Battery pole piece and battery device

Abstract

The utility model relates to the technical field of batteries, in particular to a battery pole piece and a battery device.The battery pole piece comprises a current collector and an active substance layer, the active substance layer is arranged on the surface of the current collector, a plurality of holes are formed in the active substance layer, the hole density of the active substance layer is a, the surface density of the active material layer is b, and a / b is larger than or equal to 0.07 mm < 2 > / g and smaller than or equal to 0.6 mm < 2 > / g. On one hand, the ratio of the pore density of the active material layer to the surface density of the active material layer is larger than or equal to 0.07 mm < 2 > / g, the problem that infiltration is more difficult due to the fact that an electrolyte infiltration path is lengthened under the condition of high surface density is solved, on the other hand, the ratio of the pore density of the active material layer to the surface density of the active material layer is smaller than or equal to 0.6 mm < 2 > / g, and the problem that infiltration is more difficult due to the fact that an electrolyte infiltration path is lengthened under the condition of high surface density is solved. The problem that the hole density is too large, so that the distance between holes is too small, and the holes are prone to being partially overlapped and unqualified in the hole forming process is solved.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a battery pole piece and a battery device. Background Art

[0002] A battery device is often provided in an electric vehicle, and the battery device is used to provide power to the electric vehicle. The battery device includes a plurality of batteries, and the battery includes a shell, an electrolyte and a pole piece, and the pole piece and the electrolyte are arranged in the shell. When the battery is working, the pole piece transmits electric charge through the electrolyte, so the infiltration of the electrolyte into the pole piece is closely related to the energy density and charging speed of the battery. In the related art, the surface density of the battery pole piece is getting higher and higher, and the increase in the surface density of the pole piece leads to a decrease in the wettability of the electrolyte, which is not conducive to the improvement of the battery energy density and charging speed.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] The purpose of the present disclosure is to provide a battery pole piece and a battery device, thereby improving the wettability of the battery pole piece by the electrolyte at least to a certain extent.

[0005] According to a first aspect of the present disclosure, a battery electrode sheet is provided, the battery electrode sheet comprising:

[0006] current collector;

[0007] An active material layer, the active material layer is arranged on the surface of the current collector, a plurality of holes are arranged in the active material layer, and the hole density of the active material layer is a, the hole density is the area occupied by the holes in the active material layer per unit area, and the surface density of the active material layer is b, 0.07 mm 2 / g≤a / b≤0.6mm 2 / g.

[0008] According to a second aspect of the present disclosure, a battery cell is provided, the battery cell comprising the above-mentioned battery electrode sheet.

[0009] According to a third aspect of the present disclosure, a battery is provided, comprising the above-mentioned battery cell.

[0010] The battery pole piece provided by the embodiment of the present disclosure includes a current collector and an active material layer. The active material layer is arranged on the surface of the current collector. A plurality of holes are arranged in the active material layer. By arranging holes on the active material layer, the contact area of ​​the electrolyte is increased, thereby improving the wettability of the electrolyte, forming an environment in which the active material is prone to electrochemical reaction, and improving the injection efficiency and fast charging performance. Furthermore, by setting the ratio of the pore density of the active material layer to the surface density of the active material layer to 0.07 mm 2 / g-0.6mm 2 / g, on the one hand, the ratio of the pore density of the active material layer to the surface density of the active material layer is greater than or equal to 0.07 mm 2 / g, which solves the problem that the electrolyte infiltration path becomes longer and makes infiltration more difficult under high surface density conditions. On the other hand, the ratio of the pore density of the active material layer to the surface density of the active material layer is less than or equal to 0.6mm 2 / g, avoiding the problem of too small a spacing between holes due to too high a hole density, which results in the holes partially overlapping and causing unqualified shapes during hole making.

[0011] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0013] Figure 1 A schematic diagram of a first battery pole piece provided for an exemplary embodiment of the present disclosure;

[0014] Figure 2 A schematic diagram of a second battery pole piece provided for an exemplary embodiment of the present disclosure;

[0015] Figure 3 A schematic diagram of a third battery pole piece provided for an exemplary embodiment of the present disclosure;

[0016] Figure 4 A schematic diagram of a fourth battery pole piece provided for an exemplary embodiment of the present disclosure;

[0017] Figure 5 A schematic diagram of a fifth battery electrode sheet provided for an exemplary embodiment of the present disclosure.

[0018] Description of Figure Numbers:

[0019] 10. Current collector; 20. Active material layer; 21. First active material layer; 22. Second active material layer; 201. Holes; 210. Hole row. DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0021] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0022] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0023] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to another element (one or more) "upper", "lower", or "inner", "outer", it can not only be directly connected to the other (one or more) elements "upper", "lower", "inner", "outer", but also can be indirectly connected to the other (one or more) elements "upper", "lower", "inner", "outer" through an intermediate element.

[0024] The exemplary embodiment of the present disclosure first provides a battery electrode sheet, such as Figure 1 As shown, the battery electrode includes a current collector 10 and an active material layer 20. The active material layer 20 is disposed on the surface of the current collector 10. A plurality of holes 201 are disposed in the active material layer 20. The hole density of the active material layer 20 is a, and the hole density is the area occupied by the holes 201 in the active material layer 20 per unit area. The surface density of the active material layer 20 is b, 0.07 mm2 / g≤a / b≤0.6mm 2 / g.

[0025] The battery pole piece provided by the embodiment of the present disclosure includes a current collector 10 and an active material layer 20. The active material layer 20 is arranged on the surface of the current collector 10. A plurality of holes 201 are arranged in the active material layer 20. By arranging the holes 201 on the active material layer 20, the contact area of ​​the electrolyte is increased, thereby improving the wettability of the electrolyte, forming an environment in which the active material is prone to electrochemical reaction, and improving the injection efficiency and fast charging performance. Furthermore, by setting the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 to 0.07 mm 2 / g-0.6mm 2 / g, on the one hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is greater than or equal to 0.07 mm 2 / g, which solves the problem that the electrolyte infiltration path becomes longer and makes infiltration more difficult under high surface density conditions. On the other hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is less than or equal to 0.6mm 2 / g, thus avoiding the problem that the spacing between the holes 201 is too small due to the excessive hole density, so that the holes 201 are prone to partial overlap and unqualified morphology during hole formation.

[0026] The following is a detailed description of each part of the battery electrode provided by the embodiment of the present disclosure:

[0027] The current collector 10 is a metal sheet, which is used as the current output terminal of the battery cell. For example, the current collector 10 can be a copper foil or an aluminum foil. Of course, in practical applications, the current collector can also be a composite current collector, but the embodiments of the present disclosure are not limited thereto.

[0028] In a feasible embodiment, the battery electrode is a negative electrode, 0.1 mm 2 / g≤a / b≤0.5mm 2 / g. The current collector 10 of the negative electrode sheet is a copper current collector 10, and the negative electrode active material is coated on the copper current collector 10 to form the negative electrode sheet. Of course, in practical applications, the battery sheet can also be a positive electrode sheet, and the current collector 10 of the positive electrode sheet is an aluminum current collector 10, and the positive electrode active material is coated on the surface of the aluminum current collector 10 to form a positive electrode sheet.

[0029] The active material layer 20 is disposed on the surface of the current collector 10. The active material layer 20 may be disposed on one surface of the current collector 10, or on both surfaces of the current collector 10. Figure 2As shown, the current collector 10 has a first surface and a second surface opposite to each other. A first active material layer 21 is disposed on the first surface of the current collector 10 , and a second active material layer 22 is disposed on the second surface of the current collector 10 .

[0030] The active material layer 20 is provided with a plurality of holes 201, and the holes 201 penetrate the side of the active material layer 20 away from the current collector 10. The holes 201 on the active material layer 20 can be blind holes or through holes, that is, the holes 201 extend from the side of the active material layer 20 away from the current collector 10 to the side close to the current collector 10, and the holes 201 penetrate the active material layer 20, or the holes 201 do not penetrate the active material layer 20.

[0031] The pore density of the active material layer 20 is a, the surface density of the active material layer 20 is b, and the area density of the active material layer 20 is 0.07 mm 2 / g≤a / b≤0.6mm 2 / g. Further, 0.1mm 2 / g≤a / b≤0.3mm 2 For example, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 may be 0.07 mm 2 / g, 0.1mm 2 / g, 0.5mm 2 / g or 0.6mm 2 / g, etc.

[0032] The surface density of the active material layer 20 is the weight of the active material layer 20 per unit area. For example, the surface density may be 90-400 g / cm 2 The pore density of the active material layer 20 is the area occupied by the pores per unit area of ​​the active material layer. For example, the pore density of the active material layer 20 can be calculated by the following formula:

[0033]

[0034] Here, Si is the area of ​​the hole 201 , and S is the total area of ​​the active material layer 20 .

[0035] The active material layer 20 is provided with a plurality of holes 201. The plurality of holes 201 on the active material layer 20 may be the same (same shape, area and depth), or the plurality of holes 201 on the active material layer 20 may be different (one or more of the shapes, areas and depths are different). The plurality of holes on the active material layer 20 may be arranged in a plurality of rows, each row having a plurality of holes 201, and the plurality of rows of holes 201 may be arranged in alignment, or the plurality of rows of holes 201 may be arranged in a staggered manner.

[0036] Multiple holes 201 in a row of holes 201 are arranged along a first direction, and multiple rows of holes 201 are arranged along a second direction, and the first direction and the second direction are perpendicular. The first direction is the length direction of the battery electrode (electrode conveying direction), and the second direction is the width direction of the battery electrode. Of course, in practical applications, the first direction and the second direction can also be interchanged, and the embodiments of the present disclosure are not limited thereto.

[0037] When the first active material layer 21 and the second active material layer 22 are respectively disposed on the two surfaces of the current collector 10, the holes 201 in the first active material layer 21 and the holes 201 in the second active material layer 22 may be the same. For example, the position of the hole on the first active material layer 21 and the position of the hole 201 on the second active material layer 22 are aligned, and the position of the hole on the first active material layer 21 and the shape of the hole 201 on the second active material layer 22 are the same, and the depth of the hole on the first active material layer 21 and the depth of the hole 201 on the second active material layer 22 are the same.

[0038] It is understandable that the holes 201 in the first active material layer 21 and the holes 201 in the second active material layer 22 may also be different. For example, the depth of at least some of the holes 201 in the first active material layer 21 is greater than the depth of the holes 201 in the second active material layer 22, and / or the area of ​​at least some of the holes 201 in the first active material layer 21 is greater than the area of ​​the holes 201 in the second active material layer 22.

[0039] The holes 201 in the first active material layer 21 may be round holes, square holes, or long holes, etc., and the holes 201 in the second active material layer 22 may be round holes, square holes, or long holes, etc. The first active material layer 21 may be provided with multiple rows of holes 201, and the multiple rows of holes 201 may be arranged in an aligned manner (matrix distribution), or the multiple rows of first holes may be arranged in an alternating manner. The second active material layer 22 may be provided with multiple rows of holes 201, and the multiple rows of holes 201 may be arranged in an aligned manner (matrix distribution), or the multiple rows of holes 201 may be arranged in an alternating manner.

[0040] In a feasible embodiment of the present disclosure, if Figure 3 As shown, a plurality of hole rows 210 are arranged on the active material layer 20, and the hole rows 210 include a plurality of holes 201 arranged along a first direction. The plurality of hole rows 210 are arranged along a second direction, and the first direction and the second direction are perpendicular. The holes 201 in the first hole row are aligned with the holes 201 in the second direction and the holes 201 in the second hole row. The first hole row and the second hole row are adjacent hole rows 210, and the hole length is 0.07 mm. 2 / g≤a / b≤0.5mm 2 / g.

[0041] The number of holes 201 in the first hole row is the same as the number of holes 201 in the second hole row, and the holes 201 in the first hole row correspond to the holes 201 in the second hole row. The line connecting the corresponding holes 201 in the first hole row and the holes 201 in the second hole row extends along the second direction.

[0042] The holes 201 in the first hole row and the holes 201 in the second hole row are aligned, that is, the holes in two adjacent rows are aligned. When processing holes, the holes 201 in adjacent rows are prone to partially overlap, resulting in abnormal morphology. The ratio of the hole density of the active material layer 20 to the surface density of the active material layer 20 is set to 0.07 mm 2 / g-0.5mm 2 / g, thereby avoiding the problem of abnormal morphology of the pores 201 caused by excessive surface density of the active material layer 20.

[0043] In another possible implementation, if Figure 4 As shown, a plurality of hole rows 210 are arranged on the active material layer 20, and the hole rows 210 include a plurality of holes 201 arranged along a first direction. The plurality of hole rows 210 are arranged along a second direction, and the first direction and the second direction are perpendicular. The holes 201 in the first hole row and the holes 201 in the second hole row are misaligned in the second direction. The first hole row and the second hole row are adjacent hole rows 210, and the distance between the first hole row and the second hole row is 0.1 mm. 2 / g≤a / b≤0.1mm 2 / g.

[0044] The holes 201 in the first hole row and the holes 201 in the second hole row are staggered, which means that the holes 201 in the first hole row and the holes 201 in the second hole row are not aligned in the second direction. In the plurality of hole rows 210, the holes 201 in adjacent hole rows 210 may be not aligned, and the alternate hole rows 210 may be aligned. Alternatively, in the plurality of hole rows 210, the plurality of hole rows 210 are all staggered.

[0045] The holes 201 in the first hole row and the holes 201 in the second hole row are staggered, which can increase the number of holes 201 arranged on the active material layer 20 and improve the hole density of the active material layer 20. The ratio of the hole density of the active material layer 20 to the surface density of the active material layer 20 is set to 0.1 mm 2 / g-0.1mm 2 / g, taking into account both the pore density and the surface density, and also ensuring the shape of the hole 201.

[0046] It is worth noting that in the embodiment of the present disclosure, when the first active material layer 21 and the second active material layer 22 are respectively disposed on both sides of the current collector 10 , the first hole row and the second hole row are the hole rows 210 in the same active material layer 20 .

[0047] In one embodiment, if Figure 5 As shown, the distances between the first hole and the plurality of second holes are equal, the first hole is any hole 201 on the active material layer 20, and the second hole is a hole adjacent to the first hole on the active material layer 20. That is, the plurality of holes 201 on the active material layer 20 can be divided into a plurality of hole groups, each of which has three holes, and the three holes are distributed in an equilateral triangle.

[0048] The multiple holes 201 in the hole row 210 are evenly spaced, the distance between adjacent holes 201 in the hole row 210 is w, and the distance between two adjacent hole rows 210 is The projection of the holes 201 in the first hole row along the second direction in the first hole row is located in the middle of the two holes 201 .

[0049] Optionally, the distance between adjacent holes 201 is 40 μm-2000 μm, that is, the value range of w is 40 μm-2000 μm. For example, the distance between adjacent holes 201 can be 40 μm, 50 μm, 80 μm, 100 μm, 300 μm, 500 μm, 700 μm, 1000 μm, 1100 μm, 1200 μm, 1500 μm, 1800 μm, 1900 μm, 1950 μm, 1980 μm, 1990 μm or 2000 μm, etc.

[0050] By setting the distance between adjacent holes 201 to 40μm-2000μm, effective control of the hole density is achieved, ensuring that the spacing between the holes 201 is within a reasonable range. On the one hand, the problem of being unfavorable for processing and forming due to too small a spacing is avoided. On the other hand, the problem of a limited number of holes 201 arranged due to too large a spacing is avoided, thereby improving the limited electrolyte infiltration performance and enhancing the wettability of the electrolyte.

[0051] When the hole 201 is a through hole, the hole 201 extends from the side of the active material layer 20 away from the current collector 10 to the surface of the current collector 10. When the hole 201 is a blind hole, the hole 201 starts from the side of the active material layer 20 away from the current collector 10, and ends inside the active material layer 20 in the hole 201. At this time, the ratio of the depth of the hole 201 to the thickness of the active material layer 20 ranges from 10% to 80%. For example, the ratio of the depth of the hole 201 to the thickness of the active material layer 20 can be 10%, 11%, 15%, 20%, 30%, 50%, 70%, 71%, 75%, 78% or 80%. The thickness of the active material layer 20 is the size from the side of the active material layer 20 away from the current collector 10 to the side of the active material layer 20 close to the current collector 10, and the depth of the hole 201 is the size of the hole 201 in the direction perpendicular to the current collector 10.

[0052] By setting the ratio of the depth of the hole 201 to the thickness of the active material layer 20 to a range of 10%-80%, on the one hand, the hole depth ratio is improved, which is beneficial to improving the electrolyte infiltration performance and thus improving the fast charging performance. On the other hand, it avoids the problem of loosening of the pole powder and decreased adhesion during the pore making process due to the excessive hole depth ratio, thereby ensuring the performance of the battery.

[0053] Optionally, the hole 201 is a circular hole, and the diameter of the hole 201 is 20 μm-40 μm. For example, the diameter of the hole 201 may be 20 μm, 25 μm, 30 μm, 35 μm, 38 μm or 40 μm, etc. A circular hole is easy to process and can avoid stress concentration.

[0054] In the disclosed embodiment, the battery pole piece includes a main body and a pole ear portion, the pole ear portion extends from the edge of the main body, and the pole ear portion is not coated with active material. That is, the current collector 10 includes a main body and a pole ear portion, the main body is coated with an active material layer 20, and a plurality of pole ear portions are formed into pole ears by welding or the like.

[0055] The battery pole piece provided by the embodiment of the present disclosure includes a current collector 10 and an active material layer 20. The active material layer 20 is arranged on the surface of the current collector 10. A plurality of holes 201 are arranged in the active material layer 20. By arranging the holes 201 on the active material layer 20, the contact area of ​​the electrolyte is increased, thereby improving the wettability of the electrolyte, forming an environment in which the active material is prone to electrochemical reaction, and improving the injection efficiency and fast charging performance. Furthermore, by setting the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 to 0.07 mm 2 / g-0.6mm 2 / g, on the one hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is greater than or equal to 0.07 mm 2 / g, which solves the problem that the electrolyte infiltration path becomes longer and makes infiltration more difficult under high surface density conditions. On the other hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is less than or equal to 0.6mm 2 / g, thus avoiding the problem that the spacing between the holes 201 is too small due to the excessive hole density, so that the holes 201 are prone to partial overlap and unqualified morphology during hole formation.

[0056] The exemplary embodiment of the present disclosure also provides a battery cell, which includes a battery pole piece. The battery pole piece includes a current collector 10 and an active material layer 20, wherein the active material layer 20 is disposed on the surface of the current collector 10, and a plurality of holes 201 are disposed in the active material layer 20, and the hole density of the active material layer 20 is a, and the surface density of the active material layer 20 is b, 0.07 mm 2 / g≤a / b≤0.6mm2 / g.

[0057] The battery cell provided in the embodiment of the present disclosure includes a battery pole piece, in which an active material layer 20 is arranged on the surface of a current collector 10, and a plurality of holes 201 are arranged in the active material layer 20. By arranging the holes 201 on the active material layer 20, the contact area of ​​the electrolyte is increased, thereby improving the wettability of the electrolyte, forming an environment in which the active material is prone to electrochemical reaction, and improving the injection efficiency and fast charging performance. Furthermore, by setting the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 to 0.07 mm 2 / g-0.6mm 2 / g, on the one hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is greater than or equal to 0.07 mm 2 / g, which solves the problem that the electrolyte infiltration path becomes longer and makes infiltration more difficult under high surface density conditions. On the other hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is less than or equal to 0.6mm 2 / g, thus avoiding the problem that the spacing between the holes 201 is too small due to the excessive hole density, so that the holes 201 are prone to partial overlap and unqualified morphology during hole formation.

[0058] Among them, the battery cell can be a wound battery cell or a stacked battery cell. In the wound battery cell, the battery pole sheets and the diaphragm are wound to form the battery cell, and in the stacked battery cell, the battery pole sheets and the diaphragm are folded to form the battery cell.

[0059] An embodiment of the present disclosure also provides a battery device, which includes the above-mentioned battery electrode.

[0060] Among them, the battery device can be a battery, a battery module or a battery pack, etc. When the battery device is a single battery, the battery can be a prismatic battery, such as a quadrangular battery (square battery) or a hexagonal battery, or the battery can also be a cylindrical battery. In a prismatic battery, the battery cell can be a wound battery cell or a laminated battery cell, and in a cylindrical battery, the battery cell can be a wound battery cell. In the embodiment of the present disclosure, the battery is a secondary battery. For example, the battery can be a lithium iron phosphate battery or the battery can be a ternary lithium battery, etc.

[0061] Furthermore, the battery may also include a shell, a pole and a current collector, etc. The shell has a receiving cavity, the battery cell is arranged in the receiving cavity of the shell, and an electrolyte is also arranged in the receiving cavity, and the battery cell is at least partially immersed in the electrolyte. The pole is arranged in the shell, and the pole is used as the electrode end of the battery. The current collector is arranged in the receiving cavity, and the current collector connects the battery cell and the pole. The pole piece may also be provided with a pole ear, and the pole ear is connected to the current collector.

[0062] When the battery is a square battery, the battery shell may be provided with a positive pole post and a negative pole post, the positive pole post is connected to the positive pole tab of the battery cell, and the negative pole post is connected to the negative pole tab of the battery cell. When the battery is a cylindrical battery, only one pole post may be provided on the shell, and the other output end of the battery may be served by the shell. For example, the pole post serves as the positive output section of the battery and is connected to the positive pole tab of the battery cell, and the shell serves as the negative output end of the battery and is connected to the negative pole tab of the battery cell.

[0063] When the battery device is a battery pack, the battery pack can be applied to an electric vehicle, and the battery pack is installed on the electric vehicle to provide energy to the electric vehicle. In practical applications, the battery pack can be installed on the frame of the electric vehicle. The battery pack can be fixedly connected to the frame. Alternatively, the battery pack can be a modular battery pack, which can be detachably connected to the vehicle body for easy replacement.

[0064] In the battery device provided by the embodiment of the present disclosure, in the battery electrode, the active material layer 20 is arranged on the surface of the current collector 10, and a plurality of holes 201 are arranged in the active material layer 20. By arranging the holes 201 on the active material layer 20, the contact area of ​​the electrolyte is increased, thereby improving the wettability of the electrolyte, forming an environment in which the active material is easy to undergo electrochemical reactions, and improving the injection efficiency and fast charging performance. Furthermore, by setting the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 to 0.07 mm 2 / g-0.6mm 2 / g, on the one hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is greater than or equal to 0.07 mm 2 / g, which solves the problem that the electrolyte infiltration path becomes longer and makes infiltration more difficult under high surface density conditions. On the other hand, the ratio of the pore density of the active material layer 20 to the surface density of the active material layer 20 is less than or equal to 0.6mm 2 / g, thus avoiding the problem that the spacing between the holes 201 is too small due to the excessive hole density, so that the holes 201 are prone to partial overlap and unqualified morphology during hole formation.

[0065] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A battery pole piece, characterized in that: The battery pole piece comprises: current collector; An active material layer, the active material layer is arranged on the surface of the current collector, a plurality of holes are arranged in the active material layer, and the hole density of the active material layer is a, the hole density is the area occupied by the holes in the active material layer per unit area, and the surface density of the active material layer is b, 0.07 mm 2 / g≤a / b≤0.6mm 2 / g.

2. The battery pole piece according to claim 1, characterized in that: The active material layer is provided with a plurality of hole rows, the hole rows include a plurality of holes arranged along a first direction, the plurality of hole rows are arranged along a second direction, the first direction and the second direction are perpendicular, the holes in the first hole row are aligned in the second direction and the holes in the second hole row, the first hole row and the second hole row are adjacent hole rows, 0.07mm 2 / g≤a / b≤0.5mm 2 / g.

3. The battery pole piece according to claim 1, characterized in that: The active material layer is provided with a plurality of hole rows, the hole rows include a plurality of holes arranged along a first direction, the plurality of hole rows are arranged along a second direction, the first direction and the second direction are perpendicular, the holes in the first hole row are misaligned in the second direction and the holes in the second hole row, the first hole row and the second hole row are adjacent hole rows, 0.1mm 2 / g≤a / b≤0.1mm 2 / g.

4. The battery pole piece according to claim 2 or 3, characterized in that: The first direction is the length direction of the battery electrode sheet, and the second direction is the width direction of the battery electrode sheet.

5. The battery pole piece according to claim 1, characterized in that: The distances between the first hole and the plurality of second holes are equal, the first hole is any hole on the active material layer, and the second hole is a hole on the active material layer adjacent to the first hole.

6. The battery pole piece according to claim 5, characterized in that: The distance between adjacent holes is 40 μm-2000 μm.

7. The battery pole piece according to claim 1, characterized in that: The hole is a blind hole, and the ratio of the depth of the hole to the thickness of the active material layer is in the range of 10%-80%.

8. The battery pole piece according to claim 1, characterized in that: The holes are round holes, and the diameter of the holes is 20 μm-40 μm.

9. The battery pole piece according to claim 1, characterized in that: The battery pole piece is a negative pole piece, 0.1mm 2 / g≤a / b≤0.5mm 2 / g.

10. A battery device, characterized in that: The battery device comprises the battery pole piece described in any one of claims 1-9.

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