Separator, negative electrode and lithium / sodium ion battery, and preparation method

Abstract

The present disclosure provides a diaphragm, a negative electrode and a lithium / sodium ion battery, and a preparation method, belonging to the field of batteries. The lithium / sodium supplement diaphragm comprises a diaphragm layer; a first protective layer is located on one side of the diaphragm layer; a lithium / sodium supplement layer is located on one side of the first protective layer; a patterned electronic conducting layer is located on one side of the lithium / sodium supplement layer; and a second protective layer is located on one side of the patterned electronic conducting layer. The lithium / sodium supplement negative electrode comprises a negative electrode sheet; a patterned electronic conducting layer is located on at least one side of the negative electrode sheet; a lithium / sodium supplement layer is located on one side of the patterned electronic conducting layer; and a protective layer is located on one side of the lithium / sodium supplement layer. The present disclosure sets a patterned electronic conducting layer in the diaphragm and the negative electrode, improves the interface contact and the uniform interface electric field distribution, constructs an electronic channel, improves the battery conductivity and the lithium / sodium ion transmission efficiency, improves the lithium / sodium utilization rate, reduces the non-active lithium / sodium consumption of the battery cell, and realizes the improvement of the energy density, the cycle life and the rate performance. The present disclosure solves the problems of low lithium / sodium utilization rate, low energy density, low cycle life and low rate performance in the prior art.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of batteries, in particular, to a separator, a negative electrode and a lithium / sodium ion battery, and a preparation method. BACKGROUND

[0002] Lithium ion batteries have advantages of high specific energy and long cycle life, and are widely used in electronic products, electric vehicles and other fields. However, the existing lithium ion batteries still have problems such as transition metal dissolution of cathode active material and particle breakage, which further leads to technical problems such as cycle life attenuation and energy density reduction of the battery. Sodium ion batteries also face the same technical problems.

[0003] In order to alleviate the above technical problems, the prior art proposes pre-lithiation / sodiumization of the positive electrode, the negative electrode or the separator, which improves the total amount of active lithium / sodium during the cycle, not only helps to improve the energy density of the battery, but also significantly prolongs the service life of the battery.

[0004] However, the existing pre-lithiation / sodiumization of the positive electrode, the negative electrode or the separator at least has the following technical problems: the existence of by-products after the lithium supplement reaction of the existing positive electrode will cause the cycle life to attenuate, and the lithium supplement effect is limited. The existing negative electrode lithium supplement / sodiumization is still limited by several major problems in the battery manufacturing process: the use of metal lithium / sodium is incompatible with the production environment, conventional solvents, adhesives, air and heat treatment process, etc., which makes the negative electrode lithium supplement / sodiumization have problems such as complicated operation, high risk, low utilization rate of metal lithium, high humidity requirement of storage and use environment, etc. The existing lithium supplement / sodiumization of the separator is mainly achieved by a lithium / sodium-containing functional layer or a lithium / sodium-containing gel layer. However, the lithium / sodium-containing functional coating contains catalysts, conductive agents, etc., and the lithium / sodium supplement through the lithium / sodium-containing functional layer will greatly increase the cost of the lithium / sodium supplement separator, thereby increasing the manufacturing cost of the lithium / sodium ion battery; the lithium / sodium supplement through the coating of the lithium supplement / sodium gel layer will increase the thickness of the separator, and the gel layer is easy to block the micropores of the separator after drying, hindering the transmission of lithium ions.

[0005] Therefore, how to propose a separator, a negative electrode and a lithium / sodium ion battery, and a preparation method to solve or at least alleviate the above at least one technical problem is a problem to be solved at present. SUMMARY

[0006] In view of the above technical problems, the present disclosure provides a separator, a negative electrode and a lithium / sodium ion battery, and a preparation method to solve or at least alleviate the above at least one technical problem existing in the prior art.

[0007] According to the specific embodiments of the present disclosure, in a first aspect, the present disclosure provides a lithium / sodium supplement separator, comprising:

[0008] a separator layer;

[0009] a first protective layer disposed on one side of the separator layer;

[0010] a lithium / sodium supplement layer disposed on a side of the first protective layer distal to the separator layer;

[0011] a patterned electron-conductive layer disposed on a side of the lithium / sodium supplement layer distal to the separator layer; and

[0012] a second protective layer disposed on a side of the patterned electron-conductive layer distal to the lithium / sodium supplement layer.

[0013] Optionally, the pattern of the patterned electron-conductive layer comprises at least one of a dot shape, a line shape, or a surface shape.

[0014] Optionally, the pattern of the patterned electron-conductive layer comprises at least one of a dot shape, a line shape, or a surface shape.

[0015] Optionally, the line shape is a straight line, a broken line, or a curve.

[0016] Optionally, the continuity of the patterned electron-conductive layer is 50% to 80%.

[0017] Optionally, the thickness of the patterned electron-conductive layer is 20 to 100 nm.

[0018] Optionally, the material of the patterned electron-conductive layer comprises at least one of a metal material and a carbon material.

[0019] Optionally, the metal material comprises at least one of Au, Ag, Cu, Zn, Mg, and a metal alloy thereof.

[0020] Optionally, the carbon material comprises at least one of conductive graphite, conductive carbon black, conductive carbon fiber, and graphene.

[0021] Optionally, the component of the first protective layer comprises at least one of Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, and LiF.

[0022] Optionally, the component of the second protective layer comprises at least one of Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, and LiF.

[0023] Optionally, the material of the lithium supplement layer comprises at least one of metallic lithium, lithium-silicon alloy, lithium-magnesium alloy, lithium-copper alloy, lithium-silver alloy, lithium-beryllium alloy, lithium-zinc alloy, lithium-cadmium alloy, lithium-aluminum alloy, lithium-gold alloy, and lithium-boron alloy.

[0024] Optionally, the material of the sodium supplement layer comprises at least one of metallic sodium, sodium-silicon alloy, sodium-indium alloy, sodium-zinc alloy, sodium-phosphorus alloy, sodium-arsenic alloy, sodium-tin alloy, sodium-bismuth alloy, sodium-lead alloy, and sodium-antimony alloy.

[0025] According to the specific embodiment of the present disclosure, in a second aspect, the present disclosure provides a lithium / sodium supplement negative electrode, comprising:

[0026] a negative electrode sheet comprising a negative electrode current collector and a negative electrode active material layer located on at least one surface of the negative electrode current collector;

[0027] a patterned electron conductive layer disposed on one side or both sides of the negative electrode sheet and located on the surface of the negative electrode active material layer away from the negative electrode current collector;

[0028] a lithium / sodium supplement layer disposed on the side of the patterned electron conductive layer away from the negative electrode sheet; and

[0029] a protective layer disposed on the side of the lithium / sodium supplement layer away from the patterned electron conductive layer.

[0030] Optionally, the pattern of the patterned electron conductive layer comprises at least one of a dot pattern, a line pattern, or a surface pattern.

[0031] Optionally, the dot pattern comprises a dot matrix formed by a plurality of discontinuous dots.

[0032] Optionally, the line pattern comprises a plurality of lines arranged at intervals.

[0033] Optionally, the surface pattern comprises a network structure formed by a plurality of lines arranged in a cross manner, and / or a surface structure formed by at least one line.

[0034] Optionally, the line pattern is a straight line, a broken line, or a curved line.

[0035] Optionally, the continuity of the patterned electron conductive layer is 50% to 80%.

[0036] Optionally, the thickness of the patterned electron conductive layer is 20 to 100 nm.

[0037] Optionally, the material of the patterned electron conductive layer comprises at least one of a metallic material and a carbon material.

[0038] Optionally, the metallic material comprises at least one of Au, Ag, Cu, Zn, Mg, and a metal alloy thereof.

[0039] Optionally, the carbon material comprises at least one of conductive graphite, conductive carbon black, conductive carbon fiber, and graphene.

[0040] Optionally, the component of the protective layer comprises at least one of Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, and LiF.

[0041] Optionally, the material of the lithium supplement layer comprises at least one of metallic lithium, lithium-silicon alloy, lithium-magnesium alloy, lithium-copper alloy, lithium-silver alloy, lithium-beryllium alloy, lithium-zinc alloy, lithium-cadmium alloy, lithium-aluminum alloy, lithium-gold alloy and lithium-boron alloy.

[0042] Optionally, the material of the sodium supplement layer comprises at least one of metallic sodium, sodium-silicon alloy, sodium-indium alloy, sodium-zinc alloy, sodium-phosphorus alloy, sodium-arsenic alloy, sodium-tin alloy, sodium-bismuth alloy, sodium-lead alloy and sodium-antimony alloy.

[0043] According to the specific embodiment of the present disclosure, in a third aspect, the present disclosure provides a lithium / sodium ion battery, comprising a positive electrode, a negative electrode and a separator, the separator is arranged between the positive electrode and the negative electrode, the separator is any one of the lithium / sodium supplement separators as described above; and / or the negative electrode is any one of the lithium / sodium supplement negative electrodes as described above.

[0044] According to the specific embodiment of the present disclosure, in a fourth aspect, the present disclosure provides a preparation method of the lithium / sodium supplement separator as described above, comprising the following steps:

[0045] depositing a first protective layer on one side of the separator layer;

[0046] depositing a lithium / sodium supplement layer on the side of the first protective layer away from the separator layer;

[0047] designing a shielding plate with a hollow pattern, installing the shielding plate with the hollow pattern on the side of the lithium / sodium supplement layer away from the separator layer, and evaporating the source to form a patterned electron-conductive layer on the side of the lithium / sodium supplement layer away from the separator layer through the shielding plate with the hollow pattern;

[0048] removing the shielding plate with the hollow pattern, and depositing a second protective layer on the side of the patterned electron-conductive layer away from the lithium / sodium supplement layer.

[0049] Optionally, the method for depositing the first protective layer on one side of the separator layer is vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering or reactive sputtering.

[0050] Optionally, the method for depositing the lithium / sodium supplement layer on the side of the first protective layer away from the separator layer is vacuum evaporation or magnetron sputtering.

[0051] Optionally, the method for forming the patterned electron-conductive layer on the side of the lithium / sodium supplement layer away from the separator layer is vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering or reactive sputtering.

[0052] Optionally, the method for depositing the second protective layer on the side of the patterned electron-conductive layer away from the lithium / sodium supplement layer is vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering or reactive sputtering.

[0053] According to the specific embodiment of the present disclosure, in the fifth aspect, the present disclosure provides a preparation method of the lithium / sodium supplementing negative electrode as any one of the preceding embodiments, comprising the following steps:

[0054] The shielding plate with the hollow pattern is designed, the shielding plate with the hollow pattern is installed on one side of the negative electrode sheet, and after the evaporation source is evaporated, the patterned electron conductive layer is formed on the surface of the negative electrode active material layer of the negative electrode sheet through the shielding plate with the hollow pattern;

[0055] The shielding plate with the hollow pattern is removed, and the lithium / sodium supplementing layer is deposited on the side of the patterned electron conductive layer away from the negative electrode sheet;

[0056] The protective layer is deposited on the side of the lithium / sodium supplementing layer away from the patterned electron conductive layer.

[0057] Optionally, the method for depositing the patterned electron conductive layer on the surface of the negative electrode active material layer of the negative electrode sheet is vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering or reactive sputtering.

[0058] Optionally, the method for depositing the lithium / sodium supplementing layer on the side of the patterned electron conductive layer away from the negative electrode sheet is vacuum evaporation or magnetron sputtering.

[0059] Optionally, the method for depositing the protective layer on the side of the lithium / sodium supplementing layer away from the patterned electron conductive layer is vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering or reactive sputtering.

[0060] According to the specific embodiment of the present disclosure, in the sixth aspect, the present disclosure provides a preparation method of a lithium / sodium ion battery, comprising the following steps:

[0061] The positive electrode, the separator and the negative electrode are provided, wherein the separator is obtained by the preparation method of the lithium / sodium supplementing separator as any one of the preceding embodiments, or the negative electrode is obtained by the preparation method of the lithium / sodium supplementing negative electrode as any one of the preceding embodiments;

[0062] The separator is arranged between the positive electrode and the negative electrode, the positive electrode, the separator and the negative electrode are placed in a shell, and the shell is packaged after an electrolyte is injected into the shell.

[0063] Compared with the prior art, the above-mentioned scheme of the present disclosure has at least the following beneficial effects:

[0064] (1) The present disclosure improves the interface contact and homogenizes the interface electric field distribution by arranging a patterned electron conducting layer on one side of the lithium / sodium supplementing layer in the lithium / sodium supplementing separator and between the negative electrode sheet and the lithium / sodium supplementing layer in the lithium / sodium supplementing negative electrode. The patterned electron conducting layer helps to improve the conductivity of the battery and the lithium ion transmission efficiency, improve the utilization rate of lithium / sodium in the lithium / sodium supplementing layer, reduce the consumption of non-active lithium / sodium in the battery system, and thus achieve the purposes of improving the energy density, prolonging the cycle life, and improving the rate performance.

[0065] (2) The present disclosure can also make the lithium / sodium ions in the lithium / sodium supplementing layer more orderly and transmit faster by controlling the morphology, continuity and composition of the patterned electron conducting layer, improve the lithium / sodium ion conduction efficiency, control the distribution uniformity of the lithium / sodium ions, avoid the excessive aggregation or sparseness of the lithium ions in the local area, significantly enhance the electronic conductivity of the lithium / sodium layer, improve the utilization rate of the metal lithium / sodium layer, reduce the consumption of non-active lithium / sodium in the battery system, and thus improve the energy density and electrochemical performance of the battery.

[0066] (3) The present disclosure prevents the lithium / sodium metal in the lithium / sodium supplementing layer in the separator and the negative electrode from being consumed by water and gas in the air during the assembly process, which affects the lithium / sodium supplementing efficiency, by arranging a protective layer to isolate the lithium / sodium metal in the lithium / sodium supplementing layer in the separator and the negative electrode from water and gas in the air. The lithium / sodium supplementing separator and the lithium / sodium supplementing negative electrode of the present disclosure can adapt to the assembly environment of the lithium / sodium ion battery and reduce the limitations of industrial application. Moreover, arranging a protective layer on the surface of the separator layer can also prevent lithium / sodium from entering the micropores of the separator layer during the evaporation process, block the micropores of the separator, and hinder the transmission of lithium ions.

[0067] (4) The patterned electron conducting layer and the second protective layer of the present disclosure are arranged in layers, the patterned electron conducting layer does not penetrate the second protective layer, so the thickness of the patterned electron conducting layer is not limited by the thickness of the outermost second protective layer, and the thickness of the patterned electron conducting layer can be selected in a wider range. Moreover, the protective effect on lithium / sodium metal can be enhanced.

[0068] (5) The thickness of the patterned electron conducting layer, the lithium / sodium supplementing layer and the protective layer of the present disclosure is relatively small, and the increase in the thickness of the separator and the negative electrode can be basically ignored, so the weight and volume of the battery will not be significantly increased.

[0069] (6) The preparation method of the lithium / sodium supplementing separator and the lithium / sodium supplementing negative electrode of the present disclosure is simple, has low requirements on the temperature and humidity of the environment, is safe, and has low cost. BRIEF DESCRIPTION OF DRAWINGS

[0070] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, further serve to explain the principles of the present disclosure. It is to be understood that the drawings are only schematic, and that they do not purport to be to scale with respect to one another. The specific embodiments will be described in the following description with reference to the accompanying drawings, wherein:

[0071] Figure 1 Structure diagram of the lithium / sodium supplementing separator in the first embodiment of the present disclosure;

[0072] Figure 2 Structure diagram of the lattice-shaped patterned electron-conducting layer in some embodiments of the present disclosure;

[0073] Figure 3 Structure diagram of the line-shaped patterned electron-conducting layer in some embodiments of the present disclosure, which is formed by a plurality of lines arranged in intervals;

[0074] Figure 4 Structure diagram of the network-shaped patterned electron-conducting layer in some embodiments of the present disclosure, which is formed by a plurality of lines arranged in intersections;

[0075] Figure 5 Structure diagram of the surface-shaped patterned electron-conducting layer in some embodiments of the present disclosure, which is formed by at least one line enclosing;

[0076] Figure 6 Flowchart of the preparation method of the lithium / sodium supplementing separator provided in the second embodiment of the present disclosure;

[0077] Figure 7 Structure diagram of the lithium / sodium supplementing anode provided in the third embodiment of the present disclosure;

[0078] Figure 8 Structure diagram of the lithium / sodium supplementing anode provided in some embodiments of the present disclosure;

[0079] Figure 9 Flowchart of the preparation method of the lithium / sodium supplementing anode provided in the fourth embodiment of the present disclosure;

[0080] Figure 10 Structure diagram of the lithium / sodium ion battery provided in the fifth embodiment of the present disclosure;

[0081] Figure 11 Flowchart of the preparation method of the lithium / sodium ion battery provided in the sixth embodiment of the present disclosure.

[0082] Reference signs in the detailed description of the embodiments are as follows:

[0083] Lithium / sodium ion battery 100;

[0084] Lithium / sodium supplementing separator 10, separator layer 11, first protective layer 12, lithium / sodium supplementing layer 13, patterned electron conductive layer 14, second protective layer 15; lithium / sodium supplementing negative electrode 20, negative electrode sheet 21, patterned electron conductive layer 22, lithium / sodium supplementing layer 23, protective layer 24; positive electrode 30; negative electrode 40. DETAILED DESCRIPTION

[0085] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present disclosure.

[0086] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure.

[0087] It should also be noted that the term "comprising" or any other variant is intended to cover non-exclusive inclusion, so that a product or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such product or device. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the product or device including the element.

[0088] In the description of the embodiments of the present disclosure, the terms "upper", "lower", "thickness" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the purpose of facilitating the description of the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present disclosure.

[0089] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents a "or" relationship between the front and rear associated objects.

[0090] In the description of the embodiments of the present disclosure, the symbol "~" represents all data between the two endpoints of "~" and all data between the two endpoints, for example, A~B, which represents all data greater than or equal to A and less than or equal to B.

[0091] In the description of the embodiments of the present disclosure, the terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "plurality" is two or more, unless otherwise explicitly and specifically limited.

[0092] In the present disclosure, the term "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the present disclosure. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present disclosure can be combined with other embodiments.

[0093] The prior art proposes pre-lithiation / sodiation of the positive electrode, negative electrode or separator to increase the total amount of active lithium / sodium during the cycle, which not only helps to improve the energy density of the battery, but also significantly prolongs the service life of the battery cell.

[0094] However, the inventors have found through research that the existing pre-lithiation / sodiation of the positive electrode, negative electrode or separator at least has the following technical problems: the existence of by-products after the existing positive electrode lithium supplement reaction will cause the cycle life to decay, and the lithium supplement effect is limited. The existing negative electrode lithium / sodium supplement is still limited by several major problems in the battery manufacturing process: the use and production environment of metal lithium / sodium, conventional solvents, adhesives, air and heat treatment process are incompatible, which makes the negative electrode lithium / sodium supplement have problems such as complicated operation, high risk, low utilization rate of metal lithium, high humidity requirement of storage and use environment, etc. The existing separator lithium / sodium supplement is mainly achieved by containing a lithium / sodium functional layer or coating a lithium / sodium-containing gel layer, but the lithium / sodium-containing functional coating contains catalysts, conductive agents, etc. Lithium / sodium supplement through the lithium / sodium-containing functional layer will greatly increase the cost of the lithium / sodium supplement separator, thereby increasing the production cost of the lithium / sodium ion battery; lithium / sodium supplement through the coating of a lithium-containing lithium / sodium supplement gel layer will increase the thickness of the separator, and the gel layer is easy to block the micropores of the separator after drying, hindering the transmission of lithium ions.

[0095] In order to solve the above technical problems, the present disclosure sets a patterned electron conducting layer on one side of the lithium / sodium supplement layer in the lithium / sodium supplement separator, and sets a patterned electron conducting layer between the negative electrode sheet and the lithium / sodium supplement layer in the lithium / sodium supplement negative electrode, which improves the interface contact and uniformizes the interface electric field distribution, and can respectively construct an electron channel in the separator and the negative electrode, which helps to improve the conductivity and lithium ion transmission efficiency of the battery, realizes the improvement of the utilization rate of lithium / sodium in the lithium / sodium supplement layer, and further realizes the purposes of improving the energy density, improving the cycle life and improving the rate performance.

[0096] Specifically, the embodiment of the present disclosure provides a lithium / sodium supplementing separator, comprising: a separator layer; a first protective layer arranged on one side of the separator layer; a lithium / sodium supplementing layer arranged on a side of the first protective layer away from the separator layer; a patterned electron conductive layer arranged on a side of the lithium / sodium supplementing layer away from the separator layer; and a second protective layer arranged on a side of the patterned electron conductive layer away from the lithium / sodium supplementing layer.

[0097] The embodiment of the present disclosure also provides a lithium / sodium supplementing negative electrode, comprising: a negative electrode sheet comprising a negative electrode current collector and a negative electrode active material layer located on at least one surface of the negative electrode current collector; a patterned electron conductive layer arranged on one side or both sides of the negative electrode sheet and located on a surface of the negative electrode active material layer away from the negative electrode current collector; a lithium / sodium supplementing layer arranged on a side of the patterned electron conductive layer away from the negative electrode sheet; and a protective layer arranged on a side of the lithium / sodium supplementing layer away from the patterned electron conductive layer.

[0098] In the technical solution of the present disclosure, by arranging a patterned electron conductive layer on one side of the lithium / sodium supplementing layer in the lithium / sodium supplementing separator and arranging a patterned electron conductive layer between the negative electrode sheet and the lithium / sodium supplementing layer in the lithium / sodium supplementing negative electrode, the interface contact is improved and the interface electric field distribution is homogenized; moreover, by controlling the morphology of the patterned electron conductive layer, electron channels can be respectively constructed in the separator and the negative electrode, which helps to improve the conductivity of the battery and the lithium ion transmission efficiency, realizes the improvement of the utilization rate of lithium / sodium in the lithium / sodium supplementing layer, reduces the consumption of non-active lithium / sodium in the battery system, and thus realizes the purposes of improving the energy density, prolonging the cycle life and improving the rate performance. Moreover, the lithium / sodium ions in the lithium / sodium supplementing layer can be transmitted more orderly and quickly, the lithium / sodium ion conduction efficiency is improved, the distribution uniformity of the lithium / sodium ions is regulated, and the excessive aggregation or sparseness of lithium ions in a local area is avoided. By controlling the continuity of the patterned electron conductive layer, the conductivity and the transmission of lithium ions are both high. By arranging the protective layer, the lithium / sodium metal in the lithium / sodium supplementing layer is isolated from water and gas in the air in the separator and the negative electrode, so that the lithium / sodium is not consumed by water and gas in the air during the assembly process, which affects the lithium / sodium supplementing efficiency. In addition, the patterned electron conductive layer and the second protective layer are arranged in layers, the patterned electron conductive layer does not penetrate the second protective layer, so the thickness of the patterned electron conductive layer is not limited by the thickness of the outermost second protective layer, and the thickness of the patterned electron conductive layer can be selected in a wider range; moreover, the protection effect on the lithium / sodium metal can be enhanced.

[0099] The optional embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0100] Please refer to Figure 1The first embodiment of the present disclosure provides a lithium / sodium supplementing separator 10, comprising a separator layer 11, a first protective layer 12, a lithium / sodium supplementing layer 13, a patterned electron conductive layer 14, and a second protective layer 15. The first protective layer 12 is arranged on the surface of the separator layer 11, the lithium / sodium supplementing layer 13 is arranged on the side of the first protective layer 12 away from the separator layer 11, the patterned electron conductive layer 14 is arranged on the side of the lithium / sodium supplementing layer 13 away from the separator layer 11, and the second protective layer 15 is arranged on the side of the patterned electron conductive layer 14 away from the lithium / sodium supplementing layer 13.

[0101] The separator layer 11 can be selected from conventional separators in lithium / sodium ion batteries. As an example, the separator layer 11 includes but is not limited to polyolefin-based separators such as polyethylene, polypropylene, etc., or polyazole nanomaterial separators, etc., and the surface of the separator can further comprise inorganic-organic coating layers such as aluminum oxide, polyvinylidene fluoride, etc.

[0102] The first protective layer 12 and the second protective layer 15 isolate the lithium / sodium metal of the lithium / sodium supplementing layer 13 from water, gas, etc. in the air, so as to avoid the consumption of lithium / sodium in the air during the assembly process, thereby affecting the lithium / sodium supplementing efficiency. The components of the first protective layer 12 and / or the second protective layer 15 include but are not limited to at least one of lithium / sodium salts such as Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, LiF, etc.

[0103] The thickness of the first protective layer 12 and / or the second protective layer 15 is preferably in the range of 20 nm to 5 µm. The thickness of the second protective layer 15 can be the same as or different from the thickness of the first protective layer 12, and preferably, the thickness of the second protective layer 15 is greater than the thickness of the first protective layer 12.

[0104] When the separator is a lithium supplementing separator, the material of the lithium supplementing layer includes but is not limited to one or more of metal lithium, lithium-silicon alloy, lithium-magnesium alloy, lithium-copper alloy, lithium-silver alloy, lithium-beryllium alloy, lithium-zinc alloy, lithium-cadmium alloy, lithium-aluminum alloy, lithium-gold alloy, and lithium-boron alloy. When the separator is a sodium supplementing separator, the material of the sodium supplementing layer includes but is not limited to at least one of metal sodium, sodium-silicon alloy, sodium-indium alloy, sodium-zinc alloy, sodium-phosphorus alloy, sodium-arsenic alloy, sodium-tin alloy, sodium-bismuth alloy, sodium-lead alloy, and sodium-antimony alloy.

[0105] In some embodiments, the thickness of the lithium / sodium supplementing layer 13 is in the range of 50 nm to 10 µm. Preferably, the thickness of the lithium / sodium supplementing layer 13 is in the range of 500 nm to 3 µm.

[0106] The pattern of the patterned electron-conductive layer 14 can be point-like, line-like, or plane-like. Preferably, the pattern of the patterned electron-conductive layer 14 is point-like or plane-like. The line-like can be straight, broken, or curved, etc. As an example, the plane-like includes but is not limited to square, diamond, trapezoid, triangle, polygon, cross, annular, or irregular shape, etc. Please refer to Figures 2-5 In some embodiments, the point-like includes a dot matrix formed by a plurality of discontinuous points; the line-like includes a plurality of lines arranged at intervals; the plane-like includes a network structure formed by a plurality of lines arranged in a cross manner, and / or a plane structure formed by at least one line.

[0107] The percentage of the area of the conductive material in the patterned electron-conductive layer 14 to the surface area of the separator layer 11 is referred to as the continuity. If the continuity of the patterned electron-conductive layer 14 is too low, for example less than 50%, the conductive ability of the patterned electron-conductive layer 14 is weak, and if the continuity is too high, for example higher than 80%, it will hinder the transmission of lithium / sodium ions. In some preferred embodiments, the continuity of the patterned electron-conductive layer 14 is 50% to 80%, and the patterned electron-conductive layer 14 with this range of continuity has good conductive ability and lithium / sodium ion transmission. In some embodiments, the thickness of the patterned electron-conductive layer 14 is 20 to 100 nm.

[0108] The material of the patterned electron-conductive layer 14 includes at least one of a metal material and a carbon material. The metal material includes but is not limited to Au, Ag, Cu, Zn, Mg, etc., or an alloy of two or more of the above metals. Preferably, the metal material is Ag, Cu, or Ag-Cu alloy. The carbon material includes but is not limited to at least one of conductive graphite, conductive carbon black, conductive carbon fiber, and graphene, etc. Preferably, the carbon material is conductive graphite or conductive carbon black.

[0109] By controlling the morphology, continuity, and composition of the patterned electron-conductive layer 14 to construct the electron channel, the electronic conductive ability of the lithium / sodium layer can be significantly enhanced, the utilization rate of the metal lithium / sodium layer can be improved, the consumption of non-active lithium / sodium in the cell system can be reduced, and thus the energy density and electrochemical performance of the cell can be improved.

[0110] Please refer to Figure 6 The second embodiment of the present disclosure provides a preparation method of the lithium / sodium supplementing separator 10 described in any one of the first embodiment, including the following steps:

[0111] Step (S1), depositing the first protective layer 12 on one side of the separator layer 11;

[0112] Step (S2), depositing the lithium / sodium supplementing layer 13 on the side of the first protective layer 12 away from the separator layer 11;

[0113] Step (S3), designing a shielding plate with a hollow pattern, installing the shielding plate with a hollow pattern on the side of the lithium / sodium supplement layer 13 away from the diaphragm layer 11, and evaporating the source to form the patterned electron conducting layer 14 on the side of the lithium / sodium supplement layer 13 away from the diaphragm layer 11 through the shielding plate with a hollow pattern;

[0114] Step (S4), removing the shielding plate with a hollow pattern, and depositing the second protective layer 15 on the side of the patterned electron conducting layer 14 away from the lithium / sodium supplement layer 13.

[0115] In some embodiments, in step (S1), the deposition method of the first protective layer 12 includes but is not limited to vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering, or reactive sputtering, etc. Preferably, the first protective layer 12 is deposited on one side of the diaphragm layer 11 by vacuum evaporation.

[0116] In some embodiments, in step (S2), the lithium / sodium supplement layer is deposited on one side of the first protective layer 12 by vacuum evaporation or magnetron sputtering.

[0117] Step (S3), the shielding plate with a hollow pattern is used to partially shield the lithium / sodium supplement layer 13, thereby forming a patterned electron conducting layer 14 on the surface of the lithium / sodium supplement layer 13, and the pattern of the patterned electron conducting layer 14 is the same as the hollow pattern of the shielding plate.

[0118] In some embodiments, the method for forming the patterned electron conducting layer 14 on one side of the lithium / sodium supplement layer 13 includes but is not limited to at least one of vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering, or reactive sputtering. Preferably, the patterned electron conducting layer 14 is formed on the surface of the lithium / sodium supplement layer 13 by vacuum evaporation, specifically, a shielding plate with a hollow pattern is designed according to the topography of the patterned electron conducting layer 14, then the shielding plate with a hollow pattern is introduced to the side of the lithium / sodium supplement layer 13 away from the diaphragm layer 11, and then the metal or carbon material is evaporated on the lithium / sodium supplement layer 13 by vacuum evaporation to form the patterned electron conducting layer 14.

[0119] In some embodiments, in step (S4), depositing the second protective layer 15 on the side of the patterned electron conducting layer 14 away from the lithium / sodium supplement layer 13 includes but is not limited to vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering, or reactive sputtering, etc. Preferably, the second protective layer 15 is deposited on the side of the patterned electron conducting layer 14 away from the lithium / sodium supplement layer 13 by vacuum evaporation.

[0120] Please refer to Figure 7The third embodiment of the present disclosure provides a lithium / sodium supplementing negative electrode 20, which comprises a negative electrode sheet 21, a patterned electron conductive layer 22, a lithium / sodium supplementing layer 23, and a protective layer 24. The negative electrode sheet 21 comprises a negative electrode current collector and a negative electrode active material layer on the surface of the negative electrode current collector. The patterned electron conductive layer 22 is arranged on both sides of the negative electrode sheet 21 and on the surface of the negative electrode active material layer away from the negative electrode current collector. The lithium / sodium supplementing layer 23 is arranged on the side of the patterned electron conductive layer 22 away from the negative electrode sheet 21. The protective layer 24 is arranged on the side of the lithium / sodium supplementing layer 23 away from the patterned electron conductive layer 22. That is, the lithium / sodium supplementing negative electrode 20 in the present embodiment comprises the protective layer 24, the lithium / sodium supplementing layer 23, the patterned electron conductive layer 22, the negative electrode sheet 21, the patterned electron conductive layer 22, the lithium / sodium supplementing layer 23, and the protective layer 24 arranged in sequence.

[0121] The negative electrode sheet 21 comprises a negative electrode current collector and a negative electrode active material on at least one surface of the negative electrode current collector. The negative electrode active material comprises at least one of graphite, hard carbon, soft carbon, mesocarbon microbeads, tin-based materials, and silicon-based materials.

[0122] The pattern of the patterned electron conductive layer 22 can be point-shaped, line-shaped, or planar. Preferably, the pattern of the patterned electron conductive layer 22 is point-shaped or planar. The line-shaped can be a straight line, a broken line, or a curve, etc. As an example, the planar includes, but is not limited to, a square, a rhombus, a trapezoid, a triangle, a polygon, a cross, a circular ring, or an irregular shape, etc. In some embodiments, the point-shaped includes a dot matrix formed by a plurality of intermittent points; the line-shaped includes a plurality of lines arranged at intervals; the planar includes a network structure formed by a plurality of lines arranged in cross, and / or a planar structure formed by at least one line.

[0123] The percentage of the area of the conductive material in the patterned electron conductive layer 22 to the surface area of the negative electrode sheet 21 is referred to as the continuity. If the continuity of the patterned electron conductive layer 22 is too low, for example, less than 50%, the conductive ability of the patterned electron conductive layer 22 is weak. If the continuity is too high, for example, higher than 80%, the transmission of lithium / sodium ions will be hindered. In some preferred embodiments, the continuity of the patterned electron conductive layer 22 is 50% to 80%. The patterned electron conductive layer 22 with the continuity in this range has both good conductive ability and transmission of lithium / sodium ions. In some embodiments, the thickness of the patterned electron conductive layer 22 is 20 to 100 nm.

[0124] The material of the patterned electron-conductive layer 22 includes at least one of a metal material and a carbon material. The metal material includes, but is not limited to, Au, Ag, Cu, Zn, Mg, and the like, or an alloy of two or more of the above metals. Preferably, the metal material is Ag, Cu, or an Ag-Cu alloy. The carbon material includes, but is not limited to, at least one of conductive graphite, conductive carbon black, conductive carbon fiber, graphene, and the like. Preferably, the carbon material is conductive graphite or conductive carbon black.

[0125] By controlling the morphology, continuity, and composition of the patterned electron-conductive layer 22 to construct an electron channel, the electron-conducting ability of the lithium / sodium layer can be significantly enhanced, the utilization rate of the metal lithium / sodium layer can be improved, the consumption of non-active lithium / sodium in the cell system can be reduced, and thus the energy density and electrochemical performance of the cell can be improved.

[0126] When the negative electrode is a lithium supplementing negative electrode, the material of the lithium supplementing layer 23 includes, but is not limited to, one or more of metal lithium, lithium-silicon alloy, lithium-magnesium alloy, lithium-copper alloy, lithium-silver alloy, lithium-beryllium alloy, lithium-zinc alloy, lithium-cadmium alloy, lithium-aluminum alloy, lithium-gold alloy, and lithium-boron alloy. When the negative electrode is a sodium supplementing negative electrode, the material of the sodium supplementing layer 23 includes, but is not limited to, at least one of metal sodium, sodium-silicon alloy, sodium-indium alloy, sodium-zinc alloy, sodium-phosphorus alloy, sodium-arsenic alloy, sodium-tin alloy, sodium-bismuth alloy, sodium-lead alloy, and sodium-antimony alloy.

[0127] In some embodiments, the thickness of the lithium / sodium supplementing layer 23 is 50 nm to 10 µm. Preferably, the thickness of the lithium / sodium supplementing layer 23 is 500 nm to 3 µm.

[0128] The protective layer 24 is used to protect the lithium / sodium supplementing layer 23, so that the lithium / sodium metal of the lithium / sodium supplementing layer 23 is isolated from water and gas in the air, and the lithium / sodium supplementing efficiency is not affected by the consumption of lithium / sodium in the air during the assembly process. The components of the protective layer 24 include, but are not limited to, at least one of Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, LiF, and the like. The thickness of the protective layer 24 is preferably in the range of 20 nm to 5 µm.

[0129] Referring to FIG. 1, in some embodiments, the patterned electron-conductive layer 22 is arranged on one side of the negative electrode sheet 21, and the lithium / sodium supplementing negative electrode 20 includes the negative electrode sheet 21, the patterned electron-conductive layer 22, the lithium / sodium supplementing layer 23, and the protective layer 24 arranged in sequence. Figure 8 In some embodiments, the patterned electron-conductive layer 22 is arranged on one side of the negative electrode sheet 21, and the lithium / sodium supplementing negative electrode 20 includes the negative electrode sheet 21, the patterned electron-conductive layer 22, the lithium / sodium supplementing layer 23, and the protective layer 24 arranged in sequence.

[0130] Referring to FIG. 1, in some embodiments, the patterned electron-conductive layer 22 is arranged on one side of the negative electrode sheet 21, and the lithium / sodium supplementing negative electrode 20 includes the negative electrode sheet 21, the patterned electron-conductive layer 22, the lithium / sodium supplementing layer 23, and the protective layer 24 arranged in sequence. Figure 9 The fourth embodiment of the present disclosure provides a preparation method of the lithium / sodium supplementing negative electrode 20 of any one of the third embodiments, including the following steps:

[0131] Step (I), designing a shielding plate with a hollow pattern, installing the shielding plate with the hollow pattern on one side of the negative electrode sheet 21, and evaporating a source to deposit the patterned electron-conductive layer 22 on the surface of the negative electrode active material layer of the negative electrode sheet 21 through the shielding plate with the hollow pattern after evaporation of the source;

[0132] Step (II), removing the shielding plate with the hollow pattern, and depositing the lithium / sodium supplementing layer 23 on the side of the patterned electron-conductive layer away from the negative electrode sheet 21;

[0133] Step (III), depositing the protective layer 24 on the side of the lithium / sodium supplementing layer 23 away from the patterned electron-conductive layer 22.

[0134] In some embodiments, in step (I), the shielding plate with the hollow pattern is used to shield part of the surface of the negative electrode sheet 21, thereby enabling the formation of the patterned electron-conductive layer 22 on one side or both sides of the negative electrode sheet 21. In some embodiments, the method for forming the patterned electron-conductive layer 22 on at least one side of the negative electrode sheet 21 includes but is not limited to vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering, or reactive sputtering, etc. Preferably, the patterned electron-conductive layer 22 is formed on at least one side of the negative electrode sheet 21 by vacuum evaporation. Specifically, a shielding plate with a hollow pattern is designed according to the topography of the patterned electron-conductive layer 22, and then the shielding plate with the hollow pattern is installed in the working position. Then, a metal or carbon material is evaporated on one side or both sides of the negative electrode sheet 21 by vacuum evaporation to form the patterned electron-conductive layer 14.

[0135] In some embodiments, in step (II), the lithium / sodium supplementing layer 23 is deposited on the side of the patterned electron-conductive layer 22 away from the negative electrode sheet 21 by vacuum evaporation or magnetron sputtering.

[0136] In some embodiments, in step (III), the method for depositing the protective layer 24 on the side of the lithium / sodium supplementing layer 23 away from the patterned electron-conductive layer 22 includes but is not limited to vacuum evaporation, ion plating, radio frequency sputtering, magnetron sputtering, or reactive sputtering, etc. Preferably, the protective layer 24 is deposited on the side of the lithium / sodium supplementing layer 23 away from the patterned electron-conductive layer 22 by vacuum evaporation.

[0137] The fifth embodiment of the present disclosure provides a lithium / sodium ion battery, comprising a positive electrode, a negative electrode, and a separator, the separator being arranged between the positive electrode and the negative electrode, the separator being the lithium / sodium supplementing separator 10 of any one of the first embodiments, and / or the negative electrode being the lithium / sodium supplementing negative electrode 20 of any one of the third embodiments.

[0138] Please refer to Figure 10In some embodiments, the lithium / sodium ion battery 100 comprises a positive electrode 30, a negative electrode 40, and a lithium / sodium supplementing separator 10, the lithium / sodium supplementing separator 10 is located between the positive electrode 30 and the negative electrode 40, and the second protective layer 15 is close to the negative electrode 40, and the separator layer 11 is close to the positive electrode 30.

[0139] Referring to Figure 11 The sixth embodiment of the present disclosure also provides a preparation method of a lithium / sodium ion battery, comprising the following steps:

[0140] providing a positive electrode, a separator and a negative electrode, wherein the separator is obtained by the preparation method of the lithium / sodium supplementing separator as described in the second embodiment, or the negative electrode is obtained by the preparation method of the lithium / sodium supplementing negative electrode as described in the fourth embodiment;

[0141] arranging the separator between the positive electrode and the negative electrode, and placing the positive electrode, the separator and the negative electrode in a shell, and then injecting an electrolyte into the shell and sealing the shell.

[0142] The preparation process, test method and test data of the examples and comparative examples are described as follows: Example 1:

[0143] The lithium supplementing separator of the present embodiment comprises, in sequence, a separator layer 11, a first protective layer 12, a lithium supplementing layer, a patterned electron conducting layer 14 and a second protective layer 15. The separator layer 11 is a polypropylene (PP) separator layer, the lithium supplementing layer is a metal lithium layer, the patterned electron conducting layer 14 is a dot matrix metal copper layer, and the first protective layer 12 and the second protective layer 15 are Li2CO3 layers with different thicknesses. The preparation method comprises the following steps:

[0144] Start the vacuum evaporation coating equipment, adjust the working vacuum degree to 5x10 -2 Pa~5x10 -3 Pa, start the evaporation source device, and after the evaporation state is stable, evaporate a 50nm-thick Li2CO3 protective layer on the surface of the PP separator;

[0145] Adjust the evaporation parameters and the evaporation source, and evaporate a 3µm-thick metal lithium layer on the Li2CO3 layer;

[0146] Design a shielding plate with a dot matrix pattern, install the shielding plate in the working position, replace the evaporation source with a metal copper, and evaporate a 50nm-thick dot matrix metal copper layer above the metal lithium layer;

[0147] Remove the shielding plate, adjust the evaporation parameters and the evaporation source, and evaporate a 100nm-thick Li2CO3 protective layer on the surface of the metal copper layer;

[0148] After the evaporation is completed, turn off the evaporation source power, break the vacuum, open the equipment, and obtain a pre-lithiated separator. Example 2:

[0149] The difference between this embodiment and Example 1 is that the shielding plate with a square pattern is designed in this embodiment, and a metal copper layer with a square pattern is obtained. Example 3:

[0150] The difference between this embodiment and Example 1 is that the shielding plate with a linear pattern is designed in this embodiment, and a metal Ag-Cu alloy layer with a linear pattern is obtained. Example 4:

[0151] The difference between this embodiment and Example 1 is that a conductive graphite layer is evaporated on the metal lithium layer in this embodiment. Example 5:

[0152] The difference between this embodiment and Example 1 is that the shielding plate with a linear pattern is designed in this embodiment, and a conductive graphite-conductive carbon fiber mixed electron conducting layer with a linear pattern is obtained. Example 6:

[0153] This embodiment provides a lithium supplement negative electrode. Since the subsequent evaluation adopts a button cell, this embodiment only performs unilateral pre-lithiation of the negative electrode, and the lithium supplement negative electrode includes a negative electrode sheet 21, a patterned electron conducting layer 22, a lithium supplement layer 23, and a protective layer 24. The patterned electron conducting layer 22 is a dot matrix metal copper layer, the lithium supplement layer 23 is a 3µm metal lithium layer, and the protective layer 24 is a 100nm Li3N protective layer. The specific preparation method is as follows:

[0154] The negative electrode active material is selected as a graphite+silicon-oxygen negative electrode sheet, a shielding plate with a dot matrix pattern is designed, the shielding plate is installed in the working position, the vacuum evaporation coating equipment is started, the working vacuum degree is adjusted to 5×10 -2 Pa~5×10 -3 Pa; the evaporation source device is started, the evaporation boat is preheated, and then a 20nm thick metal copper layer with a dot matrix pattern is evaporated on the surface of the negative electrode sheet;

[0155] After evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, the shielding plate is removed, the metal copper is replaced with metal lithium, and a 3µm thick metal lithium layer is evaporated on the surface of the metal copper layer;

[0156] After evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, the evaporation source is replaced, and a 100nm thick Li3N protective layer is evaporated on the metal lithium layer;

[0157] After the evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, and the lithium supplement negative electrode is obtained. Example 7

[0158] The difference between this example and example 6 is that a shielding plate with a square pattern is designed in this example, and a square metal copper layer is obtained.

[0159] Example 8

[0160] The difference between this example and example 6 is that a shielding plate with a linear pattern is designed in this example, and a metal Ag-Cu alloy layer is evaporated on the surface of the negative electrode sheet, and a linear metal Ag-Cu alloy layer is obtained. Example 9

[0161] The difference between this example and example 6 is that a conductive graphite layer is evaporated on the surface of the negative electrode sheet in this example.

[0162] Example 10

[0163] The difference between this example and example 6 is that a shielding plate with a linear pattern is designed in this example, and a conductive graphite-conductive carbon fiber mixed electron conducting layer is evaporated on the surface of the negative electrode, and a linear conductive graphite-conductive carbon fiber mixed electron conducting layer is obtained.

[0164] Example 11

[0165] The sodium supplement diaphragm of this example comprises a diaphragm layer 11, a first protective layer 12, a sodium supplement layer, a patterned electron conducting layer 14 and a second protective layer 15 in sequence. The diaphragm layer 11 is a PP diaphragm layer, the sodium supplement layer is a metal sodium layer, the patterned electron conducting layer 14 is a dot matrix metal copper layer, and the first protective layer 12 and the second protective layer 15 are Na2CO3 protective layers with different thicknesses. The preparation method comprises the following steps:

[0166] Start the vacuum evaporation film device, adjust the working vacuum degree to 5x10 -2 Pa~5x10 -3 Pa, start the evaporation source device, and evaporate a 50nm thick Na2CO3 protective layer on the surface of the PP diaphragm after the evaporation state is stable;

[0167] Adjust the evaporation parameters and the evaporation source, and evaporate a 3µm metal sodium layer on the Na2CO3 layer;

[0168] Design a shielding plate with a dot matrix pattern, install the shielding plate in the working position, replace the evaporation source with a metal copper, and evaporate a 20nm dot matrix metal copper layer above the metal sodium layer;

[0169] After the shielding plate is removed, the evaporation parameters and the evaporation source are adjusted, and a 100 nm thick Na2CO3 protective layer is evaporated on the surface of the metal copper layer again.

[0170] After the evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, and the sodium-supplemented diaphragm is obtained.

[0171] Example 12

[0172] This embodiment provides a sodium-supplemented negative electrode. Since the subsequent evaluation adopts a button cell, this embodiment only performs unilateral sodium pre-supplementation of the negative electrode. The sodium-supplemented negative electrode comprises a negative electrode sheet 21, a patterned electronic conducting layer 22, a sodium-supplemented layer 23, and a protective layer 24. The patterned electronic conducting layer 22 is a dot-matrix metal copper layer, the sodium-supplemented layer 23 is a 3 µm metal sodium layer, and the protective layer 24 is a 100 nm NaF protective layer. The specific preparation method is as follows:

[0173] A negative electrode sheet with hard carbon as the negative electrode active material is selected, a shielding plate with a dot-matrix pattern is designed, the shielding plate is installed at the working position, the vacuum evaporation film coating equipment is started, the working vacuum degree is adjusted to 5 × 10 -2 Pa~5×10 -3 Pa; the evaporation source device is started, the evaporation boat is preheated, and then a 20 nm thick dot-matrix metal copper layer is evaporated on the surface of the negative electrode sheet;

[0174] After the evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, the shielding plate is removed, and the evaporation source metal copper is replaced with metal sodium. A 3 µm metal sodium layer is evaporated on the surface of the copper layer again;

[0175] After the evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, and a 100 nm NaF protective layer is evaporated on the metal sodium layer after the evaporation source is replaced;

[0176] After the evaporation is completed, the evaporation source power is turned off, the vacuum is broken, the equipment is opened, and the sodium-supplemented negative electrode sheet is obtained.

[0177] Comparative Example 1

[0178] In Comparative Example 1, neither the diaphragm nor the negative electrode sheet is subjected to lithium supplementation. The diaphragm is a PP diaphragm, and the negative electrode active material in the negative electrode is a graphite + silicon-oxygen negative electrode sheet.

[0179] Comparative Example 2

[0180] In Comparative Example 2, the diaphragm is a lithium-supplemented diaphragm, which comprises a diaphragm base and a lithium-supplemented layer. The diaphragm base is a PP diaphragm, and the lithium-supplemented layer is a 3 µm metal lithium layer. The negative electrode active material in the negative electrode is a graphite + silicon-oxygen negative electrode sheet.

[0181] Comparative Example 3

[0182] The sodium supplement measures are not taken for the separator and the negative electrode sheet in Comparative Example 3. The separator is a PP separator, and the negative electrode active material in the negative electrode is a hard carbon negative electrode sheet.

[0183] The separators, negative electrode sheets of Comparative Examples 1-2, and the lithium supplement separators or lithium supplement negative electrodes of Examples 1-10 are respectively used to make button cells, and the production process is as follows:

[0184] The positive and negative electrode sheets come from the cell production line, the positive electrode uses a ternary 8 system NCM material, and the negative electrode uses a graphite + silicon oxygen material. After wiping one side of the double-sided electrode sheet, it is dried;

[0185] The positive and negative electrodes and the separator are punched, wherein the negative electrode has a diameter of 14 mm, the positive electrode has a diameter of 12 mm, and the separator has a diameter of 16 mm;

[0186] The electrolyte uses 1M LiPF6 (lithium hexafluorophosphate), wherein the solvent ratio is ethylene carbonate (EC): diethyl carbonate (DEC): methyl ethyl carbonate (EMC) = 1:1:1;

[0187] According to the order of negative electrode shell-negative electrode-separator-positive electrode-gasket-elastic piece-positive electrode shell, a CR2032 battery is assembled.

[0188] The charge and discharge capacity, the first coulombic efficiency, the capacity retention rate after 50 cycles, and the capacity ratio at charge rates of 0.2C and 0.33C of the assembled button cell are tested, and the results are shown in Table 1.

[0189]

[0190] Comparing the results of Examples 1-10 with those of Comparative Examples 1-2, it can be seen that the charge capacity of Examples 1-10 is substantially less than that of Comparative Examples 1-2, the discharge capacity, the first coulombic efficiency, the capacity retention rate, and the 2C / 0.33C capacity ratio are all greater than those of Comparative Examples 1-2, and the first coulombic efficiency is significantly improved. It is shown that compared with the traditional separator, lithium supplement separator and negative electrode in lithium ion battery, the lithium supplement separator and lithium supplement negative electrode of the present disclosure can significantly improve the utilization rate of lithium by setting a patterned electronic conducting layer and constructing an electronic channel, thereby greatly improving the energy density, the first coulombic efficiency, the cycle performance, and the rate performance of the lithium ion battery.

[0191] It can also be seen from Table 1 that the performance of the battery of Example 2 is better than that of Example 1, and the performance of the battery of Example 7 is better than that of Example 6, which shows that compared with the lithium supplement separator or lithium supplement negative electrode with a dot matrix patterned electronic conducting layer, the lithium supplement separator or lithium supplement negative electrode with a square patterned electronic conducting layer has a better effect on improving the energy density, the first coulombic efficiency, the cycle performance, and the rate performance of the lithium ion battery.

[0192] It can also be seen from Table 1 that compared with the lithium supplementing separator of Example 5 and the lithium supplementing negative electrode of Example 10, the performance of the battery assembled by the lithium supplementing separator of Example 3 and the lithium supplementing negative electrode of Example 8 is obviously improved, which indicates that compared with the material of the patterned electronic conductive layer being a carbon mixed material, when the material of the patterned electronic conductive layer is a metal alloy, the utilization rate of lithium ions is higher, and the performance of the battery is better.

[0193] The separator, the negative electrode sheet of Comparative Example 3, and the sodium supplementing separator or the sodium supplementing negative electrode of Examples 11 and 12 were respectively used to make button cells, and the production process was as follows:

[0194] The positive and negative electrode sheets were from the cell production line, the positive electrode used NaNiFeMnO2 material, and the negative electrode used hard carbon material, and the double-sided electrode sheet was wiped on one side and then dried;

[0195] The positive and negative electrodes and the separator were punched, wherein the negative electrode had a diameter of 14 mm, the positive electrode had a diameter of 12 mm, and the separator had a diameter of 16 mm;

[0196] The electrolyte used 1M NaPF6 (sodium hexafluorophosphate), wherein the solvent ratio was ethylene carbonate (EC): diethyl carbonate (DEC): methyl ethyl carbonate (EMC) = 1:1:1;

[0197] The CR2032 battery was assembled in the order of negative electrode shell-negative electrode-separator-positive electrode-gasket-elastic piece-positive electrode shell.

[0198] The charge and discharge capacity, the first coulombic efficiency, the capacity retention rate after 50 cycles, and the capacity ratio at the charge rate of 0.2C and 0.33C of the assembled button cell were tested, and the results are shown in Table 2.

[0199]

[0200] It can be seen from the results of Examples 11 and 12 and the results of Comparative Example 3 that the charge capacity of Examples 11 and 12 is smaller than that of Comparative Example 3, and the discharge capacity, the first coulombic efficiency, the capacity retention rate, and the 2C / 0.33C capacity ratio are all significantly greater than those of Comparative Example 3. It is indicated that compared with the traditional separator and negative electrode in the sodium ion battery, the sodium supplementing separator and the sodium supplementing negative electrode of the present disclosure can significantly improve the utilization rate of sodium by setting a patterned electronic conductive layer to construct an electronic channel, thereby greatly improving the energy density, the first coulombic efficiency, the cycle performance, and the rate performance of the sodium ion battery.

[0201] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present disclosure, and they should be covered in the scope of the claims and the specification of the present disclosure. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A lithium / sodium supplementation membrane, characterized in that, include: Diaphragm layer; A first protective layer is disposed on one side of the membrane layer; the components of the first protective layer include at least one of Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, and LiF. A lithium / sodium supplement layer is disposed on the side of the first protective layer away from the membrane layer; A patterned electron conduction layer is disposed on the side of the lithium / sodium supplement layer away from the separator layer; as well as The second protective layer is disposed on the side of the patterned electron conduction layer away from the lithium / sodium supplementation layer; the components of the second protective layer include at least one of Na2CO3, NaTiO3, NaF, Na3N, Li2CO3, Li3N, LiTiO3, Li3P, and LiF.

2. The lithium / sodium supplementation membrane according to claim 1, characterized in that, The pattern of the patterned electron conductor layer includes at least one of dot-like, line-like, or area-like patterns.

3. The lithium / sodium supplementation membrane according to claim 2, characterized in that, The dotted structure includes a dot matrix formed by multiple discontinuous dots; and / or the linear structure includes multiple lines spaced apart; and / or the planar structure includes a network structure formed by multiple intersecting lines, and / or a planar structure formed by at least one line enclosing the area.

4. The lithium / sodium supplementation membrane according to any one of claims 1-3, characterized in that, The continuity of the patterned electron conductive layer is 50% to 80%.

5. A lithium / sodium-ion battery, comprising a positive electrode, a negative electrode, and a separator, wherein the separator is disposed between the positive electrode and the negative electrode, characterized in that, The diaphragm is the lithium / sodium supplementation diaphragm according to any one of claims 1-4.

6. A method for preparing a lithium / sodium supplemental separator as described in any one of claims 1-4, characterized in that, Includes the following steps: The first protective layer is deposited on one side of the membrane layer; The lithium / sodium supplement layer is deposited on the side of the first protective layer away from the membrane layer; Design a shield with a hollow pattern, install the shield with the hollow pattern on the side of the lithium / sodium replenishment layer away from the separator layer, and after the evaporation source evaporates, it passes through the shield with the hollow pattern to deposit the patterned electron conduction layer on the side of the lithium / sodium replenishment layer away from the separator layer. Remove the mask with the hollowed-out pattern and deposit the second protective layer on the side of the patterned electron conduction layer away from the lithium / sodium supplement layer.

7. A method for preparing a lithium / sodium ion battery, characterized in that, Includes the following steps: A positive electrode, a separator, and a negative electrode are provided, wherein the separator is obtained by the method for preparing a lithium / sodium-supplemented separator as described in claim 6; The diaphragm is placed between the positive electrode and the negative electrode, and the positive electrode, diaphragm and negative electrode are placed in the housing. Electrolyte is injected into the housing and then the housing is sealed.

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