Electrode sheets, laminated cells, batteries and electrical equipment

Abstract

The present application relates to the technical field of battery assembly and manufacturing, and in particular to a pole piece, a laminated battery cell, a battery and an electrical device. The pole piece includes: a current collector; an active material layer, wherein the active material layer is located on at least one side of the current collector surface along the thickness direction of the current collector; and a groove is provided on the active material layer, wherein the groove is located in the region of the current collector where lithium is easily deposited. By providing a groove in the region where lithium is easily deposited on the active material layer, the active material in the region where lithium is easily deposited on the pole piece is removed, so that the lithium ion concentration in the region is reduced, and no or only a small amount of lithium ion is deintercalated, thereby reducing the possibility of lithium deposition on the pole piece during charging.

Description

Technical Field

[0001] The present application relates to the technical field of battery assembly and manufacturing, and in particular to a pole piece, a laminated battery cell, a battery and an electrical device. Background Art

[0002] At present, for large-capacity laminated batteries with large length and width differences, in order to reduce the path of current flow in the length direction, a solution of having positive and negative tabs at both ends of the battery can be adopted. Compared with the solution of having a battery of the same size but only having tabs at one end, the path of electron flow is shortened by half, thereby reducing the internal resistance of the battery, reducing the heat generated by the battery, and improving the energy efficiency of the battery.

[0003] However, the above-mentioned battery is prone to overcharge and lithium deposition, which affects the performance of the battery. Summary of the invention

[0004] Based on this, the present application provides a pole piece, a laminated battery cell, a battery and an electrical device to solve the problem of uneven current density distribution in the local area of ​​the pole piece, excessive local current density leading to overcharging and lithium deposition, and affecting battery performance.

[0005] On the one hand, the present application provides a pole piece for use in a laminated battery cell, comprising:

[0006] current collector;

[0007] Two pole ears, along the length direction of the current collector, the two pole ears are oppositely arranged on two sides of the current collector;

[0008] An active material layer, along the thickness direction of the current collector, the active material layer is located on at least one side of the current collector surface;

[0009] The active material layer is provided with a groove, and along the length direction of the current collector, the groove is located in the middle of the current collector.

[0010] In a possible implementation, the groove extends to one side of the current collector along the width direction of the current collector, and the notch of the groove is located at the edge of the current collector extending along the length direction.

[0011] In a possible implementation, along the thickness direction of the current collector, the active material layers are located on both sides of the surface of the current collector, and grooves are provided on both active material layers.

[0012] In a possible implementation, along the thickness direction of the current collector, the grooves on the two active material layers are arranged opposite to each other.

[0013] In a possible implementation, along the thickness direction of the current collector, the depth of the groove is equal to the thickness of the active material layer.

[0014] In a possible implementation, along the thickness direction of the current collector, the depth of the groove is less than the thickness of the active material layer.

[0015] In a possible implementation, the pole piece further includes a ceramic layer, and the ceramic layer is disposed in the groove.

[0016] In a possible implementation, along the thickness direction of the current collector, the orthographic projection of the ceramic layer coincides with the orthographic projection of the groove.

[0017] In a possible implementation, along the thickness direction of the current collector, the surface of the ceramic layer is flush with the surface of the active material layer.

[0018] In a possible implementation, along the thickness direction of the current collector, the total area of ​​the orthographic projection of the groove is S1, and the area of ​​the current collector surface is S;

[0019] S1 and S satisfy: 0.01≤S1 / S≤0.3.

[0020] In a possible implementation, the two electrode tabs are located at opposite sides of the current collector in the width direction.

[0021] In one possible implementation, the electrode sheet is a positive electrode sheet, which includes a positive electrode collector, a positive electrode ear and a positive electrode active material layer. Along the length direction of the positive electrode collector, the two positive electrode ears are relatively arranged on both sides of the positive electrode collector, and along the thickness direction of the positive electrode collector, the positive electrode active material layer is located on at least one side of the surface of the positive electrode collector.

[0022] In one possible implementation, the electrode sheet is a negative electrode sheet, which includes a negative electrode collector, a negative electrode ear and a negative electrode active material layer. Along the length direction of the negative electrode collector, the two negative electrode ears are relatively arranged on both sides of the negative electrode collector, and along the thickness direction of the negative electrode collector, the negative electrode active material layer is located on at least one side of the surface of the negative electrode collector.

[0023] On the other hand, the present application provides a laminated battery cell, including a positive electrode sheet, a separator and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are stacked, the separator is arranged between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet is the above-mentioned electrode sheet.

[0024] In a possible implementation, the negative electrode sheet is the electrode sheet mentioned above.

[0025] On the other hand, the present application provides a battery, including a shell and the above-mentioned laminated battery core, wherein the laminated battery core is arranged in the shell.

[0026] On the other hand, the present application provides an electrical device including the above-mentioned battery.

[0027] The pole piece, laminated battery cell, battery and electrical equipment provided by the present application, by providing a groove in the area where lithium is easily deposited on the active material layer, removes the active material in the area where lithium is easily deposited on the pole piece, so that the lithium ion concentration in the area is reduced, no or only a small amount of lithium ion is deintercalated, so that the problem of overcharge and lithium deposition in the area with the highest SOC (state of charge) in the pole piece is reduced. In this way, the performance of the battery with the pole piece is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a simulation result diagram of the charge state of the local electrode material at the end of the electrode sheet charging;

[0030] Figure 2 One of the structural schematic diagrams of the laminated battery cell provided in the embodiment of the present application;

[0031] Figure 3 for Figure 2 A schematic diagram of the structure of the positive electrode sheet of the laminated battery cell shown;

[0032] Figure 4 for Figure 2 A schematic diagram of the structure of the negative electrode sheet of the laminated battery cell shown;

[0033] Figure 5 A schematic diagram of the structure of the pole piece provided in the embodiment of the present application;

[0034] Figure 6 The second structural schematic diagram of the laminated battery cell provided in the embodiment of the present application;

[0035] Figure 7 The third structural schematic diagram of the laminated battery cell provided in the embodiment of the present application;

[0036] Figure 8 The fourth structural schematic diagram of the laminated battery cell provided in the embodiment of the present application;

[0037] Fig. 9 The fifth structural schematic diagram of the laminated battery cell provided in the embodiment of the present application;

[0038] Fig.10 A schematic diagram of the structure of a battery provided in an embodiment of the present application;

[0039] Fig.11for Fig.10 a front view of the battery shown;

[0040] Fig.12 for Fig.10 Side view of the battery shown.

[0041] Description of reference numerals:

[0042] 100-pole piece; 10-current collector; 11-positive current collector; 12-negative current collector; 20-pole ear; 21-positive ear; 22-negative ear; 30-active material layer; 31-positive active material layer; 32-negative active material layer; 33-groove; 40-ceramic layer; 200-laminated cell; 201-positive electrode piece; 202-negative electrode piece; 203-diaphragm; 300-battery; 301-housing; 302-positive electrode column; 303-negative electrode column. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0044] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0046] The terms "first", "second" and "third" (if any) in the specification and claims of this application and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0047] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display comprising a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0048] During the charge and discharge process of lithium-ion batteries, due to various reasons such as low negative electrode potential and insufficient lithium insertion space, electrons are deposited on the surface of the electrode to form lithium dendrites, which reduces the cycle life and energy efficiency of the battery. At present, for large-capacity laminated batteries with large length and width differences, in order to reduce the path of current flow in the length direction, a solution can be adopted to have positive and negative tabs at both ends of the battery. Compared with a battery of the same size but with tabs at only one end, the flow path of electrons is shortened by half, thereby reducing the internal resistance of the battery, reducing the heat generated by the battery, and improving the energy efficiency of the battery.

[0049] However, due to the internal resistance between the current collector and the dressing, the current density and potential distribution along the length direction of the electrode are easily uneven, resulting in inconsistent lithium insertion states in various regions during the charging process. It is easy to have problems such as excessive local current density and overcharging and lithium deposition, which affects the performance of the battery.

[0050] After repeated thinking and verification, the inventor found that if Figure 1 As shown in the figure, according to the simulation results, due to the pole ears at both ends of the pole piece, the SOC (state of charge) in the middle area of ​​the pole piece is the highest, and the problem of overcharge and lithium precipitation is very likely to occur, where x is the length direction of the pole piece, y is the width direction of the pole piece, and z is the height direction of the pole piece. If the dressing in the middle area of ​​the pole piece is removed, the lithium ion concentration in this area is low, and no or only a small amount of lithium ion deintercalation is performed, the possibility of lithium precipitation in this area can be reduced. At the same time, dense ceramics can be backfilled in the place where the dressing is removed, which can not only enhance the strength of the pole piece, but also isolate lithium ions, further reduce the possibility of lithium precipitation, and help improve the performance of the battery with the pole piece.

[0051] In view of this, the present application provides a pole piece, comprising: a current collector; an active material layer, wherein the active material layer is located on at least one side of the current collector surface along the thickness direction of the current collector; a groove is provided on the active material layer, and the groove is located in the area of ​​the current collector where lithium is easily deposited.

[0052] By setting grooves in the area of ​​the active material layer where lithium is easily deposited, the active material in the area on the electrode that is easy to deposit lithium is removed, so that the lithium ion concentration in this area is reduced, and no or only a small amount of lithium ion is deintercalated, thereby reducing the possibility of lithium deposition on the electrode during charging.

[0053] The contents of the present application will be described in detail below in conjunction with the accompanying drawings so that those skilled in the art can understand the contents of the present application more clearly and in detail.

[0054] Figure 1 This is a simulation result diagram of the charge state of the local electrode material at the end of electrode charging. Figure 2 This is one of the structural schematic diagrams of the laminated battery cell provided in the embodiment of the present application. Figure 3 for Figure 2 Schematic diagram of the structure of the positive electrode sheet of the laminated battery cell shown. Figure 4 for Figure 2 Schematic diagram of the structure of the negative electrode sheet of the laminated battery cell shown. Figure 5 A schematic diagram of the structure of the pole piece provided in an embodiment of the present application. Figure 6 This is the second structural schematic diagram of the laminated battery cell provided in the embodiment of the present application. Figure 7 This is the third structural schematic diagram of the laminated battery cell provided in the embodiment of the present application. Figure 8 This is the fourth structural schematic diagram of the laminated battery cell provided in an embodiment of the present application. Fig. 9 This is the fifth structural schematic diagram of the laminated battery cell provided in the embodiment of the present application. Fig.10 A schematic diagram of the structure of a battery provided in an embodiment of the present application. Fig.11 for Fig.10 Front view of the battery shown. Fig.12 for Fig.10 Side view of the battery shown.

[0055] like Figure 2 and Figure 3 As shown, the electrode sheet 100 provided in the embodiment of the present application is applied to the laminated battery cell 200. The laminated battery cell 200 includes a positive electrode sheet 201, a negative electrode sheet 202 and a separator 203. The positive electrode sheet 201 and the negative electrode sheet 202 are stacked, and the separator 203 is arranged between the positive electrode sheet 201 and the negative electrode sheet 202. Among them, the positive electrode sheet 201 is the electrode sheet 100 provided in the embodiment of the present application.

[0056] The electrode sheet 100 includes a current collector 10, a tab 20 and an active material layer 30. The tab 20 and the active material layer 30 are disposed on the current collector 10, respectively.

[0057] There are two electrode tabs 20 . Along the length direction of the current collector 10 , the two electrode tabs 20 are oppositely disposed on two sides of the current collector 10 and extend out of the current collector 10 .

[0058] Along the thickness direction of the current collector 10 , the active material layer 30 is located on at least one side of the surface of the current collector 10 .

[0059] like Figure 2 and Figure 3 As shown, the length direction of the current collector 10 is A, the width direction of the current collector 10 is B, and the thickness direction of the current collector 10 is C.

[0060] The active material layer 30 is provided with a groove 33 , and the groove 33 is located in the region of the current collector 10 where lithium is easily deposited.

[0061] In a possible implementation, along the length direction of the current collector 10 , the groove 33 is located in the middle of the current collector 10 .

[0062] In a possible implementation, the groove 33 is formed by intermittently coating the active material layer 30 on the current collector 10 or adding a gasket to the coating head so that the middle area of ​​the pole piece 100 is the groove 33 .

[0063] The positive electrode sheet 201 includes a positive electrode collector 11, a positive electrode ear 21 and a positive electrode active material layer 31. Along the length direction of the positive electrode collector 11, the two positive electrode ears 21 are relatively arranged on both sides of the positive electrode collector 11. Along the thickness direction of the positive electrode collector 11, the positive electrode active material layer 31 is located on at least one side of the surface of the positive electrode collector 11.

[0064] like Figure 3 As shown, in a possible implementation, the groove 33 extends to one side of the current collector 10 along the width direction of the current collector 10. The notch of the groove 33 is located at the edge of the current collector 10 extending along the length direction.

[0065] Optionally, the extension length of the groove 33 is equal to the width of the current collector 10 , that is, the groove 33 extends to both sides of the current collector 10 .

[0066] like Figure 2 As shown, in a possible implementation, along the thickness direction of the current collector 10 , the active material layers 30 are located on both sides of the surface of the current collector 10 , and grooves 33 are provided on the two active material layers 30 .

[0067] In a possible implementation, along the thickness direction of the current collector 10 , the grooves 33 on the two active material layers 30 are arranged opposite to each other.

[0068] In a possible implementation, along the thickness direction of the current collector 10 , the depth of the groove 33 is equal to the thickness of the active material layer 30 , that is, the groove 33 penetrates the active material layer 30 , with the surface of the current collector 10 as the groove bottom.

[0069] In one possible implementation, the shape and number of the grooves 33 are not limited. The grooves 33 can be multiple discontinuous blind holes or one or more continuous linear grooves, as long as the grooves 33 are located in the area on the current collector 10 where lithium deposition is prone to occur. In the embodiment of the present application, since the pole ears 20 are arranged on both sides, the middle area of ​​the current collector 10 is a lithium deposition-prone area, and the grooves 33 can be located in the middle of the current collector 10.

[0070] like Figure 3 As shown, in a possible implementation, the two pole tabs 20 are respectively located on opposite sides of the current collector 10 in the width direction, that is, the two pole tabs 20 are centrally symmetrically arranged on the pole piece 100 .

[0071] By arranging two pole ears 20 symmetrically on the pole piece 100 , it is not necessary to distinguish the left and right sides of the pole piece 100 during use, which is convenient for use during assembly and improves assembly efficiency.

[0072] like Figure 4 As shown, the negative electrode sheet 202 includes a negative electrode collector 12, a negative electrode ear 22 and a negative electrode active material layer 32. Along the length direction of the negative electrode collector 12, the two negative electrode ears 22 are relatively arranged on both sides of the negative electrode collector 12. Along the thickness direction of the negative electrode collector 12, the negative electrode active material layer 32 is located on at least one side of the surface of the negative electrode collector 12.

[0073] The negative electrode active material layer 32 does not have any groove 33 .

[0074] By providing a groove 33 in the middle area of ​​the positive electrode sheet 201, that is, removing the positive electrode active material layer 31 in the middle area of ​​the positive electrode sheet 201, while keeping the middle area of ​​the negative electrode sheet 202 ungrooved, retaining the negative electrode active material layer 32 in the middle area of ​​the negative electrode sheet 202. As a result, in the laminated battery cell 200, the middle area is the area with the lowest lithium ion concentration, which greatly reduces the possibility of lithium deposition in the middle area during charging. In addition, since the negative electrode active material layer 32 in the middle area of ​​the negative electrode sheet 202 is retained, the portion of the negative electrode sheet 202 in the length and width direction outside the positive electrode sheet 201 in the overall battery cell is increased, that is, the overhang area is increased, and the overall safety of the battery can also be improved.

[0075] like Figure 5 As shown, in a possible implementation, the pole piece 100 further includes a ceramic layer 40 , and the ceramic layer 40 is disposed in the groove 33 .

[0076] The ceramic layer 40 is dense and insulating, does not conduct electrons, and isolates lithium ions.

[0077] The ceramic layer 40 is refilled in the area of ​​the positive electrode sheet 201 where the positive electrode active material layer 31 is removed, so as to enhance the strength of the positive electrode sheet 201 .

[0078] In a possible implementation, along the thickness direction of the current collector 10 , the orthographic projection of the ceramic layer 40 coincides with the orthographic projection of the groove 33 , that is, the groove 33 is covered by the ceramic layer 40 .

[0079] In a possible implementation, along the thickness direction of the current collector 10 , the surface of the ceramic layer 40 is flush with the surface of the active material layer 30 .

[0080] The ceramic layer 40 is flush with the active material layer 30 , and the thickness of the pole piece 100 does not need to be increased, thereby reducing the influence of the filling ceramic on the thickness direction of the laminated battery core 200 and improving the energy density.

[0081] like Figure 6 As shown, in a possible implementation, along the thickness direction of the current collector 10 , the depth of the groove 33 is less than the thickness of the active material layer 30 , that is, the groove 33 does not penetrate the active material layer 30 .

[0082] The active material layer 30 in the middle area of ​​the positive electrode sheet 201 is thinned, that is, the active material layer 30 is partially removed, thereby reducing the lithium ion concentration in the middle area. This can ensure that the energy density of the laminated battery cell 200 is maintained to the greatest extent under the premise that lithium deposition does not occur on the negative electrode sheet 202 even during large current charging and discharging.

[0083] like Figure 7 As shown, in a possible implementation, a ceramic layer 40 may be further provided in the groove 33 of the positive electrode sheet 201 that does not penetrate the active material layer 30 . The ceramic layer 40 is dense and insulating, does not conduct electrons, and isolates lithium ions, thereby improving the strength of the positive electrode sheet 201 .

[0084] like Figure 8 As shown, in a possible implementation, a groove 33 may also be provided on the negative electrode sheet 202 .

[0085] Optionally, a groove 33 is provided in the middle region of the positive electrode sheet 201, and the groove 33 penetrates the active material layer 30; a groove 33 is provided in the middle region of the negative electrode sheet 202, and the groove 33 does not penetrate the active material layer 30. At the same time, a ceramic layer 40 is provided in the grooves 33 of the positive electrode sheet 201 and the negative electrode sheet 202.

[0086] Depend on Figure 1It can be seen from the simulation results that during the charging process, the state of charge on the surface of the negative electrode sheet is greater than the surface close to the current collector. Therefore, by removing the negative active material layer 32 of the negative electrode sheet 202 away from the surface of the negative current collector 12 and backfilling the ceramic layer 40, since the ceramic layer 40 is dense, insulating, non-conductive and isolated from lithium ions, the lithium ions in the electrolyte will not diffuse from the area of ​​the ceramic layer 40 close to the electrolyte to the area of ​​the ceramic layer 40 close to the negative active material layer 32 for lithium ion deintercalation, thereby reducing the problem of lithium deposition in the middle area of ​​the negative electrode sheet 202.

[0087] like Fig. 9 As shown, in a possible implementation, a groove 33 is provided in the middle area of ​​the positive electrode sheet 201 and the negative electrode sheet 202, and the groove 33 penetrates the active material layer 30. At the same time, a ceramic layer 40 is provided in the groove 33 of the positive electrode sheet 201 and the negative electrode sheet 202.

[0088] By removing the active material layer 30 on the surface of the middle area of ​​the positive electrode sheet 201 and the negative electrode sheet 202 and backfilling the ceramic layer 40, since the ceramic layer 40 is dense, insulating, non-conductive and isolated from lithium ions, the lithium ions in the electrolyte will not be deintercalated in the middle area where the ceramic layer 40 is set, and only electrons will flow through the current collector 10. Therefore, the problem of lithium deposition in the middle area of ​​the negative electrode sheet 202 is fundamentally solved.

[0089] In a possible implementation, along the thickness direction of the current collector 10 , the total area of ​​the orthographic projection of the grooves 33 on the surface of the current collector 10 is S1 , and the area of ​​the surface of the current collector 10 is S.

[0090] S1 and S satisfy: 0.01≤S1 / S≤0.3.

[0091] Since it is necessary to open a groove 33 in the middle of the pole piece 100 to reduce the possibility of lithium deposition in the middle area during charging, the setting area of ​​the groove 33 cannot be too small, otherwise it cannot achieve the effect of reducing the lithium ion concentration in the area and cannot solve the problem of lithium deposition in the middle area. At the same time, since the setting of the groove 33 will reduce the use of the active material layer 30, the setting area of ​​the groove 33 cannot be too large, otherwise too much active material layer 30 will be removed, affecting the energy density of the single cell. Therefore, the setting area of ​​the groove 33 needs to meet 0.01≤S1 / S≤0.3.

[0092] The pole piece 100 provided in the embodiment of the present application includes a current collector 10 and an active material layer 30. Along the thickness direction of the current collector 10, the active material layer 30 is located on at least one side of the surface of the current collector 10; a groove 33 is provided on the active material layer 30, and the groove 33 is located in the area of ​​the current collector 10 where lithium is easily deposited.

[0093] By setting a groove 33 in the area of ​​the active material layer 30 where lithium is easily deposited, the active material in the area on the electrode 100 where lithium is easily deposited is removed, so that the lithium ion concentration in the area is reduced, and no or only a small amount of lithium ion is deintercalated, thereby reducing the possibility of lithium deposition in the electrode 100 during charging.

[0094] In addition, the embodiment of the present application also provides a laminated battery cell 200, including a positive electrode sheet 201, a separator 203 and a negative electrode sheet 202, the positive electrode sheet 201 and the negative electrode sheet 202 are stacked, the separator 203 is arranged between the positive electrode sheet 201 and the negative electrode sheet 202, and the positive electrode sheet 201 is the above-mentioned electrode sheet 100.

[0095] By setting a groove 33 in the middle area of ​​the positive electrode sheet 201, that is, removing the positive electrode active material layer 31 in the middle area of ​​the positive electrode sheet 201, the middle area of ​​the laminated battery cell 200 is the area with the lowest lithium ion concentration, which greatly reduces the possibility of lithium deposition in the middle area during charging.

[0096] Furthermore, the negative active material layer 32 in the middle area of ​​the negative electrode sheet 202 can be retained, and the length and width of the negative electrode sheet 202 in the overall battery cell beyond the positive electrode sheet 201 can be increased, that is, the overhang area is increased, and the overall safety of the battery can also be improved.

[0097] In a possible implementation, the negative electrode sheet 202 is the electrode sheet 100 described above.

[0098] In a possible implementation, the positive electrode current collector 11 is an aluminum foil. The positive electrode active material layer 31 includes a positive electrode active material, a conductive agent, and a binder.

[0099] In a possible implementation, the negative electrode current collector 12 is a copper foil. The negative electrode active material layer 32 includes a negative electrode active material, a conductive agent, and a binder.

[0100] By removing the active material layer 30 on the surface of the middle area of ​​the positive electrode sheet 201 and the negative electrode sheet 202, and refilling the ceramic layer 40 in the groove 33, since the ceramic layer 40 is dense, insulating, non-conductive and isolated from lithium ions, the lithium ions in the electrolyte will not be deintercalated in the middle area where the ceramic layer 40 is set, and only electrons will flow through the current collector 10. Therefore, the problem of lithium deposition in the middle area of ​​the negative electrode sheet 202 is fundamentally solved.

[0101] In addition, if Figures 10 to 12 As shown, the embodiment of the present application further provides a battery 300 , including a shell 301 and the above-mentioned laminated battery core 200 , wherein the laminated battery core 200 is located in the shell 301 .

[0102] The battery 300 further includes a positive electrode column 302 and a negative electrode column 303. The positive electrode column 302 and the negative electrode column 303 are respectively disposed on the housing 301.

[0103] In a possible implementation, the battery 300 includes a plurality of laminated battery cells 200 .

[0104] like Fig.11 and Fig.12 As shown, a positive pole 302 and a negative pole 303 are respectively provided on both sides of the length direction of the shell 301. The positive pole 302 on each side is connected to multiple positive pole ears 21 on the same side of the laminated battery core 200; and the negative pole 303 on each side is connected to multiple negative pole ears 22 on the same side of the laminated battery core 200.

[0105] In a possible implementation, the two positive poles 302 are respectively located on opposite sides of the shell 301 in the width direction, and the two positive poles 302 are centrally symmetrically arranged on the shell 301. The two negative poles 303 are respectively located on opposite sides of the shell 301 in the width direction, and the two negative poles 303 are centrally symmetrically arranged on the shell 301.

[0106] By arranging two positive poles 302 and negative pole 303 symmetrically on the shell 301, it is not necessary to distinguish the left and right sides of the battery 300 during use, which is convenient for use during assembly and improves assembly efficiency.

[0107] In other possible implementations, the two positive poles 302 may be located only on opposite sides of the housing 301 in the width direction, but the two positive poles 302 are not centrally symmetrically arranged on the housing 301. The two negative poles 303 may also be located only on opposite sides of the housing 301 in the width direction, but the two negative poles 303 are not centrally symmetrically arranged on the housing 301. This adapts to the installation requirements of the battery 300 for different devices.

[0108] The embodiment of the present application further provides an electric device, comprising an electric device and the battery 300 described in any of the above embodiments. The battery 300 is used to provide electric energy to the electric device.

[0109] The electrical equipment in the embodiments of the present application may be a vehicle, for example, a vehicle may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. Accordingly, the electrical device may be a driving mechanism of the vehicle or a control system of the vehicle.

[0110] In addition, the electrical equipment may also be other energy storage devices, such as mobile phones, portable devices, laptop computers, electric toys, electric tools, ships and spacecraft, etc., among which the spacecraft may include airplanes, rockets, space shuttles or spacecraft.

[0111] Since the electric device in this embodiment includes the battery 300 described in any of the above embodiments, the structure and beneficial effects of the electric device including the battery 300 will not be described in detail in this embodiment.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A pole piece used in a laminated battery cell, characterized in that: include: Current collector(10); Two pole ears (20), along the length direction of the current collector (10), the two pole ears (20) being arranged opposite to each other on two sides of the current collector (10); An active material layer (30), along the thickness direction of the current collector (10), the active material layer (30) being located on at least one side of the surface of the current collector (10); A groove (33) is provided on a side of the active material layer (30) away from the current collector (10), and along the length direction of the current collector (10), the groove (33) is located in the middle of the current collector (10); A ceramic layer (40), wherein the ceramic layer (40) is filled in the groove (33).

2. The pole piece according to claim 1, characterized in that: Along the width direction of the current collector (10), the groove (33) extends to one side of the current collector (10), and the notch of the groove (33) is located at the edge of the current collector (10) extending along the length direction.

3. The pole piece according to claim 1, characterized in that: Along the thickness direction of the current collector (10), the active material layers (30) are located on both sides of the surface of the current collector (10), and the grooves (33) are provided on both active material layers (30).

4. The pole piece according to claim 3, characterized in that: Along the thickness direction of the current collector (10), the grooves (33) on the two active material layers (30) are arranged opposite to each other.

5. The pole piece according to claim 1, characterized in that: Along the thickness direction of the current collector (10), the depth of the groove (33) is equal to the thickness of the active material layer (30).

6. The pole piece according to claim 1, characterized in that: Along the thickness direction of the current collector (10), the depth of the groove (33) is less than the thickness of the active material layer (30).

7. The pole piece according to claim 1, characterized in that: Along the thickness direction of the current collector (10), the orthographic projection of the ceramic layer (40) coincides with the orthographic projection of the groove (33).

8. The pole piece according to claim 1, characterized in that: Along the thickness direction of the current collector (10), the surface of the ceramic layer (40) is flush with the surface of the active material layer (30).

9. The pole piece according to any one of claims 1 to 6, characterized in that: Along the thickness direction of the current collector (10), the total area of ​​the orthographic projection of the groove (33) is S1, and the area of ​​the surface of the current collector (10) is S; S1 and S satisfy: 0.01≤S1 / S≤0.

3.

10. The pole piece according to claim 1, characterized in that: The two electrode tabs (20) are respectively located on opposite sides of the current collector (10) in a width direction.

11. The pole piece according to claim 1, characterized in that: The electrode sheet (100) is a positive electrode sheet (201), and the positive electrode sheet (201) comprises a positive electrode collector (11), a positive electrode ear (21) and a positive electrode active material layer (31). Along the length direction of the positive electrode collector (11), the two positive electrode ears (21) are arranged on two sides of the positive electrode collector (11) opposite to each other, and along the thickness direction of the positive electrode collector (11), the positive electrode active material layer (31) is located on at least one side of the surface of the positive electrode collector (11).

12. The pole piece according to claim 1, characterized in that: The electrode sheet (100) is a negative electrode sheet (202), and the negative electrode sheet (202) comprises a negative electrode current collector (12), a negative electrode ear (22), and a negative electrode active material layer (32). Along the length direction of the negative electrode current collector (12), the two negative electrode ears (22) are arranged on two sides of the negative electrode current collector (12) opposite to each other, and along the thickness direction of the negative electrode current collector (12), the negative electrode active material layer (32) is located on at least one side of the surface of the negative electrode current collector (12).

13. A laminated battery cell, characterized in that: The invention comprises a positive electrode sheet (201), a separator (203) and a negative electrode sheet (202), wherein the positive electrode sheet (201) and the negative electrode sheet (202) are stacked, the separator (203) is arranged between the positive electrode sheet (201) and the negative electrode sheet (202), and the positive electrode sheet (201) is a electrode sheet (100) according to any one of claims 1 to 11.

14. A laminated battery cell, characterized in that: The invention comprises a positive electrode sheet (201), a separator (203) and a negative electrode sheet (202); the positive electrode sheet (201) and the negative electrode sheet (202) are stacked, the separator (203) is arranged between the positive electrode sheet (201) and the negative electrode sheet (202), and the negative electrode sheet (202) is a electrode sheet (100) according to any one of claims 1 to 10 and 12.

15. A battery, characterized in that: It comprises a shell (301) and a laminated battery core (200) according to any one of claims 13 to 14, wherein the laminated battery core (200) is arranged in the shell (301).

16. An electrical equipment, characterized in that: Comprising the battery of claim 15.

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