Metal battery, negative pole piece, preparation method of metal battery and power utilization device

Abstract

The invention relates to the technical field of batteries, in particular to a metal battery, a negative pole piece, a preparation method of the metal battery and an electric device. The metal battery is an A metal battery, the metal battery comprises a negative electrode piece, the negative electrode piece comprises a negative electrode current collector and a metal layer arranged on the surface of at least one side of the negative electrode current collector, the metal layer comprises A-philic metal, and / or the dyne value of the surface of the metal layer is larger than that of the surface of the negative electrode current collector. The metal layer is arranged on the surface of at least one side of the negative electrode current collector, the metal layer comprises the A-philic metal, the A-philic metal and the A metal easily form an alloy, uniform deposition of the A metal on the surface of the metal layer is facilitated, and metal dendrites are not easily formed on the surface of the metal layer when A metal ions migrate from the positive electrode to the negative electrode; the risk of short circuit caused by metal dendritic crystal piercing the diaphragm is reduced; therefore, the cycle performance of the battery is improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a metal battery, a negative electrode sheet, a method for preparing the metal battery, and an electrical device thereof. Background Technology

[0002] Secondary batteries have attracted much attention due to their high energy density, long cycle life, low self-discharge, and good safety performance.

[0003] Metal batteries have a much higher energy density than conventional ion batteries and have extremely high development potential.

[0004] However, during the process of metal ions migrating from the positive electrode to the negative electrode and depositing there, metal dendrites are easily deposited on the surface of the negative electrode, thus reducing the cycle performance of the battery. Summary of the Invention

[0005] The main objective of this invention is to provide a metal battery that improves the battery's cycle performance.

[0006] To achieve the above objectives, the present invention proposes a metal battery, wherein the metal battery is an A metal battery, the metal battery includes a negative electrode sheet, the negative electrode sheet includes a negative current collector and a metal layer disposed on at least one side surface of the negative current collector, the metal layer includes an A-loving metal, and / or, the dyne value of the surface of the metal layer is greater than the dyne value of the surface of the negative current collector.

[0007] In one embodiment, the present application provides a metal layer on at least one side surface of the negative electrode current collector. The metal layer includes an A-friendly metal. The A-friendly metal readily forms an alloy with the A metal, which helps the A metal to be uniformly deposited on the surface of the metal layer. When the A metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the surface of the metal layer, reducing the risk of metal dendrites piercing the separator and causing a short circuit; thereby improving the cycle performance of the battery.

[0008] Alternatively, in another embodiment, the dyne value of the metal layer surface is greater than the dyne value of the negative electrode current collector surface. The increased dyne value of the metal layer contributes to the uniformity of the conductive layer coating on the metal layer surface, reduces the risk of incomplete coating, and improves the uniformity of metal deposition on the negative electrode, thereby improving the battery's cycle performance. For example, in one embodiment, a carbon layer (conductive layer) is coated on the metal layer surface. The dyne value of the metal layer surface is greater than the dyne value of the negative electrode current collector surface, which can reduce the risk of incomplete carbon layer coating.

[0009] Furthermore, in another embodiment, the metal layer includes an A-friendly metal. Simultaneously, the dyne value of the metal layer surface is greater than that of the negative electrode current collector surface. This contributes to the uniformity of the conductive layer coating on the metal layer surface. Furthermore, even if there are gaps in the conductive layer coating on the metal layer surface, the inclusion of an A-friendly metal facilitates alloying with A-metals, promoting uniform deposition of A-metals on the metal layer surface. When A-metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the surface of the metal layer with missing conductive layers, reducing the risk of metal dendrites piercing the separator and causing a short circuit; thereby improving the battery's cycle performance.

[0010] Optionally, the A-metal battery includes an alkali metal battery, and the A-loving metal includes an alkali-loving metal;

[0011] Alternatively, the A-metal battery may include an alkaline earth metal battery, and the A-loving metal may include an alkaline earth metal-loving metal.

[0012] It is understandable that metal A batteries include alkali metal batteries, and for alkali metal batteries, metals that are affinity for metal A include metals that are affinity for alkali metals.

[0013] In one embodiment, when the metal battery includes a Na metal battery, the A-loving metal includes a Na-loving metal, that is, the metal layer on at least one side surface of the negative electrode current collector includes a Na-loving metal. The Na-loving metal has a greater affinity for Na and is more likely to form an alloy with Na, so that when Na ions migrate from the positive electrode to the negative electrode, it is not easy to form Na dendrites on the surface of the metal layer.

[0014] It is also understandable that metal A batteries include alkaline earth metal batteries, and metals that are affinity for metal A include metals that are affinity for alkaline earth metals.

[0015] Optionally, the alkali-loving metal includes group P metals.

[0016] The valence electron configurations of Group P elements range from ns²np¹ to ns²np⁴, and they are generally prone to losing electrons, exhibiting strong nonmetallic properties. Alkali metals, on the other hand, have strong metallic properties, resulting in a good affinity between Group P metals and alkali metals. For example, Na has strong metallic properties, thus Group P metals have a good affinity for Na. Therefore, including a Group P metal in the metal layer on at least one side of the negative electrode current collector can improve the uniform deposition of Na.

[0017] Optionally, the P-group metals include at least one of Ga, In, Tl, Sn, Pb, Sb, and Bi.

[0018] The metal layer on at least one side surface of the negative electrode current collector may include at least one of the metals mentioned above, or a combination of the metals mentioned above.

[0019] Optionally, the thickness of the metal layer is from 100 nm to 2000 nm.

[0020] Considering that some Group P metals expand significantly when combined with alkali metals (such as Na), such as Sn, the metal layer, including Sn, is prone to detachment during long-term cycling. Controlling the metal layer thickness within the aforementioned range helps to control the volume change of the metal layer and reduce the risk of Group P metal detachment.

[0021] Optionally, the metal layer has a carbon layer on the side opposite to the negative electrode current collector.

[0022] Considering that some Group P metals form alloys with alkali metals (such as Na), resulting in significant volume changes, excessive volume changes during cycling can easily create gaps between the metal layer and the negative electrode current collector, increasing the risk of metal layer detachment. To address this issue, a carbon layer is deposited on the metal layer surface. The carbon layer does not form alloys with alkali metals (such as Na), while the metal layer provides numerous nucleation sites and a stable conductive network, facilitating the uniform deposition of alkali metals (such as Na). Furthermore, the carbon layer provides nucleation sites without undergoing volume changes; therefore, depositing a carbon layer on the metal layer surface effectively reduces the impact of metal layer expansion.

[0023] Optionally, the dynes value of the surface of the metal layer is from 38 dynes / cm to 50 dynes / cm.

[0024] In this application, the dyne value of the metal layer surface meets the above-mentioned range, which helps to reduce the phenomenon of carbon layer incomplete coating and the risk of carbon layer peeling off. For example, taking a Na metal battery as an example, a carbon layer is set after the aluminum foil surface is modified with a metal layer, wherein the metal layer includes a P group metal, which not only has good oxidation resistance and is not easy to form an oxide film, but also has a higher surface dyne value, making the carbon layer less likely to be incompletely coated. At the same time, it has a high affinity with Na and is easy to form an alloy. Therefore, once the carbon layer is incompletely coated, it is not easy for dendrites to form.

[0025] Optionally, the potential difference between the alkali-loving metal and the carbon layer is -0.5V to +0.5V.

[0026] It is understandable that, for example, taking a Na metal battery, if the difference between the potential of the Na-loving metal and the potential of the carbon layer meets the above range, it means that the potential of the Na-loving metal is similar to the potential of the carbon layer. Na is not easily deposited into the metal layer, and sodium is not easily deposited in the gap between the metal layer and the carbon layer. This reduces the risk of the carbon layer easily falling off due to sodium deposition between the metal layer and the carbon layer after the carbon layer is not properly coated.

[0027] Optionally, the potential of the alkali-loving metal is -0.8V to -0.1V.

[0028] In one embodiment, taking a Na metal battery as an example, the potential of the Na-loving metal is -0.8V to -0.1V, for example, In. + The standard electrode potential for +e≡In is -0.14V.

[0029] Optionally, the nucleation overpotential of the alkali-loving metal is higher than the nucleation overpotential of the carbon layer.

[0030] Understandably, for example, in a sodium metal battery, the smaller the absolute value of the nucleation overpotential on the negative electrode surface, the easier it is for sodium ions to deposit on the negative electrode. Furthermore, the nucleation overpotential of the sodium-loving metal in the metal layer is higher than that of the carbon layer, so sodium ions preferentially deposit on the carbon layer. This reduces the risk of the carbon layer easily detaching due to sodium deposition between the metal and carbon layers.

[0031] Optionally, the nucleation overpotential of the alkali-loving metal is -100mV to -200mV.

[0032] In one embodiment, taking a Na metal battery as an example, the nucleation overpotential of Na-loving metals is -100mV to -200mV. For example, the nucleation overpotential of In metal is -162mV.

[0033] Optionally, the thickness of the carbon layer is from 0.5 μm to 2 μm;

[0034] And / or, the particle size Dv99 of the carbon material in the carbon layer is 5 nm to 30 nm;

[0035] And / or, the carbon material in the carbon layer includes at least one of carbon nanotubes, graphene, and carbon black;

[0036] And / or, the mass of carbon material in the carbon layer accounts for 5% to 20% of the total mass of the carbon layer.

[0037] A carbon layer thickness within the above range can improve the energy density of the battery. It is understandable that metal is deposited on the surface of the carbon layer and it is difficult to deposit inside the carbon layer and in the pores. Increasing the thickness of the carbon layer will reduce the volumetric energy density of the battery.

[0038] The particle size Dv99 of the carbon material in the carbon layer meets the above-mentioned range, which helps to ensure the uniformity of the overall current density of the carbon layer. Within the above range, the particle size of the carbon material has good consistency, resulting in a uniform overall current density of the carbon layer.

[0039] The carbon material in the carbon layer includes at least one of carbon nanotubes, graphene, and carbon black.

[0040] Considering that the surface of carbon materials contains oxygen-containing photoenergy groups, which will adsorb sodium and cause capacity loss, the capacity loss can be reduced if the percentage of the mass of carbon material in the carbon layer is within the above range.

[0041] Optionally, the A metal battery includes a Na metal battery, a K metal battery, a Ca metal battery, and a Mg metal battery, and the material of the negative electrode current collector includes at least one of aluminum, copper, and nickel;

[0042] Alternatively, the A metal battery may include a Li metal battery, and the negative electrode current collector may be made of at least one of copper and nickel.

[0043] When the A metal battery includes Na metal battery, K metal battery, Ca metal battery, and Mg metal battery, the material of the negative electrode current collector includes at least one of aluminum, copper, and nickel.

[0044] When A metal battery includes Li metal battery, the material of the negative electrode current collector includes at least one of copper and nickel.

[0045] Optionally, the metal layer includes an adjacent first metal layer and a second metal layer, wherein the first metal layer is disposed on the negative electrode current collector, and the second metal layer is disposed on the side of the first metal layer away from the negative electrode current collector;

[0046] The negative electrode current collector is made of aluminum;

[0047] The first metal layer comprises copper or nickel;

[0048] The second metal layer comprises an A-philic metal;

[0049] Alternatively, the negative electrode current collector may include at least one of metal foil, porous metal plate, or composite negative electrode current collector composed of metal material and polymer material.

[0050] Considering that in some cases the adhesion of the second metal layer (including an A-friendly metal) to the surface of the negative electrode current collector is poor, in order to improve the bonding force between the negative electrode current collector and the second metal layer (A-friendly metal), a first metal layer is provided between the negative electrode current collector and the second metal layer (A-friendly metal). For example, in one embodiment, the negative electrode current collector is an aluminum foil, a first metal layer (Cu layer, for example, by electroplating) is provided on the surface of the aluminum foil, and then a second metal layer (for example, an A-friendly metal Sn) is provided on the surface of the first metal layer (Cu layer).

[0051] In one embodiment, the negative electrode current collector includes at least one of metal foil, porous metal plate, or composite negative electrode current collector composed of metal material and polymer material.

[0052] In one embodiment, in a Na metal battery, the negative electrode current collector is made of aluminum. For example, using aluminum can reduce costs; however, an oxide film easily forms on the surface of the aluminum negative electrode current collector, affecting the current distribution and causing uneven sodium deposition. The metal layer on the surface of the aluminum negative electrode current collector includes group P metal elements, which have a good affinity for Na and can be deposited uniformly.

[0053] In one embodiment, the negative electrode current collector is made of aluminum. In another embodiment, the metal layer is made of Cu.

[0054] Optionally, the metal layer has a carbon layer on the side opposite to the negative electrode current collector.

[0055] A carbon layer is provided on the side of the metal layer away from the negative electrode current collector. Since the dyne value of the metal layer surface is greater than that of the negative electrode current collector surface, the risk of carbon layer leakage is reduced.

[0056] Optionally, this application also provides a negative electrode sheet, the negative electrode sheet comprising a negative current collector and a metal layer disposed on at least one side surface of the negative current collector, the metal layer comprising an alkali-loving metal.

[0057] Optionally, the alkali-loving metal includes group P metals.

[0058] Optionally, the thickness of the metal layer is from 100 nm to 2000 nm;

[0059] And / or, the dynes value of the surface of the metal layer is from 38 dynes / cm to 50 dynes / cm.

[0060] Optionally, the metal layer has a carbon layer on the side opposite to the negative electrode current collector.

[0061] Optionally, the potential difference between the alkali-loving metal and the carbon layer is -0.5V to +0.5V;

[0062] And / or, the nucleation overpotential of the alkali-loving metal is higher than the nucleation overpotential of the carbon layer.

[0063] Optionally, this application also provides a method for preparing a metal battery, wherein the metal battery is an A metal battery, comprising disposing an A-friendly metal layer on at least one side surface of the negative electrode current collector.

[0064] Placing an A-friendly metal layer on the surface of the negative electrode current collector helps to improve the uniformity of A metal deposition on the negative electrode and improves the cycle performance of the battery.

[0065] Optionally, the step of forming an A-friendly metal layer on at least one side surface of the negative electrode current collector includes forming the A-friendly metal layer on at least one side surface of the negative electrode current collector by magnetron sputtering.

[0066] In the step of setting an A-friendly metal layer on the surface of the negative electrode current collector, electroplating can be used. However, due to the poor adhesion of electroplating, the A-friendly metal layer is easy to fall off from the surface of the negative electrode current collector. Therefore, magnetron sputtering can be used to set an A-friendly metal layer on the surface of the negative electrode current collector.

[0067] Optionally, after the step of forming an A-loving metal layer on at least one side of the negative electrode current collector, a carbon layer is formed on the surface of the A-loving metal layer.

[0068] Optionally, this application also provides an electrical device, which includes the aforementioned metal battery.

[0069] The metal battery of this application is an A-metal battery. The metal battery includes a negative electrode sheet, which includes a negative current collector and a metal layer disposed on at least one side surface of the negative current collector. The metal layer includes an A-friendly metal, and / or the dyne value of the metal layer surface is greater than the dyne value of the negative current collector surface. This application provides a metal layer on at least one side surface of the negative current collector, and the metal layer includes an A-friendly metal. The A-friendly metal readily forms an alloy with the A-metal, which facilitates the uniform deposition of the A-metal on the metal layer surface. When A-metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the metal layer surface, reducing the risk of metal dendrites piercing the separator and causing a short circuit; thereby improving the cycle performance of the battery.

[0070] Alternatively, if the dyne value of the metal layer surface is greater than that of the negative electrode current collector surface, the increased dyne value of the metal layer helps to improve the coating uniformity of the conductive layer on the metal layer surface, reduces the risk of missing coating, improves the uniformity of metal deposition on the negative electrode, and thus improves the cycle performance of the battery.

[0071] Alternatively, the metal layer may include an A-philic metal, and the dyne value of the metal layer surface may be greater than that of the negative electrode current collector surface. This will help ensure the uniformity of the conductive layer coating on the metal layer surface. Furthermore, even if there are gaps in the conductive layer coating on the metal layer surface, the inclusion of an A-philic metal will facilitate the formation of alloys with A metals, which will help the A metals to be deposited uniformly on the metal layer surface. When A metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the surface of the metal layer with gaps in the conductive layer coating, thus reducing the risk of metal dendrites piercing the separator and causing a short circuit; thereby improving the cycle performance of the battery. Attached Figure Description

[0072] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0073] Figure 1 This is a schematic diagram of the structure of an embodiment of the negative electrode sheet of this application;

[0074] Figure 2 This is a schematic diagram of another embodiment of the negative electrode sheet of this application;

[0075] Figure 3 This is a schematic diagram of a secondary battery according to one embodiment of this application;

[0076] Figure 4 yes Figure 3 An exploded view of a secondary battery according to an embodiment of this application is shown.

[0077] Figure 5 This is a schematic diagram of a battery module according to one embodiment of this application;

[0078] Figure 6 This is a schematic diagram of a battery pack according to one embodiment of this application;

[0079] Figure 7 yes Figure 6 An exploded view of a battery pack according to one embodiment of this application is shown;

[0080] Figure 8 This is a schematic diagram of an electrical device that uses a secondary battery as a power source according to one embodiment of this application.

[0081] Explanation of icon numbers:

[0082] label name label name 10 Negative current collector 4 Battery Module 20 Metal layer 5 Secondary batteries 30 carbon layer 51 case 1 battery pack 52 Electrode assembly 2 Upper box 53 Top cover assembly 3 Lower box

[0083] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0084] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0085] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the metal battery, negative electrode sheet, method for preparing the metal battery, and electrical device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0086] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0087] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0088] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0089] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0090] In metal batteries, during the process of metal ions migrating from the positive electrode to the negative electrode and depositing there, metal dendrites are easily deposited on the surface of the negative electrode, thus reducing the battery's cycle performance.

[0091] For example, taking sodium metal batteries as an example, in order to reduce costs, the copper foil of the negative electrode can be replaced with aluminum foil. However, an oxide film easily forms on the surface of aluminum foil, which affects the current distribution on the surface. In other words, aluminum oxide has poor conductivity, and sodium ions are deposited slowly on the surface of aluminum foil with poor conductivity, resulting in uneven sodium deposition. This can easily lead to the formation of metal dendrites, which can puncture the separator and cause a short circuit risk, thus reducing the cycle performance of the battery.

[0092] In metal batteries, to improve the cycle performance of batteries by mitigating the problem of metal ion deposition on the negative electrode and forming metal dendrites, this application proposes a metal battery, specifically an A-metal battery. The metal battery includes a negative electrode sheet, which comprises a negative current collector and a metal layer disposed on at least one side surface of the negative current collector. The metal layer comprises an A-loving metal, and / or the dyne value of the metal layer surface is greater than the dyne value of the negative current collector surface.

[0093] A metal battery is an A-metal battery, where A metal refers to the metal that migrates from the positive electrode to the negative electrode and deposits there. For example, when the metal battery is a sodium metal battery, A metal refers to Na. In other words, A-metal batteries include sodium metal batteries, potassium metal batteries, magnesium metal batteries, calcium metal batteries, etc.

[0094] Metals that are affinity for metals (A) are those that readily form alloys with metals of the same metal (A). This facilitates the uniform deposition of metals of the same metal on the surface of the metal layer, and makes it less likely for metal ions of the same metal to form metal dendrites on the surface of the metal layer when migrating from the positive electrode to the negative electrode.

[0095] The metal layer refers to the layered structure disposed on the surface of the negative electrode current collector. For example... Figure 1 As shown, the surface of the negative electrode current collector 10 is provided with a metal layer 20.

[0096] In one embodiment, the metal layer comprises an A-loving metal. It is understood that, generally, the metal layer may also comprise other materials, such as carbon materials, or other materials added as needed.

[0097] In one embodiment, the present application provides a metal layer on at least one side surface of the negative electrode current collector. The metal layer includes an A-friendly metal. The A-friendly metal readily forms an alloy with the A metal, which helps the A metal to be uniformly deposited on the surface of the metal layer. When the A metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the surface of the metal layer, reducing the risk of metal dendrites piercing the separator and causing a short circuit; thereby improving the cycle performance of the battery.

[0098] In another embodiment, the dyne value of the metal layer surface is greater than the dyne value of the negative electrode current collector surface. The increased dyne value of the metal layer contributes to the uniformity of the conductive layer coating on the metal layer surface, reduces the risk of incomplete coating, and improves the uniformity of metal deposition on the negative electrode, thereby improving the battery's cycle performance. For example, in one embodiment, a carbon layer (conductive layer) is coated on the metal layer surface. The dyne value of the metal layer surface is greater than the dyne value of the negative electrode current collector surface, which can reduce the risk of incomplete carbon layer coating.

[0099] Furthermore, in another embodiment, the metal layer includes an A-friendly metal. Simultaneously, the dyne value of the metal layer surface is greater than that of the negative electrode current collector surface. This contributes to the uniformity of the conductive layer coating on the metal layer surface. Furthermore, even if there are gaps in the conductive layer coating on the metal layer surface, the inclusion of an A-friendly metal facilitates alloying with A-metals, promoting uniform deposition of A-metals on the metal layer surface. When A-metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the surface of the metal layer with missing conductive layers, reducing the risk of metal dendrites piercing the separator and causing a short circuit; thereby improving the battery's cycle performance.

[0100] In one embodiment, the A-metal battery includes an alkali metal battery, and the A-loving metal includes a metal that is alkali-loving; or, the A-metal battery includes an alkaline earth metal battery, and the A-loving metal includes a metal that is alkaline earth metal.

[0101] It is understandable that metal A batteries include alkali metal batteries, and for alkali metal batteries, metals that are affinity for metal A include metals that are affinity for alkali metals. It is also understandable that metal A batteries include alkaline earth metal batteries, and metals that are affinity for metal A include metals that are affinity for alkaline earth metals.

[0102] In one embodiment, the metal battery includes a Na metal battery, and the A-loving metal includes a Na-loving metal.

[0103] When a metal battery includes a Na metal battery, the metal that is affinity for Na includes the metal that is affinity for Na. That is, the metal layer on at least one side of the negative electrode current collector includes the metal that is affinity for Na. The metal that is affinity for Na has a greater affinity for Na and is more likely to form an alloy with Na, so that when Na ions migrate from the positive electrode to the negative electrode, it is not easy for Na dendrites to form on the surface of the metal layer.

[0104] In one embodiment, the alkali-loving metal includes group P metals.

[0105] In one embodiment, the Na-loving metal includes P-group metals.

[0106] Group P elements, also known as p-block elements, include elements in columns 13 to 18 of the periodic table, namely Groups IIIA to VIIA and Group 0.

[0107] The valence electron configurations of Group P elements range from ns²np¹ to ns²np⁴, and they are generally prone to losing electrons, exhibiting strong nonmetallic properties. Alkali metals, on the other hand, have strong metallic properties, resulting in a good affinity between Group P metals and alkali metals. For example, Na has strong metallic properties, thus Group P metals have a good affinity for Na. Therefore, including a Group P metal in the metal layer on at least one side of the negative electrode current collector can improve the uniform deposition of Na.

[0108] Furthermore, oxide films easily form on the surface of some negative electrode current collectors, affecting the current distribution on the surface and thus the deposition. For example, taking aluminum foil as an example, aluminum foil is generally cheaper than copper foil. When aluminum foil is used as the negative electrode current collector, an oxide film easily forms on its surface. Aluminum oxide has poor conductivity, and sodium ions deposit slowly on the poorly conductive aluminum foil surface, leading to uneven sodium deposition and the easy formation of metal dendrites. Group P metals have better oxidation resistance and are less prone to oxide film formation. Having a metal layer of at least one side of the negative electrode current collector containing a Group P metal can improve the uniform deposition of Na.

[0109] In one embodiment, the P-group metals include at least one of Ga, In, Tl, Sn, Pb, Sb, and Bi. That is, the metal layer on at least one surface of the negative electrode current collector may include at least one of the aforementioned metals, or a combination of multiple metals.

[0110] In one embodiment, the thickness of the metal layer is 100 nm to 2000 nm.

[0111] Considering that some group P metals expand significantly when combined with alkali metals (such as Na), such as Sn, and that the metal layer on at least one side of the negative electrode current collector includes Sn, the metal layer is prone to detachment during long-term cycling. Controlling the metal layer thickness within the aforementioned range helps to control the volume change of the metal layer and reduce the risk of group P metal detachment.

[0112] The values ​​in the range of 100nm to 2000nm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 100nm, 200nm, 500nm, 800nm, 1000nm, 1500nm, 2000nm, etc.

[0113] Metal layer thickness testing steps: Disassemble the battery, remove the negative electrode sheet, ion polish the negative electrode sheet, then observe the cross-section using a scanning electron microscope, and measure the thickness by scribing. Take the average of 10 measurements as the corresponding thickness.

[0114] In one embodiment, a carbon layer is provided on the side of the metal layer facing away from the negative electrode current collector.

[0115] A carbon layer, which includes carbon materials. For example... Figure 2 As shown, a metal layer 20 and a carbon layer 30 are sequentially disposed on the surface of the negative electrode current collector 10.

[0116] Considering that some Group P metals form alloys with alkali metals (such as Na), resulting in significant volume changes, excessive volume changes during cycling can easily create gaps between the metal layer and the negative electrode current collector, increasing the risk of metal layer detachment. To address this issue, a carbon layer is deposited on the metal layer surface. The carbon layer does not form alloys with alkali metals (such as Na), and it provides numerous nucleation sites and a stable conductive network, facilitating the uniform deposition of alkali metals (such as Na). Furthermore, the carbon layer provides nucleation sites without undergoing volume changes; therefore, depositing a carbon layer on the metal layer surface effectively reduces the impact of metal layer expansion.

[0117] In one embodiment, the dynes value of the metal layer surface is from 38 dynes / cm to 50 dynes / cm.

[0118] The dyne value is a parameter used to quantify the surface tension of a material, typically used to assess the wettability and adhesion of liquids on solid surfaces. Generally speaking, a higher dyne value indicates better wettability. This is because a higher dyne value indicates a larger surface energy of the material, making it easier for the liquid to spread on the surface and form a continuous and uniform liquid film.

[0119] Test method and procedure for dyne value of metal layer surface: Use a dyne pen to test. Use dyne pens of different specifications to draw on the surface of the current collector, observe and judge the wetting situation, and determine whether its surface free energy is lower or higher than the value represented by the dyne pen.

[0120] To improve surface conductivity and achieve a uniform current distribution density, a conductive layer (such as a carbon layer) is often deposited on the surface of some negative electrode current collectors. However, in some negative electrode current collectors with low dyne values, carbon layer incomplete coating may occur. For example, in sodium metal batteries, taking aluminum foil as an example, a conductive carbon layer is coated on the surface of the aluminum foil to improve surface conductivity. However, incomplete coating is prone to occur. Furthermore, the potential of aluminum is lower than that of the carbon layer, and the nucleation energy barrier after the oxide film on the aluminum foil surface is low (comparable to that of the carbon layer). Therefore, sodium deposition tends to preferentially grow on the surface of the corroded aluminum foil or along the gap between the aluminum foil and the carbon layer, eventually leading to the carbon layer detaching.

[0121] Aluminum foil is produced by rolling, which leaves residual rolling oil on the surface. In addition, the aluminum foil itself has a low dyne value, which makes it easy to miss coating. By adding other metals to the surface of the aluminum foil, the dyne value of the surface can be increased, thereby reducing the problem of surface coating omission.

[0122] For example, taking Na metal batteries as an example, the Na-affinity metal dyne value in this application meets the above-mentioned range, which helps to reduce the phenomenon of carbon layer incomplete coating and at the same time reduces the risk of carbon layer peeling off. Furthermore, the aluminum foil surface is modified with a metal layer before the carbon layer is applied. This metal layer includes P-group metals, which not only have good oxidation resistance and are less prone to oxide film formation, but also have a higher surface dyne value, making the carbon layer less prone to incomplete coating. Simultaneously, it has a high affinity for Na, easily forming alloys; therefore, if the carbon layer is incompletely coated, dendrites are less likely to form.

[0123] The values ​​in the range of 38 dynes / cm to 50 dynes / cm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 38 dynes / cm, 39 dynes / cm, 40 dynes / cm, 41 dynes / cm, 43 dynes / cm, 45 dynes / cm, 47 dynes / cm, 49 dynes / cm, 50 dynes / cm, etc.

[0124] In one embodiment, the potential difference between the alkali-loving metal and the carbon layer is -0.5V to +0.5V.

[0125] The potential of a metal usually refers to the electrode potential of the metal.

[0126] The potential of the carbon layer refers to the electrode potential of the carbon material.

[0127] Methods and procedures for testing the potential of metals and carbon materials: The electrode to be tested is connected to a standard hydrogen electrode to form a galvanic cell, and the electrode potential of the electrode is measured by a potentiometer.

[0128] It is understandable that, for example, taking a Na metal battery, if the difference between the potential of the Na-loving metal and the potential of the carbon layer meets the above range, it means that the potential of the Na-loving metal is similar to the potential of the carbon layer. Na is not easily deposited into the metal layer, and sodium is not easily deposited in the gap between the metal layer and the carbon layer. This reduces the risk of the carbon layer easily falling off due to sodium deposition between the metal layer and the carbon layer after the carbon layer is not properly coated.

[0129] Specific examples of the above-mentioned -0.5V to +0.5V range include, but are not limited to, the point values ​​in the embodiments, as well as -0.5V, 0V, +0.5V, etc.

[0130] In one embodiment, the potential of the alkali-loving metal is -0.8V to -0.1V.

[0131] In one embodiment, taking a Na metal battery as an example, the potential of the Na-loving metal is -0.8V to -0.1V, for example, In. + The standard electrode potential of +e=In is -0.14V.

[0132] In one embodiment, the nucleation overpotential of the alkali-loving metal is higher than that of the carbon layer. It is understood that the negative electrode charging process involves two processes: sodium nucleation and growth. For example, in a Na metal battery, the deposition potential refers to the sodium growth process, while the nucleation overpotential refers to the potential required for sodium ions to nucleate at the negative electrode.

[0133] Test method and procedure for nucleation overpotential: A galvanic cell is formed by the target electrode and sodium metal, with sodium metal as the positive electrode and the target electrode as the negative electrode. The cell is charged by an electrochemical workstation, and sodium metal is deposited on the target electrode.

[0134] Understandably, the smaller the absolute value of the nucleation overpotential on the negative electrode surface, the easier it is for sodium ions to deposit on the negative electrode. The nucleation overpotential of the Na-loving metal in the metal layer is higher than that of the carbon layer, so sodium ions preferentially deposit on the carbon layer. This reduces the risk of the carbon layer easily detaching due to sodium deposition between the metal and carbon layers.

[0135] In one embodiment, the nucleation overpotential of the alkali-loving metal is -100mV to -200mV.

[0136] In one embodiment, the thickness of the carbon layer is 0.5 μm to 2 μm.

[0137] In one embodiment, the particle size Dv99 of the carbon material in the carbon layer is 5 nm to 30 nm.

[0138] In one embodiment, the carbon material in the carbon layer includes at least one of carbon nanotubes, graphene, and carbon black.

[0139] In one embodiment, the mass of carbon material in the carbon layer accounts for 5% to 20% of the total mass of the carbon layer.

[0140] Particle size Dv99 refers to the particle size value at which the cumulative distribution in the particle size distribution curve reaches 99%. Specifically, Dv99 indicates that 99% of all particles have a particle size less than or equal to the value corresponding to Dv99. Testing can be performed using methods known in the art. For example, GB / T19077-2016 can be referenced for characterization testing using a Malvern laser particle size analyzer, such as the Malvern Mastersizer-3000.

[0141] A carbon layer thickness within the above range can improve the energy density of the battery.

[0142] The particle size Dv99 of the carbon material in the carbon layer meets the above-mentioned range, which helps to ensure the uniformity of the overall current density of the carbon layer. Within the above range, the particle size of the carbon material has good consistency, resulting in a uniform overall current density of the carbon layer.

[0143] The carbon material in the carbon layer includes at least one of carbon nanotubes, graphene, and carbon black.

[0144] Considering that the surface of carbon materials contains oxygen-containing photoenergy groups, which will adsorb sodium and cause capacity loss, the capacity loss can be reduced if the percentage of the mass of carbon material in the carbon layer is within the above range.

[0145] The values ​​in the range of 0.5μm to 2μm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments and 0.5μm, 0.6μm, 0.8μm, 1μm, 1.2μm, 1.5μm, 1.8μm, 2μm, etc.

[0146] The values ​​in the range of 5nm to 30nm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments and 5nm, 7nm, 10nm, 15nm, 20nm, 25nm, 30nm, etc.

[0147] The values ​​in the range of 5% to 20% include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments and 5%, 7%, 9%, 10%, 12%, 15%, 18%, 20%, etc.

[0148] In one embodiment, the A metal battery includes a Na metal battery, a K metal battery, a Ca metal battery, and a Mg metal battery, and the negative electrode current collector is made of at least one of aluminum, copper, and nickel; or, the A metal battery includes a Li metal battery, and the negative electrode current collector is made of at least one of copper and nickel.

[0149] When the A metal battery includes Na metal battery, K metal battery, Ca metal battery, and Mg metal battery, the material of the negative electrode current collector includes at least one of aluminum, copper, and nickel.

[0150] When A metal battery includes Li metal battery, the material of the negative electrode current collector includes at least one of copper and nickel.

[0151] In one embodiment, the metal layer includes an adjacent first metal layer and a second metal layer, the first metal layer being disposed on the negative electrode current collector, and the second metal layer being disposed on the side of the first metal layer away from the negative electrode current collector; the negative electrode current collector is made of aluminum; the first metal layer includes copper or nickel; and the second metal layer includes an alkanesitic metal.

[0152] The second metal layer is located on the side of the first metal layer away from the negative electrode current collector, meaning that the first metal layer is located between the negative electrode current collector and the second metal layer.

[0153] Considering that in some cases the adhesion of the second metal layer (including an A-friendly metal) to the surface of the negative electrode current collector is poor, in order to improve the bonding force between the negative electrode current collector and the second metal layer (A-friendly metal), a first metal layer is provided between the negative electrode current collector and the second metal layer (A-friendly metal). For example, in one embodiment, the negative electrode current collector is an aluminum foil, a first metal layer (Cu layer, for example, by electroplating) is provided on the surface of the aluminum foil, and then a second metal layer (for example, an A-friendly metal Sn) is provided on the surface of the first metal layer (Cu layer).

[0154] In one embodiment, the negative electrode current collector includes at least one of metal foil, porous metal plate, or composite negative electrode current collector composed of metal material and polymer material.

[0155] In one embodiment, in a Na metal battery, the negative electrode current collector is made of aluminum. For example, using aluminum can reduce costs; however, an oxide film easily forms on the surface of the aluminum negative electrode current collector, affecting the current distribution and causing uneven sodium deposition. The metal layer on the surface of the aluminum negative electrode current collector includes group P metal elements, which have a good affinity for Na and can be deposited uniformly.

[0156] In addition, to address the issue of large volume changes caused by the alloying of some Group P metals with Na, which can easily create gaps between the metal layer and the negative electrode current collector during cycling and lead to metal layer detachment, a carbon layer is placed on the surface of the metal layer. The carbon layer does not form an alloy with Na and provides a large number of nucleation sites and a stable conductive network, which helps to ensure uniform sodium deposition and improves the cycle performance of the battery.

[0157] In one embodiment, the metal battery includes a positive electrode and a negative electrode. The negative electrode includes a negative current collector and a metal layer disposed on at least one side of the negative current collector. The dyne value of the surface of the metal layer is greater than the dyne value of the surface of the negative current collector. For example, the negative current collector is an aluminum foil, and a metal layer is disposed on the surface of the aluminum foil. The metal layer includes Cu, and the dyne value of Cu is greater than that of the aluminum foil, which can improve the coating uniformity of the carbon layer.

[0158] In one embodiment, a carbon layer is provided on the side of the metal layer facing away from the negative electrode current collector.

[0159] A carbon layer is provided on the side of the metal layer away from the negative electrode current collector. Since the dyne value of the metal layer surface is greater than that of the negative electrode current collector surface, the risk of carbon layer leakage is reduced.

[0160] In one embodiment, this application also provides a negative electrode sheet, which includes a negative current collector and a metal layer disposed on at least one side surface of the negative current collector, the metal layer including a Na-loving metal.

[0161] In one embodiment, the alkali-loving metal includes group P metals.

[0162] In one embodiment, the thickness of the metal layer is 100 nm to 2000 nm.

[0163] In one embodiment, the dynes value of the metal layer surface is from 38 dynes / cm to 50 dynes / cm.

[0164] In one embodiment, a carbon layer is provided on the side of the metal layer facing away from the negative electrode current collector.

[0165] In one embodiment, the potential difference between the alkali-loving metal and the carbon layer is -0.5V to +0.5V.

[0166] In one embodiment, the nucleation overpotential of the alkali-loving metal is higher than that of the carbon layer.

[0167] In one embodiment, this application also provides a method for preparing a metal battery, wherein the metal battery is an A metal battery, and includes forming an A-friendly metal layer on at least one side surface of the negative electrode current collector.

[0168] Placing an A-friendly metal layer on the surface of the negative electrode current collector helps to improve the uniformity of A metal deposition on the negative electrode and improves the cycle performance of the battery.

[0169] In one embodiment, the step of forming an A-friendly metal layer on at least one side surface of the negative electrode current collector includes forming the A-friendly metal layer on at least one side surface of the negative electrode current collector by magnetron sputtering.

[0170] In the step of setting an A-friendly metal layer on the surface of the negative electrode current collector, electroplating can be used. However, due to the poor adhesion of electroplating, the A-friendly metal layer is easy to fall off from the surface of the negative electrode current collector. Therefore, magnetron sputtering can be used to set an A-friendly metal layer on the surface of the negative electrode current collector.

[0171] In one embodiment, after the step of forming an A-loving metal layer on at least one side surface of the negative electrode current collector, a carbon layer is formed on the surface of the A-loving metal layer.

[0172] In one embodiment, this application also provides an electrical device, which includes the metal battery described above.

[0173] Since the metal battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0174] In addition, the battery (secondary battery, battery module, battery pack) and power supply device of this application will be described below with appropriate reference to the accompanying drawings.

[0175] In one embodiment of this application, a secondary battery is provided.

[0176] This application does not impose any particular limitation on the shape of the secondary battery; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 3 This is an example of a square-structured secondary battery 5.

[0177] In some implementations, refer to Figure 4 The outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 can be placed over the opening to close the receiving cavity. The positive electrode, negative electrode, and separator may be formed into an electrode assembly 52 by a winding process or a stacking process. The electrode assembly 52 is encapsulated within the receiving cavity. Electrolyte is immersed in the electrode assembly 52. ​​The secondary battery 5 may contain one or more electrode assemblies 52, which can be selected by those skilled in the art according to specific practical needs.

[0178] In some implementations, the secondary batteries can be assembled into a battery module, and the number of secondary batteries contained in the battery module can be one or more, the specific number of which can be selected by those skilled in the art according to the application and capacity of the battery module.

[0179] Figure 5 This is battery module 4, used as an example. (See reference...) Figure 5 In battery module 4, multiple secondary batteries 5 can be arranged sequentially along the length of battery module 4. Of course, they can also be arranged in any other manner. Furthermore, these multiple secondary batteries 5 can be fixed in place using fasteners.

[0180] Optionally, the battery module 4 may also include a housing with a receiving space in which a plurality of secondary batteries 5 are received.

[0181] In some embodiments, the battery modules described above can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, the specific number of which can be selected by those skilled in the art according to the application and capacity of the battery pack.

[0182] Figure 6 and Figure 7 This is battery pack 1 as an example. (See reference...) Figure 6 and Figure 7 The battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0183] In addition, this application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided in this application. The secondary battery, battery module, or battery pack can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0184] As an electrical device, a secondary battery, battery module, or battery pack can be selected according to its usage requirements.

[0185] Figure 8 This is an example of an electrical device. The device could be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the secondary battery for this device, a battery pack or battery module can be used.

[0186] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use a rechargeable battery as their power source.

[0187] Example

[0188] Example 1

[0189] Preparation of the positive electrode sheet:

[0190] Positive electrode active material (polyanionic sodium ion positive electrode), conductive carbon, and PVDF were dissolved in NMP solvent in a ratio of 8:1:1, coated onto aluminum foil, and dried to obtain a coating weight of 10 mg / cm³. 2 The positive electrode sheet.

[0191] Preparation of negative electrode sheet:

[0192] A 500nm thick Sn metal layer is deposited on the surface of the aluminum foil by magnetron sputtering.

[0193] Electrolyte preparation:

[0194] The sodium salt is NaTFSI, and the solvents are DOL (1,3-dioxolane) and DME (ethylene glycol dimethyl ether) in a 1:1 ratio, which are miscible. NaTFSI is dissolved in the solvent to form an electrolyte with a concentration of 1 mol / L.

[0195] Battery assembly:

[0196] The cells are obtained by overlapping and winding the diaphragm, negative electrode, diaphragm, and positive electrode. The top cover and outer shell are then welded together to obtain the wound square-shell cell. Finally, the cells are liquefied and formed to obtain the complete cell.

[0197] Nucleation overpotential testing procedure: Using the negative electrode as the negative electrode and the sodium sheet as the positive electrode, a galvanic cell is formed by the positive electrode / separator / negative electrode. The cell is then tested using an electrochemical workstation at a rate of 1 mAh / cm². 2 The charging current charges the material, and the lowest potential point on the charging curve is the nucleation overpotential.

[0198] The test procedure for the first efficiency of a coin cell is as follows: using the negative electrode sheet as the negative electrode and the sodium electrode positive electrode as the positive electrode, the positive electrode / separator / negative electrode form a galvanic cell, and charge and discharge at a rate of 0.1C. The ratio of the first discharge capacity to the first charge capacity is used as the first efficiency.

[0199] The test procedure for 90% SOH (State of Health) of coin cell cycle life is as follows: use the negative electrode as the negative electrode and the sodium electrode as the positive electrode to form a primary cell, and charge and discharge at a rate of 1C; when the SOH drops to 90%, record the number of cycles at this time, which means that the battery has reached 90% of its expected life.

[0200] Examples 2 to 4

[0201] Based on Example 1, the Sn metal layer was adjusted to 100nm, 250nm, and 2000nm respectively.

[0202] Example 5

[0203] Based on Example 3, CNT paste was coated on the surface of the Sn metal layer to form a 1 μm thick carbon layer.

[0204] Example 6

[0205] Based on Example 2, a 250nm thick Cu layer was deposited on the surface of the aluminum foil by electroplating.

[0206] Example 7

[0207] Based on Example 6, CNT paste was coated on the surface of the Cu layer to form a 1 μm thick carbon layer. Cu is a non-P group element, but it has a high dyne value, which improves the problem of incomplete coating of CNTs. At the same time, the metal potential of Cu is similar to that of CNTs.

[0208] Example 8

[0209] Based on Example 6, a 250nm thick Cu layer is electroplated onto the surface of the aluminum foil, followed by a 250nm thick Sn layer (Sn is a P-group element; due to the poor adhesion of electroplating, Cu can be used as a transition layer for effective adhesion). CNT paste is then applied to the surface of the Sn layer to form a 1μm thick carbon layer.

[0210] Example 9

[0211] Based on Example 1, Sn is replaced with In.

[0212] Example 10

[0213] Based on Example 9, a carbon layer is coated on the surface of the In metal layer.

[0214] Comparative Example 1

[0215] Based on Example 1, no Sn metal layer is set on the surface of the aluminum foil in the preparation of the negative electrode sheet.

[0216] Example 11

[0217] Preparation of the positive electrode sheet:

[0218] The positive electrode active material (lithium iron phosphate), conductive carbon, and PVDF were dissolved in NMP solvent in a ratio of 8:1:1, coated onto aluminum foil, and dried to obtain a coating weight of 10 mg / cm³. 2 The positive electrode sheet.

[0219] Preparation of negative electrode sheet:

[0220] A 500nm thick In metal layer is deposited on the surface of the copper foil by magnetron sputtering.

[0221] Electrolyte preparation:

[0222] The sodium salt is LiTFSI, and the solvents are DOL (1,3-dioxolane) and DME (ethylene glycol dimethyl ether) in a 1:1 ratio, which are miscible. LiTFSI is dissolved in the solvent to form an electrolyte with a concentration of 1 mol / L.

[0223] Comparative Example 2

[0224] Based on Example 11, no In metal layer is set on the surface of the copper foil in the preparation of the negative electrode sheet.

[0225] Table 1. List of Experimental Data

[0226]

[0227]

[0228] As shown in Table 1 above, the aluminum foil surface of the negative electrode current collector in Examples 1 to 4 and Example 9 is provided with Na-loving metals (Sn, In), while Comparative Example 1 uses pure aluminum foil. The battery cycle performance was improved after providing Na-loving metals on the surface of the negative electrode current collector. This indicates that the metal layer includes Na-loving metals, which readily form alloys with Na-loving metals, facilitating the uniform deposition of Na-loving metals on the metal layer surface. When Na-loving metal ions migrate from the positive electrode to the negative electrode, they are less likely to form metal dendrites on the metal layer surface, reducing the risk of metal dendrites piercing the separator and causing a short circuit; thus improving the battery cycle performance.

[0229] As in Examples 5 and 10, further providing a carbon layer on the surface of the metal layer can further improve the cycle performance of the battery.

[0230] As shown in Example 6, a Cu layer is formed on the surface of the aluminum foil of the negative electrode current collector. Cu is a non-aluminophilic metal with a dyne value greater than that of the aluminum foil, and its cycle performance is better than that of Comparative Example 1. As shown in Example 7, a carbon layer is formed on the surface of the Cu layer, which can reduce the undercoating of the carbon layer.

[0231] As shown in Comparative Example 2 and Example 11, the negative electrode current collector in the lithium metal battery is made of Cu, and an In metal layer is provided on the surface of Cu, which improves the cycle performance of the battery.

[0232] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A metal battery, characterized in that, The metal battery is an A-metal battery, the metal battery includes a negative electrode sheet, the negative electrode sheet includes a negative current collector and a metal layer disposed on at least one side surface of the negative current collector, the metal layer includes an A-friendly metal, and / or, the dyne value of the surface of the metal layer is greater than the dyne value of the surface of the negative current collector.

2. The metal battery as described in claim 1, characterized in that, The A-metal battery includes an alkali metal battery, and the A-loving metal includes an alkali-loving metal; Alternatively, the A-metal battery may include an alkaline earth metal battery, and the A-loving metal may include an alkaline earth metal-loving metal.

3. The metal battery as described in claim 2, characterized in that, The alkali-loving metals include metals from the P group.

4. The metal battery as described in claim 3, characterized in that, The P-group metals include at least one of Ga, In, Tl, Sn, Pb, Sb, and Bi.

5. The metal battery according to any one of claims 1 to 4, characterized in that, The thickness of the metal layer is from 100 nm to 2000 nm.

6. The metal battery according to any one of claims 1 to 5, characterized in that, The metal layer has a carbon layer on the side opposite to the negative electrode current collector.

7. The metal battery according to any one of claims 1 to 6, characterized in that, The dynes value of the surface of the metal layer is between 38 dynes / cm and 50 dynes / cm.

8. The metal battery as described in claim 6 or 7, characterized in that, The difference between the potential of the alkali-loving metal and the potential of the carbon layer is -0.5V to +0.5V.

9. The metal battery as described in claim 8, characterized in that, The potential of the alkali-loving metal is -0.8V to -0.1V.

10. The metal battery according to any one of claims 6 to 9, characterized in that, The nucleation overpotential of the alkali-loving metal is higher than that of the carbon layer.

11. The metal battery as described in claim 10, characterized in that, The nucleation overpotential of the alkali-loving metal is -100mV to -200mV.

12. The metal battery according to any one of claims 7 to 11, characterized in that, The thickness of the carbon layer is 0.5 μm to 2 μm; And / or, the particle size Dv99 of the carbon material in the carbon layer is 5 nm to 30 nm; And / or, the carbon material in the carbon layer includes at least one of carbon nanotubes, graphene, and carbon black; And / or, the mass percentage of carbon material in the carbon layer is 5% to 20% of the total mass of the carbon layer.

13. The metal battery according to any one of claims 1 to 12, characterized in that, The A metal battery includes Na metal battery, K metal battery, Ca metal battery, and Mg metal battery, and the material of the negative electrode current collector includes at least one of aluminum, copper, and nickel; Alternatively, the A metal battery may include a Li metal battery, and the negative electrode current collector may be made of at least one of copper and nickel.

14. The metal battery according to any one of claims 1 to 13, characterized in that, The metal layer includes an adjacent first metal layer and a second metal layer, wherein the first metal layer is disposed on the negative electrode current collector, and the second metal layer is disposed on the side of the first metal layer opposite to the negative electrode current collector. The negative electrode current collector is made of aluminum; The first metal layer comprises copper or nickel; The second metal layer comprises an A-philic metal; Alternatively, the negative electrode current collector may include at least one of metal foil, porous metal plate, or composite negative electrode current collector composed of metal material and polymer material.

15. A negative electrode sheet, characterized in that, The negative electrode sheet includes a negative current collector and a metal layer disposed on at least one side surface of the negative current collector, the metal layer including an alkali-loving metal.

16. The negative electrode sheet as described in claim 15, characterized in that, The alkali-loving metals include metals from the P group.

17. The negative electrode sheet as described in claim 15 or 16, characterized in that, The thickness of the metal layer is from 100 nm to 2000 nm; And / or, the dynes value of the surface of the metal layer is from 38 dynes / cm to 50 dynes / cm.

18. The negative electrode of the metal battery as described in any one of claims 15 to 17, characterized in that, The metal layer has a carbon layer on the side opposite to the negative electrode current collector.

19. The negative electrode of the metal battery as described in claim 18, characterized in that, The potential difference between the alkali-loving metal and the carbon layer is -0.5V to +0.5V; And / or, the nucleation overpotential of the alkali-loving metal is higher than the nucleation overpotential of the carbon layer.

20. A method for preparing a metal battery, characterized in that, The metal battery is an A-metal battery, comprising an A-friendly metal layer disposed on at least one side surface of the negative electrode current collector.

21. The method for preparing a metal battery as described in claim 20, characterized in that, The step of forming an A-friendly metal layer on at least one side of the surface of the negative electrode current collector includes forming the A-friendly metal layer on at least one side of the surface of the negative electrode current collector by magnetron sputtering.

22. The method for preparing a metal battery as described in claim 20 or 21, characterized in that, After the step of forming an A-loving metal layer on at least one side of the negative electrode current collector, a carbon layer is formed on the surface of the A-loving metal layer.

23. An electrical appliance, characterized in that, The electrical device includes a metal battery as described in any one of claims 1 to 14.

Images