An integrated alkali metal electrode with a multi-layer structure, its preparation method and application

Abstract

The present invention provides a multi-layer structure integrated alkali metal electrode, a preparation method thereof and an application, belonging to the field of new energy. The multi-layer structure integrated alkali metal electrode of the present invention includes a current collector layer, a transition layer and an active layer. The electrode surface capacity and electrode activity can be regulated through the transition layer. It has excellent mechanical properties, chemical and electrochemical stability. The preparation process is simple and the alkali metal content and distribution in the electrode can be flexibly regulated. When the lithium, sodium and potassium-based alkali metal electrodes prepared by the present invention are used as negative electrodes in lithium metal batteries, sodium metal batteries and potassium metal batteries respectively, the battery performance can be improved, and they have broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of new energy, and more specifically, relates to an alkali metal electrode with an integrated multi-layer structure, a preparation method thereof, and an application thereof. Background Art

[0002] With the popularization of smart devices, new energy vehicles, and the construction of large-scale energy storage facilities, the development of secondary batteries with higher energy density and good safety is an eternal pursuit in the market. Taking lithium-ion batteries as an example, they are widely used in electric vehicles and portable electronic devices, but traditional lithium-ion batteries are already difficult to meet the actual application requirements. Alkali metal lithium, due to its low redox potential (–3.04V versus standard hydrogen electrode) and high theoretical specific capacity (more than ten times that of the existing graphite anode), is regarded as the most important anode material in future lithium batteries. Similar to lithium, sodium (1165 mAh g -1 , which is more than ten times that of the existing graphite anode), and potassium (687 mAh g -1 , -2.71V versus standard hydrogen electrode) in the alkali metal group are also ideal anode materials for secondary batteries. These alkali metal anodes are expected to be widely used in the next generation of secondary metal ion batteries, all-solid-state batteries, metal-sulfur batteries, and metal-gas batteries, significantly improving the energy density of the batteries. -1 , -2.93V versus standard hydrogen electrode) in the alkali metal group are also ideal anode materials for secondary batteries. These alkali metal anodes are expected to be widely used in the next generation of secondary metal ion batteries, all-solid-state batteries, metal-sulfur batteries, and metal-gas batteries, significantly improving the energy density of the batteries.

[0003] However, during the charge and discharge process of the battery, the uneven deposition and dissolution on the surface of the alkali metal cause the growth of dendrites, which easily pierce the separator and cause serious safety hazards such as battery short circuit; moreover, the super strong reducibility of the alkali metal causes a large number of side reactions at the electrode / electrolyte interface, consuming the electrolyte and active alkali metal, resulting in low charge and discharge efficiency of the electrode and rapid capacity decay with cycling. In addition, the disordered deposition and dissolution process of the alkali metal is accompanied by a huge change in the volume of the electrode, causing the internal structure of the battery to be damaged and fail. At the same time, the specific capacity of existing commercial cathode materials is relatively low. When using alkali metal as the anode, the specific capacity of the anode is much larger than that of the cathode, and it is difficult to prepare an alkali metal anode with a suitable areal capacity in a conventional way, and its mechanical properties cannot meet the actual electrode application requirements. The mismatch of the areal capacity between the anode and the cathode not only leads to a significant reduction in the utilization rate of active alkali metal, but also causes an increase in the cost of battery materials and waste of resources. These problems greatly restrict the actual application process of alkali metal as an electrode for high-energy density secondary batteries.

[0004] For electrodes based on alkali metal-based alloys, by introducing other elements that are more chemically inert to adjust the chemical potential of the alkali metal electrodes, the deposition can be made orderly and controllable, the change in the electrode volume can be reduced, and the electrochemical performance and safety of the battery can be improved. Currently, alkali metal-based alloy electrodes are usually prepared by a melting and smelting process. However, melting and smelting require high temperatures, and the preparation process has high safety requirements. It is difficult to adjust the content and distribution of alkali metals in the alkali metal-based alloy electrodes. Moreover, when using only alkali metal-based alloys as electrodes, their mechanical properties are difficult to guarantee. Due to the soft texture of alkali metals, the electrodes are extremely prone to wrinkling defects, which affect their electrochemical performance.

[0005] In view of this, it is necessary to develop an alkali metal electrode with excellent mechanical properties, chemical and electrochemical stability, which can inhibit the volume effect, and whose alkali metal distribution and electrode surface capacity can be flexibly regulated. It is of great significance to apply it to the negative electrode of high-energy density batteries, endowing it with excellent electrochemical performance and safety to meet the actual application requirements. Summary of the Invention

[0006] Aiming at the defects of the prior art, the purpose of the present invention is to provide a multi-layer structure integrated alkali metal electrode, its preparation method and application. A transition layer is provided on the current collector layer, and an alkali metal active component is introduced by an in-situ reaction on the transition layer to prepare a multi-layer structure integrated alkali metal electrode. The electrode surface capacity, electrode activity and electrochemical performance are regulated by using different compositions and thicknesses of the transition layer. The alkali metal electrode prepared by the present invention has excellent mechanical properties, chemical and electrochemical stability, and the alkali metal content and distribution can be flexibly regulated to meet the actual application requirements.

[0007] To achieve the above object, the present invention provides a multi-layer structure integrated alkali metal electrode, which includes a current collector layer, a transition layer prefabricated on the current collector layer, and an active layer generated by the reaction of the transition layer. The active layer is in-situ obtained by a spontaneous chemical reaction when the transition layer contacts an active reaction solution. The active reaction solution contains an active alkali metal that can react with the transition layer. The transition layer is transformed into the active layer in-situ by obtaining the active alkali metal in all or part of its thickness, and the active layer can undertake the negative electrode function in the battery to provide an electrochemical active capacity.

[0008] Furthermore, the active alkali metal in the active layer is one or more of Li, Na, and K.

[0009] Furthermore, the transition layer material is one or more of a single element, an alloy, or / and a composite material. Among them, the single element is a single element formed by element L, and L is selected from one or more of Zn, In, Al, Mg, Pb, Sn, Si, Ca, Ag, Au, Ga, Bi, Sb, and Ge that can form an alloy with an alkali metal. By changing the type of element L, the electrode activity and areal capacity can be adjusted. The reason for this is that element L is an element that can chemically react with the active alkali metals Li, Na, and K, and can "absorb" or "capture" the active alkali metals from the active reaction solution. For example, In can react with the active alkali metal Li to form LiIn. After the reaction, the part of the In transition layer that has absorbed the active alkali metal Li contains LiIn, and LiIn can act as the negative electrode. The thickness of the part that has turned into LiIn changes from the transition layer to the active layer. Another example is that Ge can also chemically react with Li and "absorb" or "capture" the active alkali metal Li from the active reaction solution to obtain Li 4.4 Ge, and the thickness part of Ge in the transition layer turns into Li 4.4 Ge and becomes the active layer. One In atom can "capture" at most one Li atom, while one Ge atom can "capture" up to 4.4 Li atoms. Therefore, the content of the active alkali metal in the active layer can be regulated by controlling the type of element L, and the areal capacity of the electrode is different when the content of the alkali metal is different.

[0010] Among them, the alloy is formed by element L and element M. Element M is inert with respect to the active reaction solution, and element M is selected from one or more of Cu, Ti, V, Cr, Fe, Co, Ni, Cs, Zr, and Ta. In the alloy, the addition of element M can regulate the electrode composition and reduce the volume change and areal capacity of the electrode during the contact process with the active reaction solution and the subsequent alkali metal deposition and dissolution processes. The specific reason is that element M is inert with respect to the active reaction solution and does not react with the active alkali metal. Only element L in it will "absorb" or "capture" the active alkali metal from the active reaction solution. Therefore, by regulating the type of alloy formed by element M and L, the content of element L in the alloy can be regulated, and then the content of the alkali metal can be regulated. Since element L in the alloy "captures" the active alkali metal element, it will cause the overall volume of the electrode to expand. By regulating the alloy type and then regulating the content of element L, ultimately, not only the areal capacity of the electrode can be regulated but also the volume change of the electrode can be regulated. In addition, since the inert element M does not participate in the reaction and is stable in the alloy, it will bring structural stability, and ultimately will bring chemical stability and structural stability to the transition layer and the corresponding active layer.

[0011] Among them, the composite material is composed of at least two of element L, element M, and element X, and element X is selected from one or more of B, C, S, N, P, O, and F. Element X is used to improve the electrochemical stability of the electrode. Specifically, in the composite material, the non-metal X can adjust the soft hardness and surface chemical state of the electrode, and form a solid electrolyte interface film on the electrode surface during the charge and discharge cycle of the battery, improving the electrochemical performance. The specific reason is that elements such as B, C, S, N, and P can react with alkali metal ions during the battery cycle, and then form an alkali metal-non-metal solid electrolyte interface film, that is, SEI film, on the electrode surface, such as LiF, Li2O, Li3N, Li2S, etc., which can promote the ion transport and distribution at the electrode / electrolyte interface, improve the stability of the electrode interface, and thus help to improve the cycle performance and service life of the electrode and improve the electrochemical performance of the electrode.

[0012] Furthermore, the thickness of the transition layer is 1 nm to 80 μm. The setting of the thickness of the transition layer can play a role in adjusting the areal capacity of the electrode. Because the active alkali metal is in-situ obtained in all or part of the thickness of the transition layer, and the corresponding all or part of the thickness itself is transformed into an active layer. The thicker the transition layer, the thicker the active layer that can be obtained, and the more active alkali metal contained in the thicker active layer, the larger the areal capacity of the electrode. Conversely, the areal capacity of the electrode is smaller. According to the requirements of the final areal capacity of the electrode, the flexible regulation of the alkali metal content and the areal capacity of the electrode can be achieved by adjusting the thickness of the transition layer.

[0013] Furthermore, the surface of the current collector layer has a planar, concave-convex or / and wavy pattern, and the surface pattern of the transition layer is consistent with that of the current collector layer. On the one hand, the pattern can increase the specific surface area of the electrode to provide a larger reaction interface, thereby reducing the local current density of the electrode during charge and discharge, and enabling more uniform deposition and dissolution of alkali metals; on the other hand, it can increase the adhesion between the transition layer and the current collector layer, and between the active layer and the transition layer, and can also buffer the volume change of the electrode during the deposition and dissolution of alkali metals, so that the electrode can better maintain the structural integrity during the battery cycle, without falling off, cracking or pulverizing. Specifically, when the current collector has surface irregularities and patterns, during evaporation coating or preparation of the transition layer, it can increase the adhesion between the transition layer and the current collector layer, making the two layers more tightly combined and not easily falling off, with good mechanical properties. Moreover, since the thickness of the transition layer is relatively thin and evenly covers the surface of the current collector, it can inherit and retain the same irregularities and patterns as the current collector, giving the entire electrode a large reaction specific surface area;;; when the transition layer itself has a certain thickness, it can directly have an independent pattern through patterning design during the preparation of the transition layer, which can also provide a large surface area for the electrode, generate an active layer with a three-dimensional structure when reacting with the active reaction solution, and buffer the volume change of the electrode during the deposition and dissolution of alkali metals during subsequent battery operation. In addition, different surface patterns have different surface areas, and by changing their surface areas, it is also possible to adjust the amount of active alkali metal absorbed in situ during the reaction between the transition layer and the active reaction solution, and thus control the electrode surface capacity.

[0014] Furthermore, the current collector layer is a foil, sheet, thin film or mesh formed of a metal material with good conductivity and capable of independent self-support, the metal material is stainless steel, or the metal material is selected from one or more of the elements Cu, Al, Ti, Ni, Zn to form a single substance, alloy or composite material. Or, the current collector layer is a carbon cloth, carbon felt or carbon film with good conductivity and capable of independent self-support, and its material is one or more of carbon nanotubes, graphene, reduced graphene oxide, carbon black.

[0015] In the above inventive concept, the current collector layer plays a major mechanical support role in the entire multi-layer integrated electrode, and is the main source of mechanical strength. Its thickness is relatively thick, and the total thickness of the transition layer and the active layer can be very thin. The role of the transition layer is to transform itself or a part of itself into an active layer that can provide negative electrode capacity through chemical reactions. By regulating the thickness, composition and morphology of the transition layer itself, the thickness, composition, morphology and distribution of active metals of the active layer can be indirectly changed, ultimately playing a role in regulating the electrode surface capacity, chemical stability and mechanical stability. The thickness, composition and morphology of the transition layer can be freely and flexibly regulated.

[0016] According to the second aspect of the present invention, there is also provided a method for preparing the above-mentioned alkali metal electrode. First, a current collector layer is prepared, and then a transition layer with a set shape is prepared on the current collector layer by one-step or multi-step sputtering, evaporation coating, electroplating, pressing, or coating. Then, the transition layer is brought into contact with an active reaction solution containing an active alkali metal and maintained in contact for a set duration, or the active reaction solution containing the active alkali metal is drop-coated on the transition layer and continued for a set duration. The transition layer absorbs the active alkali metal, and the part of the transition layer that has absorbed the active alkali metal is in-situ transformed into an active layer. The active reaction solution does not react violently with air or water, and reacts mildly with the transition layer, having good operation safety.

[0017] In the above inventive concept, the preparation method of the transition layer is extremely flexible and can adopt various methods such as sputtering, evaporation coating, electroplating, pressing, and coating. Such a flexible preparation method can prepare a transition layer with diverse morphologies, structures, compositions, and distributions. Indirectly, it is possible to prepare an active layer with diverse morphologies, structures, compositions, and distributions. To make the transition layer combine more closely with the current collector layer to form an integrated structure and regulate the thickness of the transition layer and the volume change at the electrode reaction interface during the charge and discharge cycle of the battery, the structure of the transition layer can be consistent with the surface structure of the current collector, or a separate pattern structure can be designed and obtained during the preparation process by sputtering, evaporation coating, electroplating, pressing, or coating. Specifically, regardless of the morphology of the current collector layer, the morphology of the transition layer can be independently prepared, such as being prepared into a planar shape, a concave-convex shape, or / and a wavy shape, which is consistent with the morphology of the current collector, or being prepared into its own unique shape. For another example, a Ge transition layer can be prepared, and then an In transition layer can be prepared on the Ge transition layer. The number of layers, morphology, and composition can be changed according to needs, and all are achievable, which is very flexible.

[0018] Furthermore, by controlling the composition of the transition layer, the thickness of the transition layer, and the contact duration between the transition layer and the active reaction solution, the thickness of the active layer and the content of active alkali metals contained in the active layer are controlled. Specifically, when the content of element L that can chemically react with active alkali metals Li, Na, and K in the transition layer is relatively high, the amount of active alkali metals that can be "absorbed" or "captured" from the active reaction solution is larger, the content of active alkali metals contained in the active layer is higher, and the areal capacity of the electrode is larger. Conversely, the areal capacity of the electrode is smaller. When the content of element M that is inert with respect to the active reaction solution in the transition layer is relatively high, since element M does not react with active alkali metals, the amount of active alkali metals that can be "absorbed" or "captured" from the active reaction solution is smaller, the content of active alkali metals contained in the active layer is lower, and the areal capacity of the electrode is smaller. Conversely, the areal capacity of the electrode is larger. The setting of the thickness of the transition layer can play a role in adjusting the areal capacity of the electrode. Because the transition layer in all or part of its thickness in-situ obtains active alkali metals and transforms the corresponding all or part of its thickness itself into the active layer. The thicker the transition layer, the thicker the active layer that can be obtained. The more active alkali metals contained in the thicker active layer, the larger the areal capacity of the electrode. Conversely, the areal capacity of the electrode is smaller. In addition, when the contact duration between the transition layer and the active reaction solution is longer, the reaction time is longer, the amount of active alkali metals that can be "absorbed" or "captured" from the active reaction solution is larger, the content of active alkali metals contained in the active layer is higher, and the areal capacity of the electrode is larger. Conversely, the areal capacity of the electrode is smaller. When the concentration of alkali metals in the active electrolyte is higher, the amount of active alkali metals that the transition layer can "absorb" or "capture" from it is also larger, and the formation of the active layer is easier and the capacity is also larger.

[0019] Furthermore, the active reaction solution includes a complexing solute and an organic solvent. The complexing solute is formed by a complexing metal Y and a complexing agent. The complexing metal Y is one or more of Li, Na, and K. The complexing solute is dissolved in the organic solvent.

[0020] The complexing agent is selected from one or more of naphthalene and its derivatives, biphenyl and its derivatives, anthracene and its derivatives, phenanthrene and its derivatives, pyrene and its derivatives, and tetracene and its derivatives.

[0021] The organic solvent is selected from one or more of ethylene glycol dimethyl ether, tetrahydrofuran, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0022] According to the third aspect of the present invention, there is also provided the application of the alkali metal electrode as described above. When the active layer contains alkali metal Li, it is used in a lithium-ion battery; when the active layer contains alkali metal Na, it is used in a sodium-ion battery; when the active layer contains alkali metal K, it is used in a potassium-ion battery.

[0023] In the present invention, a transition layer is prefabricated on the current collector layer, and then an alkali metal component is introduced through a contact reaction between the active reaction solution and the transition layer to in-situ generate an active layer, forming an alkali metal electrode with an integrated multi-layer structure. Through the integrated design of the multi-layer structure, the current collector layer provides excellent mechanical properties for the electrode, the transition layer improves the chemical and electrochemical stability of the alkali metal electrode, and the in-situ generated active layer enables flexible regulation of the alkali metal areal capacity. As an electrode, it needs to have good conductivity and mechanical properties. Therefore, the current collector layer is a foil, sheet, thin film or mesh with good conductivity and capable of independent self-support, and the material is selected from one or more of Cu, Al, Ti, Ni, Zn, stainless steel, or includes but is not limited to carbon cloth, carbon felt, and carbon film composed of one or more of carbon nanotubes, graphene, reduced graphene oxide, and carbon black.

[0024] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the method and product of the present invention have extremely high engineering application value, and specifically have the following beneficial effects:

[0025] (1) In the present invention, by integrally designing the alkali metal electrode through a multi-layer structure, the problem that it is difficult to guarantee the mechanical properties of the electrode and thus affect its electrochemical performance when simply using alkali metal or alkali metal-based alloy as the electrode is avoided. Through the integrated design of the multi-layer structure, the mechanical strength of the electrode can be improved to meet the actual application requirements. At the same time, through the regulation of the preparation process of the transition layer, arbitrary regulation of the thickness of the active layer can be realized, and the change in the volume of the electrode can be reduced. The composition of the transition layer is adjustable, which can realize the regulation of the alkali metal content and activity of the electrode, and can also regulate the areal capacity of the electrode according to actual needs.

[0026] (2) In the present invention, a liquid-phase solution reaction is used to prepare the alkali metal active layer, which avoids the melting and smelting method used in the traditional preparation of alkali metal alloys and the problems of difficult adjustment of alkali metal content and distribution brought by it, and can also overcome the safety problems brought by the melting and smelting method. The method of the present invention is simple and easy to operate, has a short time period, does not require precision and expensive production equipment, the degree of alkali metalization is controllable, and the safety is strong.

[0027] (3) In the present invention, the integrated multi-layer structure alkali metal electrode introduces other elements with more chemical inertness to form an alkali metal-based alloy to regulate the chemical potential and activity of the alkali metal electrode, making the deposition of alkali metal orderly and controllable during the battery cycling process, and reducing the change in the volume of the electrode. When the integrated multi-layer structure alkali metal electrode is used as the battery negative electrode, it can improve the electrochemical performance of the battery and also enhance the safety, having broad application prospects. Description of the Drawings

[0028] Figure 1Schematic diagram of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention, where the current collector layer, the transition layer, and the active layer are all planar.

[0029] Figure 2 Schematic diagram of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention, where the current collector layer is planar, and the transition layer has an independent concave-convex pattern shape.

[0030] Figure 3 Schematic diagram of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention, where the current collector layer has a concave-convex pattern shape, and the transition layer has the same concave-convex pattern shape as the current collector layer.

[0031] Figure 4 Flow chart for preparing a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention.

[0032] Figure 5 Scanning electron microscope (SEM) image of a multi-layer structure integrated alkali metal electrode with a concave-convex pattern shape provided by an embodiment of the present invention.

[0033] Figure 6 Scanning electron microscope (SEM) image of a multi-layer structure integrated alkali metal electrode with a mesh pattern provided by an embodiment of the present invention.

[0034] Figure 7 XRD comparison chart before and after preparing the active layer by contact reaction of a pure indium transition layer provided by an embodiment of the present invention.

[0035] Figure 8 XRD chart of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention.

[0036] Figure 9 Alkali metal surface capacity curve obtained after charging a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention. Detailed implementation manners

[0037] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] The present invention provides a multi-layer structure integrated lithium, sodium, potassium-based alkali metal electrode, a preparation method thereof and an application. The alkali metal electrode includes a current collector layer, a transition layer and an active layer. A transition layer is prefabricated on the current collector layer, and alkali metal active components are in-situ introduced on the transition layer through a one-step reaction to prepare a multi-layer structure integrated alkali metal electrode. The electrode surface capacity, electrode activity and electrochemical performance are regulated by using different components and thicknesses of the transition layer. The alkali metal electrode prepared by the present invention has excellent mechanical properties, chemical and electrochemical stability, and the alkali metal content and distribution can be arbitrarily regulated to meet the actual application requirements.

[0039] Figure 1 FIG. 4 is a schematic diagram of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention, in which the current collector layer, the transition layer and the active layer are all planar. Figure 2 FIG. 6 is a schematic diagram of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention, in which the current collector layer is planar, and the transition layer has an independent concave-convex pattern shape. Figure 3 FIG. 8 is a schematic diagram of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention, in which the current collector layer has a concave-convex pattern shape, and the transition layer has the same concave-convex pattern shape as the current collector layer. Figure 4 FIG. 10 is a preparation flow chart of a multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention. Combining Figure 1 、 Figure 2 、 Figure 3 and Figure 4 it can be seen that a multi-layer structure integrated lithium, sodium, potassium-based alkali metal electrode and a preparation method thereof provided by the present invention include the following steps:

[0040] First, a current collector layer is prepared. Then, a transition layer is prepared by one-step or multi-step sputtering, evaporation, electroplating, pressing, coating, etc., and the transition layer is firmly bonded to the current collector layer. Finally, an active reaction solution is contacted with the transition layer to prepare an active layer, and a multi-layer structure integrated alkali metal electrode is obtained.

[0041] In the above method, the current collector layer is a foil, sheet, thin film or mesh with good conductivity and capable of independent self-support, and the material is selected from one or more of Cu, Al, Ti, Ni, Zn, stainless steel, or includes but is not limited to carbon cloth, carbon felt, carbon film composed of one or more of carbon nanotubes, graphene, reduced graphene oxide, carbon black. According to the requirements of the final electrode, the surface of the current collector includes but is not limited to one or more of planar, concave-convex, wavy pattern structures.

[0042] In one embodiment of the present invention, the transition layer material is selected from one or more of simple substances, alloys, and composite materials composed of metal / non-metal composites. Among them, the simple substance is composed of element L, and element L includes one or more of Zn, In, Al, Mg, Pb, Sn, Si, Ca, Ag, Au, Ga, Bi, Sb, and Ge that can form alloys with alkali metals. The alloy material includes an alloy material formed by element L and element M, where element M includes one or more of Cu, Ti, V, Cr, Fe, Co, Ni, Cs, Zr, and Ta. The metal / non-metal composite material includes a metal L / non-metal X composite material or a metal L / metal M / non-metal X composite material, where element X includes one or more of B, C, S, N, P, O, and F. The transition layer structure can be consistent with the surface structure of the current collector or can be prepared by sputtering, evaporation coating, electroplating, pressing, or coating to obtain a separate pattern structure.

[0043] The active layer is an alloy containing active alkali metals, where the active alkali metals are formed by element Y, and element Y is selected from one or more of Li, Na, and K. The active layer is in-situ generated by bringing the current collector with the transition layer into contact with an active reaction solution. Among them, the active reaction solution includes a complexing solute and an organic solvent. The complexing solute is composed of a complexing metal Y and a complexing agent, and the complexing solute is dissolved in the organic solvent. The complexing agent is selected from one or more of naphthalene and its derivatives, biphenyl and its derivatives, anthracene and its derivatives, phenanthrene and its derivatives, pyrene and its derivatives, and tetracene and its derivatives. The organic solvent is selected from one or more of ethylene glycol dimethyl ether, tetrahydrofuran, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0044] In fact, the complexing agent is not limited to the above several types. As long as the following conditions are met, it can be used as a complexing agent: (1) a polycyclic aromatic hydrocarbon; (2) it can receive the electrons of alkali metals to form a stable radical anion. The organic solvent is not limited to the above several types. As long as the following conditions are met, it can also be used as an organic solvent: the solvent can dissolve the complexing agent and will not react with alkali metals.

[0045] To illustrate the method of the present invention in more detail, the following further elaborates with specific examples.

[0046] Example 1

[0047] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 5 μm, 100 nm of pure indium is deposited by evaporation on the copper foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the pure indium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto the surface with the pure indium transition layer, and it reacts with the pure indium transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.8 mAh / cm 2 The electrode is assembled with a lithium manganese oxide cathode into a full cell, and the reversible capacity can reach 115 mAh g -1 and remains almost unchanged after 50 cycles.

[0048] Example 2

[0049] In a protective atmosphere, on the surface of an aluminum foil current collector with a thickness of 10 μm, 1 nm of pure indium is sputtered on the aluminum foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The aluminum foil with the pure indium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto the surface with the pure indium transition layer, and it reacts with the pure indium transition layer for 1 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.01 mAh / cm 2 The electrode is assembled with a lithium manganese oxide cathode into a full cell, and the reversible capacity can reach 110 mAh g -1 and remains almost unchanged after 100 cycles.

[0050] Example 3

[0051] In a protective atmosphere, on the surface of a titanium foil current collector with a thickness of 20 μm, 2 nm of pure silver is sputtered on the titanium foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The titanium foil with the pure silver transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto the surface with the pure silver transition layer, and it reacts with the pure silver transition layer for 3 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.02 mAh / cm 2 The electrode is assembled with a lithium manganese oxide cathode into a full cell, and the reversible capacity can reach 112 mAh g -1 and remains almost unchanged after 200 cycles.

[0052] Example 4

[0053] In a protective atmosphere, on the surface of a stainless-steel foil current collector with a thickness of 50 μm, 4 nm of pure zinc is sputtered on the stainless-steel foil surface by sputtering as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The stainless-steel foil with the pure zinc transition layer is laid out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure zinc transition layer, and it is allowed to react with the pure zinc transition layer for 5 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.1 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 200 cycles.

[0054] Example 5

[0055] In a protective atmosphere, on the surface of a nickel foil current collector with a thickness of 30 μm, 6 nm of pure bismuth is sputtered on the nickel foil surface by sputtering as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The nickel foil with the pure bismuth transition layer is laid out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure bismuth transition layer, and it is allowed to react with the pure bismuth transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.1 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 158 mAh / g -1 and remains almost unchanged after 200 cycles.

[0056] Example 6

[0057] In a protective atmosphere, on the surface of an aluminum foil current collector with a thickness of 12 μm, 15 μm of pure indium is pressed on the aluminum foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The aluminum foil with the pure indium transition layer is laid out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure indium transition layer, and it is allowed to react with the pure indium transition layer for 20 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 3 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 200 cycles.

[0058] Example 7

[0059] In a protective atmosphere, on the surface of the carbon nanotube film, 8 nm of pure gold is deposited by evaporation on the surface of the carbon nanotube film as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon nanotube film with the pure gold transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure gold transition layer, and allowed to react with the pure gold transition layer for 30 min to obtain a multi-layer structure integrated alkali metal electrode with a areal capacity of 0.06 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 155 mAh / g -1 and remains almost unchanged after 200 cycles.

[0060] Example 8

[0061] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 100 μm, 10 nm of pure tin is deposited by evaporation on the copper foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the pure tin transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure tin transition layer, and allowed to react with the pure tin transition layer for 40 min to obtain a multi-layer structure integrated alkali metal electrode with a areal capacity of 0.2 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 500 cycles.

[0062] Example 9

[0063] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 200 μm, 12 nm of antimony and phosphorus are co-deposited by co-evaporation on the copper foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the antimony and phosphorus transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the antimony and phosphorus transition layer, and allowed to react with the antimony and phosphorus transition layer for 60 min to obtain a multi-layer structure integrated alkali metal electrode with a areal capacity of 0.06 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 162 mAh / g -1 and remains almost unchanged after 200 cycles.

[0064] Example 10

[0065] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 500 μm, 50 nm of silver is first vapor-deposited by vapor deposition, and then 50 nm of tin is vapor-deposited on the copper foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the silver and tin transition layers is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the silver and tin transition layers, and allowed to react with the silver and tin transition layers for 60 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.4 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 200 cycles.

[0066] Example 11

[0067] In a protective atmosphere, on the surface of a carbon cloth current collector with a thickness of 10 μm, 5 nm of germanium is first vapor-deposited by vapor deposition, and then 20 nm of phosphorus is vapor-deposited on the carbon cloth surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon cloth with the germanium and phosphorus transition layers is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the germanium and phosphorus transition layers, and allowed to react with the germanium and phosphorus transition layers for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.1 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 300 cycles.

[0068] Example 12

[0069] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 3 μm of indium is vapor-deposited by vapor deposition on the copper foil surface as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the indium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium transition layer, and allowed to react with the indium transition layer for 30 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 1 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 155 mAh / g -1 and remains almost unchanged after 200 cycles.

[0070] Example 13

[0071] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 8 μm of aluminum is pressed on the copper foil surface by a pressing method as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with an aluminum transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the aluminum transition layer, and it is allowed to react with the aluminum transition layer for 30 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 3 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 155 mAh / g -1 and remains almost unchanged after 200 cycles.

[0072] Example 14

[0073] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 12 μm of aluminum is pressed on the copper foil surface by a pressing method as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with an aluminum transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the aluminum transition layer, and it is allowed to react with the aluminum transition layer for 20 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 4 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 151 mAh / g -1 and remains almost unchanged after 300 cycles.

[0074] Example 15

[0075] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 20 μm of aluminum is electroplated on the copper foil surface by an electroplating method as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with an aluminum transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the aluminum transition layer, and it is allowed to react with the aluminum transition layer for 20 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 5 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 156 mAh / g -1 and remains almost unchanged after 300 cycles.

[0076] Example 16

[0077] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 30 μm of antimony is pressed onto the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.5 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the antimony transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the antimony transition layer, and allowed to react with the antimony transition layer for 30 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 3 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 156 mAh / g -1 and remains almost unchanged after 250 cycles.

[0078] Example 17

[0079] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 40 μm of magnesium is pressed onto the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.5 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the magnesium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the magnesium transition layer, and allowed to react with the magnesium transition layer for 30 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 4 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 153 mAh / g -1 and remains almost unchanged after 300 cycles.

[0080] Example 18

[0081] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 50 μm of antimony is pressed onto the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the antimony transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the antimony transition layer, and allowed to react with the antimony transition layer for 30 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 5 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 156 mAh / g -1 and remains almost unchanged after 300 cycles.

[0082] Example 19

[0083] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 60 μm of germanium is pressed on the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.5 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with a germanium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the germanium transition layer, and it is allowed to react with the germanium transition layer for 30 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 15 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 156 mAh / g -1 and remains almost unchanged after 300 cycles.

[0084] Example 20

[0085] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 70 μm of germanium is pressed on the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 3 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with a germanium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the germanium transition layer, and it is allowed to react with the germanium transition layer for 60 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 20 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 156 mAh / g -1 and remains almost unchanged after 300 cycles.

[0086] Example 21

[0087] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 10 μm, 80 μm of magnesium is pressed on the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.5 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with a magnesium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the magnesium transition layer, and it is allowed to react with the magnesium transition layer for 60 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 10 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 150 mAh / g -1 and remains almost unchanged after 400 cycles.

[0088] Example 22

[0089] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 20 μm, 75 μm of indium is pressed on the copper foil surface by a pressing method as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with an indium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium transition layer, and allowed to react with the indium transition layer for 45 minutes to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 15 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 154 mAh / g -1 and remains almost unchanged after 400 cycles.

[0090] Example 23

[0091] In a protective atmosphere, on the surface of a carbon cloth current collector with a thickness of 1 μm, 5 nm of indium is evaporated on the carbon cloth surface by an evaporation method as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon cloth with an indium transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium transition layer, and allowed to react with the indium transition layer for 10 minutes to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.05 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 155 mAh / g -1 and remains almost unchanged after 200 cycles.

[0092] Example 24

[0093] In a protective atmosphere, on the surface of a carbon cloth current collector with a thickness of 1 μm, 5 nm of indium is first evaporated and then 50 nm of sulfur is evaporated on the carbon cloth surface by an evaporation method as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon cloth with indium and sulfur transition layers is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium and sulfur transition layers, and allowed to react with the indium and sulfur transition layers for 10 minutes to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.06 mAh / cm 2 The electrode is assembled with a lithium iron phosphate cathode into a full cell, and the reversible capacity can reach 158 mAh / g -1 and remains almost unchanged after 300 cycles.

[0094] Example 25

[0095] In a protective atmosphere, on the surface of a planar carbon cloth current collector with a thickness of 1 μm, 5 nm of indium is first vapor-deposited by vapor deposition, and then 50 nm of sulfur is vapor-deposited on the carbon cloth surface as a transition layer, where the transition layer is vapor-deposited in a wavy shape; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon cloth with an indium and sulfur transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium and sulfur transition layer, and it is allowed to react with the indium and sulfur transition layer for 10 min to obtain a multi-layer structure integrated alkali metal electrode with a areal capacity of 0.07 mAh / cm 2 The electrode is assembled with a lithium iron phosphate positive electrode into a full cell, and the reversible capacity can reach 158 mAh / g -1 and remains almost unchanged after 400 cycles.

[0096] Example 26

[0097] In a protective atmosphere, on the surface of a mesh carbon cloth current collector with a thickness of 1 μm, 5 nm of indium is first vapor-deposited by vapor deposition, and then 50 nm of sulfur is vapor-deposited on the carbon cloth surface as a transition layer, where the transition layer is also in a mesh shape; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon cloth with an indium and sulfur transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium and sulfur transition layer, and it is allowed to react with the indium and sulfur transition layer for 10 min to obtain a multi-layer structure integrated alkali metal electrode with a areal capacity of 0.08 mAh / cm 2 The electrode is assembled with a lithium iron phosphate positive electrode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 400 cycles.

[0098] Example 27

[0099] In a protective atmosphere, on the surface of a carbon cloth with a thickness of 500 nm, 30 nm of gallium is first vapor-deposited on the surface of a copper foil by vapor deposition, and then in a fluorine gas atmosphere, a transition layer is formed; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.3 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The carbon cloth with a gallium and fluorine transition layer is spread out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the gallium and fluorine transition layer, and it is allowed to react with the gallium and fluorine transition layer for 10 min to obtain a multi-layer structure integrated alkali metal electrode with a areal capacity of 0.1 mAh / cm 2 The electrode is assembled with a lithium iron phosphate positive electrode into a full cell, and the reversible capacity can reach 160 mAh / g -1 and remains almost unchanged after 180 cycles.

[0100] Example 28

[0101] In a protective atmosphere, on the surface of a copper foil with a thickness of 10 μm, 1 μm of silicon was first vapor-deposited on the copper foil surface by vapor deposition, and then a transition layer was formed in an oxygen atmosphere; a certain amount of sodium and naphthalene were weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.4 mol / L sodium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil containing the silicon and oxygen transition layer was spread out, and the sodium-naphthalene / ethylene glycol dimethyl ether organic solution was dropped onto its surface containing the silicon and oxygen transition layer, and allowed to react with the silicon and oxygen transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity was 1 mAh / cm 2 . The electrode was assembled with a Prussian blue positive electrode into a full battery, and the reversible capacity could reach 120 mAh / g -1 , and it remained almost unchanged after 200 cycles.

[0102] Example 29

[0103] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 8 μm, 50 nm of tin and nickel were evaporated on the copper foil surface by electron beam evaporation as a transition layer; a certain amount of sodium and naphthalene were weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 0.5 mol / L sodium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil containing the tin and nickel transition layer was spread out, and the sodium-naphthalene / ethylene glycol dimethyl ether organic solution was dropped onto its surface containing the tin and nickel transition layer, and allowed to react with the indium and nickel transition layer for 5 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity was 0.03 mAh / cm 2 . The electrode was assembled with a Prussian blue positive electrode into a full battery, and the reversible capacity could reach 110 mAh / g -1 , and it remained almost unchanged after 200 cycles.

[0104] Example 30

[0105] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 8 μm, 10 nm of zinc was first sputtered, and then 1 nm of gold was sputtered on the copper foil surface as a transition layer; a certain amount of potassium and naphthalene were weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 1 mol / L potassium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil containing the gold and zinc transition layer was spread out, and the potassium-naphthalene / ethylene glycol dimethyl ether organic solution was dropped onto its surface containing the gold and silver transition layer, and allowed to react with the gold and zinc transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity was 0.04 mAh / cm 2 . The electrode was assembled with a Prussian blue positive electrode into a full battery, and the reversible capacity could reach 120 mAh / g -1 , and it remained almost unchanged after 150 cycles.

[0106] Example 31

[0107] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 8 μm, 10 μm of pure silver is pressed onto the copper foil surface by pressing as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 2 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the pure silver transition layer is laid out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure silver transition layer, and it is allowed to react with the pure silver transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 2 mAh / cm 2 . The electrode is assembled with a Prussian blue positive electrode into a full cell, and the reversible capacity can reach 125 mAh g -1 , and it remains almost unchanged after 250 cycles.

[0108] Example 32

[0109] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 30 μm, 5 μm of indium and carbon composite material is coated onto the copper foil surface by coating as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 3 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the indium and carbon composite material transition layer is laid out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the indium and carbon composite material transition layer, and it is allowed to react with the indium and carbon composite material transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 1 mAh / cm 2 . The electrode is assembled with a lithium iron phosphate positive electrode into a full cell, and the reversible capacity can reach 160 mAh g -1 , and it remains almost unchanged after 200 cycles.

[0110] Example 33

[0111] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 70 μm and a corrugated pattern, 100 nm of pure gold is evaporated onto the copper foil surface by evaporation as a transition layer; a certain amount of lithium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 5 mol / L lithium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with the pure gold transition layer is laid out, and the lithium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure gold transition layer, and it is allowed to react with the pure gold transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.5 mAh / cm 2 . The electrode is assembled with a lithium iron phosphate positive electrode into a full cell, and the reversible capacity can reach 160 mAh g -1 , and it remains almost unchanged after 200 cycles.

[0112] Example 34

[0113] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 200 μm, pure indium with a reticular pattern of 200 nm is sputtered on the copper foil surface by sputtering as a transition layer; a certain amount of sodium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 6 mol / L sodium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with a pure indium transition layer is spread out, and the sodium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure indium transition layer, and it is allowed to react with the pure indium transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.5 mAh / cm 2 The electrode is assembled with a Prussian blue positive electrode into a full cell, and the reversible capacity can reach 130 mAh / g -1 and remains almost unchanged after 200 cycles.

[0114] Example 35

[0115] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 8 μm, 2 μm of pure tin is electroplated on the copper foil surface by electroplating as a transition layer; a certain amount of sodium and naphthalene are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare an 8 mol / L sodium-naphthalene / ethylene glycol dimethyl ether organic solution. The copper foil with a pure tin transition layer is spread out, and the sodium-naphthalene / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure tin transition layer, and it is allowed to react with the pure tin transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 1 mAh / cm 2 The electrode is assembled with a Prussian blue positive electrode into a full cell, and the reversible capacity can reach 128 mAh / g -1 and remains almost unchanged after 200 cycles.

[0116] Example 36

[0117] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 8 μm, 500 nm of pure zinc is evaporated on the copper foil surface by evaporation as a transition layer; a certain amount of potassium and biphenyl are weighed and uniformly dissolved in a certain amount of ethylene glycol dimethyl ether to prepare a 9 mol / L potassium-biphenyl / ethylene glycol dimethyl ether organic solution. The copper foil with a pure zinc transition layer is spread out, and the potassium-biphenyl / ethylene glycol dimethyl ether organic solution is dropped onto its surface with the pure zinc transition layer, and it is allowed to react with the pure zinc transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.5 mAh / cm 2 The electrode is assembled with a Prussian blue positive electrode into a full cell, and the reversible capacity can reach 130 mAh / g -1 and remains almost unchanged after 200 cycles.

[0118] Example 37

[0119] In a protective atmosphere, on the surface of a copper foil current collector with a thickness of 100 μm, 800 nm of pure zinc is deposited by evaporation as a transition layer on the copper foil surface; a certain amount of potassium and naphthalene are weighed and uniformly dissolved in a certain amount of tetrahydrofuran to prepare a 10 mol / L potassium-naphthalene / tetrahydrofuran organic solution. The copper foil with the pure zinc transition layer is spread out, and the potassium-naphthalene / tetrahydrofuran organic solution is dropped onto its surface with the pure zinc transition layer, and allowed to react with the pure zinc transition layer for 10 min to obtain an integrated alkali metal electrode with a multi-layer structure, and the areal capacity is 0.8 mAh / cm 2 The electrode is assembled with a Prussian blue positive electrode into a full cell, and the reversible capacity can reach 125 mAh / g -1 and remains almost unchanged after 200 cycles.

[0120] The following further lists the examples in the form of a table to further illustrate in detail the electrodes, preparation methods and applications of the present invention.

[0121] Table 1 shows the detailed data of alkali metal electrodes with different current collector layers, transition layers and their thicknesses, and liquid phase solutions in the examples to obtain different alkali metal contents

[0122]

[0123]

[0124]

[0125] Figure 5 is a scanning electron microscope (SEM) image of an integrated alkali metal electrode with a multi-layer structure provided by an embodiment of the present invention, and its surface has a reticular pattern.

[0126] Figure 6 is a scanning electron microscope (SEM) image of an integrated alkali metal electrode with a multi-layer structure provided by an embodiment of the present invention, and its surface has a concave-convex pattern shape.

[0127] Figure 7 is an XRD comparison chart before and after the contact reaction of a pure indium transition layer to prepare an active layer provided by an embodiment of the present invention. It can be seen from the figure that the pure indium transition layer obtains an active layer with an indium-lithium alloy phase after the contact reaction with the lithium-naphthalene / ethylene glycol dimethyl ether solution.

[0128] Figure 8 is an XRD pattern of an integrated alkali metal electrode with a multi-layer structure provided by an embodiment of the present invention. Among them, the current collector layer is a copper foil, the transition layer prefabricated on the current collector layer is pure indium, and an active layer with an indium-lithium alloy phase is obtained after the contact reaction with the lithium-naphthalene / ethylene glycol dimethyl ether solution.

[0129] Figure 9It is the alkali metal surface capacity curve obtained after charging the multi-layer structure integrated alkali metal electrode provided by an embodiment of the present invention. As can be seen from the figure, the alkali metal surface capacity in the obtained alkali metal electrode is 3 mAh / cm -2 , which is relatively high.

[0130] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated alkali metal electrode with a multi-layer structure, characterized in that, It includes a current collector layer, a transition layer prefabricated on the current collector layer, and an active layer formed by the reaction of the transition layer. The active layer is obtained by an in-situ chemical reaction spontaneously generated when the transition layer contacts an active reaction solution. The active reaction solution contains an active alkali metal capable of reacting with the transition layer. The transition layer is transformed into the active layer in-situ by obtaining the active alkali metal in all or part of its thickness, and the active layer can provide capacity in the battery and thus undertake the negative electrode function. The transition layer material is one or more of single substances or alloys, where the single substance is a single substance formed by element L, and L is selected from one or more of Zn, In, Al, Mg, Pb, Sn, Si, Ca, Ag, Au, Ga, Bi, Sb, and Ge that can form alloys with alkali metals. The alloy is formed by element L and element M, and element M is selected from one or more of Cu, Ti, V, Cr, Fe, Co, Ni, Cs, Zr, and Ta. Element M is inert with respect to the active reaction solution.

2. The integrated alkali metal electrode with a multi-layer structure according to claim 1, wherein The active alkali metal in the active layer is one or more of Li, Na, and K.

3. The integrated alkali metal electrode with a multi-layer structure according to claim 1, characterized in that, The thickness of the transition layer is 1 nm to 80 μm.

4. The integrated alkali metal electrode with a multi-layer structure according to claim 3, wherein, The surface of the current collector layer has a planar, concave-convex, or / and wavy pattern, and the surface pattern of the transition layer is the same as that of the current collector layer surface or the transition layer surface has its own unique pattern.

5. A multi-layer structure integrated alkali metal electrode according to any one of claims 1-4, characterized in that, The current collector layer is a foil, sheet, thin film, or mesh formed of a metal material with good electrical conductivity and capable of independent self-support. The metal material is stainless steel, or the metal material is selected from one or more of the single substances, alloys, or composite materials formed by elements Cu, Al, Ti, Ni, and Zn, or the current collector layer is a carbon cloth, carbon felt, or carbon film with good electrical conductivity and capable of independent self-support, and its material is one or more of carbon nanotubes, graphene, reduced graphene oxide, and carbon black.

6. A method for preparing an alkali metal electrode according to any one of claims 1-5, characterized in that first prepare the current collector layer, and then prepare a transition layer with a set pattern on the current collector layer by one-step or multi-step sputtering, evaporation coating, electroplating, pressing, or coating methods. Then, contact or immerse the transition layer with an active reaction solution containing an active alkali metal and maintain the contact for a specific duration, or drop the active reaction solution containing the active alkali metal on the transition layer and maintain it for a set duration. The transition layer absorbs the active alkali metal and in-situ transforms the part that has absorbed the active alkali metal into the active layer.

7. The method according to claim 6, wherein By regulating the composition of the transition layer, the thickness of the transition layer, the concentration of the active reaction solution, and the contact duration between the transition layer and the active reaction solution, regulate the thickness of the active layer and the content of the active alkali metal contained in the active layer.

8. The method according to claim 7, wherein The active reaction solution includes a complexing solute and an organic solvent. The complexing solute is formed by a complexing metal Y and a complexing agent. The complexing metal Y is one or more of Li, Na, and K, and the complexing solute is dissolved in the organic solvent. The complexing agent is selected from one or more of naphthalene and its derivatives, biphenyl and its derivatives, anthracene and its derivatives, phenanthrene and its derivatives, pyrene and its derivatives, and tetracene and its derivatives. The organic solvent is selected from one or more of ethylene glycol dimethyl ether, tetrahydrofuran, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

9. Use of an alkali metal electrode according to any one of claims 1-5, characterized in that, When the active layer contains alkali metal Li, it is used for lithium-ion batteries; when the active layer contains alkali metal Na, it is used for sodium-ion batteries; when the active layer contains alkali metal K, it is used for potassium-ion batteries.

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