Battery pole piece, pole core, battery, electric equipment and preparation method of battery pole piece

Abstract

The embodiment of the invention provides a battery pole piece, a pole core, a battery, electric equipment and a preparation method of the battery pole piece, and relates to the technical field of batteries, the battery pole piece comprises a current collector, the current collector comprises a tab and a main body part, the tab is located on one side of the main body part, and a filler groove is formed in the main body part; and the dressing layer is positioned on at least one surface of the main body part and is filled in the filler groove, so that the surface of the dressing layer or the current collector is smooth, and compared with a traditional battery pole piece, the use amount of the current collector can be effectively reduced, and the cost of the battery pole piece is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pole piece, a pole core, a battery, an electrical device, and a method for preparing a battery pole piece. Background Art

[0002] The pole piece is an important part of the battery. It is a combination of the carrier of the positive electrode and the negative electrode and the conductive material. The pole piece usually includes a metal current collector and an active material layer, and the active material layer is coated on the metal current collector.

[0003] At present, when the active material layer is coated on the metal current collector, only one side of the metal current collector is left blank as the pole ear. The size of the pole ear is small, so the length and width of the metal current collector are basically equal to the length and width of the active material layer, resulting in a large amount of metal current collector and high cost of metal current collector, which makes the production cost of the pole piece also high. Summary of the invention

[0004] The embodiments of the present application provide a battery pole piece, a pole core, a battery, an electrical device and a method for preparing a battery pole piece, so as to achieve the effect of reducing the production cost of the battery pole piece.

[0005] In a first aspect, an embodiment of the present application provides a battery electrode, comprising:

[0006] A current collector, the current collector comprising a tab and a main body, the tab being located at one side of the main body, and a filling groove being provided on the main body;

[0007] A dressing layer is located on at least one surface of the main body and is filled in the filling groove to make the surface of the dressing layer or the current collector smooth.

[0008] In a possible implementation manner, an extending direction of the filling groove is the same as an extending direction of the main body.

[0009] In a possible implementation, at least two filling grooves are arranged side by side at one end of the main body along the width direction of the main body, and a spacing portion is provided between adjacent filling grooves.

[0010] In a possible implementation manner, the width of the spacer is the same as that of the filling groove.

[0011] In a possible implementation manner, an extension direction of the electrode tab is the same as an extension direction of the filling slot, and the electrode tab and the filling slot are respectively arranged at two ends of the main body.

[0012] In a possible implementation manner, the sum of the length of the electrode tab and the length of the filling slot is equal to the length of the current collector.

[0013] In a possible implementation, the width of the filling groove is 0.1 mm-1000 mm.

[0014] In a possible implementation, the width of the filling groove is 0.1 mm-10 mm.

[0015] In a possible implementation, an insulating layer is further included, and an isolation portion is provided between the main body and the tab, a portion of the insulating layer covers the isolation portion, and another portion of the insulating layer covers a portion of the active dressing surface.

[0016] In a possible implementation, a separator is further included, and the separator is connected to a surface of the current collector facing away from the dressing layer or a surface of the dressing layer facing away from the current collector.

[0017] In a second aspect, an embodiment of the present application provides a method for preparing a battery electrode sheet, comprising:

[0018] A current collector is provided, the current collector comprising a tab and a main body, the tab is located on one side of the extension direction of the main body, and a filling groove is provided on the main body;

[0019] An active dressing is coated on the current collector, the active dressing is coated on at least one surface of the main body portion, and is filled in the filling groove to form a dressing layer.

[0020] In a possible implementation manner, providing a current collector includes:

[0021] A substrate is provided, and the substrate is cut to form two current collectors on the substrate.

[0022] In a possible embodiment, the main bodies of the two current collectors formed by cutting the substrate are rotationally symmetrical, and the filling groove on one of the two current collectors matches the spacer on the other, so that when the spacer and the filling groove of the two current collectors are assembled with each other, the length of the formed sheet is the same as the length of the substrate.

[0023] In a possible implementation, the method further includes: providing a diaphragm, disposing the diaphragm on one side of the current collector and connecting to a surface of the current collector facing away from the dressing layer or a surface of the dressing layer facing away from the current collector.

[0024] In a possible implementation, providing a diaphragm includes:

[0025] Provide the diaphragm, wherein one side of the diaphragm used for connecting with the current collector or the dressing layer is provided with hot melt adhesive, and the diaphragm is placed under the template, wherein the template is provided with a through groove, the length and width of the through groove are the same as the length and width of the main body, and the side wall of the through groove is provided with a card slot, the shape of the card slot is adapted to the shape of the pole ear;

[0026] Providing the current collector, and positioning the main body in the through groove, and positioning the tab in the clamping groove;

[0027] The active dressing is provided, filled in the through groove, baked, and rolled flat, so that the separator and the active dressing are both adhered to the current collector to form the battery pole piece.

[0028] In the third aspect, an embodiment of the present application provides a pole core, comprising a stacked positive pole sheet and a negative pole sheet, wherein at least one of the positive pole sheet and the negative pole sheet is the battery pole sheet described in any one of the first aspect, or a battery pole sheet prepared by the method for preparing the battery pole core described in any one of the second aspect.

[0029] In a possible embodiment, both the positive electrode sheet and the negative electrode sheet are the battery sheets described in any one of the first aspect, or the battery sheets prepared by the battery core preparation method described in any one of the second aspect, and the projection of the active dressing of the positive electrode sheet in the stacking direction is located within the active dressing of the negative electrode sheet.

[0030] In a possible implementation, at least two positive electrode sheets and the negative electrode sheet are included, and the positive electrode sheet and the negative electrode sheet are arranged at intervals.

[0031] In a fourth aspect, an embodiment of the present application provides a battery, comprising a housing and the pole core described in the third aspect, wherein the pole core is located inside the housing.

[0032] In a fifth aspect, an embodiment of the present application provides an electrical device, comprising a device body and the battery described in the fourth aspect, wherein the battery is used to supply power to the device body.

[0033] In the battery pole pieces, pole cores, batteries, electrical equipment and methods for preparing battery pole pieces provided in the embodiments of the present application, a filling groove is provided on the main body of the current collector of the battery pole piece, and the dressing layer is directly filled in the filling groove and is located on at least one surface of the main body. When such a battery pole piece is used in a battery, the capacity is close to that of a traditional battery, but the cost of the dressing layer made of the same volume of active dressing is significantly lower than the cost of the current collector, thereby effectively reducing the production cost of the battery pole piece while ensuring the capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0035] Figure 1 A schematic diagram of the structure of a battery electrode provided in an embodiment of the present application;

[0036] Figure 2 A schematic structural diagram of a substrate used in a method for preparing a battery electrode is provided for an embodiment of the present application;

[0037] Figure 3 for Figure 2 A schematic diagram of the structure of the current collector obtained after cutting the substrate in the method for preparing the battery pole piece;

[0038] Figure 4 A schematic structural diagram of a template in a method for preparing a battery electrode is provided for an embodiment of the present application;

[0039] Figure 5 Another structural schematic diagram of a template in a method for preparing a battery electrode is provided for an embodiment of the present application.

[0040] Reference numerals:

[0041] 10 - substrate, 20 - template, 21 - through groove, 22 - card groove, 100 - current collector, 110 - main body, 120 - pole ear, 130 - filling groove, 200 - dressing layer, 300 - diaphragm.

[0042] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0044] For batteries with a single-sided pole or terminal, it is usually necessary to leave a blank space on one side of the current collector as the pole ear during design. That is, the area of ​​the entire battery pole is basically the same as the area of ​​the current collector. The current collector is generally made of more expensive materials such as metal foil, which leads to a higher overall cost of the battery pole and thus a higher battery cost.

[0045] In this regard, an embodiment of the present application provides a battery electrode, in which a filling groove is opened on the current collector, and the filling groove is filled with an active dressing. The cost of the same volume of active dressing is much lower than the cost of the current collector, thereby effectively reducing the production cost of the battery electrode while ensuring the battery capacity, thereby reducing the cost of the battery.

[0046] It can be understood that the battery electrode in the embodiment of the present application can be used as a positive electrode or a negative electrode, as long as the type of active dressing is adjusted accordingly.

[0047] At the same time, the positive and negative electrode sheets made of battery electrodes can be stacked in sequence and wrapped with a diaphragm to form an electrode core, and the electrode core can be assembled with an electrolyte, a casing and other auxiliary components to form a battery. The battery can be used in various electrical equipment that needs to be powered by batteries, including but not limited to electric vehicles, household appliances, electric ships, aviation equipment and other equipment.

[0048] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0049] In some embodiments of the present application, the battery includes an outer shell, a positive terminal, a negative terminal and a pole core, the pole core and the electrolyte are both located in the outer shell, the pole core and the electrolyte can undergo electrochemical reactions to achieve energy storage and release, and the positive terminal and the negative terminal are both connected to the pole core.

[0050] Among them, according to different types of batteries, the shell can be made of different materials. For example, the shell can be a hard shell, including but not limited to hard plastic shell, aluminum shell, steel shell, etc. The battery shell can also be a soft package, including but not limited to composite aluminum-plastic film, polypropylene, etc., which can be determined according to actual conditions.

[0051] It is understandable that the electrolyte plays a role in conducting ions between the positive electrode plate and the negative electrode plate. A suitable electrolyte can be selected according to actual conditions, and this embodiment does not limit it.

[0052] Among them, the electrode core includes a positive electrode sheet and a negative electrode sheet stacked to form an electrode sheet group, and a diaphragm wrapped outside the electrode sheet group. Of course, the projection of the dressing layer 200 of the positive electrode sheet in the stacking direction is located within the dressing layer 200 of the negative electrode sheet. It can be understood that the ratio of the capacity of the dressing layer 200 of the negative electrode sheet per unit area to the capacity of the dressing layer 200 of the positive electrode sheet per unit area is >1.0, so as to ensure that the electrochemical reaction can proceed normally.

[0053] It is understandable that the diaphragm can be a porous structure diaphragm with good chemical stability and mechanical stability, as long as it can meet the use requirements of the battery pole piece. At the same time, the surface of the diaphragm can also be coated with functional coatings such as PVDF glue and alumina ceramics to improve the performance of the diaphragm in battery products.

[0054] The number of positive pole sheets and negative pole sheets can be adjusted according to actual usage requirements. When at least two positive pole sheets and at least two negative pole sheets are provided, the positive pole sheets and the negative pole sheets can be arranged in sequence and spaced apart.

[0055] In addition, the positive electrode plates and negative electrode plates used in the electrode core are both battery plates in the following embodiments. It is only necessary to replace the active dressing corresponding to the dressing layer 200 with the positive electrode active material corresponding to the positive electrode plate, or the negative electrode active material corresponding to the negative electrode plate.

[0056] In some embodiments of this application, see Figure 1 and Figure 3 As shown, the battery electrode includes a current collector 100 and a dressing layer 200 .

[0057] The current collector 100 includes a pole ear 120 and a main body 110. The pole ear 120 is located on one side of the extension direction of the main body 110. A filling groove 130 is provided on the main body 110. The filling groove 130 can be located at any position of the current collector 100 and can also be of any shape as long as it does not block the current. The active dressing is coated on at least one surface of the main body 110 to form a dressing layer 200, that is, the active dressing is coated on the large surface of the main body 110, and whether the two large surfaces of the main body 110 are coated with the active dressing or only on one of the surfaces can be adjusted according to actual use requirements. At the same time, the active dressing 200 is also filled in the filling groove 130, and the filling groove 130 is completely filled to make the surface of the dressing layer 200 or the current collector 100 smooth, thereby ensuring the performance of the battery pole piece.

[0058] For example, if the dressing layer 200 is only provided on one large surface of the current collector 100 , the active material used in the dressing layer 200 is completely filled in the filling groove 130 , so that the surface of the dressing layer 200 and the large surface of the current collector 100 facing away from the dressing layer 200 are both kept flat.

[0059] For example, if dressing layers 200 are disposed on both large surfaces of the current collector 100 , the surfaces of the two dressing layers 200 facing away from the current collector 100 are both flat, so as to ensure the performance of the battery electrode.

[0060] It can be understood that the flatness in this embodiment refers to relative flatness, and processing errors are allowed. Usually, the flatness can be maintained within 1 μm~100 μm.

[0061] The current collector 100 may be a metal foil or a composite current collector 100. For example, the metal foil may be an aluminum foil or a copper foil. The composite current collector 100 may be a conductive sheet material formed by a composite of a metal and a polymer material. For example, the positive electrode sheet often uses aluminum foil as the current collector 100, and the negative electrode sheet often uses copper foil as the current collector 100.

[0062] The composition of the active dressing used in the dressing layer 200 can be determined according to the type of battery electrode.

[0063] For the positive electrode sheet, the active dressing may include positive electrode active materials for batteries known in the art, including but not limited to one of the following materials: olivine-structured lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds.

[0064] Among them, the lithium transition metal oxide includes but is not limited to at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and modified compounds thereof. The lithium phosphate containing olivine structure includes but is not limited to at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0065] Of course, other materials may be selected as active dressings as long as they meet the requirements for the use of positive electrode materials, and this embodiment does not limit them.

[0066] Typically, the active dressing of the positive electrode sheet also contains a binder and a conductive agent. The binder includes but is not limited to at least one of vinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, and fluorine-containing acrylate resin. The conductive agent includes but is not limited to at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. The specific type of use can be selected according to the actual situation, and this embodiment does not limit it here.

[0067] For the negative electrode plate, the active dressing may include common negative electrode active materials of batteries, including but not limited to one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials and lithium titanate. Of course, this is just an example, and other active materials that meet the requirements for the use of negative electrode plates can be used.

[0068] Usually, the active dressing of the negative electrode plate also contains additives such as a binder, a conductive agent and a thickener. The binder includes but is not limited to at least one of styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid and carboxymethyl chitosan. The conductive agent includes but is not limited to at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers. The thickener includes but is not limited to sodium carboxymethyl cellulose and lithium carboxymethyl cellulose. Of course, here only examples of additives such as binders, conductive agents and thickeners are given, not to limit them, and other additives that can play a similar role can be used.

[0069] The active dressing is directly filled in the filling groove 130. Compared with the traditional electrode plates, the amount of the current collector 100 used in the battery plates of the same size is greatly reduced, and the cost of the active dressing of the same volume is significantly lower than the cost of the current collector 100, thereby effectively reducing the production cost of the battery plates.

[0070] When this type of battery electrode is used in a battery, its capacity is close to that of a traditional battery. Therefore, while ensuring the battery capacity, it can effectively reduce the production cost of the battery electrode, thereby reducing the cost of the battery.

[0071] Furthermore, the extending direction of the filling groove 130 is the same as the extending direction of the main body 110 , so that the amount of the current collector 100 can be reduced while the influence on the current transfer can be minimized.

[0072] In some embodiments of the present application, at least two filling grooves 130 are provided at one end of the main body 110, and the filling grooves 130 are arranged side by side along the width direction of the main body 110. The amount of collector can be reduced by providing multiple filling grooves 130, and the size of a single filling groove 130 can be reduced to avoid affecting the performance of the battery electrode.

[0073] In addition, there is a spacing portion between adjacent filling grooves 130 , and the width of the spacing portion is the same as the width of the filling groove 130 .

[0074] By setting the main body 110 to such a shape, during production, the coated metal foil can be directly cut as the substrate 10 to obtain the current collector 100 with two main bodies 110 in rotational symmetry, thereby greatly reducing the amount of the current collector 100 used.

[0075] For example, see Figure 2 As shown, a coated metal foil with a length of L1 and a width of H1 is used as a substrate 10, wherein the direction of the substrate 10 perpendicular to the slurry coating and rolling direction is the length direction of the current collector 100, and the two current collectors 100 obtained by cutting the substrate 10 are as shown in Figure 3As shown, the length of the current collector 100 on the left is L2+L3, and the length of the current collector 100 on the right is also L2+L3, wherein the length of the filling groove 130 is L2, and the length of the main body 110 without the filling groove 130 is L3, and L1=L3+L3+L2, and the width of the filling groove 130 and the spacing part between the adjacent filling grooves are the same. When cutting, two main bodies 110 can be directly formed to be rotationally symmetrical current collectors 100.

[0076] If two current collectors 100 with a length of L3+L2 and a width of H1 are made in a conventional manner, at least one more current collector 100 with a length of L2 and a width of H1 needs to be used. Therefore, it can be clearly seen that the battery pole sheet used in this embodiment can greatly reduce the amount of current collector 100 used and reduce the production cost of the battery pole sheet.

[0077] Furthermore, in order to facilitate cutting and make the final produced current collector 100 have the same size, as shown in FIG. Figure 3 As shown, the tab 120 and the filling slot 130 can be disposed at both ends of the main body 110 , the sum of the length of the tab 120 and the length of the filling slot 130 is equal to the length of the current collector 100 , and the projections of the tab 120 and the filling slot 130 in the extension direction of the current collector 100 do not overlap.

[0078] Specifically, if Figure 2 As shown, the overall width of the current collector 100 is H1, the width of the main body 110 is H2, and the width of the tab 120 is H1-H2.

[0079] Exemplarily, the width H1 of the current collector 100 is usually set to 2cm-500cm, the width H2 of the main body 110 is usually 1cm-498cm, the width of the tab 120 is 1cm-100cm, and the coating thickness of the active dressing 200 on the main body 110 can be selected according to actual conditions.

[0080] In order to reduce the impact of the filling slot 130 on the capacity, multiple filling slots 130 can be set to reduce the width of a single filling slot 130. After many tests, it was found that the filling slot 130 can be used normally when the width is set to 0.1mm-1000mm. For lithium-ion batteries, the width of the filling slot 130 is preferably 0.1mm-10mm, which can effectively ensure the capacity of the battery while reducing the production cost of the battery pole piece.

[0081] When multiple filling grooves 130 are provided, the width of the filling grooves 130 is recorded as H3, and the width of the interval between adjacent filling grooves 130 is recorded as H4. Then, the width or the number of the filling grooves 130 can be determined according to the following formula: H3=H4=H2 / n, where n is twice the number of the filling grooves 130 on a single current collector 100.

[0082] Therefore, in actual production, the production line equipment and product design can be matched, and the single-width or multi-width coating process can be flexibly adopted to reserve the space for the tab 120 in advance, and multiple substrates 10 can be manufactured at the same time to save processing costs. In the subsequent process, two symmetrical battery pole pieces can be formed by directly cutting from the center of the pole piece. The symmetry here refers to the fact that the overall appearance of the battery pole piece is completely symmetrical after the active dressing 200 is coated.

[0083] In some embodiments of the present application, when the battery electrode is used as a positive electrode, the battery electrode may further include an insulating layer, with an isolation portion between the main body 110 and the tab 120, a portion of the insulating layer covering the isolation portion, and another portion of the insulating layer covering a portion of the surface of the dressing layer 200.

[0084] Specifically, the extension direction of the insulating layer and the isolation part is the same as the extension direction of the pole lug 120, and is equal to the length of the pole lug 120. The insulating layer partially covers the isolation part, and the other part covers the surface of the dressing layer 200, so that the edge of the dressing layer 200 is completely covered by the insulating layer, thereby improving the ultimate safety performance of the battery.

[0085] Exemplarily, the width of the insulating layer is 0.1-5 cm, the width of the isolation portion is 0.01-1 cm, the thickness of the insulating layer is 1-200 μm, and except for the width covering the isolation portion, the remaining portion of the insulating layer is covered on the dressing layer 200. The width of the dressing layer 200 is greater than the width of the insulating layer so that part of the dressing layer 200 is not covered by the insulating layer.

[0086] It is understandable that the insulating layer can be a commonly used ceramic coating, which is generally made of a ceramic material with high insulation and low dielectric constant as the main body and a polymer material with high insulation and low dielectric constant as a binder. Among them, the ceramic material includes but is not limited to aluminum oxide, aluminum oxide-based water and or modified oxides, titanium oxide, titanium oxide-based water and or modified oxides. The binder includes but is not limited to at least one of vinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, and fluorine-containing acrylate resin. Of course, the insulating layer can also be other common insulating coatings, as long as it can play a similar role, and this embodiment does not limit it here.

[0087] In some embodiments of the present application, the battery electrode further includes a separator 300 , which is located on one side of the current collector 100 and connected to a surface of the current collector 100 or a side of the active dressing 200 facing away from the current collector 100 .

[0088] Specifically, if the active dressing 200 is coated on only one surface of the current collector 100, the diaphragm 300 is located on the side of the current collector 100 facing away from the active dressing 200. If the active dressing 200 is coated on two opposite surfaces of the current collector 100, the diaphragm 300 is connected to the active dressing 200 on either side to form a battery electrode with a single-sided active dressing 200 exposed.

[0089] It is understandable that the diaphragm 300 can be a porous structure diaphragm 300 with good chemical stability and mechanical stability, as long as it can meet the use requirements of the battery pole piece. At the same time, the surface of the diaphragm 300 can also be coated with functional coatings such as PVDF glue and alumina ceramics to improve the performance of the diaphragm 300 in the battery product.

[0090] When manufacturing the electrode core, the diaphragm 300 is generally placed at the bottom, and then the positive electrode sheets and the negative electrode sheets are stacked in sequence, so that the positive electrode sheets and the negative electrode sheets are spaced in sequence to form a laminated sheet with a sandwich structure.

[0091] The present application also provides a method for preparing a battery electrode sheet, comprising:

[0092] A current collector 100 is provided. The current collector 100 includes a tab 120 and a main body 110. The tab 120 is located on one side of the extension direction of the main body 110. A filling groove 130 is provided on the main body 110.

[0093] Specifically, the metal foil may be coated and cut to form the current collector 100 .

[0094] An active dressing is provided, and the active dressing is coated on at least one surface of the main body 110 to form a dressing layer, and the active dressing is also filled in the filling groove 130 .

[0095] Specifically, for the positive electrode sheet, the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent, and the solvent can be a liquid such as N-methylpyrrolidone that can disperse the positive electrode active material to form a positive electrode dressing. Subsequently, the positive electrode dressing can be coated on the current collector 100, and after drying, rolling and other processes, the positive electrode sheet can be obtained.

[0096] If a ceramic coating is required as an insulating layer on the positive electrode, the ceramic coating can be made by dispersing ceramic materials, binders and any other components in a solvent, such as N-methylpyrrolidone solvent, to form a ceramic slurry, which is then applied to the surface of the active dressing and the separator. The ceramic slurry can be applied to form an insulating layer during the coating of the active dressing, or it can be applied at any stage before the positive electrode and negative electrode are assembled.

[0097] For the negative electrode sheet, the negative electrode active material, conductive agent, binder and any other components are dispersed in a solvent, such as deionized water, to form a negative electrode dressing; the negative electrode dressing is coated on the current collector 100, and after drying, rolling and other processes, the negative electrode sheet can be obtained.

[0098] Furthermore, the method for preparing the battery pole piece also includes providing a diaphragm 300 , arranging the diaphragm 300 on one side of the current collector 100 , and connecting the diaphragm 300 to a large surface of the current collector 100 or a side of the active dressing 200 away from the current collector 100 .

[0099] Among them, the length and width of the diaphragm 300 are generally greater than the length and width of the main body 110. For example, the difference between the length of the diaphragm 300 and the length of the main body 110 is 2mm-10mm, and the difference between the width of the diaphragm 300 and the width of the main body 110 is 2mm-10mm, so as to effectively block the electron transmission between the positive electrode plate and the negative electrode plate during use and conduct ion transmission.

[0100] In some embodiments of the present application, a method for preparing a battery electrode sheet includes:

[0101] A substrate 10 is provided, and the substrate 10 is cut to form two current collectors 100 .

[0102] Furthermore, the main bodies 110 of the two current collectors 100 formed by cutting can be rotationally symmetrical.

[0103] Specifically, see Figure 1As shown, a coated metal foil with a length of L1 and a width of H1 is used as a substrate 10, wherein the direction of the substrate 10 perpendicular to the slurry coating and rolling direction is the length direction of the current collector 100, the width of the filling groove 130 is designed to be H4, and the width of the spacing portion between the filling grooves 130 is H3. It is usually required that H3 and H4 are equal and meet the range of 0.1mm-1000mm. For power lithium-ion batteries, the preferred value is 0.1mm-10mm, and the number n of the filling grooves 130 is determined according to the width of the substrate 10. The width of the main body 110 is set to H2, the width of the pole ear 120 is set to H1-H2, the length of the pole ear 120 is set to L3, the length of the filling groove 130 and the spacer is set to L2, and the pole ear 120 and the filling groove 130 are arranged at both ends of the main body 110, and then the substrate 10 is cut with a tool or a laser cutter. When using a tool, multiple rolling tools can be selected to achieve stable cutting and smaller H3 and H4 sizes.

[0104] The two current collectors 100 obtained by cutting the substrate 10 are as follows: Figure 2 As shown, the length of the current collector 100 on the left is L2+L3, and the length of the current collector 100 on the right is also L2+L3, and L1= L3+ L3+ L2. At this time, if the two current collectors 100 are assembled, that is, the spacer of one is inserted into the filling groove 130 of the other, then a sheet can be assembled, and the length of this sheet is the same as the length of the substrate.

[0105] A diaphragm 300 is provided and placed under the template 20, wherein a through slot 21 is provided on the template 20, an opening of the through slot 21 is opposite to the diaphragm 300, the length and width of the through slot 21 are the same as the length and width of the main body 110, and a clamping slot 22 is provided on the side wall of the through slot 21, and the shape of the clamping slot 22 is adapted to the shape of the tab 120;

[0106] Specifically, the template 20 is usually made of engineering plastics, such as modified phenolic resin, which has the advantages of high strength and low cost. Figure 3 As shown, the template 20 and Figure 2 The shape of the through slot 21 is adapted to the main body 110. When the slot 22 is provided, there are at least two ways as follows:

[0107] The first one, see Figure 4As shown, a movable plate detachably connected to the main structure of the template 20 is provided at the position of the template 20 corresponding to the pole ear 120, a through groove 21 is provided on the main structure, and a clamping groove 22 is provided at the bottom of the movable plate. When placing the current collector 100 in the through groove 21, the movable plate is first separated from the main structure. When placing, the current collector 100 is engaged with the through groove 21, and then the movable plate is installed on the main structure. At this time, the movable plate cooperates with the main structure so that the through groove 21 is only open at the top, and the bottom is closed by the current collector 100 and the diaphragm 300.

[0108] For the second one, see Figure 5 As shown, a slot 22 is provided at the bottom of the side wall of the through groove 21, and the height of the slot 22 is less than the height of the side wall of the through groove 21. When in use, the diaphragm 300 is placed first, and then the current collector 100 is placed on the diaphragm 300, and finally the template 20 is placed from the top of the current collector 100. At this time, the main body 110 is inserted into the through groove 21, and the tab 120 is inserted into the slot 22. Above the current collector 100, the side wall of the through groove 21 encloses a space for the active dressing 200 to be filled, so as to facilitate subsequent baking and rolling.

[0109] Provide a current collector 100, and position the main body 110 in the through groove 21, and position the tab 120 in the clamping groove 22;

[0110] Provide active dressing, fill the through groove 21 with the active dressing, bake, and roll flat to obtain Figure 1 The electrode pads shown.

[0111] Specifically, during processing, the template 20 is first placed on the flat diaphragm 300, the current collector 100 is placed in the template 20, the bottom of the current collector 100 is fitted with the diaphragm 300, and then the active dressing corresponding to the positive or negative electrode is poured into the template 20. After baking, it is rolled flat to obtain a battery electrode with the diaphragm 300 adhered to one side.

[0112] The separator 300 is generally coated with hot melt adhesive, and during the baking and rolling process, the separator 300 can be effectively connected to the current collector 100 through the hot melt adhesive.

[0113] If a battery electrode having a dressing layer 200 on both sides is prepared, the separator 300 may not be laid first, and the dressing layer 200 may be provided on one surface of the current collector 100 in the above manner, and then the separator 300 may be adhered and the dressing layer 200 on the other side may be coated in the above manner.

[0114] Alternatively, the separator 300 may be laid under the template 20, and then filled with active dressing to a certain amount, and then the current collector 100 is placed, and then filled with active dressing, and finally baked and rolled.

[0115] It is understandable that this is just an example for illustration, and the processing can also be carried out through other common methods, which are not limited in this embodiment.

[0116] In order to effectively characterize the performance of the battery electrode, the following experimental examples are provided for illustration:

[0117] Experimental Example 1

[0118] Preparation of positive electrode sheet: Nickel-cobalt-manganese ternary material, conductive agent carbon tube, binder polyvinylidene fluoride, and N-methylpyrrolidone are stirred and mixed in a weight ratio of 100:3:1.5:40 to obtain a positive electrode dressing; a 16 μm thick rolled aluminum foil material is selected as the positive electrode substrate 10, which is then coated, dried, and cold-pressed, and the substrate 10 is cut into two current collectors 100 with filling grooves 130 having a mortise and tenon structure using a roller cutter. The length of the current collector 100 is 140 mm and the width is 110 mm. The width of the main body 110 is 90 mm. The width of the filling groove 130 and the width of the spacing portion between the filling grooves 130 are both 2 mm. The length of the filling groove 130 is 70 mm, the number of filling grooves 130 is 22, the length of the pole ear 120 is 70 mm, and the length directions of the pole ear 120 and the filling groove 130 are the same as the length direction of the current collector 100. After the active dressing 200 is applied, the overall thickness is 100 μm.

[0119] Preparation of negative electrode sheet material: Graphite material, conductive agent carbon black, styrene-butadiene rubber, sodium polymethylcellulose, and deionized water are stirred and mixed in a mass ratio of 100:2:2:2:100 to obtain an active dressing 200. An 8 μm thick electrolytic copper foil is selected as the substrate 10, and then dried, coated, dried, cold pressed, and cut to obtain a current collector 100 of target specifications. The length of the current collector 100 is 146 mm, the width is 110 mm, and the width of the main body 110 is 94 mm. The width of the filling groove 130 and the width of the spacer between the filling grooves 130 are both 2 mm, the length of the filling groove 130 is 76 mm, the number of filling grooves 130 is 23, the length of the pole ear 120 is 70 mm, and the length direction of the pole ear 120 and the filling groove 130 is the same as the length direction of the current collector 100. After applying the active dressing 200, the overall thickness is 120 μm.

[0120] The separator 300 is a 16 μm thick PE film coated with ceramic and PVDF glue on both sides, which is pre-cut to a size of 98 mm in width and 152 mm in length. The separator 300 is placed on a flat and clean machine. After the template 20 is arranged, the positive electrode collector 100 or the negative electrode collector 100 is placed, and then the corresponding active dressing 200 is filled in. After drying, cold pressing, etc., the positive electrode sheet or the negative electrode sheet is obtained. It can be understood that the positive electrode sheet and the negative electrode sheet are operated separately.

[0121] Two positive electrode sheets and two negative electrode sheets are stacked to form an electrode sheet group, and the positive electrode sheets and the negative electrode sheets are arranged in sequence at intervals, and then a diaphragm is coated on the outermost layer of the electrode sheet group to obtain a battery core.

[0122] Experimental Example 2

[0123] The battery core was manufactured in the same manner as in Experimental Example 1, except that the current collector 100 corresponding to the positive electrode sheet had a length of 60 mm and a width of 40 mm, the width of the main body 110 was 30 mm, and the length of the filling slot 130 was 30 mm and the width was 2 mm. The current collector corresponding to the negative electrode sheet had a length of 66 mm and a width of 40 mm, the width of the main body 110 was 34 mm, and the length of the filling slot 130 was 36 mm and the width was 2 mm.

[0124] Comparative Example 1

[0125] The battery electrode core is made of the same rolled aluminum foil material, active dressing and diaphragm as in Experimental Example 1, with the difference that no filling groove is provided. The size of the final battery electrode sheet is the same as that of the battery electrode sheet in Experimental Example 1. The length of the collector of the positive electrode sheet is 140 mm and the width is 110 mm. The length of the collector of the negative electrode sheet is 146 mm and the width is 110 mm.

[0126] Comparative Example 2

[0127] The battery electrode core is made of the same current collector, active dressing and diaphragm as those in Experimental Example 2, except that no filling groove is provided, and the size of the final battery electrode sheet is the same as that of the battery electrode sheet in Experimental Example 2, that is, the length of the current collector of the positive electrode sheet is 60 mm and the width is 40 mm, and the length of the current collector of the negative electrode sheet is 66 mm and the width is 40 mm.

[0128] Finally, the battery cores in Experimental Example 1, Experimental Example 2, Comparative Example 1 and Comparative Example 2 were subjected to the same hot pressing, baking, liquid injection, formation, sealing and other processes to complete the subsequent battery production to obtain four batteries. Subsequently, under the same conditions, the capacity test and cycle life test of the four batteries were carried out in accordance with GB / T 31484, and the test results are shown in the following table:

[0129]

[0130] From the comparison between Example 1, Example 2, Comparative Example 1 and Comparative Example 2, it can be seen that the battery made of the battery pole piece of the present application can achieve a capacity performance close to that of the battery supported by the traditional battery pole piece. At the same time, the amount of the battery current collector made of the battery pole piece of the present application is much smaller than the amount of the current collector in the comparative example. As a result, compared with Comparative Example 1, the battery cost of Example 1 is reduced by about 2%, and compared with Comparative Example 2, the battery cost of Example 2 is reduced by about 3%.

[0131] An embodiment of the present application also provides an electrical device, including a device body and the battery in the above embodiment, wherein the battery is used to supply power to the device body.

[0132] It is understandable that the electrical equipment herein includes but is not limited to electric vehicles, household appliances, electric ships, aviation equipment and other common equipment that require battery power supply.

[0133] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A battery pole piece, characterized in that: include: A current collector (100), the current collector (100) comprising a pole ear (120) and a main body (110), the pole ear (120) being located on one side of the main body (110), and a filling groove (130) being provided on the main body (110); A dressing layer (200) is located on at least one surface of the main body (110) and is filled in the filling groove (130) to make the surface of the dressing layer (200) or the current collector (100) flat.

2. The battery electrode according to claim 1, characterized in that: The extending direction of the filling groove (130) is the same as the extending direction of the main body (110).

3. The battery pole piece according to claim 2, characterized in that: At least two filling grooves (130) are arranged side by side at one end of the main body (110) along the width direction of the main body (110), and a spacing portion is provided between adjacent filling grooves (130).

4. The battery pole piece according to claim 3, characterized in that: The width of the spacer is the same as that of the filling groove (130).

5. The battery pole piece according to claim 4, characterized in that: The extension direction of the pole lug (120) is the same as the extension direction of the filling groove (130), and the pole lug (120) and the filling groove (130) are respectively arranged at two ends of the main body (110).

6. The battery pole piece according to claim 5, characterized in that: The sum of the length of the electrode tab (120) and the length of the filling groove (130) is equal to the length of the current collector (100).

7. The battery pole piece according to claim 2, characterized in that: The width of the filling groove (130) is 0.1 mm-1000 mm.

8. The battery pole piece according to claim 7, characterized in that: The width of the filling groove (130) is 0.1 mm-10 mm.

9. The battery pole piece according to any one of claims 1 to 8, characterized in that: It also includes an insulating layer, and there is an isolating portion between the main body (110) and the tab (120), a portion of the insulating layer covers the isolating portion, and another portion of the insulating layer covers a portion of the surface of the active dressing (200).

10. The battery pole piece according to any one of claims 1 to 8, characterized in that: It also includes a separator (300), which is connected to the surface of the current collector (100) facing away from the dressing layer (200) or the surface of the dressing layer (200) facing away from the current collector (100).

11. A method for preparing a battery electrode, characterized in that: include: A current collector (100) is provided, the current collector (100) comprising a pole ear (120) and a main body (110), the pole ear (120) being located on one side of the extension direction of the main body (110), and a filling groove (130) being provided on the main body (110); An active dressing is coated on the current collector (100), the active dressing is coated on at least one surface of the main body (110), and is filled in the filling groove (130) to form a dressing layer (200).

12. The method for preparing a battery pole piece according to claim 11, characterized in that: The step of providing a current collector (100) comprises: A substrate (10) is provided, and the substrate (10) is cut so that the substrate (10) forms two current collectors (100).

13. The method for preparing a battery pole piece according to claim 12, wherein: The main bodies (110) of the two current collectors (100) cut from the substrate are rotationally symmetrical, and the filling groove (130) on one of the two current collectors (100) matches the spacer on the other, so that when the spacer and the filling groove (130) of the two current collectors (100) are assembled with each other, the length of the formed sheet is the same as the length of the substrate.

14. The method for preparing a battery pole piece according to claim 11, characterized in that: Also includes: A diaphragm (300) is provided, and the diaphragm (300) is arranged on one side of the current collector (100) and connected to the surface of the current collector (100) facing away from the dressing layer (200) or the surface of the dressing layer (200) facing away from the current collector (100).

15. The method for preparing a battery pole piece according to claim 14, characterized in that: Providing a diaphragm comprises: The diaphragm (300) is provided, and a hot melt adhesive is arranged on one side of the diaphragm (300) for connecting with the current collector (100) or the dressing layer (200). The diaphragm (300) is placed under the template (20), wherein a through groove (21) is arranged on the template (20), and the length and width of the through groove (21) are the same as the length and width of the main body (110), and a card groove (22) is arranged on the side wall of the through groove (21), and the shape of the card groove (22) is adapted to the shape of the pole ear (120); Providing the current collector (100), and positioning the main body (110) in the through groove (21), and positioning the tab (120) in the clamping groove (22); The active dressing is provided, filled into the through groove (21), baked, and rolled flat, so that the separator (300) and the active dressing are both adhered to the current collector (100) to form the battery electrode.

16. A pole core, characterized in that: It comprises a stacked positive electrode sheet and a negative electrode sheet, wherein at least one of the positive electrode sheet and the negative electrode sheet is a battery electrode sheet according to any one of claims 1 to 10, or a battery electrode sheet prepared by the method for preparing a battery electrode sheet according to any one of claims 11 to 15.

17. The pole core according to claim 16, characterized in that: The positive electrode sheet and the negative electrode sheet are both the battery electrode sheets described in any one of claims 1 to 10, or the battery electrode sheets prepared by the method for preparing the battery electrode sheets described in any one of claims 11 to 15, and the projection of the dressing layer (200) of the positive electrode sheet in the stacking direction is located within the dressing layer (200) of the negative electrode sheet.

18. The pole core according to claim 16, characterized in that: It comprises at least two positive electrode sheets and the negative electrode sheet, and the positive electrode sheet and the negative electrode sheet are arranged at intervals.

19. A battery, characterized in that: The invention comprises a housing and the pole core according to any one of claims 16 to 18, wherein the pole core is located in the housing.

20. An electrical equipment, characterized in that: The invention comprises a device body and the battery according to claim 19, wherein the battery is used to supply power to the device body.

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