Metal negative electrode, battery, and electronic device

Abstract

The application provides a metal negative electrode, comprising a liquid metal layer, the liquid metal layer comprising a liquid storage material layer and a liquid metal solution distributed in the liquid storage material layer, the liquid metal solution comprising an alkali metal, a first organic component and a second organic component, the first organic component comprising at least one of an aromatic hydrocarbon small molecule compound with electron accepting ability and a polymer containing an aromatic hydrocarbon group, and the second organic component comprising at least one of an ether small molecule, an amine small molecule, a sulfide small molecule, a polyether polymer, a polyamine polymer and a polysulfide polymer capable of complexing alkali metal ions. The metal negative electrode comprises a liquid metal layer, and the liquid metal solution has excellent lithium solution performance, can fundamentally inhibit the nucleation and growth of dendrites, and improves the safety performance and electrochemical performance of the alkali metal battery. The application also provides a preparation method of the metal negative electrode, a battery and an electronic device.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of energy storage, in particular to a metal negative electrode, a battery and an electronic device. BACKGROUND

[0002] The development of modern society urgently needs to develop secondary batteries with high specific capacity, high safety, long cycle life and low cost. Lithium metal is the most ideal high-energy-density negative electrode material because of its high theoretical specific capacity (3860 mAh / g) and low redox potential (-3.040 V vs. standard hydrogen electrode). See Figure 1 However, the use of lithium metal batteries is prone to lithium dendrites during cycling, which can penetrate the separator in a liquid electrolyte system, causing safety problems. Even trace amounts of dendrite growth can cause side effects such as dead lithium generation, resulting in low battery coulombic efficiency and poor cycle performance. In a solid-state battery system, most solid-state electrolytes with high ionic conductivity are unstable with lithium metal, and dendrite growth also occurs, affecting battery coulombic efficiency and cycle performance. Therefore, in order to obtain a high-energy-density lithium metal battery, a method for effectively inhibiting dendrite growth needs to be found. SUMMARY

[0003] In view of this, embodiments of the present application provide a metal negative electrode, which includes a liquid metal layer. The liquid metal solution has excellent lithium solubility and can fundamentally inhibit the nucleation and growth of dendrites, thereby solving the problem of decreased battery safety performance and electrochemical performance caused by dendrite growth in alkali metal batteries.

[0004] Specifically, a first aspect of embodiments of the present application provides a metal negative electrode, which includes a liquid metal layer. The liquid metal layer includes a liquid storage material layer and a liquid metal solution distributed in the liquid storage material layer. The liquid metal solution includes an alkali metal, a first organic component and a second organic component. The first organic component includes at least one of an aromatic hydrocarbon-based small molecule compound having electron accepting ability and a polymer containing an aromatic hydrocarbon-based group. The second organic component includes at least one of an ether-based small molecule, an amine-based small molecule, a sulfide-based small molecule, a polyether-based polymer, a polyamine-based polymer and a polysulfide-based polymer capable of complexing alkali metal ions. The liquid metal solution has high ionic conductivity and electronic conductivity, and excellent fluidity, so it can quickly and effectively dissolve the alkali metal dendrites (such as lithium dendrites) deposited on the surface of the negative electrode during battery charging and discharging cycles, and fundamentally inhibit the growth of dendrites. Therefore, dendrite-free deposition can be achieved at a very high current density, improving the safety performance and electrochemical performance of the battery. Moreover, by adsorbing and fixing the liquid metal solution in the liquid storage material layer, the battery electrolyte and the positive electrode can be directly stacked and assembled, thereby greatly reducing the assembly difficulty of the battery.

[0005] In the embodiments of the present application, the metal negative electrode is an alkali metal negative electrode, which can be a lithium negative electrode, a sodium negative electrode, a potassium negative electrode, a lithium alloy negative electrode, a sodium alloy negative electrode, or a potassium alloy negative electrode. The liquid metal solution contains alkali metals, i.e., contains alkali metal elements. Specifically, the alkali metal can be metallic lithium, metallic sodium, or metallic potassium. The alkali metal can exist in multiple chemical states. Correspondingly, the alkali metal ion can be a lithium ion, a sodium ion, or a potassium ion.

[0006] In the embodiments of the present application, the metal negative electrode further includes a solid alkali metal layer arranged on one side of the liquid metal layer. The solid alkali metal layer can be a metallic lithium layer, a lithium alloy layer, a metallic sodium layer, a sodium alloy layer, a metallic potassium layer, or a potassium alloy layer. The solid alkali metal layer can serve as an alkali metal reserve layer of the negative electrode, thereby improving the battery coulomb efficiency and long cycle performance.

[0007] In the embodiments of the present application, the aromatic hydrocarbon small molecule compound includes at least one of biphenyl, naphthalene, phenanthrene, anthracene, tetracene, pyrene, and derivatives thereof. The polymer containing an aromatic hydrocarbon group contains at least one of biphenyl, naphthalene, phenanthrene, anthracene, tetracene, and pyrene aromatic groups. The aromatic hydrocarbon substance has good ability to accept electrons.

[0008] In the embodiments of the present application, the ether small molecule includes one or more of diethyl ether, dimethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, dipropyl ether, diisopropyl ether, ethyl butyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, 2-methyltetrahydrofuran, 4-methyl-1,3-dioxolane, dimethoxymethane, 1,2-dimethoxypropane, dioxolane, 1,4-dioxane, oxirane, oxetane, 1,1-diethoxyethane, 12-crown-4, 15-crown-5, and 18-crown-6.

[0009] The amine small molecule includes one or more of ethylenediamine dimethylamine, ethylenediamine tetramethylamine, and diethylenediamine tetramethylamine.

[0010] The sulfide small molecule includes one or more of ethylenedithiol dimethyl sulfide, ethylenedithiol diethyl sulfide, diethylenedithiol dimethyl sulfide, and tetraethylenedithiol dimethyl sulfide.

[0011] In the embodiments of the present application, the polyether polymer includes at least one of polyethylene oxide and polypropylene oxide; the polyamine polymer includes at least one of polyethylene diamine and polymethyl ethylene diamine; and the polythiol polymer includes at least one of polyethylene dithiol and methoxy polyethylene dithiol.

[0012] In the liquid metal layer, the molar ratio of the first organic component to the second organic component is (0.1-50):10; and the molar ratio of the alkali metal to the second organic component is (0.1-20):10. The liquid metal solution of each component in a suitable ratio has high ionic conductivity and electronic conductivity.

[0013] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium.

[0014] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium.

[0015] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium.

[0016] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium.

[0017] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium.

[0018] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium. + / Li) of the liquid metal solution.

[0019] In the liquid metal solution, the electronic conductivity at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining electrical contact of isolated elemental lithium in the liquid metal solution, thereby preventing the formation of dead lithium.

[0020] In the embodiments of the present application, the interface protection layer comprises a polymer and an alkali metal salt, the polymer comprises at least one of a polyether, a polyfluorinated olefin, a polyester, a polynitrile, and a polyacrylic polymer. The polymer can form a uniform and dense film layer, effectively preventing the liquid metal layer from contacting the solid-state electrolyte body.

[0021] In the embodiments of the present application, the polyether comprises one or more of polyethylene oxide (PEO) and polypropylene oxide (PPO); the polyfluorinated olefin comprises polyvinylidene fluoride (PVDF); the polyester comprises polycarbonate (PC); the polynitrile comprises polyacrylonitrile (PAN); and the polyacrylic polymer comprises polymethyl methacrylate (PMMA).

[0022] In the embodiments of the present application, the alkali metal salt comprises one or more of a bis-trifluoromethylsulfonylimide salt, a bis-fluorosulfonylimide salt, a triflate salt, a hexafluorophosphate salt, a tetrafluoroborate salt, and a perchlorate salt of an alkali metal. The alkali metal salt can improve the ion transport capacity of the interface protection layer.

[0023] In the embodiments of the present application, in the interface protection layer, the mass ratio of the polymer to the alkali metal salt is 1:10 to 10:1. The suitable mass ratio of the polymer and the alkali metal salt can ensure that the interface protection layer has the basic performance of the polymer film layer (such as high density, flexibility, uniformity, etc.), and at the same time ensure that the interface protection layer has good ion transport capacity.

[0024] In the embodiments of the present application, the interface protection layer comprises a sulfide layer, and the sulfide layer comprises one or more of β-Li3PS4, MoS2, CuS, and Li2S.

[0025] In the embodiments of the present application, the thickness of the interface protection layer is 0.02 μm-200 μm.

[0026] In the embodiments of the present application, the solid-state electrolyte body comprises an inorganic solid-state electrolyte, and the inorganic solid-state electrolyte comprises any one of a sulfide solid-state electrolyte, an oxide solid-state electrolyte, a hydride solid-state electrolyte, a halide solid-state electrolyte, a boride solid-state electrolyte, and a phosphide solid-state electrolyte.

[0027] Optionally, the sulfide solid electrolyte includes any one of sulfide-lithium fast ionic conductor type, glassy sulfide solid electrolyte. The oxide solid electrolyte includes any one of perovskite type solid electrolyte, garnet type solid electrolyte, sodium fast ionic conductor type solid electrolyte, lithium fast ionic conductor type solid electrolyte, glassy oxide solid electrolyte. The hydride solid electrolyte includes one or more of LiBH4, LiBH4-LiX (X = Cl, Br, I), LiNH2, Li3AlH6, Li2NH. The halide solid electrolyte includes one or more of Li3OCl, Li3YX6 (X = Cl, Br), Li3InX6 (X = Cl, Br). The boride, phosphide solid electrolyte includes one or more of Li2B4O7, Li3PO4, Li2O-B2O3-P2O5.

[0028] The metal negative electrode of the embodiment of the present application can quickly dissolve dendrites when alkali metal is deposited, and can achieve dendrite-free effect under super-large current density (for example, greater than 15 mA / cm 2 ), so as to make the high-energy-density alkali metal battery have fast charging performance.

[0029] In a second aspect, the embodiment of the present application provides a preparation method of a metal negative electrode, including:

[0030] The liquid metal solution is added into the liquid storage material layer, so that the liquid metal solution is distributed in the liquid storage material layer to form a liquid metal layer; the liquid metal solution includes alkali metal, a first organic component and a second organic component, the first organic component includes at least one of an aromatic hydrocarbon small molecule compound with electron accepting ability and a polymer containing an aromatic hydrocarbon group, and the second organic component includes at least one of an ether small molecule, an amine small molecule, a sulfide small molecule, a polyether polymer, a polyamine polymer and a polysulfide polymer capable of complexing alkali metal ions.

[0031] In the embodiment of the present application, the preparation method further includes:

[0032] The interface protection layer raw material is prepared into a solution, and a pulling method is used to form an interface protection layer on at least one side surface of the solid electrolyte body to obtain a solid electrolyte layer; or the interface protection layer raw material is prepared into a slurry, and the slurry is coated on at least one side surface of the solid electrolyte body to form an interface protection layer to obtain a solid electrolyte layer.

[0033] The preparation method of the metal negative electrode provided in the embodiment of the present application has simple process and is suitable for large-scale production and preparation.

[0034] In a third aspect, an embodiment of the present application provides a battery, comprising a positive electrode, a metal negative electrode, and an electrolyte disposed between the positive electrode and the metal negative electrode, wherein the metal negative electrode comprises the metal negative electrode according to the first aspect of the present application. The specific structural form of the battery is not limited, and can be a button cell, a soft package battery, or the like. The battery according to the present application can improve the safety performance and electrochemical performance of the battery by using the metal negative electrode.

[0035] When the metal negative electrode further comprises a solid-state electrolyte layer, the solid-state electrolyte layer acts as the electrolyte, and the solid-state electrolyte layer is located between the positive electrode and the liquid metal layer.

[0036] In an embodiment of the present application, after the battery is subjected to charge-discharge cycles, the interface between the solid-state electrolyte layer and the liquid metal layer has positive ion fragments and negative ion fragments, the positive ion fragments comprise one or more of C4H7, C2H3, C2H5, C3H7, C3H5, and C3H3, and the negative ion fragments comprise one or more of CH2OF, CHO2, and C7H5.

[0037] In an embodiment of the present application, the positive electrode comprises a positive electrode current collector and a solid-state positive electrode material layer disposed on the positive electrode current collector, and the solid-state positive electrode material layer comprises electrolyte powder, positive electrode active material, and conductive additive.

[0038] In another embodiment of the present application, the positive electrode comprises a liquid storage layer and liquid positive electrode material distributed in the liquid storage layer, and the liquid positive electrode material comprises positive electrode active material, alkali metal salt, conductive additive, and organic solvent.

[0039] In an embodiment of the present application, the positive electrode active material comprises one or more of organic polysulfide, cyclohexanehexone, anthraquinone, and derivatives thereof, and the organic solvent comprises ether and / or carbonate electrolyte solvent.

[0040] In an embodiment of the present application, the organic polysulfide comprises one or more of diphenyl polysulfide, dimethyl polysulfide, pyridyl polysulfide, and diphenyl selenosulfide.

[0041] An embodiment of the present application further provides an electronic device, comprising a shell, and electronic components and a battery accommodated in the shell, wherein the battery supplies power to the electronic components, and the battery comprises the battery according to the third aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A schematic diagram of lithium dendrite growth and dead lithium generation in a lithium metal battery in the prior art;

[0043] Figures 2 to 6A structural schematic diagram of a metal negative electrode 10 provided for an embodiment of the present application;

[0044] Figures 7 to 9 A structural schematic diagram of a battery 100 provided for an embodiment of the present application;

[0045] Figure 10 A structural schematic diagram of an electronic device 200 provided for an embodiment of the present application;

[0046] Figure 11 A structural schematic diagram of a symmetric battery ① in an embodiment of the present application;

[0047] Figure 12 A structural schematic diagram of a symmetric battery ② in an embodiment of the present application;

[0048] Figure 13 A voltage-current density curve of a symmetric battery ① in Example 1 of the present application;

[0049] Figure 14 A surface SEM (Scanning Electron Microscope) image of a solid-state electrolyte layer with a β-LPS interface protection layer after cycling in Example 1 of the present application;

[0050] Figure 15 A voltage-time curve of a symmetric battery ② under a fixed current density in Example 1 of the present application;

[0051] Figure 16 A ssNMR (ssNMR is an abbreviation of Solid State Nuclear Magnetic Resonance) of a substance at a static state at an interface between a lithium metal sheet and a liquid metal layer of a liquid metal sample of a symmetric battery ② in Example 1 of the present application 7 Li spectrum (ssNMR is an abbreviation of Solid State Nuclear Magnetic Resonance);

[0052] Figure 17 A voltage-current density curve of a symmetric battery ① tested in 2a in Example 2 of the present application;

[0053] Figure 18 A voltage-current density curve of a symmetric battery ① tested in 2b in Example 2 of the present application;

[0054] Figure 19 A surface SEM image of a solid-state electrolyte layer with a PEO interface protection layer after cycling in Example 2 of the present application;

[0055] Figure 20 A voltage-time cycle diagram of a symmetric battery ② in Example 2 of the present application;

[0056] Figure 21The first circle and the second circle charge-discharge voltage-capacity curves of the full battery provided for Example 3 of the present application;

[0057] Figure 22 The curves of the change of coulombic efficiency and charge-discharge capacity with cycle number of the full battery provided for Example 3 of the present application;

[0058] Figure 23 The first circle charge-discharge voltage-capacity curves of the full battery provided for Example 4 of the present application;

[0059] Figure 24 The polarization voltage-current density curves of the symmetric battery in Comparative Example 1;

[0060] Figure 25 The voltage-time cycle diagram of the metal Li / LPS@PEO / metal Li symmetric battery in Comparative Example 2. DETAILED DESCRIPTION

[0061] The embodiments of the present application will be described below with reference to the accompanying drawings of the embodiments of the present application.

[0062] Referring to Figures 2 to 4 , the embodiments of the present application provide a metal negative electrode 10, which can be used as a negative electrode of an alkali metal battery. The metal negative electrode 10 comprises a liquid metal layer 11, which comprises a liquid storage material layer 111 and a liquid metal solution (not shown in the figure) distributed in the liquid storage material layer 111. The liquid metal solution comprises an alkali metal, a first organic component and a second organic component. The first organic component comprises at least one of an aromatic hydrocarbon small molecule compound with electron accepting ability and a polymer containing an aromatic hydrocarbon group. The second organic component comprises at least one of an ether small molecule, an amine small molecule, a sulfide small molecule, a polyether polymer, a polyamine polymer and a polysulfide polymer capable of complexing alkali metal ions. The liquid metal solution has excellent ablative ability of alkali metal and excellent fluidity, so it can quickly and effectively dissolve the alkali metal dendrites (such as lithium dendrites) deposited and grown on the surface of the negative electrode during the charge-discharge cycle of the battery, fundamentally inhibiting the growth of dendrites, so that dendrite-free deposition can be achieved at a very large current density (greater than 15 mA / cm 2 ), and the safety performance and electrochemical performance of the battery are improved. Moreover, by adsorbing and fixing the liquid metal solution in the liquid storage material layer, the battery electrolyte and the positive electrode can be directly stacked and assembled, thereby greatly reducing the assembly difficulty of the battery.

[0063] In the embodiments of the present application, the metal negative electrode 10 is an alkali metal negative electrode, which can be a lithium negative electrode, a sodium negative electrode, a potassium negative electrode, a lithium alloy negative electrode, a sodium alloy negative electrode, or a potassium alloy negative electrode. The liquid metal solution contains alkali metals, i.e., contains alkali metal elements. Specifically, the alkali metal can be lithium metal, sodium metal, or potassium metal, and the alkali metal can exist in multiple chemical states. Correspondingly, the alkali metal ion can be a lithium ion, a sodium ion, or a potassium ion, i.e., the second organic component is a substance capable of complexing lithium ions, sodium ions, or potassium ions.

[0064] In some embodiments of the present application, as shown in FIG. 1, the metal negative electrode 10 further includes a negative electrode current collector 12, and the liquid metal layer 11 is directly disposed on the negative electrode current collector 12, i.e., the liquid metal layer 11 and the negative electrode current collector 12 are in contact and stacked. Figure 2 In some embodiments of the present application, as shown in FIG. 1, the metal negative electrode 10 further includes a negative electrode current collector 12, and the liquid metal layer 11 is directly disposed on the negative electrode current collector 12, i.e., the liquid metal layer 11 and the negative electrode current collector 12 are in contact and stacked. Figure 3 In some embodiments of the present application, as shown in FIG. 1, the metal negative electrode 10 further includes a negative electrode current collector 12, and the liquid metal layer 11 is directly disposed on the negative electrode current collector 12, i.e., the liquid metal layer 11 and the negative electrode current collector 12 are in contact and stacked. Figure 4 In some embodiments of the present application, as shown in FIG. 1, the metal negative electrode 10 further includes a negative electrode current collector 12, and the liquid metal layer 11 is directly disposed on the negative electrode current collector 12, i.e., the liquid metal layer 11 and the negative electrode current collector 12 are in contact and stacked. The negative electrode current collector 12 can be a copper foil. The solid alkali metal layer 13 can be a lithium metal layer, a lithium alloy layer, a sodium metal layer, a sodium alloy layer, a potassium metal layer, or a potassium alloy layer. The solid alkali metal layer 13 can serve as an alkali metal reserve layer of the negative electrode, thereby improving the coulombic efficiency and long cycle performance of the battery.

[0065] In the embodiments of the present application, the liquid metal solution is in a liquid state at room temperature and is obtained by mixing an alkali metal element, a first organic component, and a second organic component. The liquid metal solution can be prepared at room temperature, and the preparation process is simple and low in consumption, without the need for complicated procedures such as high-temperature heating. The first organic component has electron accepting ability, and the second organic component has the ability to complex alkali metal ions, so that the liquid metal solution has the ability to dissolve alkali metals while having high electronic conductivity and ionic conductivity. In the embodiments of the present application, the electronic conductivity of the liquid metal solution at room temperature is not less than 6 mS / cm, and the ionic conductivity at room temperature is not less than 3 mS / cm. Taking a lithium metal battery as an example, the liquid metal solution has high electronic conductivity and ionic conductivity, which can quickly dissolve the dendritic lithium while maintaining the electrical contact of the isolated lithium element in the liquid metal solution, thereby preventing the generation of dead lithium.

[0066] In the embodiments of the present application, the aromatic hydrocarbon small molecule compound includes at least one of biphenyl, naphthalene, phenanthrene, anthracene, tetracene, pyrene and derivatives thereof; the polymer containing aromatic hydrocarbon group contains at least one of biphenyl, naphthalene, phenanthrene, anthracene, tetracene, pyrene aromatic group. The aromatic hydrocarbon small molecule compound and the polymer containing aromatic hydrocarbon group have conjugated π bond, thereby having electron accepting ability.

[0067] In the embodiments of the present application, the ether small molecule includes one or more of diethyl ether, dimethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, dipropyl ether, diisopropyl ether, ethyl butyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, 2-methyltetrahydrofuran, 4-methyl-1,3-dioxolane, dimethoxymethane, 1,2-dimethoxypropane, dioxolane, 1,4-dioxane, oxirane, oxetane, 1,1-diethoxyethane, 12-crown-4, 15-crown-5 and 18-crown-6. The amine small molecule includes one or more of ethylenediamine dimethylamine, ethylenediamine tetramethylamine and diethylenediamine tetramethylamine. The sulfide small molecule includes one or more of ethylenedithiol dimethyl sulfide, ethylenedithiol diethyl sulfide, diethylenedithiol dimethyl sulfide and tetraethylenedithiol dimethyl sulfide. The polyether includes at least one of polyethylene oxide and polypropylene oxide. The polyamine includes at least one of polyethylenediamine and polymethylethylenediamine. The polysulfane includes at least one of polyethylenedithiol and methoxypolyethylenedithiol. In the embodiments of the present application, when the first organic component has relatively large solubility in the second organic component, it is beneficial to increase the capacity of the liquid metal solution to dissolve alkali metal. For example, biphenyl has high solubility in the ether small molecule solvent, and the ether small molecule has strong complexing ability with alkali metal ions, which can effectively improve the capacity of the liquid metal solution to dissolve alkali metal.

[0068] In the present application, the small molecule is relative to the polymer, and the small molecule is a compound in a non-polymerized state. For example, the aromatic hydrocarbon small molecule compound is an aromatic hydrocarbon compound in a non-polymerized state. The ether small molecule is a non-polymerized ether relative to the polyether.

[0069] In some embodiments, the ratio of the molar amount of the first organic component to the second organic component in the liquid metal layer 11 is (0.1-50):10. The ratio of the molar amount of the alkali metal to the second organic component is (0.1-20):10. The liquid metal solution with the above suitable ratio has high ionic conductivity and electronic conductivity. The amount of the first organic component can be adjusted according to its solubility in the second organic component. Too much of the first organic component cannot be completely dissolved, and too little of the first organic component cannot effectively improve the conductivity of the solution. The amount of the second organic component relative to the alkali metal also cannot be too small, and too little of the second organic component cannot effectively improve the conductivity of the solution. In some embodiments, the ratio of the molar amount of the first organic component to the second organic component is (0.5-3):10. In some embodiments, the ratio of the molar amount of the alkali metal to the second organic component is (0.5-2):10. The liquid metal solution with the above suitable ratio has higher ionic conductivity and electronic conductivity. The amount of the alkali metal element in the liquid metal layer 11 can be measured by an ICP (Inductive Coupled Plasma Emission Spectrometer) instrument. The amount of the first organic component can be measured by liquid chromatography.

[0070] In some embodiments, the liquid storage material layer 111 is used to adsorb and fix the liquid metal solution. By adsorbing and fixing the liquid metal solution in the liquid storage material layer 111, an integrated layer structure is formed, so that the liquid storage material layer 111 has good ion and electron paths, and the polarization voltage of the battery can be reduced. The liquid storage material layer 111 can maintain the effectiveness of the contact between the liquid metal solution and the negative current collector or the solid alkali metal layer. In some embodiments, the liquid storage material layer 111 includes a material having a porous structure and not chemically reacting with the liquid metal solution. Specifically, the material of the liquid storage material layer 111 includes, but is not limited to, one or more of multi-walled carbon nanotube paper, foam paper, glass fiber, and organic fiber. The foam paper can be, for example, polyolefin, polyurethane, nylon, or other high molecular materials.

[0071] In some embodiments, the porosity of the liquid storage material layer 111 can be in the range of 30%-95%. Specifically, the porosity of the liquid storage material layer 111 can be, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%. The porosity of the liquid storage material layer 111 can be selected according to the amount of the liquid metal solution to be adsorbed. It can be understood that the greater the porosity, the more the amount of the liquid metal solution that can be adsorbed. A suitable porosity can ensure that the liquid storage material layer 111 has good liquid absorption capacity and also has certain mechanical strength.

[0072] In some embodiments, the reservoir material layer 111 has a thickness of 0.05 μm to 1500 μm. A reservoir material layer 111 that is too thick can reduce the energy density of the battery, while a reservoir material layer 111 that is too thin can reduce the ability to dissolve alkali metals. A suitable thickness of the reservoir material layer 111 can provide a liquid metal layer with a high ability to dissolve alkali metals while providing a battery with a high energy density. In some embodiments, the reservoir material layer 111 has a thickness of 1 μm to 1000 μm.

[0073] Referring to Figure 5 and Figure 6 In some embodiments, the metal anode 10 further comprises a solid-state electrolyte layer 14, which comprises a solid-state electrolyte body 141 and an interface protection layer 142 disposed on at least one side surface of the solid-state electrolyte body 141. The solid-state electrolyte layer 14 is in contact with the liquid metal layer 11, and the interface protection layer 142 is disposed between the solid-state electrolyte body 141 and the liquid metal layer 11. The solid-state electrolyte layer 14 comprises a solid-state electrolyte body with high ionic conductivity and an interface protection layer that is chemically / electrochemically stable to the liquid metal solution. On one hand, the solid-state electrolyte layer 14 can function as a separator to prevent the negative electrode alkali metal from contacting the positive electrode to cause short circuit. On the other hand, the solid-state electrolyte layer 14 can function as an electrolyte to facilitate fast transport of lithium ions. Moreover, the interface protection layer 142 can improve the chemical / electrochemical stability of the solid-state electrolyte layer 14 to the liquid metal solution (potential ~ 0.3 V vs Li + / Li), so that the solid-state electrolyte layer 14 can be well compatible with the liquid metal layer 11. In some embodiments, one side surface of the solid-state electrolyte body 141 is provided with the interface protection layer 142. When the solid-state electrolyte body 141 has the interface protection layer 142 on only one side surface, the side of the solid-state electrolyte layer 14 with the interface protection layer 142 is in contact with the liquid metal layer 11. In other embodiments, as shown in Figure 5 , both side surfaces of the solid-state electrolyte body 141 are provided with the interface protection layer 142. In other embodiments, as shown in Figure 6 , the entire outer surface of the solid-state electrolyte body 141 is provided with the interface protection layer 142.

[0074] The cooperation of the solid-state electrolyte layer 14 and the liquid metal layer 11 can better inhibit dendrite growth in the alkali metal battery, improve the charge-discharge rate performance and cycle stability of the battery. Moreover, since the liquid metal layer 11 has good fluidity and maintains good contact with the negative current collector 12 or the solid-state alkali metal layer 13 and the solid-state electrolyte layer 14, the interface impedance is low, so under the premise of ensuring good contact between the battery positive electrode and the solid-state electrolyte layer 14, the alkali metal battery using the metal negative electrode 10 of the present application can maintain long-term operation of the alkali metal battery without additional external pressure, and achieve high-rate dendrite-free effect. Moreover, the alkali metal battery using the metal negative electrode 10 of the present application has a high limit current density, can realize high-rate charging, and ensures good long-cycle performance.

[0075] In the present application, the ionic conductivity of the solid-state electrolyte layer 14 is greater than 0.1 mS / cm. The solid-state electrolyte layer 14 has a large ionic conductivity to ensure the rapid transmission of alkali metal ions.

[0076] In the present application, the solid-state electrolyte body 141 is in the form of a film or a sheet, and can be an inorganic solid-state electrolyte having a high ionic conductivity, which can be one or more of a sulfide solid-state electrolyte, an oxide solid-state electrolyte, a hydride solid-state electrolyte, a halide solid-state electrolyte, a boride solid-state electrolyte, and a phosphide solid-state electrolyte.

[0077] Optionally, the sulfide solid-state electrolyte includes one or more of a sulfide-lithium fast ion conductor type and a glassy sulfide solid-state electrolyte. The oxide solid-state electrolyte includes one or more of a perovskite-type solid-state electrolyte, a garnet-type solid-state electrolyte, a sodium fast ion conductor type solid-state electrolyte (i.e., a NASICON type solid-state electrolyte), a lithium fast ion conductor type solid-state electrolyte (i.e., a LISICON type solid-state electrolyte), and a glassy oxide solid-state electrolyte. The hydride solid-state electrolyte includes one or more of LiBH4, LiBH4-LiX (X = Cl, Br, I), LiNH2, Li3AlH6, and Li2NH. The halide solid-state electrolyte includes one or more of Li3OCl, Li3YX6 (X = Cl, Br), and Li3InX6 (X = Cl, Br). The boride and phosphide solid-state electrolyte includes one or more of Li2B4O7, Li3PO4, and Li2O-B2O3-P2O5.

[0078] The interface protection layer 142 is chemically and electrochemically stable with the liquid metal layer 11, and can improve the cycle life of the battery. In some embodiments of the present application, the interface protection layer 142 includes a polymer and an alkali metal salt, and the polymer includes at least one of a polyether, a polyfluorinated olefin, a polyester, a polynitrile, and a polyacrylic polymer. Specifically, the polymer can be, but is not limited to, polyepoxy. The polyether includes one or more of polyethylene oxide (PEO) and polypropylene oxide (PPO); the polyfluorinated olefin includes polyvinylidene fluoride (PVDF); the polyester includes polycarbonate (PC); the polynitrile includes polyacrylonitrile (PAN); and the polyacrylic includes polymethyl methacrylate (PMMA). The polymer can form a uniform and dense film layer, effectively preventing the liquid metal layer 11 from contacting the solid-state electrolyte body 141.

[0079] In embodiments of the present application, the alkali metal salt includes one or more of a bis-trifluoromethylsulfonylimide salt MTFSI, a bis-fluorosulfonylimide salt MFSI, a trifluoromethanesulfonate salt MCF3SO3, a hexafluorophosphate salt MPF6, a tetrafluoroborate salt MBF4, and a perchlorate salt MClO4, where M is Li, Na, or K. For example, the lithium salt can be one or more of lithium bis-trifluoromethylsulfonylimide LiTFSI, lithium bis-fluorosulfonylimide LiFSI, lithium trifluoromethanesulfonate LiCF3SO3, lithium hexafluorophosphate LiPF6, lithium tetrafluoroborate LiBF4, and lithium perchlorate LiClO4. The alkali metal salt can improve the ion transport capability of the interface protection layer 142.

[0080] In embodiments of the present application, the mass ratio of the polymer and the alkali metal salt in the interface protection layer 142 can be 1:10 to 10:1. A suitable mass ratio of the polymer and the alkali metal salt can ensure that the interface protection layer 142 has the basic properties of the polymer film layer (such as high density, flexibility, uniformity, etc.), while ensuring that the interface protection layer 142 has good ion transport capability. Specifically, for example, it can be 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0081] In some other embodiments of the present application, the interface protection layer 142 includes a sulfide layer, and the sulfide layer can include inorganic sulfides. Specifically, the sulfide layer can include one or more of β-Li3PS4 (β-LPS), MoS2, CuS, and Li2S. The sulfide layer can be prepared by a liquid method (specifically, a pulling method), so as to form a film layer structure with uniform and dense thickness, which is conducive to improving the performance of the battery.

[0082] In the embodiments of the present application, the solid electrolyte layer 14 is in the form of a film or a sheet as a whole. The thickness of the interface protection layer 142 can be 0.02 μm-200 μm. In some embodiments, the thickness of the interface protection layer 142 can be 20 μm-100 μm. In other embodiments, the thickness of the interface protection layer 142 can be 30 μm-80 μm, or 50 μm-60 μm.

[0083] The metal negative electrode in the embodiments of the present application can quickly dissolve dendrites when the alkali metal is deposited, and can achieve the effect of dendrite-free even under an ultra-high current density (greater than 15 mA / cm 2 ), thereby enabling the high-energy-density alkali metal battery to have a fast-charging performance.

[0084] Correspondingly, the embodiments of the present application provide a preparation method of the metal negative electrode, comprising:

[0085] The liquid metal solution is added to the liquid storage material layer to distribute the liquid metal solution in the liquid storage material layer to form a liquid metal layer. The liquid metal solution comprises an alkali metal, a first organic component, and a second organic component. The first organic component comprises at least one of an aromatic hydrocarbon small molecule compound having an electron accepting ability and a polymer containing an aromatic hydrocarbon group. The second organic component comprises at least one of an ether small molecule, an amine small molecule, a sulfide small molecule, a polyether polymer, a polyamine polymer, and a polysulfide polymer capable of complexing alkali metal ions.

[0086] The liquid metal solution is prepared by mixing the alkali metal element, the first organic component, and the second organic component. The preparation of the liquid metal solution can specifically comprise: taking the first organic component and adding it to the second organic component to obtain a transparent solution, then gradually adding small-sized alkali metal elements to the transparent solution, continuously stirring until complete dissolution, and obtaining the liquid metal solution. The small-sized alkali metal element can be, for example, an alkali metal wire.

[0087] The liquid metal solution is added to the liquid storage material layer, which can be specifically: adding the liquid metal solution dropwise to the liquid storage material layer to fully infiltrate it, i.e., to make the liquid storage material layer adsorb the liquid metal solution to saturation. The dropwise operation can be performed using a dropper.

[0088] In the embodiments of the present application, the preparation method further comprises:

[0089] The interface protection layer raw material is prepared into a solution, and a pulling method is used to form the interface protection layer on at least one side surface of the solid electrolyte body to obtain the solid electrolyte layer. Alternatively, the interface protection layer raw material is prepared into a slurry, and the slurry is coated on at least one side surface of the solid electrolyte body to form the interface protection layer, thereby obtaining the solid electrolyte layer.

[0090] When the interface protection layer is a sulfide layer, it can be prepared by a pulling method. For example, when the interface protection layer is a β-LPS electrolyte, the preparation method can include:

[0091] Step one: dissolve Li2S, P2S5 and S raw materials in tetrahydrofuran (THF) and acetonitrile (ACN) to obtain a β-LPS precursor solution; step two: pull the solid electrolyte body in the above β-LPS precursor solution, and then bake and dry on a heating table; step three: repeat step two, and place the solid electrolyte body after multiple pulling-baking into an oven to dry to obtain a solid electrolyte layer. The temperature of the oven can be 150-280°C, for example, 230°C.

[0092] When the interface protection layer includes a polymer and an alkali metal salt, it can be prepared by a coating method. For example, when the interface protection layer uses PEO, the preparation method can include:

[0093] Step one: dissolve PEO and LiTFSI in acetonitrile (ACN), stir, and obtain a uniform slurry after PEO is completely dissolved; step two: take an appropriate amount of the above slurry and drop it on the surface of the solid electrolyte body and evenly coat it; step three: bake and dry on a heating table. The stirring can be stirring at 20-30°C for 12-36h, for example, stirring at 25°C for 24h.

[0094] In the embodiments of the present application, the liquid metal layer and the solid electrolyte layer can exist in the form of independent products, and when assembled into a battery, the liquid metal layer is attached to the side of the solid electrolyte layer with the interface protection layer.

[0095] In the embodiments of the present application, the solid electrolyte body can be made into a film or a sheet by using the commonly used powder tabletting method, wet coating method, flow casting method, etc. in the industry.

[0096] The preparation method of the metal negative electrode provided by the present application is simple in process and can be mass-produced.

[0097] Referring to Figure 7 , the embodiments of the present application also provide a battery 100, which includes a positive electrode 20, a metal negative electrode 10, an electrolyte 30 arranged between the positive electrode 20 and the metal negative electrode 10, and a battery shell 40. The battery 100 is an alkali metal secondary battery, which can be specifically a lithium metal battery, a sodium metal battery or a potassium metal battery.

[0098] It should be noted that, referring to Figure 8 and Figure 9 , when the metal negative electrode 10 includes a solid electrolyte layer 14, the solid electrolyte layer 14 can act as the electrolyte 30, and the solid electrolyte layer 14 is located between the positive electrode 20 and the liquid metal layer 11.

[0099] The specific structural form of the battery 100 is not limited, and can be a button cell as shown in Figure 8 , or a soft pack battery as shown in Figure 9 , etc. See Figure 8 and Figure 9 , the metal negative electrode 10 is an alkali metal negative electrode, and specifically can be a lithium negative electrode, a sodium negative electrode, a potassium negative electrode, a lithium alloy negative electrode, a sodium alloy negative electrode, or a potassium alloy negative electrode. The metal negative electrode 10 can include a negative electrode current collector 12 and a liquid metal layer 11, or can include a solid alkali metal layer 13 and a liquid metal layer 11, or can include a negative electrode current collector 12, a solid alkali metal layer 13, and a liquid metal layer 11. For the button cell of Figure 8 , the battery shell 40 can be a stainless steel type battery shell; for the soft pack battery of Figure 9 , the battery shell 40 can be an aluminum plastic film, and the soft pack battery also needs to lead out the positive and negative electrode tabs 50. In some embodiments, the battery shell 40 can directly act as an electrode current collector.

[0100] In the embodiments of the present application, after the battery 100 is cycled by charging and discharging, the interface between the solid-state electrolyte layer 14 and the liquid metal layer 11 has positive ion fragments and negative ion fragments, the positive ion fragments include one or more of C4H7, C2H3, C2H5, C3H7, C3H5, and C3H3, and the negative ion fragments include one or more of CH2OF, CHO2, and C7H5. The positive ion fragments and the negative ion fragments can also include fragments other than those listed above. The interface generates an interface layer rich in olefin fragments, which can improve the cycle stability of the interface. This result can be detected by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

[0101] In the embodiments of the present application, taking a lithium metal battery containing a solid metal layer 13 as an example, the solid-state nuclear magnetic resonance (ssNMR) of the substance at the interface between the solid metal layer 13 and the liquid metal layer 11 has no signal peak near the chemical shift of 250 ppm of lithium metal in the static 7Li spectrum (0 Hz), indicating that the chemical state of lithium at the interface exists in the form of lithium ions, and the liquid metal layer 11 has good ability to dissolve lithium.

[0102] See Figure 8 and Figure 9The positive electrode 20 includes a positive electrode current collector 21 and a positive electrode material layer 22 disposed on the positive electrode current collector 21. In the embodiments, the positive electrode 20 can be a solid-state positive electrode or a liquid-state positive electrode. In an embodiment, the positive electrode 20 is a solid-state positive electrode, and the positive electrode 20 includes the positive electrode current collector 21 and a solid-state positive electrode material disposed on (i.e., on one side surface of) the positive electrode current collector 21. The solid-state positive electrode material layer includes electrolyte powder, positive electrode active material, conductive additive, and binder. The electrolyte powder, the positive electrode active material, and the conductive additive can be mixed in a certain mass ratio as needed. The positive electrode active material can be a positive electrode active material commonly used in alkali metal batteries, and the present application does not make special limitations, for example, can be one or more of S, Li2S, NCM (nickel-cobalt-manganese ternary material), NCA (nickel-cobalt-aluminum ternary material), LiCoO2(LCO), LiFePO4, LiNbO3. The surface of the positive electrode active material can be a buffer coating layer commonly used in solid-state battery positive electrode materials, and the material of the buffer coating layer can be, but is not limited to, one or more of LiNbO3, LiTaO3, Li3PO4, Li4Ti5O12, etc. The conductive additive can be, but is not limited to, one or more of VGCF (vapor-grown carbon fiber), Super P, and multi-walled carbon nanotube (MWCNT). The binder can be, but is not limited to, polyvinylidene fluoride (PVDF). The electrolyte powder can be various inorganic solid-state electrolyte powders, such as sulfide solid-state electrolyte, oxide solid-state electrolyte, hydride solid-state electrolyte, halide solid-state electrolyte, boride solid-state electrolyte, and phosphide solid-state electrolyte. The electrolyte powder used in the positive electrode 20 can be the same as or different from the composition of the solid-state electrolyte body in the solid-state electrolyte layer 14. The positive electrode current collector 21 can be an aluminum foil. 12 When the positive electrode 20 is a solid-state positive electrode, a liquid-phase coating method can be used to mix the positive electrode active material, the electrolyte powder, the conductive agent, and the binder to prepare a slurry and coat and dry the slurry on the positive electrode current collector 21, or a dry method can be used to mix the positive electrode active material, the electrolyte powder, the conductive agent, and the binder to prepare a film and composite the film on the positive electrode current collector 21.

[0103] When the positive electrode 20 is a solid-state positive electrode, a liquid-phase coating method can be used to mix the positive electrode active material, the electrolyte powder, the conductive agent, and the binder to prepare a slurry and coat and dry the slurry on the positive electrode current collector 21, or a dry method can be used to mix the positive electrode active material, the electrolyte powder, the conductive agent, and the binder to prepare a film and composite the film on the positive electrode current collector 21.

[0104] In another embodiment of the present application, the positive electrode 20 is a liquid-type positive electrode, and the positive electrode 20 includes a liquid storage layer and a liquid positive electrode material distributed in the liquid storage layer. The liquid storage layer can be disposed on the positive electrode current collector 21 (i.e., one side surface). The liquid positive electrode material is adsorbed and fixed in the liquid storage layer, and the material of the liquid storage layer can be any one of multi-walled carbon nanotube paper, foam paper, glass fiber, and organic fiber. In some embodiments, the liquid positive electrode material includes a positive electrode active material, an alkali metal salt, a conductive additive, and an organic solvent. In an embodiment of the present application, the positive electrode active material can include one or more of organic polysulfides, cyclohexanehexone, anthraquinone, and derivatives thereof. Specifically, the organic polysulfides can include one or more of diphenyl polysulfide, dimethyl polysulfide, pyridyl polysulfide, and diphenyl selenosulfide. The alkali metal salt includes one or more of a bis-trifluoromethylsulfonylimide salt MTFSI, a bis-fluorosulfonylimide salt MFSI, a trifluoromethanesulfonate salt MCF3SO3, a hexafluorophosphate salt MPF6, a tetrafluoroborate salt MBF4, and a perchlorate salt MClO4, where M is Li, Na, or K. For example, the lithium salt can be one or more of lithium bis-trifluoromethylsulfonylimide LiTFSI, lithium bis-fluorosulfonylimide LiFSI, lithium trifluoromethanesulfonate LiCF3SO3, lithium hexafluorophosphate LiPF6, lithium tetrafluoroborate LiBF4, and lithium perchlorate LiClO4. The conductive additive can be one or more of VGCF, Super P, and multi-walled carbon nanotubes (MWCNT). The organic solvent can include ether and / or carbonate electrolyte solvents. Specifically, the organic solvent can be one or more of diethyl ether, dimethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, dipropyl ether, diisopropyl ether, ethyl butyl ether, dibutyl ether, diamyl ether, diisopentyl ether, dihexyl ether, 2-methyltetrahydrofuran, 4-methyl-1,3-dioxolane, dimethoxymethane, 1,2-dimethoxypropane, dioxolane, 1,4-dioxane, oxirane, oxetane, 1,1-diethoxyethane, ethylene carbonate, diethyl carbonate, propylene carbonate, and dimethyl carbonate.

[0105] When the positive electrode 20 is a liquid-type positive electrode, the liquid positive electrode active material, the alkali metal salt, and the conductive additive can be added to the organic solvent to obtain a uniform positive electrode solution, and the positive electrode solution can be dropped into the positive electrode liquid storage layer.

[0106] For example, in an embodiment of the present application, the preparation of the coin cell can be as follows:

[0107] Take the negative shell of the button cell, put the metal lithium or lithium-copper composite strip of a certain thickness into the negative shell, when the negative electrode is a lithium-copper composite strip, the copper side faces down; stack the liquid metal layer and the solid electrolyte layer in turn above the metal lithium or lithium-copper composite strip, ensure that the liquid metal layer directly contacts the lithium metal; place the positive electrode on the solid electrolyte layer, then stack the button cell gasket and spring sheet in turn above the positive electrode, then cover the positive shell on the spring sheet, and use the button voltage machine for packaging to obtain the button cell.

[0108] Taking the lithium metal battery as an example, in the specific embodiment of the present application, the preparation of the soft package battery can be specifically as follows:

[0109] Stack the liquid metal layer and the solid electrolyte layer in turn above the metal lithium or lithium-copper composite strip, ensure that the liquid metal layer directly contacts the lithium metal; place the positive electrode on the solid electrolyte layer, and pay attention to lead out the positive and negative electrode tabs; then package the above stacking structure into the aluminum-plastic film battery outer package, and a soft package battery can be obtained.

[0110] As shown in Figure 10 The present application also provides an electronic device 200, which can be a mobile phone, a tablet computer, a smart wearable product, a drone, an electric vehicle or the like, the electronic device 200 comprising a shell 201, and electronic components and a battery (not shown in the figure) located inside the shell 201, wherein the battery is the battery 100 provided in the above embodiments of the present application, the shell 201 can comprise a display screen assembled on the front side of the electronic device and a rear cover assembled on the rear side, and the battery can be fixed inside the rear cover to supply power to the electronic components in the electronic device 200. The electronic device 200 uses the battery 100 for power supply, and can obtain good endurance and high safety.

[0111] The embodiments of the present application will be further described in the following multiple embodiments.

[0112] Embodiment 1

[0113] In this embodiment, the lithium metal solution in the liquid metal layer is a Li-Bp-DME system, biphenyl (Bp) is used as an electron accepting molecule and ethylene glycol dimethyl ether (DME) is used as a solvent, and the liquid metal solution is marked as Li 1.5 BP3DME 10(subscript represents molar mass ratio). The total conductivity of the liquid metal solution at room temperature is 12.2 mS / cm measured by conductivity pen, and the electronic conductivity of the liquid metal solution at room temperature is 8.54 mS / cm measured by direct current polarization method, so the ionic conductivity is 3.66 mS / cm. The liquid metal layer in the liquid storage material layer is selected from glass fiber with a diameter of 10 mm, a thickness of 400 μm, and a porosity of 80%, and 300 μL of the liquid metal solution is dropped onto the glass fiber to allow it to be fully soaked. The solid electrolyte layer is composed of Li7P3S 11 type solid electrolyte body and β-LPS interface protection layer. Li7P3S 11 type solid electrolyte body is obtained by powder tabletting method, and the thickness is 0.7 mm and the diameter is 15 mm. The ionic conductivity of the solid electrolyte body is 0.6 mS / cm. The metal negative electrode in this embodiment is a lithium metal sheet with a diameter of 10 mm and a thickness of 600 μm. The positive electrode active material used in the positive electrode in this embodiment is lithium cobaltate coated with a lithium niobate buffer coating layer, the conductive additive is SuperP, and the electrolyte powder is Li7P3S 11 powder, and the adhesive is PVDF. The positive electrode is prepared by coating the positive electrode slurry on the aluminum foil by solution coating.

[0114] The lithium metal sheet, the liquid metal layer, the solid electrolyte layer and the positive electrode are sequentially stacked and packaged to obtain the button cell of this embodiment. According to its core structure, the battery is marked as: Li 1.5 BP3DME 10 / / β-LPS / Li7P3S 11 / / LCO.

[0115] In order to verify the ability of the liquid metal layer in this embodiment to inhibit dendrite growth, a symmetrical battery ① is assembled to test its limiting current density. The structure of the symmetrical battery ① is shown in Figure 11 , which includes a negative electrode shell 41, a liquid metal layer 11, a solid interface protection layer 142, a solid electrolyte body 141, a solid interface protection layer 142, a liquid metal layer 11, and a positive electrode shell 42. After each layer is prepared according to the method described above, the symmetrical battery ① is assembled in the order shown in Figure 11 . Among them, the liquid metal layer 11 is the same as the liquid metal layer of this embodiment 1, and the solid electrolyte body 141 and the interface protection layer 142 are the same as the solid electrolyte body and the interface protection layer of this embodiment 1. The symmetrical battery ① is marked as: Li 1.5 BP3DME 10 / / β-LPS / Li7P3S 11 / β-LPS / / Li 1.5 BP3DME 10 .

[0116] In addition, in order to verify the stability between the combined structure of the liquid metal layer and the solid-state electrolyte layer and the lithium metal in the embodiment, a lithium metal sheet is added on the basis of the symmetric battery ①, and a structural schematic diagram of the symmetric battery ② is as shown in Figure 12 FIG. 4, which includes a negative electrode shell 41, a lithium metal sheet 13, a liquid metal layer 11, a solid-state interface protection layer 142, a solid-state electrolyte body 141, a solid-state interface protection layer 142, a liquid metal layer 11, a lithium metal sheet 13, and a positive electrode shell 42 arranged in sequence. The symmetric battery ② is marked as: Li / / Li 1.5 BP3DME 10 / / β-LPS / Li7P3S 11 / β-LPS / / Li 1.5 BP3DME 10 / / Li。

[0117] The symmetric battery ① is tested as follows:

[0118] 1a. At 30°C, the above symmetric battery ① is tested by using a blue electric tester, and the current is started to be gradually increased from 0.1 mA, and the charge-discharge cycle test is performed until a short circuit occurs or the voltage reaches the cutoff voltage of the tester (-5V to 5V).

[0119] 1b. The battery at the end of the test is disassembled, the surface of the solid-state electrolyte layer is tested by using a scanning electron microscope (SEM), and the morphology is recorded; and the composition of the substance fragments on the surface of the electrolyte is tested by using TOF-SIMS.

[0120] The symmetric battery ② is tested as follows:

[0121] 1c. At 30°C, the above symmetric battery ② is tested by using a blue electric tester at a current density of 0.127 mA / cm 2 and a unit surface capacity of 0.254 mAh / cm 2 .

[0122] 1d. The battery after the test is disassembled, and the substance at the interface between the lithium metal sheet and the liquid metal layer (specifically, the black reaction layer on the surface of the lithium metal sheet is scraped off) is selected for solid-state nuclear magnetic resonance (ssNMR) test.

[0123] The changes of the voltage and the current density of the symmetric battery obtained in test 1a with the cycle time are as shown in Figure 13 From the curves in the figure, it can be seen that the current density of the battery using the metal negative electrode of the embodiment reaches 15.24 mA / cm 2 when the cutoff voltage of the instrument is reached, the unit surface capacity reaches 15.24 mAh / cm 2 , and no voltage drop phenomenon occurs during the cycle, indicating that no short circuit occurs.

[0124] The results of SEM in test 1b are as follows Figure 14 As shown, a dense and flat interface is formed between the liquid metal layer and the solid electrolyte layer after cycling, and this interface remains stable even after long-term cycling. TOF-SIMS results show that the interface layer contains not only ionic fragments such as S, O, PS2, PS, POS, Li, Li3O, Li2S, and Li3CO3, but also anionic fragments such as CH2OF and CHO2, and positive ionic fragments such as C4H7, C2H3, C2H5, and C3H7. This indicates that an olefin-rich interface layer is formed, which improves the cycling stability of the interface.

[0125] Battery voltage-time cycle data for test 1C is as follows: Figure 15 As shown in the figure, after 100 hours of cycling, the polarization voltage of the battery is only 0.4V, indicating that in actual lithium metal batteries, the structural combination of lithium metal sheet and liquid metal layer and solid electrolyte layer of this application has good compatibility, and this structural combination still exhibits good lithium dissolving properties on the surface of lithium metal sheet.

[0126] The static 7Li spectrum (0Hz) measured after 1 day of testing is as follows: Figure 16 As shown, no signal was detected in the spectrum near the chemical shift of lithium metal at 250 ppm, indicating that the liquid metal solution has a highly efficient dissolution effect on lithium metal.

[0127] Example 2

[0128] This embodiment fabricates a coin cell, wherein the liquid metal solution in the liquid metal layer is a Li-Bp-DME system, with biphenyl (Bp) as the electron acceptor molecule and dimethyl ethylene glycol (DME) as the solvent. The liquid metal solution is labeled according to the molar ratio as follows: Li 1.5 BP3DME 10 (Subscripts indicate molar ratios). The liquid storage material layer in the liquid metal layer is multi-walled carbon nanotube paper with a diameter of 10 mm, a thickness of 500 μm, and a porosity of 60%. 250 μL of liquid metal solution is dropped onto the multi-walled carbon nanotube paper to allow it to fully wet. The solid electrolyte layer is composed of Li7P3S... 11 The solid electrolyte body is composed of a Li7P3S interface protective layer and a PEO layer. 11 The solid electrolyte body is obtained by powder compression molding, with a thickness of 0.5 mm and a diameter of 15 mm. The ionic conductivity of the solid electrolyte body is 0.6 mS / cm. In this embodiment, the metal anode is a lithium metal sheet with a diameter of 10 mm and a thickness of 100 μm. The positive electrode in this embodiment uses NCM with a lithium niobate interface protective layer on its surface as the positive electrode active material, SuperP as the conductive additive, and Li7P3S as the electrolyte powder. 11The powder and the adhesive are PVDF, and the positive electrode is prepared by coating a positive electrode slurry on an aluminum foil by solution coating.

[0129] The lithium metal sheet, the liquid metal layer, the solid electrolyte layer and the positive electrode are sequentially stacked and packaged to obtain the button cell of the embodiment. According to the core structure, the cell is marked as: Li / / Li 1.5 BP3DME 10 / / PEO / Li7P3S 11 / / NCM.

[0130] In order to verify the ability of the liquid metal layer in the embodiment to inhibit dendrite growth, a symmetric cell ① was assembled according to the schematic diagram of Figure 11 , and its limiting current density was tested. The symmetric cell ① is marked as: Li 1.5 BP3DME 10 / / PEO / Li7P3S 11 / PEO / / Li 1.5 BP3DME 10 .

[0131] In addition, in order to verify the stability between the combined structure of the liquid metal layer and the solid electrolyte layer in the embodiment and the lithium metal, a lithium metal sheet was added on the basis of the symmetric cell ①, and a symmetric cell ② was assembled according to the schematic diagram of Figure 12 , which is marked as: Li / / Li 1.5 BP3DME 10 / / PEO / Li7P3S 11 / PEO / / Li 1.5 BP3DME 10 / / Li.

[0132] The symmetric cell ① was tested as follows:

[0133] 2a. At 30℃, the above symmetric cell ① was tested by a blue instrument, and the current was gradually increased from 0.1mA to 5mA, 6mA, 7mA, 8mA, 9mA, 10mA and so on, and the charge and discharge cycle test was carried out, until short circuit or the voltage reached the cut-off voltage of the detection instrument (-5V to 5V).

[0134] 2b. At 30℃, the current was gradually increased from 0.1mA to 5mA, 6mA, 7mA, 8mA, 9mA, 10mA and so on, and the charge and discharge cycle test was carried out, wherein 3 cycles were carried out at 5mA, 6mA, 7mA, 8mA, 9mA, 10mA and so on, until short circuit or the voltage reached the cut-off voltage of the detection instrument (-5V to 5V).

[0135] 2c. The cell at the end of the test was disassembled, the surface of the solid electrolyte layer was tested by scanning electron microscope (SEM), and the morphology was recorded; and the composition of the material fragments on the surface of the electrolyte was tested by TOF-SIMS.

[0136] The symmetrical battery ② was tested as follows:

[0137] 2d. At 30℃, a blue electric current tester was used at 0.127 mA / cm. 2 The current density is 0.254 mAh / cm³. 2 The unit surface capacity was subjected to charge-discharge cycle testing.

[0138] The changes in voltage and current density of the symmetrical cell obtained from test 2a with cycle time are as follows: Figure 17 As shown in the figure, the curves indicate that the battery using the metal negative electrode of this application achieves a current density as high as 17.78 mA / cm² when the instrument's cutoff voltage is reached. 2 The unit surface capacity is as high as 17.78mAh / cm². 2 No voltage drop occurred during the cycle, indicating that no short circuit occurred.

[0139] The changes in voltage and current density of the symmetrical cell obtained from test 2b with cycle time are as follows: Figure 18 As shown in the figure, the curves indicate that the battery using the metal negative electrode of this application still maintains a current density as high as 10.16 mA / cm² when the instrument's cutoff voltage is reached. 2 Furthermore, no voltage drop occurred during the cycling process, indicating that no short circuit occurred. This embodiment illustrates that although the number of cycles is extended from one to three under partial current, and the total cycle time is also extended, the battery using the metal negative electrode of this application embodiment still exhibits excellent performance in suppressing lithium dendrite growth and preventing battery short circuits.

[0140] The results of SEM in test 2c are as follows Figure 19 As shown, a highly dense and smooth interface is formed between the cyclic liquid metal and the solid electrolyte, which remains stable even after long-term cycling. TOF-SIMS results reveal that this interface layer contains not only ionic fragments such as S, O, PS2, PS, POS, Li, Li3O, Li2S, and Li3CO3, but also anionic fragments such as CH2OF, CHO2, and C7H5, and positive ionic fragments such as C4H7, C2H3, C2H5, C3H7, C3H5, and C3H3. This indicates the formation of an olefin-rich interface layer, which enhances the interface's cycling stability, and the variety of olefin ionic fragments is greater than that of the β-LPS interface protective layer.

[0141] The voltage-time cycle data of the symmetrical cell ② obtained from the 2-day test are as follows: Figure 20The initial polarization voltage is 0.1 V, and during the 110 h cycle process, the polarization voltage increases at the 5th cycle and then returns to 0.1 V, which may be due to the fluctuation of the polarization voltage caused by the activation of the PEO interface layer. The symmetric battery shows good cycle stability, which shows that the combination of the liquid negative material (i.e. liquid metal solution) and the solid lithium metal in the negative electrode has the potential for practical application. The liquid negative material can inhibit the generation of lithium dendrites, improve the cycle life and safety of the battery; the lithium metal sheet can provide higher capacity and promote the improvement of the energy density of the battery.

[0142] Example 3

[0143] In this embodiment, a button cell is prepared, in which the liquid metal solution is selected as Li-Bp-DME (Li 1.5 BP3DME 10 solution, the solid electrolyte body is selected as Li6PS5Cl, PEO is used as the interface protection layer material, glass fiber is used as the liquid storage material layer material, the positive electrode contains commercial lithium cobaltate material (coated with lithium zirconate interface protection layer) as the active material, Li6PS5Cl as the electrolyte powder, and VGCF as the conductive additive, and a button full cell is assembled. Other parameters are the same as in Example 1.

[0144] The obtained button cell is subjected to charge-discharge test in the voltage range of 2.5-4.0 V, and the charge-discharge rate is 0.1 C. The voltage-capacity curves of the first and second cycles of charge-discharge are shown in Figure 21 , and the coulombic efficiency and charge-discharge capacity of the first 8 cycles are shown in Figure 22 . Figure 21 The results show that the specific capacity of the battery in the first cycle reaches 154.7 mAh / g, the specific capacity in the first cycle is 136 mAh / g, and the first coulombic efficiency is 87.9%. The second cycle discharge capacity is 135.3 mAh / g, and the coulombic efficiency is 98.1. Figure 22 The results show that the battery maintains stable discharge capacity in subsequent cycles, and the coulombic efficiency is close to 99%. The test results of this embodiment show that the button full cell with the combined structure of the liquid metal layer and the solid electrolyte layer of the application can effectively charge and discharge.

[0145] Meanwhile, the negative electrode of the application is assembled into a symmetric battery ①: Li-Bp-DME / / PEO / Li6PS5Cl / PEO / / Li-Bp-DME in the manner of Example 1, and tested in the manner of 1a. It is found that the battery with the metal negative electrode of the application has a limit current density of up to 15.52 mA / cm 2 .

[0146] Example 4

[0147] In this embodiment, a soft package battery is prepared. In this embodiment, Li7P3S11 PEO as the interface protection layer material, glass fiber as the liquid storage material layer material, and Li-Bp-DME (Li 1.5 BP3DME 10 ) solution as the liquid metal solution, and other parameters being the same as in Example 1. The positive electrode is a liquid positive electrode layer, and a mixture of anthraquinone, LiTFSI, Super P, and propylene carbonate is selected. A soft-pack full cell is assembled.

[0148] The obtained soft-pack cell is subjected to charge-discharge test in the voltage range of 1.6-2.5 V, and the voltage-capacity curve of the first cycle of charge-discharge is shown in Figure 23 . Figure 23 The specific capacity of the first cycle of charge is 163.2 mAh / g, and the specific capacity of the first cycle of discharge is 104.4 mAh / g. The test results of this example show that the soft-pack full cell with the combined structure of the liquid metal layer and the solid electrolyte layer of the application can effectively work in charge-discharge.

[0149] Meanwhile, the negative electrode of the application is used to assemble a symmetric cell 1: Li-Bp-DME / / PEO / Li7P3S 11 / PEO / / Li-Bp-DME in the manner of Example 1a, and test is performed in the manner of 1a. It is found that the battery with the metal negative electrode of the application has a limit current density as high as 16.16 mA / cm 2 .

[0150] Comparative Example 1

[0151] In this comparative example, Li7P3S 11 is used as the solid electrolyte, and there is no electrolyte interface protection layer. Only lithium metal is used as the electrode, and a Li / / Li7P3S 11 / / Li symmetric cell is assembled in a glove box (O2<0.1 ppm, H2O<0.1 ppm) and subjected to cycle test with gradually increased current density.

[0152] The voltage-time cycle data of the battery are shown in Figure 24 . When the current density is increased to 0.4 mA / cm 2 , the polarization voltage is stable, but when the current density is further increased, the polarization voltage curve rapidly decreases to about 0, and short circuit occurs. It is shown that the limit current density of lithium metal with the sulfide solid electrolyte without any interface protection layer is only 0.4 mA / cm 2 .

[0153] Comparative Example 2

[0154] In this comparative example, Li7P3S 11As a solid electrolyte, PEO serves as the solid interface protective layer material. Only metallic lithium is used as the electrode, and Li / / PEO / Li7P3S is assembled inside a glove box (O2 < 0.1 ppm, H2O < 0.1 ppm). 11 A PEO / / Li symmetric cell was used, and the limiting current density was measured to be 0.2 mA / cm². 2 And at 30℃, at 0.127 mA / cm 2 The current density is 0.254 mAh / cm³. 2 The unit surface capacity was subjected to charge-discharge cycle testing.

[0155] The battery voltage-time cycle data is as follows: Figure 25 As shown, from Figure 25 It is evident that the voltage is unstable and micro-short circuits occur. This indicates that even with PEO as an interface protective layer, lithium dendrite growth remains a problem in all-solid-state batteries assembled using only lithium metal anodes after removing the liquid metal layer.

[0156] Comparative Example 3

[0157] This comparative example uses a lithium metal anode with a surface protective layer of lithium phosphorus oxynitride (LiPON) and an electrolyte of lithium bis(trifluoromethanesulfonylimide) (LiTFSI) dissolved in 1,3-dioxolane (DOL) and dimethoxyethane (DME) solvents. A Li / LiPON / / LiTFSI-DOL:DME / / LiPON / Li symmetric cell was assembled and the limiting current density was tested.

[0158] Comparative Example 4

[0159] This comparative example uses a lithium metal anode with a surface protective layer of a mixture of lithium nitride and lithium fluoride, and a Li3PS4 solid electrolyte. It is assembled into a Li / Li3N-LiF / / Li3PS4 / / Li3N-LiF / Li symmetric cell and the limiting current density is tested.

[0160] Comparative Example 5

[0161] This comparative example uses lithium metal sheet as the negative electrode and Li-24 metal sheet coated with electron barrier material (EBS) as the solid electrolyte. 6.4 La3Zr 1.4 Ta 0.6 O 12 They were assembled into Li / / LLZTO@EBS / / Li symmetric cells and the limiting current density was tested.

[0162] The test results of the limiting current density of lithium symmetric batteries assembled according to the lithium anode-electrolyte strategies in Examples 1-4 and Comparative Examples 1-5 of this application are summarized in Table 1.

[0163] Table 1 Comparison of limiting current density results of symmetrical batteries assembled with different lithium anode-electrolyte strategies

[0164]

[0165]

[0166] From the limiting current density results of Examples 1 to 4, it can be seen that the symmetrical battery using the metal anode provided by the present application can have an ultra-high (greater than 15 mA / cm 2 ) limiting current density. Moreover, from Example 1 and Example 2, it can be seen that the structural combination of PEO as a sulfide solid electrolyte protective layer is better than that of β-LPS as a protective layer, and an ultra-high limiting current density of 17.78 mA / cm 2 is obtained. In contrast, the lithium symmetrical batteries of Comparative Example 1, in which metal lithium is directly combined with a sulfide solid electrolyte, and Comparative Example 2, in which metal lithium is combined with a sulfide solid electrolyte having a PEO protective layer, have a limiting current density of less than 1 mA / cm 2 . In addition, the limiting current densities of the lithium symmetrical batteries of Comparative Examples 3 to 5 are also much smaller than those of the batteries of the present application. This shows that the metal anode provided by the present application has a very significant effect on inhibiting dendrite growth, reaching a high level in the industry. In addition, in Example 1 and Example 2 of the present application, lithium metal sheets are introduced as electrodes on the basis of symmetrical battery ①, and sulfide solid electrolytes with β-LPS protective layers and PEO protective layers are respectively selected, combined with organic liquid metal solutions to form symmetrical battery ②. At a current density of 0.127 mA / cm 2 and a unit surface capacity of 0.254 mAh / cm 2 , the polarization voltage remains stable after 100 h of charge and discharge, and the polarization voltage is small, indicating that the liquid metal layer and the solid electrolyte layer have strong compatibility with lithium metal, and as a structural combination layer on the lithium metal, can also well inhibit dendrites. In addition, in Example 3, a solid-state positive electrode is used on the positive electrode side to assemble a full battery, and in Example 4, a liquid-state positive electrode material is introduced on the positive electrode side to assemble a full battery, verifying that the metal anode provided by the present application can also reliably work in a lithium metal full battery system.

Claims

1. A metal negative electrode characterized by, The liquid metal layer comprises a liquid storage material layer and a liquid metal solution distributed in the liquid storage material layer, the liquid metal solution comprises an alkali metal, a first organic component and a second organic component, the first organic component comprises at least one of an aromatic hydrocarbon small molecule compound with electron accepting ability and a polymer containing an aromatic hydrocarbon group, and the second organic component comprises at least one of an ether small molecule, an amine small molecule, a sulfide small molecule, a polyether polymer, a polyamine polymer and a polysulfide polymer capable of complexing alkali metal ions; the solid-state electrolyte layer comprises a solid-state electrolyte body and an interface protection layer arranged on at least one side surface of the solid-state electrolyte body, the solid-state electrolyte layer is in contact and stacked with the liquid metal layer, and the solid-state electrolyte body and the liquid metal layer have the interface protection layer therebetween; wherein the interface protection layer comprises a polymer and an alkali metal salt; the alkali metal salt comprises one or more of a bis-trifluoromethylsulfonylimide salt, a bis-fluorosulfonylimide salt, a triflate salt, a hexafluorophosphate salt, a tetrafluoroborate salt and a perchlorate salt of the alkali metal.

2. The metal negative electrode of claim 1, wherein The aromatic hydrocarbon small molecule compound comprises at least one of biphenyl, naphthalene, phenanthrene, anthracene, tetracene, pyrene and derivatives thereof; and the polymer containing an aromatic hydrocarbon group contains at least one of biphenyl, naphthalene, phenanthrene, anthracene, tetracene and pyrene aromatic groups.

3. The metal negative electrode of claim 1, wherein The ether small molecule comprises one or more of diethyl ether, dimethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, dipropyl ether, diisopropyl ether, ethyl butyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, 2-methyltetrahydrofuran, 4-methyl-1,3-dioxolane, dimethoxymethane, 1,2-dimethoxypropane, dioxolane, 1,4-dioxane, oxirane, oxetane, 1,1-diethoxyethane, 12-crown-4, 15-crown-5 and 18-crown-6; The amine small molecule comprises one or more of ethylenediamine dimethylamine, ethylenediamine tetramethylamine and diethylenediamine tetramethylamine; The sulfide small molecule comprises one or more of ethanedithiol dimethyl sulfide, ethanedithiol diethyl sulfide, diethylenedithiol dimethyl sulfide and tetraethylenedithiol dimethyl sulfide.

4. The metal negative electrode of claim 2, wherein The ether small molecule comprises one or more of diethyl ether, dimethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, dipropyl ether, diisopropyl ether, ethyl butyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, 2-methyltetrahydrofuran, 4-methyl-1,3-dioxolane, dimethoxymethane, 1,2-dimethoxypropane, dioxolane, 1,4-dioxane, oxirane, oxetane, 1,1-diethoxyethane, 12-crown-4, 15-crown-5 and 18-crown-6; The amine small molecules include one or more of ethylenediamine dimethylamine, ethylenediamine tetramethylamine and diethylenediamine tetramethylamine; The sulfide small molecules include one or more of ethylenedithiol dimethyl sulfide, ethylenedithiol diethyl sulfide, diethylenedithiol dimethyl sulfide and tetraethylenedithiol dimethyl sulfide.

5. The metal negative electrode of claim 1, wherein The polyether polymer includes at least one of polyethylene oxide and polypropylene oxide; the polyamine polymer includes at least one of polyethylene diamine and polymethyl ethylene diamine; and the polysulfide polymer includes at least one of polyethylene dithiol and methoxy polyethylene dithiol.

6. The metal negative electrode according to any one of claims 1 to 5, wherein In the liquid metal layer, the molar ratio of the first organic component to the second organic component is (0.1-50):10; and the molar ratio of the alkali metal to the second organic component is (0.1-20):

10.

7. The metal negative electrode according to any one of claims 1 to 5, wherein The liquid metal solution has an electronic conductivity of not less than 6 mS / cm at room temperature and an ionic conductivity of not less than 3 mS / cm at room temperature.

8. The metal negative electrode according to any one of claims 1 to 5, wherein The liquid storage material layer includes a material having a porous structure and being non-reactive with the liquid metal solution.

9. The metal negative electrode of claim 8, wherein, The liquid storage material layer includes one or more of multi-walled carbon nanotube paper, foam paper, glass fiber and organic fiber.

10. The metal negative electrode of claim 8, wherein The porosity of the liquid storage material layer is in the range of 30%-95%.

11. The metal negative electrode of claim 8, wherein The thickness of the liquid storage material layer is 0.05 μm-1500 μm.

12. The metal negative electrode of claim 1, wherein The ionic conductivity of the solid-state electrolyte layer is greater than 0.1 mS / cm.

13. The metal negative electrode according to claim 1 or 12, wherein The polymer includes at least one of polyether, polyfluorinated olefin, polyester, polynitrile and polyacrylic polymer.

14. The metal negative electrode of claim 13, wherein The polyether includes one or more of polyethylene oxide and polypropylene oxide; the polyfluorinated olefin includes polyvinylidene fluoride; the polyester includes polycarbonate; the polynitrile includes polyacrylonitrile; and the polyacrylic polymer includes polymethyl methacrylate.

15. The metal negative electrode of claim 13, wherein In the interface protection layer, the mass ratio of the polymer to the alkali metal salt is 1:10 to 10:

1.

16. The metal negative electrode of claim 14, wherein In the interface protection layer, the mass ratio of the polymer to the alkali metal salt is 1:10 to 10:

1.

17. The metal negative electrode of any one of claims 1 or 12, wherein, The interface protection layer includes a sulfide layer including one or more of β-Li3PS4, MoS2, CuS and Li2S.

18. The metal negative electrode of any one of claims 1-5, wherein, The thickness of the interface protection layer is 0.02 μm-200 μm.

19. The metal negative electrode of any one of claims 1-5, wherein, The solid-state electrolyte body includes an inorganic solid-state electrolyte including one or more of sulfide solid-state electrolyte, oxide solid-state electrolyte, hydride solid-state electrolyte, halide solid-state electrolyte, boride solid-state electrolyte and phosphide solid-state electrolyte.

20. The metal negative electrode of any one of claims 1-5, wherein, The metal negative electrode further includes a solid-state alkali metal layer stacked on one side of the liquid metal layer.

21. A method for producing a metal negative electrode, characterized by, The method includes: adding a liquid metal solution to the liquid storage material layer to distribute the liquid metal solution in the liquid storage material layer to form a liquid metal layer; and adding a solid-state electrolyte layer to the liquid metal layer to form a solid-state electrolyte body. The liquid metal solution comprises an alkali metal, a first organic component, and a second organic component, the first organic component comprises at least one of an aromatic hydrocarbon-based small molecule compound with electron-accepting ability and a polymer containing an aromatic hydrocarbon-based group, and the second organic component comprises at least one of an ether-based small molecule, an amine-based small molecule, a sulfide-based small molecule, a polyether-based polymer, a polyamine-based polymer, and a polysulfide-based polymer capable of complexing alkali metal ions; The liquid metal layer is laminated in contact with a solid-state electrolyte layer, the solid-state electrolyte layer comprises a solid-state electrolyte body and an interface protection layer arranged on at least one side surface of the solid-state electrolyte body, and the interface protection layer is between the solid-state electrolyte body and the liquid metal layer; the interface protection layer comprises a polymer and an alkali metal salt; the alkali metal salt comprises one or more of a bis-trifluoromethylsulfonylimide salt, a bis-fluorosulfonylimide salt, a triflate salt, a hexafluorophosphate salt, a tetrafluoroborate salt, and a perchlorate salt of an alkali metal.

22. The method of producing a metal negative electrode according to claim 21, wherein Further comprising: The interface protection layer raw material is formulated into a solution, and a pulling method is used to form the interface protection layer on at least one side surface of the solid-state electrolyte body to obtain the solid-state electrolyte layer; Or the interface protection layer raw material is formulated into a slurry, and the slurry is coated on at least one side surface of the solid-state electrolyte body to form the interface protection layer to obtain the solid-state electrolyte layer.

23. A battery, characterized by The battery comprises a positive electrode, a metal negative electrode, and an electrolyte arranged between the positive electrode and the metal negative electrode, and the metal negative electrode comprises the metal negative electrode of any one of claims 1-20.

24. The battery of claim 23, wherein the cathode comprises a lithium metal oxide. When the metal negative electrode further comprises a solid-state electrolyte layer, the solid-state electrolyte layer serves as the electrolyte, and the solid-state electrolyte layer is between the positive electrode and the liquid metal layer.

25. The battery of claim 24, wherein the cathode comprises a lithium metal oxide. After the battery is subjected to charge-discharge cycles, the interface between the solid-state electrolyte layer and the liquid metal layer has positive ion fragments and negative ion fragments, the positive ion fragments comprise one or more of C4H7, C2H3, C2H5, C3H7, C3H5, and C3H3, and the negative ion fragments comprise one or more of CH2OF, CHO2, and C7H5.

26. The battery of any one of claims 23-25, wherein, The positive electrode comprises a positive electrode current collector and a solid-state positive electrode material layer arranged on the positive electrode current collector, and the solid-state positive electrode material layer comprises electrolyte powder, a positive electrode active material, and a conductive additive.

27. The battery of any one of claims 23-25, wherein, The positive electrode comprises a liquid storage layer and a liquid positive electrode material distributed in the liquid storage layer, and the liquid positive electrode material comprises a positive electrode active material, an alkali metal salt, a conductive additive, and an organic solvent.

28. The battery of claim 27, wherein the lithium metal anode is coated with a solid electrolyte interphase (SEI) layer. The positive electrode active material comprises one or more of an organic polysulfide, cyclohexanehexone, anthraquinone, and derivatives thereof, and the organic solvent comprises an ether-based and / or carbonate-based electrolyte solvent.

29. The battery of claim 28, wherein the cathode is a lithium ion cathode. The organic polysulfide comprises one or more of a diphenyl polysulfide, a dimethyl polysulfide, a pyridyl polysulfide, and a diphenyl selenosulfide.

30. An electronic device comprising a housing, and electronic components and a battery accommodated in the housing, the battery powering the electronic components, the battery comprising the battery of any one of claims 23-29.

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