disposed on the battery cell housing 40. The positive terminal 20 at one end of the battery cell 10 is connected to the first pole lugs 111 of a plurality of positive electrode sheets 11, and the positive terminal 20 at the other end of the battery cell 10 is connected to the second pole lugs 121 of a plurality of positive electrode sheets 11; the negative terminal 30 at one end of the battery cell 10 is connected to the first pole lugs 111 of a plurality of negative electrode sheets 12, and the negative terminal 30 at the other end of the battery cell 10 is connected to the second pole lugs 121 of a plurality of negative electrode sheets 12. Thus, a battery cell having a positive terminal 20 and a negative terminal 30 at the same end is formed, that is, any end of the battery cell can be used as an independent battery cell.

[0094] In some embodiments of the present application, the height of the positive terminal 20 or the negative terminal 30 can be set to any value such as 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or a range between any two values. An insulating portion is also provided between the positive terminal 20 or the negative terminal 30 and the battery cell housing 40, so that the battery cell housing 40 is not charged, thereby improving the insulation and safety of the battery cell 10.

[0095] In some embodiments of the present application, the battery cell 10 may not be provided with an external terminal, and the metal cover at the end of the battery cell 10 is used as the positive terminal 20, which is electrically connected to the tabs of several positive electrode sheets 11. At the same time, a hole is provided on the end metal cover, and the tabs of several negative electrode sheets 12 are welded to form an external negative tab. The external negative tab is passed through the hole to serve as the negative terminal 30, and an insulating member is provided between the external negative tab and the hole, thereby making the structure of the battery cell simpler and the cost lower.

[0096] The following is a schematic description of the cell production process in some embodiments of the present application:

[0097] The metal layer 102 is vacuum evaporated or electroplated onto the substrate 101, and the prepared active material layer 103 is applied to the metal layer 102 through a coating process, the size thickness is detected, and the insulating layer 104 is filled into the gap W; after curing, the pole piece is rolled, the thickness and density are detected, and then the pole piece is die-cut to cut out the required pole ear; then the positive pole piece, the negative pole piece, and the diaphragm are stacked by winding or lamination to form a pole core, and the pole ears of the positive pole piece and the negative pole piece are welded separately; then the pole core is inspected and loaded into the shell, and then the liquid is injected after baking, and the electrolyte is injected into the shell to prepare the battery cell. The above battery cell production process is only a schematic description, and other related technologies required in actual production are not repeated here.

[0098] Optionally, an embodiment of the present application further provides a single cell battery, comprising a shell and a battery cell provided by any of the above embodiments, wherein the battery cell is disposed in the shell.

[0099] According to the single cell battery of the embodiment of the present application, the battery cell 10 includes a plurality of pole pieces 100 stacked in sequence, the pole piece 100 includes a first sub-pole piece 110 and a second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected. In this way, the integrated pole piece 100 is separated into two spaced first sub-pole pieces 110 and second sub-pole pieces 120, which reduces the distance of the current flow in the current flow path, and changes the original unidirectional transmission current into a bidirectional transmission current, thereby improving the charging and discharging speed of the battery cell; on the other hand, the length of a single pole piece is reduced, thereby reducing the internal resistance of the battery cell, and further improving the performance of the battery cell.

[0100] Optionally, an embodiment of the present application further provides a battery pack, including a battery pack support structure, and a plurality of single cells according to any of the above embodiments, wherein the battery pack support structure includes a receiving cavity, and the plurality of single cells are disposed in the receiving cavity.

[0101] According to the battery pack of the embodiment of the present application, the battery cell 10 includes a plurality of pole pieces 100 stacked in sequence, the pole piece 100 includes a first sub-pole piece 110 and a second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected. In this way, the integrated pole piece 100 is separated into two spaced first sub-pole pieces 110 and second sub-pole pieces 120, which reduces the distance of the current flow from the current flow path, and changes the original unidirectional transmission current into a bidirectional transmission current, thereby improving the charging and discharging speed of the battery cell; on the other hand, the length of a single pole piece is reduced, thereby reducing the internal resistance of the battery cell, and further improving the performance of the battery cell.

[0102] Optionally, an embodiment of the present application further provides an electrical device, including a device body, and a battery cell of any of the above embodiments, or a battery pack of any of the above embodiments, wherein the battery cell or the battery pack is used to provide electrical energy to the device body.

[0103] According to the electric device of the embodiment of the present application, the battery cell 10 includes a plurality of pole pieces 100 stacked in sequence, the pole piece 100 includes a first sub-pole piece 110 and a second sub-pole piece 120, and the first sub-pole piece 110 and the second sub-pole piece 120 are insulated and connected. In this way, the integrated pole piece 100 is separated into two spaced first sub-pole pieces 110 and second sub-pole pieces 120, which reduces the distance of the current flow from the current flow path, and changes the original unidirectional transmission current into a bidirectional transmission current, thereby improving the charging and discharging speed of the battery cell; on the other hand, the length of a single pole piece is reduced, thereby reducing the internal resistance of the battery cell, and further improving the performance of the battery cell.

[0104] It should be noted that the electrical equipment in the embodiments of the present application may include the battery cells or battery packs in any of the above embodiments. The specific structures of the battery cells and battery packs can be found in the above content, and the embodiments of the present application will not be repeated here.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0106] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell (10), characterized in that: The invention comprises a plurality of pole pieces (100) which are sequentially stacked and arranged, wherein the pole piece (100) comprises a first sub-pole piece (110) and a second sub-pole piece (120), and the first sub-pole piece (110) and the second sub-pole piece (120) are insulated and connected to each other.

2. The battery cell (10) according to claim 1, characterized in that: The pole piece (100) comprises a substrate (101), and a metal layer (102) provided on at least one side of the substrate (101) along a first direction (X), wherein the first direction (X) is a stacking direction of a plurality of pole pieces (100); The metal layer (102) comprises a first metal layer (112) and a second metal layer (122) arranged at intervals along a second direction (Y), the second direction (Y) being perpendicular to the first direction (X), the first metal layer (112) and the corresponding substrate (101) forming the first sub-pole piece (110), and the second metal layer (122) and the corresponding substrate (101) forming the second sub-pole piece (120).

3. The battery cell (10) according to claim 2, characterized in that: An active material layer (103) is provided on the side of the first metal layer (112) and the second metal layer (122) facing away from the substrate (101).

4. The battery cell (10) according to claim 3, characterized in that: One end of the first metal layer (112) away from the second metal layer (122) is at least partially exposed to the active material layer (103) to form a pole ear; and / or one end of the second metal layer (122) away from the first metal layer (112) is at least partially exposed to the active material layer (103) to form a pole ear.

5. The battery cell (10) according to claim 3, characterized in that: A gap (W) is formed between the first metal layer (112) and the second metal layer (122), and an insulating layer (104) is provided in the gap (W).

6. The battery cell (10) according to claim 5, characterized in that: Along the second direction (Y), the size of the gap (W) is: 1mm-5mm.

7. The battery cell (10) according to claim 5 or 6, characterized in that: Along the first direction (X), the thickness of the insulating layer (104) is equal to the sum of the thicknesses of the metal layer (102) and the active material layer (103).

8. The battery cell (10) according to claim 5, characterized in that: Along the first direction (X), the thickness of the metal layer (102) is 1 μm-10 μm; and / or, along the first direction (X), the thickness of the active material layer (103) is 100 μm-500 μm; And / or, along the first direction (X), the thickness of the insulating layer (104) is 100 μm-500 μm.

9. The battery cell (10) according to claim 1, characterized in that: A first pole lug (111) is provided at one end of the first sub-pole piece (110) away from the second sub-pole piece (120), and a second pole lug (121) is provided at one end of the second sub-pole piece (120) away from the first sub-pole piece (110); Along the direction of the center line connecting the first sub-pole piece (110) and the second sub-pole piece (120), the orthographic projection of the first pole lug (111) and the orthographic projection of the second pole lug (121) at least partially overlap.

10. The battery cell (10) according to claim 1, characterized in that: A first pole lug (111) is provided at one end of the first sub-pole piece (110) away from the second sub-pole piece (120), and a second pole lug (121) is provided at one end of the second sub-pole piece (120) away from the first sub-pole piece (110); Along the direction of the center line connecting the first sub-pole piece (110) and the second sub-pole piece (120), the orthographic projection of the first pole ear (111) and the orthographic projection of the second pole ear (121) are staggered.

11. The battery cell (10) according to claim 9 or 10, characterized in that: In two adjacent electrode sheets (100), one electrode sheet is a positive electrode sheet (11) and the other electrode sheet is a negative electrode sheet (12), the first electrode ear (111) in the positive electrode sheet (11) and the first electrode ear (111) in the negative electrode sheet (12) are staggered with each other, and the second electrode ear (121) in the positive electrode sheet (11) and the second electrode ear (121) in the negative electrode sheet (12) are staggered with each other.

12. A single cell battery, characterized in that: It comprises a shell, and a battery cell (10) according to any one of claims 1 to 11, wherein the battery cell (10) is arranged in the shell.

13. A battery pack, characterized in that: It comprises a battery pack supporting structure, and a plurality of single cells as claimed in claim 12, wherein the plurality of single cells are arranged in the battery pack supporting structure.

14. An electrical device, characterized in that: It comprises a device body, and a single battery as claimed in claim 12, or a battery pack as claimed in claim 13, wherein the single battery or the battery pack is used to provide electrical energy to the device body.

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