Pole piece, battery cell, battery and electric equipment

Abstract

The utility model discloses a pole piece, a battery cell, a battery and electric equipment. The pole piece comprises a current collector, a liquid storage part and an active substance layer, the current collector is provided with a bearing surface, and at least one end surface of the current collector in the thickness direction is the bearing surface; the liquid storage part is connected with the bearing surface, and the liquid storage part is provided with a liquid storage area for accommodating electrolyte; the active material layer is arranged on one side where the bearing surface of the current collector is located and covers the liquid storage member. According to the design, the electrolyte can be effectively accommodated, so that the condition of battery electrolyte expansion caused by reduction of the porosity of the battery pole piece is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to an electrode sheet, a battery cell, a battery, and an electrical device. Background Art

[0002] In recent years, with the continuous improvement of the requirements for the energy density of lithium-ion batteries, the compaction density of battery electrodes has been continuously increased, and the overall battery has become thicker. In the battery design in related technologies, the porosity of the battery electrode sheet after rolling will be greatly reduced. When injecting electrolyte, the wettability of the electrolyte on the electrode sheet is poor, which ultimately leads to difficult injection process and battery swelling. Therefore, how to effectively improve the battery swelling caused by the reduction of the porosity of the battery electrode sheet has become an urgent problem to be solved. Summary of the Utility Model

[0003] The embodiments of the present application provide an electrode sheet, a battery cell, a battery, and an electrical device, which can solve the problem of battery swelling caused by the reduction of the porosity of the battery electrode sheet in related technologies.

[0004] In a first aspect, the embodiments of the present application provide an electrode sheet; the electrode sheet includes a current collector, a liquid storage member, and an active material layer. The current collector has a bearing surface, at least one end surface of the current collector in its own thickness direction is the bearing surface, the liquid storage member is connected to the bearing surface, the liquid storage member has a liquid storage area for accommodating electrolyte, and the active material layer is disposed on one side where the bearing surface of the current collector is located and covers the liquid storage member.

[0005] In a second aspect, the embodiments of the present application provide a battery cell; the battery cell includes the above-mentioned electrode sheet, and the electrode sheet is at least one of a positive electrode sheet and a negative electrode sheet.

[0006] In a third aspect, the embodiments of the present application provide a battery; the battery includes a housing, an electrolyte, and the above-mentioned battery cell. The housing has an accommodation cavity, the electrolyte is poured into the accommodation cavity of the housing, and the above-mentioned battery cell is disposed in the accommodation cavity of the housing.

[0007] In a fourth aspect, the embodiments of the present application provide an electrical device; the electrical device includes a housing and the above-mentioned battery. The housing has a battery installation slot, and the above-mentioned battery is installed in the housing corresponding to the battery installation slot.

[0008] For the electrode sheet, battery cell, battery, and electrical equipment according to the embodiments of the present application, by designing a liquid storage member and a liquid storage area for accommodating an electrolyte on the liquid storage member, when the electrolyte is poured, the electrolyte can be accommodated in the liquid storage area, which can reduce the difficulty of the liquid injection process, effectively improve the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet, and can also effectively increase the liquid retention capacity of the battery, avoid lithium plating, and ensure the cycle life performance of the battery. In addition, by embedding the liquid storage member in the active material layer, the liquid storage member reasonably occupies the internal space of the active material layer, effectively increasing the liquid storage space while avoiding excessive battery thickness; at the same time, the electrolyte accommodated in the liquid storage area of the liquid storage member can be in full contact with the active material layer, improving the wetting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0010] Figure 1 Schematic cross-sectional structure diagram of an electrode sheet in an embodiment of the present application;

[0011] Figure 2 Schematic structure diagram of a liquid storage member disposed on the bearing surface of a current collector in an embodiment of the present application;

[0012] Figure 3 Schematic structure diagram of a liquid storage member including a liquid storage tube in an embodiment of the present application;

[0013] Figure 4 Schematic structure diagram of a liquid storage member including a liquid storage column in an embodiment of the present application;

[0014] Figure 5 Schematic cross-sectional structure diagram of an electrode sheet in another embodiment of the present application.

[0015] Reference numerals: 10, electrode sheet; 11, current collector; 11a, bearing surface; 12, liquid storage member; 12a, liquid storage area; 121, liquid storage tube; 121a, through hole; 122, liquid storage column; 122a, concave hole; 13, active material layer; XX', first preset direction; YY', second preset direction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the objectives, technical solutions, and advantages of the present application clearer, the following further describes the present application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] Please refer to Figure 1 As shown, in a first aspect, an embodiment of the present application provides a pole piece 10, which can effectively accommodate electrolyte to effectively improve the battery swelling caused by the reduction of the porosity of the battery pole piece. The pole piece 10 includes a current collector 11, a liquid storage member 12, and an active material layer 13; the current collector 11 has a bearing surface 11a, and at least one end surface of the current collector 11 in its own thickness direction is the bearing surface 11a; the liquid storage member 12 is connected to the bearing surface 11a, and the liquid storage member 12 has a liquid storage area 12a for accommodating electrolyte; the active material layer 13 is disposed on one side where the bearing surface 11a of the current collector 11 is located and covers the liquid storage member 12.

[0018] The following will be combined with Figures 1-5 to introduce the specific structure of the pole piece 10 in detail.

[0019] As Figures 1-2 shown, the pole piece 10 includes a current collector 11, a liquid storage member 12, and an active material layer 13.

[0020] As a component for collecting current in the pole piece 10, the current collector 11 mainly functions to carry the active material layer 13, collect the current generated after the chemical reaction of the active material layer 13 to form a larger current and output it externally, thereby completing the process of converting chemical energy into electrical energy.

[0021] The current collector 11 has a bearing surface 11a; among them, the bearing surface 11a can be a plane, a curved surface, or a combination of a plane and a curved surface. It can be understood that the number of end surfaces of the current collector 11 in its own thickness direction is at least two, and taking two end surfaces as an example, any one of the two end surfaces of the current collector 11 can be used as the above-mentioned bearing surface 11a, or both end surfaces of the current collector 11 can be used as the above-mentioned bearing surface 11a.

[0022] As Figures 1-2 shown, the liquid storage member 12, as a component in the pole piece 10 that is independent of the active material layer 13 and can be used to accommodate electrolyte, the specific form of the liquid storage member 12 will be introduced in detail below.

[0023] The liquid storage member 12 is connected to the bearing surface 11a of the current collector 11; the specific connection method between the liquid storage member 12 and the bearing surface 11a of the current collector 11 is not limited here, and the designer can make a reasonable design according to actual needs. For example, the liquid storage member 12 can, but is not limited to, form an integral structure with the current collector 11 by injection molding. It should be noted that the number of liquid storage members 12 can be one or more (more than two). When one end face of the current collector 11 in its own thickness direction serves as the above-mentioned bearing surface 11a; if the number of liquid storage members 12 is one, then this one liquid storage member 12 is arranged on this one end face of the current collector 11 serving as the bearing surface 11a; if the number of liquid storage members 12 is more than one, then all the liquid storage members 12 are arranged on this one end face of the current collector 11 serving as the bearing surface 11a. When multiple end faces (more than two) of the current collector 11 in its own thickness direction serve as the above-mentioned bearing surface 11a, the number of liquid storage members 12 is more than one. Some of these multiple liquid storage members 12 can be arranged on one end face of the current collector 11 serving as the bearing surface 11a, and the remaining part is arranged on the other end face of the current collector 11 serving as the bearing surface 11a.

[0024] The liquid storage member 12 has a liquid storage area 12a for accommodating the electrolyte. In other words, the electrolyte can be stored in the liquid storage area 12a of the liquid storage member 12; among them, the "liquid storage area 12a" is understood as the area in the liquid storage member 12 for accommodating the electrolyte; and it can be understood that for different specific forms of the liquid storage member 12, the specific forms of the corresponding liquid storage area 12a are also different.

[0025] As Figures 1-2 shown, the active material layer 13 is a component in the electrode plate 10 that reacts with the electrolyte to generate current. The specific form of the active material layer 13 will be introduced in detail below.

[0026] The active material layer 13 is arranged on the side where the bearing surface 11a of the current collector 11 is located and covers the liquid storage member 12. That is to say, the active material layer 13 and the current collector 11 are stacked, and the liquid storage member 12 is embedded in the thickness of the active material layer 13. It is worth mentioning that by embedding the liquid storage member 12 inside the active material layer 13, the liquid storage member 12 can further strengthen the connection stability of the liquid storage member 12 on the bearing surface 11a of the current collector 11 by virtue of the binder (introduced below) in the active material layer 13.

[0027] Based on the electrode sheet 10 in the embodiments of the present application, by designing the liquid storage member 12 and providing a liquid storage area 12a for accommodating the electrolyte on the liquid storage member 12, when the electrolyte is poured, the electrolyte can be accommodated in the liquid storage area 12a. In this way, the difficulty of the liquid injection process can be reduced, the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet can be effectively improved, the liquid retention capacity of the battery can be effectively increased, lithium precipitation can be avoided, and the cycle life performance of the battery can be ensured. In addition, by embedding the liquid storage member 12 in the active material layer 13, the liquid storage member 12 reasonably occupies the internal space of the active material layer 13, effectively increasing the liquid storage space while avoiding excessive battery thickness. At the same time, the electrolyte accommodated in the liquid storage area 12a of the liquid storage member 12 can be in full contact with the active material layer 13, improving the wetting effect.

[0028] Further, as Figures 3-4 shown, the liquid storage member 12 can be used to accommodate the electrolyte, and the specific forms of the liquid storage member 12 can include but are not limited to the following embodiments.

[0029] As Figure 3 shown, in the first embodiment, the liquid storage member 12 includes a liquid storage tube 121, and the area surrounded by the inner wall surface of the liquid storage tube 121 serves as the above-mentioned liquid storage area 12a. A through hole 121a communicating with the liquid storage area 12a is provided on the outer wall surface of the liquid storage tube 121. Among them, the outer wall surface of the liquid storage tube 121 includes an outer end face and an outer circumferential surface. The number of the through holes 121a can be one or more (more than two). For example, when the number of the through holes 121a is one, the one through hole 121a can be provided on the outer end face of the liquid storage tube 121 or on the outer circumferential surface of the liquid storage tube 121. Also, for example, when the number of the through holes 121a is multiple, the multiple through holes 121a can be provided only on the outer end face of the liquid storage tube 121, or only on the outer circumferential surface of the liquid storage tube 121, or a part of them can be provided on the outer end face of the liquid storage tube 121 and the remaining part can be provided on the outer circumferential surface of the liquid storage tube 121. It should be noted that when the number of the through holes 121a is multiple, the specific arrangement manner of the multiple through holes 121a on the outer end face and / or the outer circumferential surface of the liquid storage tube 121 can be arbitrary or pre-designed according to a certain specific arrangement. By designing the liquid storage member 12 as the liquid storage tube 121 and providing the through hole 121a on the outer wall surface of the liquid storage tube 121, when the electrolyte is poured, the electrolyte can flow into the liquid storage area 12a surrounded by the inner wall surface of the liquid storage tube 121 through the through hole 121a. In this way, the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet can be effectively improved, the liquid retention capacity of the battery can be effectively increased, lithium precipitation can be avoided, and the cycle life performance of the battery can be ensured. In addition, the electrolyte accommodated in the liquid storage area 12a surrounded by the inner wall surface of the liquid storage tube 121 can be in full contact with the active material layer 13, improving the wetting effect.

[0030] It is worth mentioning that for the electrode sheet 10 with high pressure density (i.e., large compaction density), after rolling, the porosity of the active material layer 13 will be greatly reduced. However, the liquid storage tube 121 in the embodiment of the present application can provide an effective storage space for the electrolyte. When filling the electrolyte, the electrolyte can penetrate through the through holes 121a on the liquid storage tube 121 into the liquid storage area 12a formed by enclosing the inner wall surface of the liquid storage tube 121 to effectively avoid the situation of battery swelling; at the same time, during the penetration process of the electrolyte, the electrolyte can fully infiltrate the electrode sheet 10, effectively reduce corner lithium deposition, and improve the cycle life performance of the battery.

[0031] As Figure 4 shown, in the second embodiment, the liquid storage member 12 includes a liquid storage column 122, and the outer wall surface of the liquid storage column 122 is provided with concave holes 122a. The area formed by enclosing the hole wall surface of the concave holes 122a serves as the above-mentioned liquid storage area 12a. Among them, the outer wall surface of the liquid storage column 122 includes an outer end face and an outer circumferential surface. The number of the concave holes 122a can be one or more (more than two). For example, when the number of the concave holes 122a is one; this one concave hole 122a can be arranged on the outer end face of the liquid storage column 122; it can also be arranged on the outer circumferential surface of the liquid storage column 122. Another example is that when the number of the concave holes 122a is multiple; these multiple concave holes 122a can be only arranged on the outer end face of the liquid storage column 122; they can also be only arranged on the outer circumferential surface of the liquid storage column 122; or a part of them can be arranged on the outer end face of the liquid storage column 122 and the remaining part can be arranged on the outer circumferential surface of the liquid storage column 122. It should be noted that when the number of the concave holes 122a is multiple, the specific arrangement manner of these multiple concave holes 122a on the outer end face and / or the outer circumferential surface of the liquid storage column 122 can be arbitrary or can be pre-designed according to a certain specific arrangement. In addition, the concave holes 122a can penetrate through the liquid storage column 122 or not penetrate through the liquid storage column 122. By designing the liquid storage member 12 as the liquid storage column 122 and designing the concave holes 122a on the outer wall surface of the liquid storage column 122 so that the hole wall surface of the concave holes 122a encloses to form the liquid storage area 12a, when filling the electrolyte, the electrolyte can be accommodated in the liquid storage area 12a formed by enclosing the hole wall surface of the concave holes 122a. In this way, it can effectively improve the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet, and can also effectively increase the liquid retention amount of the battery, avoid lithium deposition, and ensure the cycle life performance of the battery. In addition, the electrolyte accommodated in the liquid storage area 12a formed by enclosing the hole wall surface of the concave holes 122a can be in full contact with the active material layer 13, improving the infiltration effect.

[0032] Furthermore, when the liquid storage member 12 includes the above-mentioned liquid storage tube 121, as Figure 5As shown, along the direction perpendicular to the extension direction of the liquid storage tube 121, the liquid storage tube 121 has a cross-section, and the diameter D of the cross-section of the liquid storage tube 121 and the thickness H of the active material layer 13 satisfy the conditional formula: 0.1×H ≤ D ≤ 0.2×H. For example, the specific value of D / H can be, but is not limited to, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, etc. By reasonably designing the value of the diameter D of the cross-section of the liquid storage tube 121 and the thickness H of the active material layer, so that the diameter D of the cross-section of the liquid storage tube 121 and the thickness H of the active material layer satisfy the above conditional formula, it can not only ensure that enough electrolyte can be accommodated in the liquid storage area 12a surrounded by the inner wall surface of the liquid storage tube 121, but also ensure that the active material layer 13 is sufficient to bury the liquid storage tube 121 within its thickness, so that the electrolyte accommodated in the liquid storage area 12a surrounded by the inner wall surface of the liquid storage tube 121 can be in full contact with the active material layer 13, improving the infiltration effect.

[0033] Further, when the liquid storage member 12 includes the above-mentioned liquid storage tube 121, as Figure 3 and Figure 5 shown, along the direction perpendicular to the extension direction of the liquid storage tube 121, the liquid storage tube 121 has a cross-section, and the diameter D of the cross-section of the liquid storage tube 121 and the aperture d of the through-hole 121a satisfy the conditional formula: 0.1×D ≤ d ≤ 0.2×D. For example, the specific value of d / D can be, but is not limited to, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, etc. By reasonably designing the value of the aperture d of the through-hole 121a and the diameter D of the cross-section of the liquid storage tube 121, so that the aperture d of the through-hole 121a and the diameter D of the cross-section of the liquid storage tube 121 satisfy the above conditional formula, it can not only ensure that enough electrolyte can be accommodated in the liquid storage area 12a surrounded by the inner wall surface of the liquid storage tube 121, but also avoid the excessive thickness of the battery cell.

[0034] It should be noted that the liquid storage tube 121 can be linear or curved; when the liquid storage tube 121 is linear, the extension direction of the liquid storage tube 121 is the direction parallel to the central axis of the liquid storage tube 121 (and the extension direction of the liquid storage tube 121 and the central axis of the liquid storage tube 121 are in the same plane); when the liquid storage tube 121 is curved, the extension direction of the liquid storage tube 121 is the direction parallel to the connection line between the center points of the two end faces of the liquid storage tube 121 (and the extension direction of the liquid storage tube 121 and the connection line between the center points of the two end faces of the liquid storage tube 121 are in the same plane).

[0035] Further, when the number of the liquid storage members 12 is multiple, the multiple liquid storage members 12 can be arranged arbitrarily on the bearing surface 11a of the current collector 11, and can be, but is not limited to, the following several embodiments.

[0036] As Figure 2As shown, in the first embodiment, a plurality of liquid storage members 12 are arranged in N columns on the bearing surface 11a of the current collector 11. By arranging the plurality of liquid storage members 12 in N columns, the internal space of the active material layer 13 can be reasonably occupied by the plurality of liquid storage members 12, effectively increasing the liquid storage space while avoiding excessive battery thickness. At the same time, the electrolyte contained in the liquid storage areas 12a of the plurality of liquid storage members 12 can be in full contact with the active material layer 13, improving the infiltration effect.

[0037] In the second embodiment, a plurality of liquid storage members 12 are arranged in a circular array with an arbitrary point on the bearing surface 11a of the current collector 11 as the array center.

[0038] Further, when a plurality of liquid storage members 12 are arranged in N columns on the bearing surface 11a of the current collector 11, as Figure 2 shown, all the liquid storage members 12 extend along the first preset direction XX', and the liquid storage members 12 are arranged at intervals in the second preset direction YY' to form N columns; the first preset direction XX' and the second preset direction YY' are two arbitrarily intersecting directions in the plane of the bearing surface 11a of the current collector 11; along the second preset direction YY', the distance S between two adjacent liquid storage members 12 satisfies the conditional formula: 100 μm ≤ S ≤ 120 μm. For example, the specific value of the distance S can be, but is not limited to, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, etc. Among them, the included angle between the first preset direction XX' and the second preset direction YY' can be 90 degrees (that is, the first preset direction XX' is perpendicular to the second preset direction YY'); the included angle between the first preset direction XX' and the second preset direction YY' can also be 30 degrees. By reasonably designing the value of the distance S between two adjacent liquid storage members 12 in the second preset direction YY' so that the value of the distance S satisfies the above conditional formula, the plurality of liquid storage members 12 are embedded in the active material layer 13 at a reasonable distance, enabling the plurality of liquid storage members 12 to reasonably occupy the internal space of the active material layer 13, effectively increasing the liquid storage space while avoiding excessive battery thickness; in addition, the electrolyte contained in the liquid storage areas 12a of the plurality of liquid storage members 12 can be in full contact with the active material layer 13, improving the infiltration effect while ensuring the uniformity of the electrolyte distribution. When S < 100 μm, the distance between two adjacent liquid storage members 12 is too small, resulting in high processing difficulty and production cost; when S > 120 μm, the distance between two adjacent liquid storage members 12 is too large, and it is impossible to effectively improve the battery swelling caused by the reduction of the porosity of the battery electrode sheet.

[0039] Further, other designs of the liquid storage member 12 and the active material layer 13 can be, but are not limited to, one or more of the following embodiments.

[0040] In the first embodiment, the liquid storage member 12 is formed by 3D printing. In this design, manufacturing the liquid storage member 12 by 3D printing can effectively reduce the processing difficulty of the liquid storage member 12.

[0041] In the second embodiment, the preparation material of the liquid storage member 12 is any one of graphene, carbon fiber, and artificial graphite. In this design, by designing the preparation material of the liquid storage member 12 as any one of graphene, carbon fiber, and artificial graphite, the raw material sources are extensive and easy to obtain.

[0042] In the third embodiment, the liquid storage member 12 is fixed to the bearing surface 11a of the current collector 11 by dispensing. In this design, fixing the liquid storage member 12 to the bearing surface 11a of the current collector 11 by dispensing can effectively reduce the processing difficulty between the liquid storage member 12 and the current collector 11.

[0043] In the fourth embodiment, the active material layer 13 is covered on the bearing surface 11a of the current collector 11 by coating. In this design, covering the active material layer 13 on the bearing surface 11a of the current collector 11 by coating can effectively reduce the processing difficulty between the active material layer 13 and the current collector 11.

[0044] The following introduces the specific forms when the electrode sheet 10 in the embodiment of the present application is a positive electrode sheet or a negative electrode sheet around the solution of the liquid storage member 12 including the liquid storage tube 121, and it can be but not limited to the following several:

[0045] When the electrode sheet 10 in the embodiment of the present application is a positive electrode sheet: the component of the active material layer 13 is an NCM material, which includes at least one of NCM7205, NCM811, and NCM9005; and the mass fractions of the components of the active material layer 13 are: 92%-97% of the ternary positive electrode material, 1%-4% of the conductive agent, and 1%-4% of the binder. The thickness H of the active material layer 13 is between 35 microns and 50 microns; the diameter D of the cross-section of the liquid storage tube 121 is between 3.5 microns and 10 microns; along the second preset direction YY', the distance S between two adjacent liquid storage tubes 121 is between 100 microns and 120 microns.

[0046] When the electrode sheet 10 in the embodiment of the present application is a negative electrode sheet: the component of the active material layer 13 is graphene; and the mass fractions of the components of the active material layer 13 are: 93%-96% of graphene, 1%-4% of the conductive agent, and 1%-4% of the binder. The thickness H of the active material layer 13 is between 35 microns and 50 microns; the diameter D of the cross-section of the liquid storage tube 121 is between 3.5 microns and 10 microns; along the second preset direction YY', the distance S between two adjacent liquid storage tubes 121 is between 100 microns and 120 microns.

[0047] Second aspect, an embodiment of the present application provides an electrode assembly (not shown in the figure), which includes the above-mentioned electrode sheet 10, and the electrode sheet 10 is at least one of a positive electrode sheet and a negative electrode sheet.

[0048] For example, the electrode assembly in the embodiment of the present application may include at least one of the above-mentioned electrode sheets 10, and all of the electrode sheets 10 serve as the positive electrode sheets of the electrode assembly. At this time, the electrode assembly may further include at least one other electrode sheet with a structure different from the above-mentioned electrode sheet 10 as the negative electrode sheet of the electrode assembly, and a separator (a sub-component of the electrode assembly) is provided between all the positive electrode sheets and all the negative electrode sheets of the electrode assembly. Another example is that the electrode assembly in the embodiment of the present application may include at least one of the above-mentioned electrode sheets 10, and all of the electrode sheets 10 serve as the negative electrode sheets of the electrode assembly. At this time, the electrode assembly may further include at least one other electrode sheet with a structure different from the above-mentioned electrode sheet 10 as the positive electrode sheet of the electrode assembly, and a separator (a sub-component of the electrode assembly) is provided between all the negative electrode sheets and all the positive electrode sheets of the electrode assembly. Still another example is that the electrode assembly in the embodiment of the present application may include a plurality (more than two) of the above-mentioned electrode sheets 10, some of the electrode sheets 10 serve as the positive electrode sheets of the electrode assembly, and the remaining electrode sheets 10 serve as the negative electrode sheets of the electrode assembly, and a separator (a sub-component of the electrode assembly) is provided between all the positive electrode sheets and all the negative electrode sheets of the electrode assembly.

[0049] It should be noted that the electrode assembly in the embodiment of the present application can be either a wound electrode assembly or a stacked electrode assembly.

[0050] Based on the electrode assembly in the embodiment of the present application, having the above-mentioned electrode sheet 10, it can effectively improve the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet, and can also effectively increase the liquid retention capacity of the battery, avoid lithium deposition, and ensure the cycle life performance of the battery. In addition, it can also ensure sufficient contact between the electrolyte and the active material layer 13 and improve the wetting effect.

[0051] Third aspect, an embodiment of the present application provides a battery (not shown in the figure), which includes a housing, an electrolyte, and the above-mentioned electrode assembly. The housing has a receiving cavity, the electrolyte is poured into the receiving cavity of the housing, and the above-mentioned electrode assembly is disposed in the receiving cavity of the housing.

[0052] Based on the battery in the embodiment of the present application, having the above-mentioned electrode assembly, it can effectively improve the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet, and can also effectively increase the liquid retention capacity of the battery, avoid lithium deposition, and ensure the cycle life performance of the battery. In addition, while effectively increasing the liquid storage space, it can also avoid excessive thickness of the battery.

[0053] Fourth aspect, an embodiment of the present application provides an electrical device (not shown in the figure), which includes a housing and the above-mentioned battery. The housing has a battery installation groove, and the above-mentioned battery is installed in the housing corresponding to the battery installation groove.

[0054] It should be noted that the electrical device is a device capable of converting the electrical energy of the above battery into other forms of energy; for example, the electrical device may but is not limited to being a terminal such as a mobile phone, a tablet, a computer, etc.; for another example, the electrical device may also but is not limited to being a lighting device such as a flashlight, a table lamp, a voice-activated lamp, etc.; for yet another example, the electrical device may further but is not limited to being a timing device such as an electronic watch, an electronic clock, etc.

[0055] Based on the electrical device in the embodiment of the present application, having the above battery, it can effectively improve the situation of battery swelling caused by the reduction of the porosity of the battery electrode sheet, and can also effectively increase the liquid retention capacity of the battery, avoid lithium plating, ensure the cycle life performance of the battery, so as to improve the service life of the electrical device.

[0056] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0057] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pole piece, characterized in that: include: A current collector having a bearing surface, wherein at least one end surface of the current collector in its thickness direction is the bearing surface; A liquid storage member, connected to the bearing surface, having a liquid storage area for containing electrolyte; The active material layer is arranged on the side of the current collector where the bearing surface is located and covers the liquid storage component.

2. The pole piece according to claim 1, characterized in that: The liquid storage member comprises a liquid storage tube, the area enclosed by the inner wall of the liquid storage tube serves as the liquid storage area, and the outer wall of the liquid storage tube is provided with a through hole communicating with the liquid storage area; or The liquid storage element comprises a liquid storage column, the outer wall surface of the liquid storage column is provided with a concave hole, and the area surrounded by the hole wall surface of the concave hole serves as the liquid storage area.

3. The pole piece according to claim 2, characterized in that: The liquid storage member includes the liquid storage tube; The liquid storage tube has a cross section along a direction perpendicular to the extension direction of the liquid storage tube, and the diameter D of the cross section of the liquid storage tube and the thickness H of the active material layer satisfy the conditional formula: 0.1×H≤D≤0.2×H.

4. The pole piece according to claim 2, characterized in that: The liquid storage member includes the liquid storage tube; the liquid storage tube has a cross section along a direction perpendicular to the extension direction of the liquid storage tube, and the diameter D of the cross section of the liquid storage tube and the aperture d of the through hole satisfy the conditional formula: 0.1×D≤d≤0.2×D.

5. The pole piece according to claim 1, characterized in that: There are multiple liquid storage components, and the multiple liquid storage components are arranged on the carrying surface in N rows.

6. The pole piece according to claim 5, characterized in that: All liquid storage members extend along a first preset direction, and the liquid storage members are arranged in N rows at intervals along a second preset direction; wherein the first preset direction and the second preset direction are two arbitrarily intersecting directions within the plane where the bearing surface is located; Along the second preset direction, the distance S between two adjacent liquid storage members satisfies the condition: 100 micrometers ≤ S ≤ 120 micrometers.

7. The pole piece according to any one of claims 1 to 6, characterized in that: The liquid storage member is formed by 3D printing; and / or The liquid storage member is made of any one of graphene, carbon fiber and artificial graphite; and / or The liquid storage component is fixed to the bearing surface by glue dispensing.

8. A battery cell, characterized in that: include: The pole piece according to any one of claims 1 to 7, wherein the pole piece is at least one of a positive pole piece and a negative pole piece.

9. A battery, characterized in that: include: A housing having a receiving cavity; The battery cell according to claim 8, wherein the battery cell is disposed in the accommodating cavity; and The electrolyte is poured into the containing cavity.

10. An electrical device, characterized in that: include: A housing having a battery mounting slot; and The battery as claimed in claim 9, wherein the battery is mounted on the housing corresponding to the battery mounting slot.

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