Electrode sheet, stacked cell, and battery

Abstract

An electrode sheet, a stacked cell, and a battery. The electrode sheet comprises a current collector; and an active material layer, the active material layer being located on at least one side of a surface of the current collector in the thickness direction of the current collector, the active material layer being provided with a groove, and the groove being located in a region of the current collector prone to lithium deposition. Providing a groove in a region of the active material layer that is prone to lithium deposition, and removing the active material from the region of the electrode sheet that is prone to lithium deposition reduces lithium-ion concentration in that region without or with only minimal lithium-ion deintercalation, thereby lowering the likelihood of lithium deposition of the electrode sheet during a charging process.

Description

Pole piece, laminated core and battery

[0001] The present application claims priority to the Chinese patent application No. 202411088859.2, filed on August 9, 2024, and entitled “Pole piece, laminated core, battery and electric device”, the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of battery assembly manufacturing, and in particular to a pole piece, a laminated core and a battery. BACKGROUND

[0003] At present, for laminated batteries with large capacity and large length-width difference, in order to reduce the path of current flowing in the length direction, a scheme of both ends of the battery outputting positive and negative tabs can be adopted. Compared with the scheme of the battery with the same size but only one end outputting the tab, the flow path of the electrons is shortened by half, thereby the internal resistance of the battery can be reduced, the heat generation of the battery can be reduced, and the energy efficiency of the battery can be improved.

[0004] However, in the above-mentioned battery, the problem of lithium precipitation caused by overcharge is prone to occur, which affects the performance of the battery. SUMMARY

[0005] Therefore, the present disclosure provides a pole piece, a laminated core and a battery to solve the problem that the current density distribution of the local area of the pole piece is uneven, the local current density is too large to cause lithium precipitation caused by overcharge, and the performance of the battery is affected.

[0006] In one aspect, the present disclosure provides a pole piece for use in a laminated core, comprising:

[0007] a current collector;

[0008] an active material layer, the active material layer being located on at least one side of the surface of the current collector in the thickness direction of the current collector;

[0009] a groove is provided on the active material layer, and the groove is located in the region of the current collector prone to lithium precipitation.

[0010] In one possible implementation, in the length direction of the current collector, the groove is located in the middle of the current collector.

[0011] In one possible implementation, in the width direction of the current collector, the groove extends to one side of the current collector, and the groove opening is located at the edge of the current collector extending in the length direction.

[0012] In one possible implementation, in the thickness direction of the current collector, the active material layer is located on both sides of the surface of the current collector, and grooves are provided on both active material layers.

[0013] In a possible implementation, the grooves on the two active material layers are oppositely arranged along the thickness direction of the current collector.

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

[0015] In a possible implementation, the depth of the groove is less than the thickness of the active material layer along the thickness direction of the current collector.

[0016] In a possible implementation, the pole piece further includes a ceramic layer, and the ceramic layer is arranged in the groove.

[0017] In a possible implementation, the front projection of the ceramic layer coincides with the front projection of the groove along the thickness direction of the current collector.

[0018] In a possible implementation, the surface of the ceramic layer is flush with the surface of the active material layer along the thickness direction of the current collector.

[0019] In a possible implementation, the total area of the front projection of the groove is S1, and the area of the surface of the current collector is S along the thickness direction of the current collector.

[0020] S1 and S satisfy: 0.01≤S1 / S≤0.3.

[0021] In a possible implementation, the pole piece further includes two pole tabs, and the two pole tabs are oppositely arranged on two sides of the current collector along the length direction of the current collector.

[0022] In a possible implementation, the two pole tabs are located on opposite sides in the width direction of the current collector.

[0023] In a possible implementation, the pole piece is a positive pole piece, the positive pole piece includes a positive current collector, a positive pole tab, and a positive active material layer, the two positive pole tabs are oppositely arranged on two sides of the positive current collector along the length direction of the positive current collector, and the positive active material layer is located on at least one side of the surface of the positive current collector along the thickness direction of the positive current collector.

[0024] In a possible implementation, the pole piece is a negative pole piece, the negative pole piece includes a negative current collector, a negative pole tab, and a negative active material layer, the two negative pole tabs are oppositely arranged on two sides of the negative current collector along the length direction of the negative current collector, and the negative active material layer is located on at least one side of the surface of the negative current collector along the thickness direction of the negative current collector.

[0025] In another aspect, the present disclosure provides a jelly-roll, including a positive pole piece, a separator, and a negative pole piece, the positive pole piece and the negative pole piece are stacked, the separator is arranged between the positive pole piece and the negative pole piece, and the positive pole piece is the pole piece described above.

[0026] In a possible implementation, the negative electrode sheet is the electrode sheet described above.

[0027] In another aspect, the disclosure provides a battery, comprising a shell and the jelly-roll described above, the jelly-roll being arranged in the shell.

[0028] In yet another aspect, the disclosure provides an electrical device, comprising the battery described above.

[0029] The electrode sheet, jelly-roll, battery and electrical device provided by the disclosure remove the active material in the region of the electrode sheet where lithium is prone to be deposited by arranging a groove in the region of the active material layer where lithium is prone to be deposited, so that the lithium ion concentration in the region is reduced, and a small amount of lithium ions is deintercalated or not deintercalated, so that the problem of overcharge-induced lithium deposition in the region where the SOC (state of charge) of the electrode sheet is the highest is reduced. In this way, the performance of the battery with the electrode sheet is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the disclosure, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0031] FIG. 1 is a simulation result diagram of the local electrode material state of charge at the end of the charging of the electrode sheet;

[0032] FIG. 2 is a structural schematic diagram of a jelly-roll provided by an embodiment of the disclosure;

[0033] FIG. 3 is a structural schematic diagram of a positive electrode sheet of the jelly-roll shown in FIG. 2;

[0034] FIG. 4 is a structural schematic diagram of a negative electrode sheet of the jelly-roll shown in FIG. 2;

[0035] FIG. 5 is a structural schematic diagram of an electrode sheet provided by an embodiment of the disclosure;

[0036] FIG. 6 is a structural schematic diagram of a jelly-roll provided by an embodiment of the disclosure;

[0037] FIG. 7 is a structural schematic diagram of a jelly-roll provided by an embodiment of the disclosure;

[0038] FIG. 8 is a structural schematic diagram of a jelly-roll provided by an embodiment of the disclosure;

[0039] FIG. 9 is a structural schematic diagram of a jelly-roll provided by an embodiment of the disclosure;

[0040] FIG. 10 is a structural schematic diagram of a battery provided by an embodiment of the disclosure;

[0041] Fig. 11 is a front view of the battery shown in Fig. 10;

[0042] Fig. 12 is a side view of the battery shown in Fig. 10.

[0043] BRIEF DESCRIPTION OF DRAWINGS 100 - tab; 10 - current collector; 11 - positive current collector; 12 - negative current collector; 20 - tab; 21 - positive tab; 22 - negative tab; 30 - active material layer; 31 - positive active material layer; 32 - negative active material layer; 33 - groove; 40 - ceramic layer; 200 - jelly-roll; 201 - positive tab; 202 - negative tab; 203 - separator; 300 - battery; 301 - case; 302 - positive post; 303 - negative post. DETAILED DESCRIPTION

[0044] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described in more detail below with reference to the drawings of the preferred embodiments of the present disclosure. In the drawings, the same or similar notations represent the same or similar components or components with the same or similar functions throughout. The described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present disclosure, and cannot be understood as a limitation of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present disclosure. The embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0045] In the description of the present disclosure, it should be noted that unless explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixed connection, or indirect connection through an intermediate medium, or internal communication of two elements or interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0046] In the description of the present disclosure, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present disclosure.

[0047] The terms "first", "second", "third" (if present) in the description and claims of this disclosure and the above drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence.

[0048] In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or display comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or displays.

[0049] Lithium-ion batteries deposit lithium dendrites on the surface of the electrode sheet during charging and discharging due to low negative electrode potential, insufficient lithium intercalation space and other reasons, reducing the cycle life and energy efficiency of the battery. At present, for large-capacity, large-width-difference large-capacity stacked batteries, in order to reduce the path of current flowing in the length direction, a scheme of having positive and negative tabs at both ends of the battery can be used. Compared with the scheme of having a battery with the same size but only one end of the tab, the flow path of the electrons is shortened by half, thereby reducing the internal resistance of the battery, reducing the heat generation of the battery, and improving the energy efficiency of the battery.

[0050] However, due to the internal resistance between the current collector and the dressing, it is easy to cause uneven distribution of current density and potential in the length direction of the electrode sheet, thereby causing inconsistent intercalation state of lithium in each region during charging, and easily causing the problem of excessive charging and lithium precipitation, affecting the performance of the battery.

[0051] After repeated thinking and verification, the inventors found that, as shown in FIG. 1, according to the simulation results, due to the tabs at both ends of the electrode sheet, the SOC (state of charge) in the middle region of the electrode sheet is the highest, and the problem of excessive charging and lithium precipitation is prone to occur, wherein x is the length direction of the electrode sheet, y is the width direction of the electrode sheet, and z is the height direction of the electrode sheet. If the dressing in the middle region of the electrode sheet is removed, so that the lithium ion concentration in this region is low, and no or only a small amount of lithium ion deintercalation is performed, the possibility of lithium precipitation in this region can be reduced. At the same time, the removed dressing can be backfilled with dense ceramic, which can not only enhance the strength of the electrode sheet, but also isolate lithium ions, further reduce the possibility of lithium precipitation, and help improve the performance of the battery with the electrode sheet.

[0052] Therefore, the present disclosure provides an electrode sheet, comprising: a current collector; an active material layer located on at least one side of the surface of the current collector in the thickness direction of the current collector; and a groove provided on the active material layer, the groove being located in a region prone to lithium precipitation of the current collector.

[0053] By arranging the groove in the region of the active material layer where lithium is prone to be deposited, removing the active material in the region of the pole piece where lithium is prone to be deposited, the lithium ion concentration of the region is reduced, and the lithium ion is not deintercalated or only a small amount of lithium ion is deintercalated, thereby reducing the possibility of lithium deposition of the pole piece during charging.

[0054] The content of the present disclosure will be described in detail below with reference to the drawings, so that those skilled in the art can more clearly and specifically understand the content of the present disclosure.

[0055] FIG. 1 is a simulation result diagram of the local electrode material state of charge at the end of charging of the electrode piece. FIG. 2 is a structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure. FIG. 3 is a structural schematic diagram of a positive pole piece of the stacked cell shown in FIG. 2. FIG. 4 is a structural schematic diagram of a negative pole piece of the stacked cell shown in FIG. 2. FIG. 5 is a structural schematic diagram of a pole piece provided by an embodiment of the present disclosure. FIG. 6 is a structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure. FIG. 7 is a structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure. FIG. 8 is a structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure. FIG. 9 is a structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure. FIG. 10 is a structural schematic diagram of a battery provided by an embodiment of the present disclosure. FIG. 11 is a front view of the battery shown in FIG. 10. FIG. 12 is a side view of the battery shown in FIG. 10.

[0056] As shown in FIG. 2 and FIG. 3, the pole piece 100 provided by an embodiment of the present disclosure is applied to a stacked cell 200. The stacked cell 200 includes a positive pole piece 201, a negative pole piece 202 and a separator 203. The positive pole piece 201 and the negative pole piece 202 are stacked and arranged, and the separator 203 is arranged between the positive pole piece 201 and the negative pole piece 202. Among them, the positive pole piece 201 is the pole piece 100 provided by an embodiment of the present disclosure.

[0057] The pole piece 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 respectively arranged on the current collector 10.

[0058] The tab 20 is two, and the two tabs 20 are oppositely arranged on both sides of the current collector 10 along the length direction of the current collector 10, and extend out of the current collector 10.

[0059] 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.

[0060] As shown in FIG. 2 and FIG. 3, 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.

[0061] 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 prone to be deposited.

[0062] In a possible implementation, the groove 33 is located in the middle of the current collector 10 along the length direction of the current collector 10.

[0063] In a possible implementation, the groove 33 is formed by intermittently coating the active material layer 30 on the current collector 10 or by adding a gasket to the coating head.

[0064] The positive electrode tab 201 includes a positive electrode current collector 11, a positive electrode tab 21, and a positive electrode active material layer 31. Two positive electrode tabs 21 are oppositely arranged on both sides of the positive electrode current collector 11 along the length direction of the positive electrode current collector 11. The positive electrode active material layer 31 is located on at least one side of the surface of the positive electrode current collector 11 along the thickness direction of the positive electrode current collector 11.

[0065] As shown in FIG. 3, 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 groove 33 is located at the edge of the current collector 10 extending along the length direction.

[0066] 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.

[0067] As shown in FIG. 2, in a possible implementation, the active material layer 30 is located on both sides of the surface of the current collector 10 along the thickness direction of the current collector 10, and the groove 33 is arranged on both the active material layers 30.

[0068] In a possible implementation, the grooves 33 on the two active material layers 30 are oppositely arranged along the thickness direction of the current collector 10.

[0069] In a possible implementation, the depth of the groove 33 is equal to the thickness of the active material layer 30 along the thickness direction of the current collector 10, that is, the groove 33 penetrates the active material layer 30, and the surface of the current collector 10 serves as the bottom of the groove.

[0070] In a possible implementation, the shape and number of the groove 33 are not limited. The groove 33 can be a plurality of discontinuous blind holes or one or more continuous line grooves, as long as the groove 33 is located in the region of the current collector 10 where lithium precipitation is prone to occur. In the embodiment of the present disclosure, since the tabs 20 are arranged on both sides, the middle region of the current collector 10 is the region where lithium precipitation is prone to occur, and the groove 33 is located in the middle of the current collector 10.

[0071] As shown in FIG. 3, in a possible implementation, the two tabs 20 are respectively located on the opposite sides of the width direction of the current collector 10, that is, the two tabs 20 are centrally symmetrically arranged on the tab 100.

[0072] By arranging two tabs 20 on the center of the pole piece 100, the left and right of the pole piece 100 can be distinguished in use, facilitating the use in assembly and improving the efficiency of assembly.

[0073] As shown in FIG. 4, the negative pole piece 202 includes a negative current collector 12, a negative tab 22, and a negative active material layer 32. Along the length direction of the negative current collector 12, two negative tabs 22 are arranged on the two sides of the negative current collector 12, and along the thickness direction of the negative current collector 12, the negative active material layer 32 is located on at least one side of the surface of the negative current collector 12.

[0074] The negative active material layer 32 is not provided with a groove 33.

[0075] By arranging the groove 33 in the middle region of the positive pole piece 201, i.e. removing the positive active material layer 31 in the middle region of the positive pole piece 201, while keeping the middle region of the negative pole piece 202 not grooved and retaining the negative active material layer 32 in the middle region of the negative pole piece 202. Thus, in the jelly-roll battery 200, the middle region is the region with the smallest lithium ion concentration, greatly reducing the possibility of lithium deposition in the middle region during charging. And because the negative active material layer 32 in the middle region of the negative pole piece 202 is retained, the overhang area of the negative pole piece 202 in the length and width directions of the whole battery is increased, i.e. the overhang area is increased, and the safety of the whole battery can also be improved.

[0076] As shown in FIG. 5, in a possible implementation, the pole piece 100 further includes a ceramic layer 40, which is arranged in the groove 33.

[0077] The ceramic layer 40 is dense, insulating, does not conduct electrons, and is isolated from lithium ions.

[0078] In the region where the positive active material layer 31 of the positive pole piece 201 is removed, the ceramic layer 40 is backfilled, which can enhance the strength of the positive pole piece 201.

[0079] In a possible implementation, along the thickness direction of the current collector 10, the orthogonal projection of the ceramic layer 40 coincides with the orthogonal projection of the groove 33, i.e. the groove 33 is covered by the ceramic layer 40.

[0080] 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.

[0081] The ceramic layer 40 is flush with the active material layer 30, which can not increase the thickness of the pole piece 100, thereby reducing the impact of ceramic filling on the thickness direction of the jelly-roll battery 200 and improving the energy density.

[0082] As shown in FIG. 6, in one possible implementation, the depth of the groove 33 is less than the thickness of the active material layer 30 along the thickness direction of the current collector 10, i.e., the groove 33 does not penetrate the active material layer 30.

[0083] The active material layer 30 in the middle region of the positive electrode sheet 201 is thinned, i.e., the active material layer 30 is partially removed, which reduces the lithium ion concentration in the middle region, so that the jelly-roll battery cell 200 can maximize the energy density of the jelly-roll battery cell 200 while meeting the condition that lithium deposition does not occur on the negative electrode sheet 202 even when a large current is charged and discharged.

[0084] As shown in FIG. 7, in one possible implementation, the ceramic layer 40 can also be arranged 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, insulating, does not conduct electrons, and is isolated from lithium ions, thereby improving the strength of the positive electrode sheet 201.

[0085] As shown in FIG. 8, in one possible implementation, the groove 33 can also be arranged on the negative electrode sheet 202.

[0086] Optionally, the groove 33 is arranged in the middle region of the positive electrode sheet 201, and the groove 33 penetrates the active material layer 30; the groove 33 is arranged in the middle region of the negative electrode sheet 202, and the groove 33 does not penetrate the active material layer 30. Meanwhile, the ceramic layer 40 is arranged in the groove 33 of the positive electrode sheet 201 and the negative electrode sheet 202.

[0087] As can be known from the simulation result of FIG. 1, during the charging process, the state of charge of the surface of the negative electrode sheet is greater than that of the surface close to the current collector. Therefore, by removing the negative electrode active material layer 32 away from the surface of the negative electrode current collector 12 of the negative electrode sheet 202 and backfilling the ceramic layer 40, since the ceramic layer 40 is dense, insulating, does not conduct electrons, and is isolated from lithium ions, lithium ions in the electrolyte cannot diffuse from the region of the ceramic layer 40 close to the electrolyte to the region of the ceramic layer 40 close to the negative electrode active material layer 32 to deintercalate lithium ions, thereby reducing the problem of lithium deposition in the middle region of the negative electrode sheet 202.

[0088] As shown in FIG. 9, in one possible implementation, the groove 33 is arranged in the middle region of the positive electrode sheet 201 and the negative electrode sheet 202, and the groove 33 penetrates the active material layer 30. Meanwhile, the ceramic layer 40 is arranged in the groove 33 of the positive electrode sheet 201 and the negative electrode sheet 202.

[0089] By removing the active material layer 30 on the surface of the middle region 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, not conductive to electrons and isolates lithium ions, lithium ions in the electrolyte will not deintercalate lithium ions in the middle region where the ceramic layer 40 is provided, and only flow over the current collector 10. Therefore, the problem of lithium deposition in the middle region of the negative electrode sheet 202 is fundamentally solved.

[0090] In one possible implementation, the total area of the projection of the groove 33 on the surface of the current collector 10 in the thickness direction of the current collector 10 is S1, and the area of the surface of the current collector 10 is S.

[0091] S1, S satisfy: 0.01≤S1 / S≤0.3.

[0092] Since the groove 33 needs to be provided in the middle of the electrode sheet 100 to reduce the possibility of lithium deposition in the middle region during charging, the setting area of the groove 33 cannot be too small, otherwise the effect of reducing the lithium ion concentration in the region cannot be achieved, and the problem of lithium deposition in the middle region cannot be solved. At the same time, since the provision 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 battery cell. Therefore, the setting area of the groove 33 needs to satisfy 0.01≤S1 / S≤0.3.

[0093] The electrode sheet 100 provided by the embodiment of the present disclosure includes a current collector 10 and an active material layer 30, and the active material layer 30 is located on at least one side of the surface of the current collector 10 in the thickness direction of the current collector 10. The active material layer 30 is provided with a groove 33, and the groove 33 is located in a region where the current collector 10 is prone to lithium deposition.

[0094] By providing the groove 33 in the region where the active material layer 30 is prone to lithium deposition, the active material in the region prone to lithium deposition on the electrode sheet 100 is removed, so that the lithium ion concentration in the region is reduced, and only a small amount of lithium ion deintercalation is performed, thereby reducing the possibility of lithium deposition of the electrode sheet 100 during charging.

[0095] In addition, the embodiment of the present disclosure also provides a stacked battery cell 200, which includes 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.

[0096] By providing the groove 33 in the middle region of the positive electrode sheet 201, i.e., removing the positive active material layer 31 in the middle region of the positive electrode sheet 201, so that in the stacked battery cell 200, the middle region is the region with the smallest lithium ion concentration, and the possibility of lithium deposition in the middle region during charging is greatly reduced.

[0097] And also can keep the negative active material layer 32 in the middle region of the negative sheet 202, increase the length and width direction of the negative sheet 202 in the overall battery, that is, increase the overhang area, and also improve the safety of the overall battery.

[0098] In a possible implementation, the negative sheet 202 is the sheet 100 described above.

[0099] In a possible implementation, the positive current collector 11 is an aluminum foil. The positive active material layer 31 includes a positive active material, a conductive agent, and a binder.

[0100] In a possible implementation, the negative current collector 12 is a copper foil. The negative active material layer 32 includes a negative active material, a conductive agent, and a binder.

[0101] By removing the active material layer 30 on the surface of the middle region of the positive sheet 201 and the negative sheet 202, and backfilling the ceramic layer 40 in the groove 33, since the ceramic layer 40 is dense, insulating, not conductive to electrons, and isolates lithium ions, lithium ions in the electrolyte will not be deintercalated in the middle region where the ceramic layer 40 is arranged, and only flow through the electrons on the current collector 10, thus fundamentally solving the problem of lithium deposition in the middle region of the negative sheet 202.

[0102] In addition, as shown in FIGS. 10-12, the embodiment of the present disclosure further provides a battery 300, which includes a shell 301 and the above-mentioned jelly-roll battery 200, and the jelly-roll battery 200 is located in the shell 301.

[0103] The battery 300 further includes a positive pole 302 and a negative pole 303. The positive pole 302 and the negative pole 303 are respectively arranged on the shell 301.

[0104] In a possible implementation, the battery 300 includes a plurality of jelly-roll batteries 200.

[0105] As shown in FIGS. 11 and 12, on both sides of the length direction of the shell 301, one positive pole 302 and one negative pole 303 are respectively arranged. Among them, the positive pole 302 on each side is connected with the plurality of positive tabs 21 on the same side of the jelly-roll battery 200; and the negative pole 303 on each side is connected with the plurality of negative tabs 22 on the same side of the jelly-roll battery 200.

[0106] In a possible implementation, the two positive poles 302 are respectively located on the opposite sides in the width direction of the shell 301, and the two positive poles 302 are centrally symmetrically arranged on the shell 301. The two negative poles 303 are respectively located on the opposite sides in the width direction of the shell 301, and the two negative poles 303 are centrally symmetrically arranged on the shell 301.

[0107] By arranging the two positive poles 302 and the two negative poles 303 on the shell 301 in a central symmetry, the left and right of the battery 300 can be distinguished in use, which facilitates the use in assembly and improves the assembly efficiency.

[0108] In other possible implementations, the two positive poles 302 can also be located only on opposite sides of the shell 301 in the width direction, but the two positive poles 302 are not arranged in a central symmetry on the shell 301. The two negative poles 303 can also be located only on opposite sides of the shell 301 in the width direction, but the two negative poles 303 are not arranged in a central symmetry on the shell 301. Thus, the installation requirements of different devices on the battery 300 can be adapted.

[0109] The disclosed embodiments also provide a power-using device, which includes a power-using apparatus and the battery 300 described in any of the above embodiments. The battery 300 is used to provide power for the power-using apparatus.

[0110] The power-using device in the disclosed embodiments can be a vehicle, for example, the vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric vehicle, a hybrid electric vehicle or a range extended vehicle, etc. Correspondingly, the power-using apparatus can be a driving mechanism of the vehicle, or a control system of the vehicle.

[0111] In addition, the power-using device can also be other energy storage devices, such as a mobile phone, a portable device, a notebook computer, an electric toy, an electric tool, a ship and a spacecraft, etc. The spacecraft can include an airplane, a rocket, a space shuttle or a spaceship.

[0112] Since the power-using device in the disclosed embodiments includes the battery 300 described in any of the above embodiments, the power-using device includes the structure and advantages of the battery 300, which will not be described here again.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limit them.

Claims

1. A pole piece for use in a jelly-roll battery, characterized in that, The electrode piece (100) comprises: a current collector (10); an active material layer (30) located on at least one side of the surface of the current collector (10) in the thickness direction of the current collector (10); the active material layer (30) is provided with a groove (33), and the groove (33) is located in a region of the current collector (10) prone to lithium precipitation.

2. The pole piece of claim 1, wherein In the length direction of the current collector (10), the groove (33) is located in the middle of the current collector (10).

3. The pole piece of claim 2, wherein In the width direction of the current collector (10), the groove (33) extends to one side of the current collector (10), and the opening of the groove (33) is located at the edge of the current collector (10) extending in the length direction.

4. The pole piece according to any one of claims 1 to 3, characterized in that In the thickness direction of the current collector (10), the active material layer (30) is located on both sides of the surface of the current collector (10), and the groove (33) is provided on both the active material layers (30).

5. The pole piece of claim 4, wherein In the thickness direction of the current collector (10), the grooves (33) on the two active material layers (30) are oppositely arranged.

6. The pole piece of any one of claims 1-5, wherein, In 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).

7. The pole piece of any of claims 1-6, wherein, In 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).

8. The pole piece of any of claims 1-7, wherein, The electrode piece (100) further comprises a ceramic layer (40) arranged in the groove (33).

9. The pole piece of claim 8, wherein, In the thickness direction of the current collector (10), the orthogonal projection of the ceramic layer (40) coincides with the orthogonal projection of the groove (33).

10. The pole piece of claim 8, wherein, In 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).

11. The pole piece of any of claims 1-10, wherein, In the thickness direction of the current collector (10), the total area of the orthogonal 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.

12. The pole piece of any of claims 2-11, wherein, The electrode piece further comprises two tabs (20), and the two tabs (20) are oppositely arranged on both sides of the current collector (10) in the length direction of the current collector (10).

13. The pole piece of claim 12, wherein, The two tabs (20) are respectively located on opposite sides in the width direction of the current collector (10).

14. The pole piece of claim 12, wherein, The electrode piece (100) is a positive electrode piece (201), which comprises a positive current collector (11), a positive tab (21), and a positive active material layer (31), and two positive tabs (21) are oppositely arranged on both sides of the positive current collector (11) in the length direction of the positive current collector (11), and the positive active material layer (31) is located on at least one side of the surface of the positive current collector (11) in the thickness direction of the positive current collector (11).

15. The pole piece of claim 12, wherein, The pole piece (100) is a negative pole piece (202), the negative pole piece (202) comprises a negative current collector (12), a negative tab (22) and a negative active material layer (32), along the length direction of the negative current collector (12), two negative tabs (22) are oppositely arranged on both sides of the negative current collector (12), and the negative active material layer (32) is located on at least one side of the surface of the negative current collector (12) along the thickness direction of the negative current collector (12).

16. A jelly-roll cell characterized by, The battery cell (200) comprises a positive pole piece (201), a separator (203) and a negative pole piece (202), the positive pole piece (201) and the negative pole piece (202) are stacked, and the separator (203) is arranged between the positive pole piece (201) and the negative pole piece (202), and the positive pole piece (201) is the pole piece (100) according to any one of claims 1-14.

17. The jellyroll of claim 16, wherein, The negative pole piece (202) is the pole piece (100) according to any one of claims 1-13 and 15.

18. A battery, characterized by The battery cell (200) comprises a shell (301) and the pole piece (100) according to any one of claims 16-17, and the pole piece (100) is arranged in the shell (301).

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