CELL AND LITHIUM ION SECONDARY BATTERY

Abstract

The present application provides a cell and a lithium-ion secondary battery. The cell comprises a positive electrode plate, a separator, and a negative electrode plate. The negative electrode plate includes a current collector for the negative electrode and an active material layer for the negative electrode, wherein first recesses are formed on a surface of the active material layer for the negative electrode, the first recess having a depth of H µm and the cell having a length of L mm and a width of W mm, and wherein H, L, and W are satisfied by the following relationship: 0.05H ≤ L / W ≤ 0.5H. It is ensured that the above relationship holds for the depth of the first recess, as well as for the cell length and width. Because the positive and negative electrodes of the lithium-ion secondary battery are located on the same side of the cell, a large cell length results in strong polarization.By increasing the depth of the first recess, the polarization of the electrode plate can be reduced, thus increasing the charging rate of the cell.

Description

Technical field

[0001] The present application relates to the technical field of lithium-ion secondary batteries, in particular a cell or battery cell and a lithium-ion secondary battery. State of the art

[0002] With the rapid development of lithium-ion secondary battery technology, further improvements in electrical performance, energy density, and charging rate are becoming a key focus of research and development for various lithium-ion secondary battery manufacturers. To increase the energy density of a lithium-ion secondary battery, the density of the active material layer is typically increased. However, this can easily lead to polarization of the lithium-ion secondary battery during charging, reducing the mobility of lithium ions and consequently lowering the charging rate. Furthermore, the electrolyte solution content is low, resulting in a shorter battery lifespan. Disclosure of the invention

[0003] In light of this, the present application provides a cell, or rather an electrochemical cell, in particular a secondary cell, to solve problems such as the low charging rate and short battery life of a lithium-ion secondary battery. The present application further provides a lithium-ion secondary battery comprising one of the above-mentioned cells.

[0004] To solve the aforementioned problem, the following technical solutions are provided in this application: A cell comprising a positive electrode plate, a separator and a negative electrode plate, wherein the negative electrode plate comprises a current collector for the negative electrode and an active material layer for the negative electrode, wherein first recesses are formed on a surface of the active material layer for the negative electrode, wherein the first recess has a depth of H µm and the cell has a length of L mm and a width of W mm, and wherein H, L and W are: 0.05H ≤ L / W ≤ 0.5H.

[0005] Optionally, it is provided that 1 ≤ L / W ≤ 5 applies. where H lies within the following range: 2 ≤ H ≤ 40; and / or where L lies within the following range: 20 ≤ L ≤ 160; and / or where W lies within the following range: 15 ≤ W ≤ 80.

[0006] Optionally, the first recesses may have a distance of S mm from each other, where W and S are: 0.01 ≤ S / W ≤ 0.06; and where preferably S lies in the following range: 0.5 ≤ S ≤ 3.

[0007] Optionally, the first recesses may have a distance of S mm from each other, where H, L, W and S are given by: 0.04H ≤ L*S / W ≤ 0.45H; and where preferably S lies in the following range: 0.5 ≤ S ≤ 3.

[0008] Optionally, the separator is located between the positive electrode plate and the negative electrode plate, wherein the separator comprises a ceramic layer facing the positive electrode plate, the ceramic layer having a thickness of M µm, where for M and H: 2.5 ≤ H / M ≤ 40; and where preferably M lies in the following range: 0.3 ≤ M ≤ 5.

[0009] Optionally, the separator is located between the positive electrode plate and the negative electrode plate, the separator comprising the ceramic layer facing the positive electrode plate, the ceramic layer Dv50 having a thickness of N µm and the first recess having a width of V µm, where N and V are: 3 ≤ V / N ≤ 3000; where preferably V is in the following range: 20 ≤ V ≤ 200; and / or where N is in the following range: 0.02 ≤ N ≤ 2.

[0010] Optionally, the active material layer for the negative electrode is arranged on at least one side of the current collector for the negative electrode, the active material layer for the negative electrode comprises a first active layer facing the current collector for the negative electrode and a second active layer facing away from the current collector for the negative electrode, and the Dv50 of an active material in the first active layer is greater than the Dv50 of an active material in the second active layer, wherein the second active layer has a thickness of P µm, where for P and H: 1 < P / H ≤ 5; and where preferably P lies in the following range: 8 ≤ P ≤ 1000.

[0011] Optionally, the positive electrode plate includes a current collector for the positive electrode and an active material layer for the positive electrode, wherein the sum of the aluminum and magnesium content of an active material in the active material layer for the positive electrode is Q ppm, and the silicon content of an active material in the active material layer for the negative electrode is R, where Q, R, and H are given by: 1*10 3 ≤ Q / (R*H) ≤ 1*10 5 ; where Q is in the following range: 1000 ≤ Q ≤ 10000; and / or where R is in the following range: 1% ≤ R ≤ 30%.

[0012] Optionally, the negative electrode plate may have an extension section in a longitudinal direction of the cell that extends beyond the positive electrode plate, and the extension section may have a dimension of D mm in the longitudinal direction of the cell, where D and H are: 0.05 ≤ D / H ≤ 0.25; and where preferably D lies in the following range: 0.1 ≤ D ≤ 2.

[0013] Optionally, it is provided that in a thickness direction of the cell, second recesses are formed in an area of ​​the active material layer for the negative electrode, which corresponds to a tab for the positive electrode of the cell, and that in a width direction of the cell, the distances between edges on both sides of the second recess and the respective adjacent first recesses are T mm and U mm, respectively, and T and U are greater than 0.

[0014] Optionally, a housing and a cell arranged in the housing are included according to one of the above specifications.

[0015] By forming initial recesses on the negative electrode plate of the cell according to the present application, a channel for the flow of the electrolyte solution can be improved, the wetting of the electrode plate by the electrolyte solution can be accelerated, the contact distance between the active material layer for the negative electrode and the electrolyte solution can be shortened, polarization on the surface and inside the electrode plate can be reduced, and thus the charging power can be increased. The formation of these initial recesses increases the contact area between the active material and the electrolyte solution, the movement efficiency of the lithium ions during charging of the lithium-ion secondary battery is increased, and the charging efficiency is improved. Gas may be produced during operation of the lithium-ion secondary battery.The formation of the first recesses allows for easy gas venting, improving the gas venting function of the lithium-ion secondary battery and preventing bulging, thus increasing the battery's safety. These recesses also increase the electrolyte solution's storage capacity, improve the residual electrolyte ratio, and consequently extend the battery's lifespan. Furthermore, they ensure that the depth of the first recess, as well as the cell's length and width, are within a range of 0.05H ≤ L / W ≤ 0.5H. Having the positive and negative electrodes on the same side of the lithium-ion secondary battery can lead to strong polarization in longer cells.By increasing the depth of the first recess, the polarization of the electrode plate can be reduced, thus increasing the charging rate of the lithium-ion secondary battery, the cycle performance of the lithium-ion secondary battery, and the safety of the lithium-ion secondary battery. Brief description of the characters

[0016] To clarify the embodiments of the present application or the technical solutions in the prior art, the drawings required to describe these embodiments or the prior art are briefly presented below. Obviously, the drawings in the following description merely represent embodiments of the present application. Based on these accompanying drawings, a person skilled in the art can obtain further drawings without any inventive step. Fig. 1 shows a front view of a cell according to an embodiment of the present application; Fig. 2 shows a top view of an area of ​​a tab for a positive electrode plate; Fig. Figure 3 shows a top view of an area of ​​a negative electrode plate corresponding to the tab for the positive electrode; Fig. Figure 4 shows an enlarged view of point F from Fig. 3; Fig. 5 shows a cross-sectional view of the point GG from Fig. 3; Fig. Figure 6 shows an enlarged section of the Fig. 1; and Fig. Figure 7 shows a schematic structural representation of a separator and an electrode plate.

[0017] In Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7: 1 - negative electrode plate, 2 - positive electrode plate, 3 - separator, 4 - first recess, 5 - second recess, 6 - adhesive paper, 7 - tab for the positive electrode; 11 - Current collector for the negative electrode, 12 - Active material layer for the negative electrode, 13 - Extension section, 21 - Current collector for the positive electrode, 22 - Active material layer for the positive electrode, 31 - Ceramic layer, 32 - Adhesive layer, 33 - Substrate layer. Detailed descriptions

[0018] The present application provides a cell. The present application further provides a lithium-ion secondary battery comprising one of the above cells.

[0019] The technical solutions in the embodiments of the application are described below in detail and in full with reference to the drawings in those embodiments. Naturally, the described embodiments represent not all, but only a subset of the embodiments in the application. All other embodiments that could be obtained by a person skilled in the art in this field from the embodiments in the present application without any inventive step are also within the scope of protection of the application.

[0020] As in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. Figure 7 shows an embodiment of the present application providing a cell. The cell, together with an electrolyte solution and structures such as a housing and the like, can form a lithium-ion secondary battery. The cell mainly comprises a positive electrode plate 2, a separator 3, and a negative electrode plate 1, wherein the negative electrode plate 1 includes a current collector for the negative electrode 11 and an active material layer for the negative electrode 12, and wherein first recesses 4 are formed on a surface of the active material layer for the negative electrode 12 facing the positive electrode plate 2.The formation of initial recesses 4 improves the flow of electrolyte solution, accelerates the wetting of the electrode plate by the electrolyte solution, reduces the contact distance between the active material layer for the negative electrode 12 and the electrolyte solution, reduces polarization on the surface and inside the electrode plate, and thus increases charging power. Simultaneously, the initial recesses 4 serve to store the electrolyte solution and allow gas to escape, thereby improving the cycle life and safety of the lithium-ion secondary battery.It should be noted that the depth of the first recess 4 is smaller than the thickness of the active material layer for the negative electrode 12, so that exposure of the current collector for the negative electrode 11, the risk of a short circuit occurring when using the cell, an excessive amount of reduced active material layer for the negative electrode 12, and an excessive reduction in the energy density of the cell can be avoided.

[0021] In particular, it is provided that the first recess 4 has a depth of H µm and the cell has a length of L mm and a width of W mm, where H, L, and W are given by: 0.05H ≤ L / W ≤ 0.5H. Since the tab of the cell is usually located at one end in the longitudinal direction of the cell, it is specifically provided that, with a constant cell width, the distance from the end of the cell with the tab to the other end without the tab is greater during charging as the cell length increases, thus more easily leading to polarization of the cell. Therefore, it is provided that the relationship 0.05H ≤ L / W ≤ 0.5H applies to the depth of the first recess 4, the length of the cell, and the width of the cell.By increasing the length-to-width ratio through the increased depth of the first recess 4, the polarization of the electrode plate in the longitudinal direction of the cell is reduced by decreasing the polarization of the electrode plate in the thickness direction, thus improving the system's charging performance. Furthermore, by reducing the polarization during charging of the lithium-ion secondary battery in both high-temperature and low-temperature environments, the stability of the lithium-ion secondary battery is increased.

[0022] In some embodiments, H is specified as being within the following range: 2 ≤ H ≤ 40; and / or L as being within the following range: 20 ≤ L ≤ 160; and / or W as being within the following range: 15 ≤ W ≤ 80. H can be, for example, 2, 3, 5, 10, 20, 30, 35, 38, 40, etc. L can be 20, 22, 25, 30, 40, 50, 80, 100, 130, 150, 155, 160, etc. W can be 15, 16, 18, 20, 30, 50, 70, 75, 78, 80, etc. By ensuring that the above ranges apply to H, L and W and reducing polarization during charging of the lithium-ion secondary battery, it is possible to increase the stability of the lithium-ion secondary battery, thus increasing the stability of the lithium-ion secondary battery in a high-temperature or low-temperature environment.

[0023] It should be noted that the width W of the cell refers to a dimension of the cell in a line defined by the double arrow A in Fig. The direction shown in 1 indicates the vertical direction of the cell, as seen by arrow B in Fig. 1. The direction shown represents the length L of the cell to a dimension of the cell in a direction that is simultaneously perpendicular to double arrow A and double arrow B. Fig. 1 runs, i.e., onto the line formed by the double arrow Z in Fig. 3 direction shown, and the depth H of the first recess 4 to a dimension of the first recess 4 in a direction indicated by the double arrow C in Fig. 5 refers to the direction shown.

[0024] It should also be noted that the first recess 4 may be a groove or bore formed by laser, the groove being formed by a through bore.

[0025] By forming initial recesses 4 on the negative electrode plate 1 of an electrode plate with the structure described above, the channel for the flow of the electrolyte solution can be improved, the wetting of the electrode plate by the electrolyte solution accelerated, the contact distance between the active material layer for the negative electrode 12 and the electrolyte solution shortened, the polarization on the surface and inside the electrode plate reduced, and thus the charging power increased. The formation of these initial recesses 4 increases the contact area between the active material and the electrolyte solution, increases the movement efficiency of the lithium ions during charging of the lithium-ion secondary battery, and improves the charging efficiency. Gas may be produced during operation of the lithium-ion secondary battery.The formation of the first recesses 4 allows for easy gas venting, improving the gas venting function of the lithium-ion secondary battery and preventing bulging, thus increasing the battery's safety. These recesses also increase the electrolyte solution's storage capacity, improve the residual electrolyte solution coefficient, and consequently extend the battery's lifespan. Furthermore, they ensure that the depth of the first recess 4, as well as the cell's length and width, are within the specified range of 0.05H ≤ L / W ≤ 0.5H. Having the positive and negative electrodes of the lithium-ion secondary battery located on the same side of the cell can lead to strong polarization in longer cells.By increasing the depth of the first recess 4, the polarization of the electrode plate can be reduced, thus increasing the charging rate of the lithium-ion secondary battery, mitigating the lithium deposition of the lithium-ion secondary battery, improving the cycle performance of the lithium-ion secondary battery, and increasing the safety of the lithium-ion secondary battery.

[0026] In some embodiments, the cell is designed to be of a narrow type when 1 ≤ L / W ≤ 5, particularly when 1 ≤ L / W ≤ 3, resulting in a larger dimension along the cell's length. During charging, the distance from the end of the cell with the tab to the other end without the tab is greater along the cell's length, leading to greater polarization along the cell's length and consequently lower charging efficiency. Therefore, when 1 ≤ L / W ≤ 3, it is ensured that 0.05H ≤ L / W ≤ 0.5H.By increasing the depth of the groove, the polarization of the lithium-ion secondary battery is further mitigated, and when increasing the energy density of the lithium-ion secondary battery, excessive polarization and an excessive reduction in the rate of the lithium-ion secondary battery are avoided at the same time, in order to achieve a balance between the energy density and the charging rate of the lithium-ion secondary battery.

[0027] In some embodiments, L is provided for in the following range: 20 ≤ L ≤ 160; and / or W is provided for in the following range: 15 ≤ W ≤ 80. L can be, for example, 20, 22, 25, 30, 40, 50, 80, 100, 130, 150, 155, 160, etc. W can be 15, 16, 18, 20, 30, 50, 70, 75, 78, 80, etc. Because the above ranges apply to L and W, the polarization of the lithium-ion secondary battery is further mitigated, and when increasing the energy density of the lithium-ion secondary battery, excessive polarization and excessive reduction of the rate of the lithium-ion secondary battery are avoided at the same time, in order to achieve a balance between the energy density and the charging rate of the lithium-ion secondary battery.

[0028] In some embodiments, the first recesses 4 are spaced S mm apart, where W and S are: 0.01 ≤ S / W ≤ 0.06. It is ensured that the ratio between the spacing of the first recesses 4 and the cell width is within the range specified above. This further improves the channel for electrolyte flow, accelerates the wetting of the negative electrode plate 1 and the positive electrode plate 2 by the electrolyte solution, further reduces the contact distance between an internal paste and an interface, further reduces polarization on the surface and inside the electrode plate, and thus increases the charging power of the system. Simultaneously, a linear channel provides electrolyte solution storage and gas venting capabilities, thereby improving the long-term cycle performance and safety of the lithium-ion secondary battery.

[0029] The ratio between the distance of the first recesses 4 and the width of the cell can be, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, etc.

[0030] It should be noted that the distance S of the first recesses 4 corresponds to a dimension of the adjacent first recesses 4 in a line defined by the double arrow E in Fig. 5 refers to the direction shown.

[0031] In some embodiments, W is specified in the following range: 15 ≤ W ≤ 80; and / or S is specified in the following range: 0.5 ≤ S ≤ 3. W can be, for example, 15, 16, 18, 20, 30, 50, 70, 75, 78, 80, etc. S can be 0.5, 0.52, 0.55, 0.6, 0.8, 1, 1.5, 2, 2.6, 2.9, 2.95, 2.98, 3, etc. It is ensured that S and W are within the above ranges. This allows the contact distance between the inner paste and the interface to be further reduced, the polarization on the surface and inside the electrode plate to be further reduced, and thus the charging power of the system to be increased. At the same time, the linear channel has functions for storing the electrolyte solution and gas removal, thus improving the long-term cycle performance and safety of the lithium-ion secondary battery.

[0032] In some embodiments, the first recesses 4 are arranged with a spacing of S mm from each other, where H, L, W, and S are given by: 0.04H ≤ L*S / W ≤ 0.45H. For example, the polarization of the cell in the longitudinal direction is stronger the greater the ratio between the cell's length and its width L / W. The polarization described above can be reduced, and thus the charging rate increased, by increasing the groove depth H of the first recesses 4, decreasing the groove spacing S of the first recesses 4, or by increasing the groove depth H of the first recesses 4 and decreasing the groove spacing S of the first recesses 4, i.e., by increasing the groove depth of the first recesses 4 and / or by increasing the number of first recesses 4.

[0033] In particular, it is provided that after determining the cell dimensions, i.e., after determining the ratio between the cell length and the cell width, 0.04H ≤ L*S / W ≤ 0.45H is ensured when, on the one hand, the cell polarization is to be reduced by adjusting the spacing of the first recesses 4. This prevents the spacing of the first recesses 4 and the groove depth of the first recesses 4 from being too small, and thus avoids a significant reduction in the cell's polarization and its ability to store the electrolyte solution. On the other hand, when the cell polarization is to be reduced by adjusting the groove depth of the first recesses 4, 0.04H ≤ L*S / W ≤ 0.45H is ensured.This prevents the groove depth and spacing of the first recesses 4 from being too large, the first recesses 4 from being too sparsely spaced, and the effect of the first recesses 4 on reducing the local polarization of the cell from being too far apart, while the effect on reducing the polarization of the rest of the cell is insignificant. It also prevents the first recesses 4 from being too close together and from likely overlapping. Furthermore, the first recesses 4 are typically laser-slit, which can deactivate part of the active material layer at a slit location, so the energy density of the cell can also be increased by avoiding the first recesses 4 being too close together.

[0034] In some embodiments, H is specified as being in the following range: 2 ≤ H ≤ 40; and / or L as being in the following range: 20 ≤ L ≤ 160; and / or W as being in the following range: 0.5 ≤ W ≤ 3; and / or S as being in the following range: 0.5 ≤ S ≤ 3. H can be, for example, 2, 3, 5, 10, 20, 30, 35, 38, 40, etc. L can be 20, 22, 25, 30, 40, 50, 80, 100, 130, 150, 155, 160, etc. W can be 15, 16, 18, 20, 30, 50, 70, 75, 78, 80, etc. S can be 0.5, 0.52, 0.55, 0.6, 0.8, 1, 1.5, 2, 2.6, 2.9, 2.95, 2.98, 3, etc. By applying the above ranges to H, L, W, and S, the first recesses 4 are not positioned too close together, and overlapping is avoided.Furthermore, the first recesses 4 are usually slotted by laser, which can lead to the deactivation of part of the active material layer at a slotted location, so that the energy density of the cell can also be increased by avoiding the arrangement of the first recesses 4 at too close a distance from each other.

[0035] In some embodiments, the separator 3 is located between the positive electrode plate 2 and the negative electrode plate 1. The separator 3 comprises a ceramic layer 31 facing the positive electrode plate 2, the ceramic layer 31 having a thickness of M µm, and where M and H are given by: 2.5 ≤ H / M ≤ 40. By providing the surface of the active material layer for the negative electrode 12 facing the positive electrode plate 2 with the first recesses 4, the negative electrode plate 1 is brought into close contact with the separator 3 after the cell has been subjected to formation and thermal compression at high temperature. It is ensured that the ratio between the depth of the first recess 4 and the thickness of the ceramic layer 31 of the separator 3 facing the negative electrode plate 1 is within the range specified above.This allows the ceramic layer 31 to abut the first recesses 4 after the ceramic layer 31 and an adhesive layer 32 of the separator 3 have been subjected to thermal compression. This prevents the actual first recesses 4 from being filled with the ceramic layer 31 and thus prevents the first recesses 4 from losing their effect of increasing the capacity for storing the electrolyte solution. As in . Fig. As shown in Figure 7, the separator 3 comprises a substrate layer 33, a ceramic layer 31, and an adhesive layer 32, wherein the ceramic layer 31 is located on one side of the substrate layer 33 associated with the positive electrode plate 2, the adhesive layer 32 is located on one side of the ceramic layer 31 associated with the positive electrode plate 2, and the adhesive layer 32 is located on one side of the substrate layer 33 associated with the negative electrode plate 1. That is, for the separator 3, the adhesive layer 32, the substrate layer 33, the ceramic layer 31, and the adhesive layer 32 are arranged sequentially in the direction from the negative electrode plate 1 to the positive electrode plate 2.

[0036] The ratio between the depth of the first recess 4 and the thickness of the ceramic layer 31 of the separator 3 facing the negative electrode plate 1 can be, for example, 2.5, 3, 5, 8, 10, 15, 20, 30, 35, 38, 39, 40, etc.

[0037] It should be noted that the ceramic layer 31 has a thickness M, and that the thickness of the ceramic layer 31 corresponds to a dimension of the ceramic layer 31 in a dimension defined by the double arrow B in Fig. 7 refers to the direction shown.

[0038] In some embodiments, H is provided for in the following range: 2 ≤ H ≤ 40; and / or M is provided for in the following range: 0.3 ≤ M ≤ 5. H can be, for example, 2, 3, 5, 10, 20, 30, 35, 38, 40, etc. M can be 0.3, 0.4, 0.8, 1.5, 3, 4, 4.5, 4, 8, 5, etc. Because the above ranges apply to H and M, the ceramic layer 31 can be in contact with the first recesses 4 after the ceramic layer 31 and the adhesive layer 32 of the separator 3 have been subjected to thermal compression. This prevents the actual first recesses 4 from being filled with the ceramic layer 31, and prevents the first recesses 4 from losing the effect of increasing the capacity for storing the electrolyte solution.

[0039] In some embodiments, the separator 3 is located between the positive electrode plate 2 and the negative electrode plate 1, the separator 3 comprising a ceramic layer 31 facing the positive electrode plate 2, the ceramic layer 31 having a thickness of N µm, the first recess 4 having a width of V µm, and N and V being such that 3 ≤ V / N ≤ 3000. Since the ceramic layer 31 of the separator 3 faces the first recesses 4 and the ceramic layer 31 comprises several ceramic particles, it is particularly intended that channels for the movement of lithium ions through the spaces between the ceramic particles are formed during charging and discharging of the cell.Because the ratio between the width of the first recess 4 and the ceramic particles is in the above range, the width of the first recess 4 can be increased when the outer diameter of the ceramic particles is increased, in order to prevent the first recess 4 from being blocked by excessively large ceramic particles and thus affecting the movement of the lithium ions, thereby increasing the mobility of the lithium ions and thus the charging rate of the cell.

[0040] It should be noted that Dv50 of the ceramic layer 31 is determined by the particle size of the laser. The width of the first recess 4 refers to a dimension in a line indicated by the double arrow E in Fig. 5 direction shown.

[0041] In some embodiments, V is provided for in the following range: 20 ≤ V ≤ 200; and / or N is provided for in the following range: 0.02 ≤ N ≤ 2. V can be, for example, 20, 22, 25, 30, 50, 80, 100, 150, 180, 190, 192, 195, 198, 200, etc. Because the above ranges apply to V and N, the width of the first recess 4 can be increased when the outer diameter of the ceramic particles is increased. This prevents the first recess 4 from becoming clogged by excessively large ceramic particles and thus affecting the movement of the lithium ions, thereby increasing the mobility of the lithium ions and consequently the charging rate of the cell.

[0042] In some embodiments, the active material layer for the negative electrode 12 is arranged on at least one side of the current collector for the negative electrode 11. In lithium-ion secondary batteries, the density of the active material layer is typically increased to increase the cell's energy density. This, however, hinders the movement of lithium ions during charging and discharging. Therefore, the active material layer for the negative electrode 12 is configured as a first active layer facing the current collector for the negative electrode 11 and a second active layer facing away from the current collector for the negative electrode 11. The Dv50 of the active material in the first active layer is greater than the Dv50 of the active material in the second active layer.Thus, the spaces between the first active layer facing the active material layer can be increased to improve the efficiency of lithium ion movement, facilitate lithium ion movement, and thereby increase the charging rate.

[0043] In particular, the first active layer and the second active layer can consist of graphite or silicon materials with different particle diameters, wherein the doped content of silicon-carbon materials is 1% to 30%, wherein the first active layer is graphite with large particles and the second active layer is graphite with small particles, and, for example, the graphite with large particles has a particle diameter of 5 to 30 µm and the graphite with small particles has a particle diameter of 3 to 22 µm, wherein the graphite-doped silicon material of the first active layer and the second active layer can be either the same silicon material or different types of silicon materials.wherein the graphite material or the graphite-doped silicon material of the second active layer has a smaller particle diameter than the particle diameter of the graphite material or the graphite-doped silicon material of the first active layer, and wherein the thickness of the paste (the graphite material or the graphite-doped silicon material) of the second active layer is 20% to 60% of the total thickness of the active material layer for the negative electrode 12. The concept of the double-layer structure for the negative electrode is that the second active layer, consisting of small particles and used for rapid charging, is located on a side facing away from the active material layer for the negative electrode 12, and the first active layer, consisting of large particles and designed to be pressure-resistant, is located on a side facing the current collector for the negative electrode 11.so that the polarization in the thickness direction of the negative electrode plate 1 is reduced while ensuring a high pressing density of the electrode plate.

[0044] It should be noted that the above silicon materials include materials such as silicon-carbon, silicon-oxygen, elemental silicon, silicon alloy and the like, and preferably use the silicon-carbon material.

[0045] In the present embodiment, the second active layer is further provided to have a thickness of P µm, where P and H are such that 1 < P / H ≤ 3. By forming the first recesses 4 in the second active layer, the distance between the large-particle graphite of the first active layer and the interface of the separator 3 can be reduced, thereby reducing polarization in the thickness direction of the negative electrode plate 1. In conjunction with the formation of the active material layer for the negative electrode 12 with the first and second active layers, optimal ranges exist for the depth of the first recess 4 and the thickness of the graphite of the second active layer, so that both technologies simultaneously maintain their advantageous effects in controlling the polarization of the electrode plate at a low level and increasing the charging capacity of the system.

[0046] In some embodiments, H is specified as being in the following range: 2 ≤ H ≤ 40; and / or P is specified as being in the following range: 8 ≤ P ≤ 1000. H can be, for example, 2, 3, 5, 10, 20, 30, 35, 38, 40, etc. P can be 8, 10, 50, 100, 300, 500, 800, 950, 990, 996, 1000, etc. Because the above ranges apply to P and H, and in connection with this the active material layer for the negative electrode 12 is formed with the first active layer and the second active layer, optimal ranges exist for the depth of the first recess 4 and the thickness of the graphite of the second active layer, so that both technologies retain their advantageous effects at the same time to control the polarization of the electrode plate at a low level and to increase the charging capability of the system.

[0047] In some embodiments, the first recesses 4 reduce the polarization on the surface and inside the negative electrode plate 1, thus increasing the potential of the electrode of the negative electrode plate 1. At a certain voltage, this in turn increases the potential of the electrode of the positive electrode plate 2. Therefore, in a system operating at the same voltage, a material with higher voltage stability must be used for the positive electrode plate 2. Simultaneously, the silicon-doped active material in the active material layer for the negative electrode 12 can lead to serious side reactions involving gas and heat generation, which exacerbate damage to the entire system.The structural change of the lithium cobaltate of the active material for the positive electrode of the active material layer for the positive electrode 22 leads to irreversible damage and thus affects the performance of the lithium-ion secondary battery, which is why aluminum and magnesium are doped in the active material of the active material layer for the positive electrode 22.

[0048] It is further provided that the positive electrode plate 2 comprises a current collector for the positive electrode 21 and an active material layer for the positive electrode 22, wherein the active material layer for the positive electrode 22 comprises a material for the positive electrode that is doped with Al and Mg, wherein the sum of the aluminum and magnesium content is Q ppm, wherein the silicon content of an active material in the active material layer for the negative electrode 12 is R, and wherein Q, R and H are given by: 1*10 3 ≤ Q / (R*H) ≤ 1*10 5It is ensured that the above relationship holds true for the sum of the aluminum and magnesium content of the active material in the active material layer for the positive electrode 22, the silicon content of the active material in the active material layer for the negative electrode 12, and the groove depth of the first recesses 4. Increasing the silicon content of the active material layer for the negative electrode 12 or the groove depth of the first recess 4 can suppress problems such as cell polarization by increasing the sum of the aluminum and magnesium content, thereby increasing cell stability and extending cell lifetime. It should be noted that the aluminum and magnesium content is achieved by doping the aluminum and magnesium into the material for the positive electrode.

[0049] The material for the positive electrode is preferably lithium cobaltate.

[0050] In some embodiments, H is specified as being within the following range: 2 ≤ H ≤ 40; and / or Q is within the following range: 1000 ≤ Q ≤ 10000; and / or R is within the following range: 1% ≤ R ≤ 30%. H can be, for example, 2, 3, 5, 10, 20, 30, 35, 38, 40, etc. Q can be 1000, 1005, 1050, 2000, 3000, 5000, 8000, 9000, 9500, 9990, 10000, etc. The above ranges apply to H and Q. If the silicon-doped content of the active material layer for the negative electrode 12 or the groove depth of the first recess 4 is increased, problems such as polarization of the cell and the like can be suppressed by increasing the sum of the aluminum-doped content and the magnesium-doped content in order to increase the stability of the cell and thus extend the lifetime of the cell.

[0051] In some embodiments, the negative electrode plate 1 has an extension section 13 that extends beyond the positive electrode plate 2 in a longitudinal direction of the cell, and the extension section 13 has a dimension of D mm in the longitudinal direction of the cell, where D and H are: 0.05 ≤ D / H ≤ 0.25. It is ensured that the above relationship holds for the dimension of the extension section 13 and the groove depth of the first recess 4. This reduces polarization, allowing the lithium ions diffusing to the extension section 13 to return more quickly to the positive electrode during discharge, thus mitigating their accumulation at the extension section 13 and consequently the lithium deposition at an edge.

[0052] It should be noted that the longitudinal direction of the cell is defined by the double arrow Z in Fig. 3 refers to the direction shown.

[0053] In some embodiments, H is provided for in the following range: 2 ≤ H ≤ 40; and / or D is provided for in the following range: 0.1 ≤ D ≤ 2. H can be, for example, 2, 3, 5, 10, 20, 30, 35, 38, 40, etc. D can be 0.1, 0.2, 0.5, 1, 1.5, 1.8, 1.95, 1.98, 2, etc. Because D and H fall within the above ranges, the polarization can be reduced, allowing the lithium ions diffusing to extension section 13 to return more quickly to the positive electrode during discharge. This reduces their accumulation at extension section 13 and thus the lithium deposition at an edge.

[0054] The ratio between the dimension of the extension section and the groove depth of the first recess 4 can be, for example, 0.05, 0.055, 0.06, 0.08, 0.1, 0.15, 0.2, 0.24, 0.25, etc.

[0055] With a centrally arranged tab, second recesses 5 are formed on the positive electrode plate 2. To prevent a short circuit caused by contact between the tab for the positive electrode and the negative electrode plate 1, an adhesive paper 6 is arranged between the tab for the positive electrode and the negative electrode plate 1. The arrangement of the adhesive paper 6 allows the thickness of the lithium-ion secondary battery to be increased, which leads to a reduction in the energy density of the lithium-ion secondary battery. In some embodiments, second recesses 5 are formed in a region of the active material layer for the negative electrode 12, corresponding to the tab for the positive electrode 7 of the cell, in one thickness direction of the cell. An adhesive paper 6 is arranged in the second recess 5. The adhesive paper 6 is located in a projection of the second recess 5.The thickness of the adhesive paper 6 ≤ the depth of the second recess 5 < the thickness of the active material layer for the negative electrode 12 on one side. This reduces the overlap thickness of the tab, the adhesive paper 6 for the tab, and the adhesive paper 6, thus reducing the cell's thickness and increasing its energy density. Furthermore, the recesses improve the electrolyte solution storage capacity of the lithium-ion secondary battery.

[0056] In the lateral direction of the cell, the distances from the edges on both sides of the second recess 5 to the adjacent first recesses 4 are T mm and U mm, respectively, where T and U are greater than 0. This allows the second recesses 5 and the first recesses 4 to be offset. The design of the second recesses 5 enables the electrolyte solution to wet the active material layer more quickly. Furthermore, it ensures that the electrolyte solution is better retained in the second recesses 5, thus further improving the cell's electrolyte retention capacity.

[0057] It should be noted that the depth of the first recess 4 and the depth of the second recess 5 are not defined. For example, the depth of the second recess 5 can be greater than the depth of the first recess 4. The depth of the second recess 5 can also be less than the depth of the first recess 4. Furthermore, the depth of the second recess 5 can be the same as the depth of the first recess 4.

[0058] It should also be noted that the distances of edges on both sides of the second recess 5 to the respective adjacent first recesses 4 are designated by T and U and refer to dimensions at the edges of the second recess 5 in a direction indicated by the double arrow E. Fig. Refer to the direction shown in section 5.

[0059] The distances T and U from edges on both sides of the second recess 5 to the respective adjacent first recesses 4 can be, for example, 0,1, 0,2, 0,5, 0,6, 0,8, 1, 2, 3, 5, 8, 10, 20 etc.

[0060] A lithium-ion secondary battery comprises a casing and the cell located within the casing. Since the lithium-ion secondary battery includes the cell, the beneficial effects of the lithium-ion secondary battery that are inherent in the cell are already described above and will not be repeated here.

[0061] The following examples and comparative examples are used to describe the embodiments of the present application in more detail. Various tests and evaluations are carried out according to the following procedures. Test procedure:

[0062] Lithium deposition window: After charging the lithium-ion secondary battery to its target voltage in a thermostatically controlled room at 25°C, it was left stationary for 5 minutes and then discharged at 1C to 3.0V. After 30 cycles, it was disassembled. If the electrode plate shows no lithium deposition at any point, the cell's charge capability is determined to be within this control window. The charge controller is adjusted (towards a higher rate or voltage) until the electrode plate shows lithium deposition at a specific charge controller setting, at which point the cell's maximum charge capability is reached. This setting then represents the lithium deposition window.

[0063] Particle diameter: The Dv50 test is performed using a laser particle size analyzer.

[0064] Dimensioning of a linear groove: The test is performed using a 3D microscope. Example 1

[0065] Step 1: Production of a positive electrode plate 2: A lithium cobaltate material with an Al and Mg doping concentration of 7500 ppm was prepared as an active material slurry for the positive electrode. The active material slurry for the positive electrode was applied to the surface of a current collector for the positive electrode 21. After drying, rolling, and cutting, a positive electrode plate 2 with a web width of 77 mm was obtained. The positive electrode plate 2 was provided with a groove of constant dimensions at a specific location. A tab was welded into this groove by laser or ultrasonic welding.

[0066] Step 2: A graphite doped with 10% silicon-carbon material with a Dv50 of 15 and a graphite doped with 10% silicon-carbon material with a Dv50 of 10 were each prepared as an active layer slurry for the negative electrode and simultaneously coated onto a carbon-coated copper foil (a current collector for the negative electrode 11). The graphite doped with 10% silicon-carbon material with large particles was applied to the carbon-coated copper foil, and the graphite doped with 10% silicon-carbon material with small particles was applied to the surface of the graphite doped with 10% silicon-carbon material with large particles. After drying, rolling, and cutting, a double-layered negative electrode plate 1 with a web width of 78.5 mm, a total thickness of 100 µm, and a second active layer thickness of 30 µm was obtained.The negative electrode plate 1 was provided with a groove of constant dimensions at a specific location. A tab made of nickel-plated copper was welded into this groove by laser or ultrasonic welding. Additionally, secondary recesses 5 were milled onto the negative electrode plate 1 at projections of the weld area of ​​a tab for the positive electrode 7, with the secondary recesses 5 having a depth of 25 µm. Uniform linear first recesses 4 were created on a surface of the negative electrode plate 1 by laser at a specific intensity. The first recesses 4 have a depth of 15 µm, a width of 80 µm, and a groove spacing of 1.2 mm. The minimum distance between an edge of the second recess 5 and the adjacent first recess 4 is 0.6 mm.

[0067] Step 3: After cutting and plate preparation, the positive or negative electrode plate 1 was wound with a separator 3 to obtain a winding cell with a width of 32 mm and a length of 80 mm, wherein the separator 3 consists of a substrate film of 5 µm, a ceramic layer 31 of 2 µm and an adhesive layer 32 of 2 µm, and wherein Dv50 of a particle diameter of the ceramic is 100 nm.

[0068] Step 4: A lithium-ion secondary battery was then obtained after packaging, drying, injection of the electrolyte solution, formation, resealing, sorting and OCV.

[0069] The electrolyte solution is a commercially available solution, specifically a lithium salt based on LiFP6. The target voltage of a lithium-ion secondary battery, in this example or comparison, is 4.5 V.

[0070] It should be noted that when charging the lithium-ion secondary battery, the lithium deposition window of a Fig. The battery shown in Figure 1 has a charging rate of 3.5C-4.3V to 2C-4.5V. This means that the battery is charged at a rate of 3.5C to 4.3V, and for further charging, the rate must be reduced to 2C. The size of the lithium deposition window can, to some extent, reflect the charging rate of the lithium-ion secondary battery. Examples 2-4

[0071] With the exception of the depth of the first recess 4 in Example 1, the remaining values ​​are the same as in Example 1. The values ​​for the depth of the first recess 4 in Examples 2-4 can be found in Table 1. Comparative examples 1-2

[0072] With the exception of the depth of the first recess 4 in Example 1, the remaining values ​​are the same as in Example 1. The values ​​for the depth of the first recess 4 in comparison examples 1-2 can be found in Table 1.

[0073] See Table 1. As can be seen from Examples 1 to 6 and Comparative Examples 1 to 3: if the relationship 0.05H ≤ L / W ≤ 0.5H applies to the depth of the first recesses 4, the cell length, and the cell width, it may turn out that the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 1 to 6 are larger than the coefficients of the residual electrolyte solution and the lithium deposition windows in Comparative Examples 1 to 3. Since the lithium-ion secondary battery fails after the electrolyte solution is consumed, the coefficient of the residual electrolyte solution in the cell represents the electrolyte solution concentration in the cell. The coefficient of the residual electrolyte solution can, to some extent, represent a cycle life; therefore, the larger the coefficient of the residual electrolyte solution, the longer the battery life.When charging the lithium-ion secondary battery, the lithium deposition window shown in Example 4 is wide, allowing it to be charged directly at a rate of 3.5C to 4.4V. In contrast, the lithium deposition window shown in comparative Example 3 is narrow, limiting the battery to a charging rate of 3.5C to 4.25V, and requiring a rate reduction for further charging. Compared to Example 4, the charging process takes longer. Therefore, the charging speed increases with the width of the lithium deposition window, resulting in a faster charging speed and a wider charging window. Examples 7-11

[0074] With the exception of the ratio between the distance of the first recesses 4 and the width of the cell in Example 1, the remaining ratios are the same as in Example 1. The ratio between the distance of the first recesses 4 and the width of the cell in Examples 7-11 can be found in Table 2.

[0075] See Table 2. As can be seen in Examples 1, 7 through 11: if the cell width and the spacing of the first recesses 4 are given by the relationship 0.01 ≤ S / W ≤ 0.06, then the coefficients of the remaining electrolyte solution and the lithium deposition windows in Examples 1, 7 through 9 are larger than the coefficients of the remaining electrolyte solution and the lithium deposition windows in Examples 10 and 11. The larger the coefficient of the remaining electrolyte solution in the cell, the longer the battery life. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 12-16

[0076] With the exception of the ratio between the product of the distance of the first recesses 4 with the length of the cell and the product of the width of the cell with the groove depth in Example 1, the remaining ratios are the same as in Example 1. The ratio between the product of the distance of the first recesses 4 with the length of the cell and the product of the width of the cell with the groove depth in Examples 12-16 can be found in Table 3.

[0077] See Table 3. As can be seen in Examples 1, 12, and 16: if the relationship 0.04H ≤ L*S / W ≤ 0.45H holds for the cell length, cell width, slot depth, and the distance between the first recesses 4, then the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 1, 12, and 14 are larger than the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 15 and 16. The larger the coefficient of the residual electrolyte solution in the cell, the longer the battery life. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 17-21

[0078] With the exception of the ratio between the groove depth and the thickness of the ceramic layer 31 in Example 1, the remaining values ​​are the same as in Example 1. The ratio between the groove depth and the thickness of the ceramic layer 31 in Examples 17-21 can be found in Table 4.

[0079] See Table 4. As can be seen in Examples 1, 17 to 21: if the relationship 2.5 ≤ H / M ≤ 40 holds for the depth of the first recess 4 and the thickness of the ceramic layer 31 of the separator 3, then the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 1, 17 to 19 are larger than the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 20 and 21. The larger the coefficient of the residual electrolyte solution in the cell, the longer the battery life. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 22-26

[0080] With the exception of the ratio between the width of the first recess 4 and the Dv50 of the ceramic particles in Example 1, the remaining values ​​are the same as in Example 1. The ratio between the width of the first recess 4 and the Dv50 of the ceramic particles in Examples 22-26 can be found in Table 5.

[0081] See Table 5. As can be seen in Examples 1, 22 to 26: if the relationship 3 ≤ V / N ≤ 3000 holds for the width of the first recess 4 and the outer diameter of the ceramic particles, then the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 1, 22 to 24 are larger than the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 25 and 26. The larger the coefficient of the residual electrolyte solution in the cell, the longer the battery life. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 27-31

[0082] With the exception of the ratio between the thickness of the second active layer and the groove depth in Example 1, the remaining values ​​are the same as in Example 1. The ratio between the thickness of the second active layer and the groove depth in Examples 27-31 can be found in Table 6.

[0083] See Table 6. As can be seen in Examples 1, 27 to 31: if the relationship 1 < P / H ≤ 5 holds for the depth of the first recess 4 and the thickness of the second active layer, then the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 1, 27 to 29 are larger than the coefficients of the residual electrolyte solution and the lithium deposition windows in Examples 30 and 31. The larger the coefficient of the residual electrolyte solution in the cell, the longer the battery life. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 32-36

[0084] With the exception of the ratio between the sum of the aluminum and magnesium content and the product of the silicon content and the groove depth in Example 1, the remaining values ​​are the same as in Example 1. The ratio between the sum of the aluminum and magnesium content and the product of the silicon content and the groove depth in Examples 32-36 can be found in Table 7.

[0085] See Table 7. It can be seen from Example 1, Example 32 to Example 36: if the relationship 1*10 applies to the sum of the aluminum and magnesium content, the silicon content, and the groove depth 3 ≤ Q / (R*H) ≤ 1*10 5 Therefore, the lithium deposition windows in Example 1, Example 32 to Example 34 are larger than the lithium deposition windows in Example 35 and Example 36. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 37-41

[0086] With the exception of the ratio between the dimension of extension section 13 (difference in the widths of negative electrode plate 1 and positive electrode plate 2) and the groove depth in Example 1, the remaining values ​​are the same as in Example 1. The ratio between the dimension of extension section 13 and the groove depth in Examples 37-41 can be found in Table 8. Table 8

[0087] See Table 8. As can be seen in Example 1, Example 37 to Example 41: if the relationship 0.05 ≤ D / H ≤ 0.25 holds for the dimension of the extension section 13 and the groove depth, the lithium deposition windows in Example 1, Example 37 to Example 39 are larger than the lithium deposition windows in Example 40 and Example 41. The wider the lithium deposition window, the wider the charging window and the faster the charging speed. Examples 42-43

[0088] With the exception of the minimum distance between an edge of the second recess 5 and the nearby first recess 4 in Example 1, the remaining distances are the same as in Example 1. The minimum distances between edges of the second recess 5 and the nearby first recess 4 in Examples 42 and 43 can be found in Table 9. Table 9

[0089] See Table 9. As can be seen from Example 1, as well as Example 42 and Example 43: if the minimum distance between an edge of the second recess 5 and the nearby first recess 4 is greater than 0, the coefficients of the residual electrolyte solution in Example 1 and Example 42 are greater than the coefficient of the residual electrolyte solution in Example 43. The larger the coefficient of the residual electrolyte solution of the cell, the longer the battery life.

[0090] The basic principle of the present application has been described above in conjunction with detailed embodiments. It should be noted, however, that the advantages, benefits, effects, etc., presented in the present application are merely examples, not limitations. These advantages, benefits, effects, etc., cannot be considered essential for any particular embodiment of the present application. Furthermore, the specific details disclosed above serve only for illustrative purposes and to simplify understanding, and not as limitations. The above details do not restrict the present application to being implemented using the above specific details.

[0091] The block diagrams for the means, devices, apparatus, or systems concerned in the present application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured according to the block diagrams. As the person skilled in the art will recognize, these means, devices, apparatus, or systems can be connected, arranged, or configured in any way. Words such as "comprise," "contain," "have," etc., are open terms, refer to "comprise, but are not limited to," and can be used interchangeably. The terms "or" and "and" used herein refer to the term "and / or" and can be used interchangeably with it unless expressly stated otherwise. The term "such as" used herein refers to the phrase "such as, for example, but are not limited to it" and can be used interchangeably with it.

[0092] It should also be noted that individual components or steps of the facilities, devices, and methods of the present application can be divided and / or recombined. These divisions and / or recombinations should be considered equivalent approaches of the present application.

[0093] The above description of the disclosed aspects is provided to enable any person skilled in the art to implement or use the present application. The various modifications to these aspects are obvious to the person skilled in the art, and the general principles defined herein can be applied to other aspects without deviating from the scope of the present application. Accordingly, the present application is not intended to be limited to the aspects presented herein, but rather to the broadest possible scope consistent with the principles disclosed herein and the novel features.

[0094] It is understood that the defining words used in the description of the embodiments of the present application, such as "first", "second", "third", "fourth", "fifth" and "sixth", serve only to provide a clearer description of the technical solutions, without being able to limit the scope of protection of the present application.

[0095] To provide examples and descriptions, the above descriptions have already been given. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although several exemplary aspects and embodiments have already been discussed above, the person skilled in the art will recognize certain variations, modifications, changes, additions, and sub-combinations thereof.

Claims

[1] cell, characterized by , that it comprises a positive electrode plate, a separator and a negative electrode plate, wherein the negative electrode plate comprises a current collector for the negative electrode and an active material layer for the negative electrode, wherein first recesses are formed on a surface of the active material layer for the negative electrode, wherein the first recess has a depth of H µm and the cell has a length of L mm and a width of W mm, and wherein for H, L and W: 0.05H ≤ L / W ≤ 0.5H. [2] Cell according to claim 1, characterized by , that 1 ≤ L / W ≤ 5 holds true; where H lies within the following range: 2 ≤ H ≤ 40; and / or where L lies within the following range: 20 ≤ L ≤ 160; and / or where W lies within the following range: 15 ≤ W ≤ 80. [3] Cell according to claim 1 or 2, characterized by, that the first recesses have a distance of S mm from each other, where for W and S: 0.01 ≤ S / W ≤ 0.06; that the first recesses have a distance of S mm from each other, where for H, L, W and S: 0.04H ≤ L*S / W ≤ 0.45H, and where preferably S lies in the following range: 0.5 ≤ S ≤ 3. [4] Cell according to any one of claims 1 to 3, characterized by , that the separator is located between the positive electrode plate and the negative electrode plate, wherein the separator comprises a ceramic layer facing the positive electrode plate, wherein the ceramic layer has a thickness of M µm, where M and H are: 2.5 ≤ H / M ≤ 40; and wherein M is preferably in the following range: 0.3 ≤ M ≤ 5. [5] Cell according to any one of claims 1 to 3, characterized by, that the separator is located between the positive electrode plate and the negative electrode plate, wherein the separator comprises the ceramic layer facing the positive electrode plate, wherein the ceramic layer Dv50 has a thickness of N µm and the first recess has a width of V µm, wherein N and V are: 3 ≤ V / N ≤ 3000; wherein V is preferably in the following range: 20 ≤ V ≤ 200; and / or where N lies within the following range: 0.02 ≤ N ≤ 2. [6] Cell according to any one of the preceding claims, characterized by, that the active material layer for the negative electrode is arranged on at least one side of the current collector for the negative electrode, that the active material layer for the negative electrode comprises a first active layer facing the current collector for the negative electrode and a second active layer facing away from the current collector for the negative electrode, and that Dv50 of an active material in the first active layer is greater than Dv50 of an active material in the second active layer, wherein the second active layer has a thickness of P µm, where for P and H: 1 < P / H ≤ 5; and wherein P is preferably in the following range: 8 ≤ P ≤ 1000. [7] cell one of the preceding claims, characterized by, that the positive electrode plate comprises a current collector for the positive electrode and an active material layer for the positive electrode, wherein the sum of the aluminum and magnesium content of an active material in the active material layer for the positive electrode is Q ppm, wherein the silicon content of an active material in the active material layer for the negative electrode is R, where Q, R and H are given by: 1*10 3 ≤ Q / (R*H) ≤ 1*10 5 ; where Q is in the following range: 1000 ≤ Q ≤ 10000; and / or where R is in the following range: 1% ≤ R ≤ 30%. [8] Cell according to any one of the preceding claims, characterized by, that the negative electrode plate has an extension section extending beyond the positive electrode plate in a longitudinal direction of the cell, and that the extension section has a dimension of D mm in the longitudinal direction of the cell, wherein D and H are: 0.05 ≤ D / H ≤ 0.25; and wherein D is preferably in the following range: 0.1 ≤ D ≤ 2. [9] Cell according to any one of the preceding claims, characterized by , that in a thickness direction of the cell second recesses are formed in a region of the active material layer for the negative electrode, which corresponds to a tab for the positive electrode of the cell, and that in a width direction of the cell the distances between edges on both sides of the second recess and the respective adjacent first recesses are T mm and U mm, respectively, where T and U are greater than 0. [10] Lithium-ion secondary battery, characterized by, that it comprises a housing and a cell arranged in the housing according to any one of claims 1 to 9.

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