Pole piece, full-tab cylindrical battery and electric equipment

Abstract

The invention relates to a pole piece, a full-tab cylindrical battery and electric equipment, and relates to the technical field of batteries, the pole piece comprises an active material layer and a current collector, the current collector comprises an empty foil part and a coating part which are distributed along a first direction, the empty foil part is provided with tabs, and the coating part is provided with the active material layer; the coating part and the active material layer located on the coating part are divided into a plurality of working areas in the first direction, a plurality of through holes are formed in at least part of the working areas, and the through holes penetrate through the coating part and the active material layer; for any two adjacent working areas, the hole density of the working area relatively close to the tab is A, the hole density of the working area relatively far away from the tab is B, and A and B meet the condition that A is smaller than or equal to B. According to the pole piece, the full-tab cylindrical battery and the electric equipment, the problem of non-uniform current density distribution of the current collector in the length direction can be improved, and the performance of the full-tab cylindrical battery is ensured.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a pole piece, a full-pole-ear cylindrical battery, and an electrical device. Background Art

[0002] In related technologies, a pole piece includes a current collector and a tab. The tab is located at one end of the current collector, through which current enters and exits the current collector. Due to the current collector's resistive properties and the fact that all current flows through the tab, the current density in the area near the tab is significantly higher than that in the area far from the tab. This means that the current density distribution along the length of the current collector is uneven, affecting battery performance. Summary of the Invention

[0003] In order to solve the above technical problems, the embodiments of the present application provide a pole piece, a full-tab cylindrical battery and an electrical device, which can improve the problem of uneven current density distribution of the current collector in the length direction and ensure the performance of the full-tab cylindrical battery.

[0004] In a first aspect, a pole piece is provided, comprising:

[0005] active material layer;

[0006] A current collector comprising a hollow foil portion and a coating portion distributed along a first direction, the hollow foil portion being provided with a tab, and the coating portion being provided with the active material layer; the coating portion and the active material layer located on the coating portion being divided into a plurality of working areas along the first direction, at least some of the working areas being provided with a plurality of through holes, the through holes penetrating the coating portion and the active material layer; for any two adjacent working areas, the pore density of the working area relatively close to the tab is A, and the pore density of the working area relatively far from the tab is B, and A and B satisfy: A≤B;

[0007] The first direction represents a direction extending from the tab along the length of the current collector; and the hole density represents the number of the through holes within a unit area of ​​the working region.

[0008] According to the first aspect of the present application, the areas of the plurality of working areas are equal;

[0009] For any two adjacent working areas, the sum of the cross-sectional areas of the plurality of through holes in the working area relatively close to the tab is C, and the sum of the cross-sectional areas of the plurality of through holes in the working area relatively far from the tab is D, and C and D satisfy: C≤D.

[0010] According to the first aspect of the present application, the ratio of the sum of the cross-sectional areas of the plurality of through holes in the same working area to the area of ​​the corresponding working area is E, and E satisfies: 0≤E≤((n-1) / n) n-1 ; wherein, the n represents the position of the corresponding working area along the first direction.

[0011] According to the first aspect of the present application, n satisfies: 3≤n≤50.

[0012] According to the first aspect of the present application, the through hole includes at least one of a circular hole, an elliptical hole, and a polygonal hole.

[0013] According to the first aspect of the present application, the sum of the maximum and minimum distances between the center point and the edge of the through hole is F, and F satisfies: 20 μm≤F≤200 μm.

[0014] According to the first aspect of the present application, the through holes include circular holes, the diameters of the through holes in the same working area are equal, and the hole density A or B satisfies: A or B = S / (0.785F 2 S e );

[0015] Wherein, S represents the sum of the cross-sectional areas of the plurality of through holes in the same working area; F represents the sum of the maximum and minimum distances between the center point and the edge of the through hole; S e Characterize the area of ​​the working area.

[0016] According to the first aspect of the present application, both sides of the coating portion along the thickness direction are covered with the active material layer, the through hole penetrates the active material layers on both sides, and the penetration direction of the through hole is perpendicular to the surface of the active material layer.

[0017] In the second aspect, a full-ear cylindrical battery is also provided, including:

[0018] case;

[0019] The electrode assembly is disposed in the shell, and the electrode assembly includes a diaphragm and the pole piece as described in the previous embodiment, and the diaphragm and the pole piece are stacked and distributed.

[0020] In a third aspect, an electrical device is also provided, including:

[0021] A full-tab cylindrical battery as described in the previous embodiment.

[0022] In the pole piece, full-tab cylindrical battery, and electrical equipment provided in the embodiments of the present application, for any two adjacent working areas, the pore density of the working area relatively close to the tab is A, and the pore density of the working area relatively far from the tab is B, and A and B satisfy: A ≤ B. In this way, the increase in current density in the working area relatively close to the tab is smaller, and the increase in current density in the working area relatively far from the tab is larger. Since the original current density in the working area relatively close to the tab is larger, and the original current density in the working area relatively far from the tab is smaller, after the through holes are opened in different working areas, the difference in current density between the different working areas in the first direction is reduced (or tends to be equal), which can effectively improve the problem of uneven current density distribution of the current collector in the first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other purposes, features, and advantages of the present application will become more apparent through a more detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are intended to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0024] Figure 1 A schematic structural diagram of a full-tab cylindrical battery provided as an exemplary embodiment of the present application.

[0025] Figure 2 A schematic structural diagram of an electrode assembly provided as an exemplary embodiment of the present application.

[0026] Figure 3 A schematic structural diagram of a pole piece provided in an exemplary embodiment of the present application.

[0027] Figure 4 A schematic structural diagram of a current collector provided as an exemplary embodiment of the present application.

[0028] Figure 5 A schematic structural diagram of a current collector provided for another exemplary embodiment of the present application.

[0029] Figure numerals: 100 - pole piece; 110 - active material layer; 120 - current collector; 121 - hollow foil portion; 122 - coating portion; 123 - pole tab; 124 - working area; 125 - through hole; 200 - full pole tab cylindrical battery; 210 - shell; 220 - electrode assembly; 221 - positive pole piece; 222 - negative pole piece; 223 - diaphragm; 230 - positive current collecting disc; 240 - negative current collecting disc; 250 - cap. DETAILED DESCRIPTION

[0030] Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the exemplary embodiments described herein.

[0031] Figure 1 This is a schematic diagram of the structure of a full-tab cylindrical battery provided by an exemplary embodiment of the present application. Figure 1 As shown, the full-tab cylindrical battery 200 provided in the embodiment of the present application may include a shell 210 and an electrode assembly 220. The electrode assembly 220 is disposed in the shell 210, and the shell 210 protects the electrode assembly 220.

[0032] like Figure 1 As shown, the full-electrode-tab cylindrical battery 200 can also include a positive electrode current collecting plate 230 and a negative electrode current collecting plate 240. The positive electrode tab and the negative electrode tab are respectively provided at the opposite ends of the electrode assembly 220. The positive electrode current collecting plate 230 is welded to the positive electrode tab, and the negative electrode current collecting plate 240 is welded to the negative electrode tab. The positive electrode current collecting plate 230 and the negative electrode current collecting plate 240 converge the current of the positive electrode tab and the negative electrode tab to achieve efficient connection with the external circuit.

[0033] like Figure 1 As shown, the full-tab cylindrical battery 200 may further include a cap 250 , which is disposed on the top of the positive electrode current collecting disc 230 . The cap 250 may provide protection for the positive electrode current collecting disc 230 .

[0034] Figure 2 This is a schematic diagram of the structure of an electrode assembly provided by an exemplary embodiment of the present application. Figure 2 As shown, the electrode assembly 220 may include a diaphragm 223 and a pole piece 100 ( Figure 3 In practical applications, the electrode sheet 100 may include a positive electrode sheet 221 and a negative electrode sheet 222. The positive electrode sheet 221, the separator 223, and the negative electrode sheet 222 are stacked. The separator 223 prevents direct contact between the positive electrode sheet 221 and the negative electrode sheet 222, thereby preventing short circuits. In addition, the separator 223 allows ions to pass freely during the charge and discharge process, maintaining the electrochemical reaction.

[0035] It should be noted that in the wound electrode assembly 220, after the positive electrode sheet 221, the negative electrode sheet 222 and the separator 223 are wound, it can be ensured that both sides of the positive electrode sheet 221 are covered with the separator 223, and both sides of the negative electrode sheet 222 are covered with the separator 223. In this way, direct contact between the positive electrode sheet 221 and the negative electrode sheet 222 can be effectively prevented, thereby avoiding short circuit accidents.

[0036] Figure 3 This is a schematic diagram of the structure of a pole piece provided by an exemplary embodiment of the present application. Figure 3As shown, the electrode 100 provided in the embodiment of the present application can be applied to the positive electrode 221 and / or the negative electrode 222 mentioned above. Specifically, the electrode 100 may include an active material layer 110 and a current collector 120. The current collector 120 includes a first direction (which can be understood as the length direction of the electrode 100, for details, see Figure 3 In the Y-axis direction, a hollow foil portion 121 and a coating portion 122 are distributed. The hollow foil portion 121 is provided with a tab 123, and the coating portion 122 is provided with an active material layer 110.

[0037] In one embodiment, the hollow foil portion 121 may be provided with one tab 123 or multiple tabs 123 .

[0038] In one embodiment, the entire edge of the hollow foil portion 121 can be welded to form a continuous tab strip, that is, a full tab can be formed.

[0039] In the related art, due to the resistance characteristics of the current collector 120 and all current flows through the pole tab 123, the current density in the area of ​​the coating portion 122 close to the pole tab 123 is significantly higher than the current density in the area of ​​the coating portion 122 far from the pole tab 123, that is, the current density distribution of the current collector 120 in its length direction is uneven, affecting the performance of the full-pole tab cylindrical battery 200.

[0040] to this end, Figure 4 This is a schematic diagram of the structure of the current collector provided by an exemplary embodiment of the present application. Figure 4 As shown, in the embodiment of the present application, the coating portion 122 and the active material layer 110 located on the coating portion 122 are arranged along a first direction (refer to Figure 4 The spherical portion 124 is divided into a plurality of working areas 124 (in the Y-axis direction), and a plurality of through holes 125 are provided in at least part of the working areas 124.

[0041] It should be noted that after the through hole 125 is opened in the working area 124 , the through hole 125 will reduce the effective conductive area of ​​the corresponding working area 124 , and the current density corresponding to the working area 124 will also increase accordingly.

[0042] It should be noted that, along the first direction, from the area of ​​the coating portion 122 close to the pole tab 123 to the area away from the pole tab 123, the current density shows a gradually decreasing trend, that is, the closer the area of ​​the coating portion 122 is to the pole tab 123, the greater the current density. Therefore, in order to improve the problem of uneven current density of the current collector 120 in the first direction, the pore density in the working area 124 close to the pole tab 123 (which can be understood as the number of through holes 125 per unit area of ​​the working area 124) should be smaller, and the pore density in the working area 124 away from the pole tab 123 should be greater (increase more current density to be close to the current density of the area close to the pole tab 123). Moreover, in actual applications, considering that the current densities corresponding to the two adjacent working areas 124 are equal, the case where the pore density of the two adjacent working areas 124 is equal is also considered accordingly.

[0043] In summary, for any two adjacent working areas 124, the pore density of the working area 124 relatively close to the tab 123 is A, and the pore density of the working area 124 relatively far from the tab 123 is B, and A and B satisfy: A ≤ B. In this way, the increase in current density in the working area 124 relatively close to the tab 123 is small, and the increase in current density in the working area 124 relatively far from the tab 123 is large. Since the original current density in the working area 124 relatively close to the tab 123 is large, and the original current density in the working area 124 relatively far from the tab 123 is small, after the through holes 125 are opened in different working areas 124, the difference between the current densities of different working areas 124 in the first direction is reduced (or tends to be equal), which can effectively improve the problem of uneven current density distribution of the current collector 120 in the first direction.

[0044] It should be noted that the embodiment of the present application provides a through hole 125 in the working area 124, which can not only improve the problem of uneven current density distribution, but also maintain its original conductive performance while reducing the weight of the current collector 120, thereby effectively improving the mass energy density of the full-tab cylindrical battery 200.

[0045] In one embodiment, all the working areas 124 are provided with a plurality of through holes 125 .

[0046] In one embodiment, a portion of the working area 124 is provided with a plurality of through holes 125, while another portion of the working area 124 is not provided with through holes 125. For example, Figure 5 This is a schematic diagram of the structure of the current collector provided by another exemplary embodiment of the present application. Figure 5 As shown, the working area 124 marked with serial number 1 (ie, the working area 124 closest to the tab 123 ) is not provided with a through hole 125 , while the working areas 124 with other serial numbers (eg, 2, 3 . . . n) are all provided with a through hole 125 .

[0047] In related technologies, the active material layer 110 can be used to store and release ions, serving as a site for redox reactions. The movement of ions from one active material layer 110 to the other requires complete diffusion through the electrolyte. Due to the large tortuosity within the electrode 100, ion transport is greatly hindered during high-rate charge and discharge conditions, resulting in an uneven ion concentration distribution across the thickness of the electrode 100. This leads to polarization, impacting the charge and discharge performance of the full-tab cylindrical battery 200 and severely reducing the utilization rate of the active material layer 110.

[0048] To this end, the through-hole 125 in the embodiment of the present application passes through the coating portion 122 and the active material layer 110. In this way, some ions on one side of the current collector 120 can be directly transferred to the other side of the current collector 120 through the through-hole 125, which can effectively shorten the ion transmission path, improve the uneven concentration distribution of ions in the thickness direction of the electrode sheet 100 caused by the obstruction of ion transmission, improve the high-rate charge and discharge performance of the full-tab cylindrical battery 200, and improve the utilization rate of the active material layer 110.

[0049] In one embodiment, both sides of the coating portion 122 along the thickness direction are covered with the active material layer 110, and the through-holes 125 penetrate the active material layers 110 on both sides, with the penetration direction of the through-holes 125 being perpendicular to the surface of the active material layer 110. Thus, compared to a case where the penetration direction of the through-holes 125 is inclined with respect to the surface of the active material layer 110, the penetration direction of the through-holes 125 is perpendicular to the surface of the active material layer 110, which can shorten the length of the through-holes 125, thereby further shortening the path for ion transmission through the through-holes 125, and further improving the high-rate charge and discharge performance of the full-tab cylindrical battery 200.

[0050] In one embodiment, the areas of the plurality of working areas 124 are equal, so that the process of dividing the plurality of working areas 124 along the first direction can be more convenient, which can effectively improve production efficiency.

[0051] It should be noted that, when the areas of the multiple working areas 124 are equal, for any two adjacent working areas 124, the sum of the cross-sectional areas of the multiple through-holes 125 in the working area 124 relatively close to the tab 123 is C, and the sum of the cross-sectional areas of the multiple through-holes 125 in the working area 124 relatively far from the tab 123 is D, and C and D satisfy: C ≤ D. In this way, it is ensured that the area ratio of the multiple through-holes 125 in the working area 124 relatively close to the tab 123 to the corresponding working area 124 is less than or equal to the area ratio of the multiple through-holes 125 in the working area 124 relatively far from the tab 123 to the corresponding working area 124, thereby ensuring that the pore density of the working area 124 relatively close to the tab 123 is less than or equal to the pore density of the working area 124 relatively far from the tab 123.

[0052] In one embodiment, the areas of multiple working areas 124 may not be equal. By adjusting the number of through holes 125 in different working areas 124, the aperture of the through holes 125 and other parameters, the area ratio of the multiple through holes 125 in the working area 124 close to the pole ear 123 and the corresponding working area 124 can be made less than or equal to the area ratio of the multiple through holes 125 in the working area 124 relatively far away from the pole ear 123 and the corresponding working area 124, thereby ensuring that the hole density of the working area 124 relatively close to the pole ear 123 is less than or equal to the hole density of the working area 124 relatively far away from the pole ear 123.

[0053] The inventors have discovered that the current density of the current collector 120 along the first direction does not change in an arithmetic or geometric manner, but rather changes according to a specific rule. Based on the discovered rule, when the areas of multiple working areas 124 are equal, the ratio E of the sum of the cross-sectional areas of the multiple through holes 125 in the same working area 124 to the area of ​​the corresponding working area 124 is defined as: 0≤E≤((n-1) / n) n-1 , n represents the position of the corresponding working area 124 along the first direction (for example Figure 3 In this way, the variation trend of the ratio E of the sum of the cross-sectional areas of the plurality of through holes 125 to the area of ​​the corresponding working area 124 along the first direction is adapted to the variation trend of the current density of the current collector 120 in the first direction. Correspondingly, the variation trend of the hole density of the plurality of working areas 124 along the first direction is adapted to the variation trend of the current density of the current collector 120 in the first direction. This can make the current density of the punched current collector 120 more uniform along the first direction, further improving the performance of the full-tab cylindrical battery 200.

[0054] It should be noted that, when the length of the electrode 100 remains unchanged, if n is too large, the area of ​​each working area 124 will be too small, which will make it difficult to distinguish the hole density in adjacent working areas 124 and will be detrimental to the drilling operation; if n is too small, the step-by-step change in current density along the first direction will have little effect, and the effect of improving the uneven distribution of current density will not be obvious.

[0055] To this end, the embodiment of the present application limits n to the following range: 3≤n≤50. In this way, the aforementioned position caused by n being too large or too small can be effectively improved.

[0056] In one embodiment, n is preferably 3≤n≤10.

[0057] In one embodiment, n can be selected from 3, 10, or 50.

[0058] In one embodiment, the through hole 125 may include at least one of a circular hole, an elliptical hole, and a polygonal hole.

[0059] In one embodiment, the polygonal hole may include a triangular hole, a rectangular hole, a pentagonal hole, etc.

[0060] In one embodiment, the through hole 125 may also include other types of special-shaped holes, such as a cross hole, a star-shaped hole, etc.

[0061] It should be noted that circular holes are easy to manufacture and can more conveniently calculate the hole density of the working area 124. Specifically, when the plurality of through holes 125 are all circular holes and the diameters of the plurality of through holes 125 are the same, the hole density A or B of the working area 124 satisfies: A or B = S / (0.785F 2 S e ), where S represents the sum of the cross-sectional areas of the plurality of through holes 125 in the same working area 124; F represents the sum of the maximum and minimum distances between the center point and the edge of the through hole 125; S e Characterizes the area of ​​the working area 124.

[0062] It should be noted that, when the through hole 125 is a circular hole, F is the diameter of the circular hole.

[0063] In one embodiment, when the through hole 125 is an elliptical hole, F is the sum of the length of the minor axis and the length of the major axis.

[0064] It should be noted that if F is too large, it will easily lead to insufficient structural strength of the current collector 120, excessive concentration of current density, and excessively high local temperature; if F is too small, it will increase process difficulty and increase manufacturing costs.

[0065] Therefore, in the embodiment of the present application, the sum of the maximum and minimum distances F between the center point and the edge of the through hole 125 is limited to the following range: 20 μm ≤ F ≤ 200 μm. This can effectively improve the aforementioned problems caused by F being too large or too small.

[0066] In one embodiment, F can be selected from 20 μm, 30 μm, 100 μm, and 150 μm.

[0067] In one embodiment, multiple through-holes 125 within the same working area 124 have the same shape. This facilitates rapid batch drilling within the same working area 124, effectively improving production efficiency. Furthermore, because different shapes of through-holes 125 have different effects on current density, providing multiple through-holes 125 of the same shape within the same working area 124 also helps alleviate the problem of uneven current density distribution within the same working area 124.

[0068] The present application will be further described below with reference to specific embodiments and comparative examples.

[0069] Example 1

[0070] The electrode 100 may include an active material layer 110 and a current collector 120, the current collector 120 includes a hollow foil portion 121 and a coating portion 122 distributed along a first direction, the hollow foil portion 121 is provided with a pole ear 123, and the coating portion 122 is provided with an active material layer 110, the coating portion 122 and the active material layer 110 located on the coating portion 122 are divided into multiple working areas 124 along the first direction, at least part of the working area 124 is provided with multiple through holes 125, and the through holes 125 pass through the coating portion 122 and the active material layer 110; for any two adjacent working areas 124, the pore density of the working area 124 relatively close to the pole ear 123 is A, and the pore density of the working area 124 relatively far away from the pole ear 123 is B, and A and B satisfy: A≤B.

[0071] The electrode materials used are: NMC811 for the positive electrode sheet 221 and graphite for the negative electrode sheet 222. Along the first direction, there are three active areas 124. The ratio E of the sum of the cross-sectional areas of the through-holes 125 within a single active area 124 to the area of ​​the corresponding active area 124 is within the range of 0-0.56. Specifically, the ratio E of the sum of the cross-sectional areas of the through-holes 125 within active areas 124 numbered 1, 2, and 3 to the area of ​​the corresponding active area 124 is 0, 0.3, and 0.56, respectively. The through-holes 125 are circular, 50 μm in diameter, and are mechanically punched.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 1 is that:

[0074] The current collector 120 is not provided with the working area 124 and the through-hole 125 .

[0075] Test results:

[0076] The results are shown in Table 1.

[0077] Table 1

[0078] Performance indicators Comparative Example 1 Example 1 Mass energy density (Wh / kg) 252 265 10C discharge SOD 0.72 0.95 3C charging SOC 0.61 0.73

[0079] As shown in Table 1, 10C discharge SOD can be understood as the battery's depth of discharge (SOD) at a 10C discharge rate. 10C represents 10 times the rated capacity, while SOD represents the percentage of the discharged capacity compared to the rated capacity. Similarly, 3C charge SOC can be understood as the battery's state of charge (SOC) at a 3C discharge rate. 3C represents 3 times the rated capacity, while SOC represents the percentage of the rated capacity remaining.

[0080] As can be seen from Table 1, compared with Comparative Example 1, Example 1 shows significant advantages in both mass energy density and electrochemical performance (including charging performance and discharging performance): the capacity retention rate (SOD = 0.95) during 10C high-rate discharge is greatly improved, and the remaining capacity (SOC = 0.73) under 3C charging is also higher, indicating that Example 1 has higher energy density and better high-rate charge and discharge performance.

[0081] Example 2

[0082] The electrode 100 may include an active material layer 110 and a current collector 120, the current collector 120 includes a hollow foil portion 121 and a coating portion 122 distributed along a first direction, the hollow foil portion 121 is provided with a pole ear 123, and the coating portion 122 is provided with an active material layer 110, the coating portion 122 and the active material layer 110 located on the coating portion 122 are divided into multiple working areas 124 along the first direction, at least part of the working area 124 is provided with multiple through holes 125, and the through holes 125 pass through the coating portion 122 and the active material layer 110; for any two adjacent working areas 124, the pore density of the working area 124 relatively close to the pole ear 123 is A, and the pore density of the working area 124 relatively far away from the pole ear 123 is B, and A and B satisfy: A≤B.

[0083] The electrode materials for the positive electrode sheet 221 are NCA, and the negative electrode sheet 222 are 95% graphite plus 5% silicon oxide. Along the first direction, there are five active areas 124. The ratio E of the sum of the cross-sectional areas of the through-holes 125 within a single active area 124 to the area of ​​the corresponding active area 124 is in the range of 0-0.8. Specifically, the ratio E of the sum of the cross-sectional areas of the through-holes 125 within active areas 124 numbered 1, 2, 3, 4, and 5 to the area of ​​the corresponding active area 124 is 0, 0.2, 0.36, 0.48, and 0.59, respectively. The through-holes 125 are circular, with diameters of 0, 20 μm, 50 μm, 80 μm, and 100 μm, respectively, and are laser-drilled.

[0084] Comparative Example 2

[0085] The difference between this comparative example and Example 2 is that:

[0086] The current collector 120 is not provided with the working area 124 and the through-hole 125 .

[0087] Test results:

[0088] The results are shown in Table 2.

[0089] Table 2

[0090] Performance indicators Comparative Example 2 Example 2 Mass energy density (Wh / kg) 278 292 10C discharge SOD 0.76 0.98 3C charging SOC 0.63 0.71

[0091] The meaning of the relevant performance indicators in Table 2 can be referred to the relevant introduction in Table 1 above. No further details will be given here.

[0092] As can be seen from Table 2, compared with Comparative Example 2, Example 2 shows significant advantages in both mass energy density and electrochemical performance (including charging performance and discharging performance): the capacity retention rate (SOD = 0.98) during 10C high-rate discharge is greatly improved, and the remaining capacity under 3C charging (SOC = 0.71) is also higher, indicating that Example 2 has higher energy density and better high-rate charge and discharge performance.

[0093] An embodiment of the present application further provides an electrical device, which may include the full-tab cylindrical battery 200 as described in the previous embodiment and has all the functions of the full-tab cylindrical battery 200.

[0094] It should be noted that the beneficial effects of the electrical equipment can refer to the beneficial effects of the aforementioned full-tab cylindrical battery 200.

[0095] In one embodiment, the electrical device may further include an electronic control component and a motor. The full-tab cylindrical battery 200 provides electrical energy for the motor. The electronic control component is electrically connected to the full-tab cylindrical battery 200. The electronic control component can be used to control the charging and discharging of the full-tab cylindrical battery 200.

[0096] In one embodiment, the electrical equipment may include a vehicle, a mobile phone, a ship, an elevator, etc.

[0097] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0098] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0099] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0100] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0101] The above description has been provided for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed, those skilled in the art will recognize certain variations, modifications, changes, additions, and sub-combinations thereof.

Claims

1. A pole piece, characterized in that: include: active material layer; A current collector comprising a hollow foil portion and a coating portion distributed along a first direction, wherein the hollow foil portion is provided with a tab, and the coating portion is provided with the active material layer; The coating portion and the active material layer located on the coating portion are divided into a plurality of working areas along the first direction, and a plurality of through holes are provided in at least some of the working areas, wherein the through holes penetrate the coating portion and the active material layer; for any two adjacent working areas, the pore density of the working area relatively close to the tab is A, and the pore density of the working area relatively far from the tab is B, and A and B satisfy: A≤B; Wherein, the first direction represents the direction extending from the tab along the length of the current collector; The hole density represents the number of the through holes per unit area of ​​the working region.

2. The pole piece according to claim 1, characterized in that: The areas of the plurality of working areas are equal; For any two adjacent working areas, the sum of the cross-sectional areas of the plurality of through holes in the working area relatively close to the tab is C, and the sum of the cross-sectional areas of the plurality of through holes in the working area relatively far from the tab is D, and C and D satisfy: C≤D.

3. The pole piece according to claim 2, characterized in that: The ratio of the sum of the cross-sectional areas of the plurality of through holes in the same working area to the area of ​​the corresponding working area is E, and E satisfies: 0≤E≤((n-1) / n) n-1 ; wherein, the n represents the position of the corresponding working area along the first direction.

4. The pole piece according to claim 3, characterized in that: The n satisfies: 3≤n≤50.

5. The pole piece according to any one of claims 1 to 4, characterized in that: The through hole includes at least one of a circular hole, an elliptical hole, and a polygonal hole.

6. The pole piece according to any one of claims 1 to 4, characterized in that: The sum of the maximum and minimum distances between the center point and the edge of the through hole is F, and F satisfies: 20 μm≤F≤200 μm.

7. The pole piece according to any one of claims 1 to 4, characterized in that: The through holes include circular holes. The diameters of the through holes in the same working area are equal. The hole density A or B satisfies: A or B = S / (0.785F 2 S e ); Wherein, S represents the sum of the cross-sectional areas of the plurality of through holes in the same working area; F represents the sum of the maximum and minimum distances between the center point and the edge of the through hole; S e Characterize the area of ​​the working area.

8. The pole piece according to any one of claims 1 to 4, characterized in that: Both sides of the coating portion in the thickness direction are covered with the active material layer, the through hole penetrates the active material layers on both sides, and the penetration direction of the through hole is perpendicular to the surface of the active material layer.

9. A full-tab cylindrical battery, characterized in that: include: case; An electrode assembly is disposed in the shell, and the electrode assembly includes a diaphragm and a pole piece according to any one of claims 1 to 8, wherein the diaphragm and the pole piece are stacked and distributed.

10. An electrical device, characterized in that: include: The full-tab cylindrical battery according to claim 9.

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