Use of dual-ion conductor compound in improving stability of interface layer of energy storage device

Abstract

A use of a dual-ion conductor compound in improving the stability of an interface layer of an energy storage device. The energy storage device comprises a lithium ion energy storage device and a sodium ion energy storage device, and comprises a positive electrode, an electrolyte, and a negative electrode; and during charging and discharging of the dual-ion conductor compound, cations and halogen anions can simultaneously reciprocatingly migrate under the driving of an electric field. Also provided is a method for improving the stability of the mechanical structure of an interface layer between a negative electrode and an electrolyte in an energy storage device. The halogen anions of the dual-ion conductor compound can reciprocatingly migrate under the driving of an electric field during charging and discharging, so as to form a halide dynamic self-adaptive interface layer between the negative electrode and the electrolyte, thereby naturally adjusting the morphology of the interface layer and self-adaptively repairing cracks and pores of the negative electrode caused by a volume effect, and thus ensuring a close solid-solid contact between the negative electrode and the solid electrolyte during stripping / electroplating.

Description

Application of dual ion conductor compounds in improving the stability of interfacial layers in energy storage devices Technical Field

[0001] The present invention belongs to the field of energy storage technology. Specifically, the present invention relates to the use of a dual ion conductor in improving the stability of the mechanical structure of the interface layer between the negative electrode and the electrolyte in an energy storage device. Background Art

[0002] Solid-state batteries, as a new energy storage technology, are attracting widespread attention due to their potential to meet the high safety, high specific energy, and long life requirements of chemical power sources. However, solid-state batteries still face several key challenges before achieving large-scale application.

[0003] During the assembly of solid-state batteries, since the interfaces within and between key materials are solid / solid rigid, poor contact and interfacial gaps exist between the layers of key materials. Furthermore, during battery cycling, the volume changes of high-energy-density electrode materials such as metallic lithium, silicon, and tin can cause a large number of pores to form within the negative electrode and at the interface between the negative electrode and the electrolyte, rapidly increasing the battery's internal impedance and ultimately leading to rapid battery failure. These interfacial pores can further induce uneven lithium deposition, accelerating the growth of lithium dendrites and severely impacting the cycle life of solid-state batteries.

[0004] The traditional approach is to pre-build a buffer layer at the interface between the electrode and the electrolyte, but this does not solve the problem of a large number of cracks and pores formed inside the electrode due to the negative electrode volume effect during cycling. Alternatively, a three-dimensional skeleton structure is constructed for the negative electrode to accommodate the active material to buffer the volume change of the negative electrode, but this will significantly reduce the energy density of the battery. Therefore, a method that allows the battery to self-repair mechanical damage at the interface and within the electrode during cycling is of great significance for the practical application of solid-state batteries.

[0005] The prior art "Promoting favorable interfacial properties in lithium-based batteries using chlorine-rich sulfide inorganic solid-state electrolytes" discloses a lithium chloride-doped sulfide electrolyte Li 7-x PS 6-x Cl x(x=0.6 or 1.3). Figure 9 of the prior art shows that after the battery has been cycled for 200 hours, a layer of LiCl-rich interface is accumulated on the negative electrode interface, and the original electrolyte becomes loose and porous. Those skilled in the art can know from Figure 9 of the prior art that the movement speed of chloride ions during the battery cycle is slow, and they cannot return to the electrolyte, but can only gradually accumulate at the interface. Therefore, this cannot adapt to the high volume effect of the negative electrode during a cycle of charge and discharge of the battery. The prior art discloses that the battery in Figure 6 can only be used at a low surface capacity (<0.5mAh cm) under a high stacking pressure (6MPa). -2 ) for 30 cycles. In addition, the prior art states that the electrolyte needs to be cold pressed into a sheet and then annealed at 500°C for 12 hours, which is a harsh preparation condition.

[0006] CN 109728342 B discloses a polymer-based solid-state battery self-repair method that uses an inorganic solid electrolyte and a self-repairing polymer to achieve the polymer's self-repair function for solid-state batteries. This patent addresses the issue of solid-solid contact between key materials during solid-state battery assembly. However, this method requires the addition of more than 50% polymer. This large amount of polymer addition affects the electrolyte's ionic conductivity and is unable to effectively repair pores and cracks within the electrode during battery cycling.

[0007] CN 112687971 A discloses a self-repairing functional interface layer for solid-state batteries. This layer uses a self-repairing polymer, an inorganic solid electrolyte, a lithium salt, and an ether composite. The polymer utilizes intermolecular and intramolecular hydrogen bonds to achieve self-repair of the electrolyte. However, this method cannot effectively repair pores and cracks within the electrode during battery cycling.

[0008] Therefore, there is an urgent need to develop an electrochemically driven self-repair technology to continuously repair the pores and cracks formed in the battery interface layer or inside the electrode during the cycle of solid-state batteries.

[0009] Summary of the Invention

[0010] The present invention aims to provide a dual-ion conductor for improving the mechanical stability of the interface layer between the negative electrode and the electrolyte in lithium and sodium ion energy storage devices. During battery cycling, the present invention forms a dynamic, adaptive interface layer of lithium and sodium halides at the negative electrode and electrolyte interface through the reciprocating movement of halogen anions, thereby achieving in-situ self-repair, maintaining good contact between the electrolyte and the negative electrode interface, and thereby improving the cycle life of solid-state batteries. Furthermore, stable cycling is achieved without additional stacking pressure.

[0011] The above-mentioned object of the present invention is achieved through the following technical solutions.

[0012] In the context of the present invention, the term "non-functional components" includes some components commonly used in the art, such as carbon materials as conductive additives, polytetrafluoroethylene, polyvinylidene fluoride, sodium carboxymethyl cellulose or styrene-butadiene rubber as binders, etc.

[0013] In one aspect, the present invention provides a use of a dual ion conductor compound in improving the stability of the mechanical structure of the interface layer between the negative electrode and the electrolyte in an energy storage device, wherein the energy storage device includes a lithium ion energy storage device and a sodium ion energy storage device and includes a positive electrode, an electrolyte and a negative electrode;

[0014] In the dual ion conductor compound, cations (such as lithium cations or sodium cations) and halogen anions can simultaneously migrate back and forth between the interface layer and the electrolyte under the driving of an electric field during the charge and discharge process;

[0015] The dual ion conductor compound is selected from one or more of alkali metal halides, alkaline earth metal halides and halide-doped sulfides.

[0016] The inventors of the present application unexpectedly discovered that by adding the dual-ion conductor compound of the present invention to the energy storage device, the stability of the mechanical structure of the interface layer between the negative electrode and the electrolyte in the lithium-ion energy storage device can be improved. Without wishing to be bound by theory, this may be attributed to the reciprocating migration of the halogen anions of the dual-ion conductor compound under the drive of the electric field, thereby forming a dynamic adaptive interface layer of halides between the negative electrode and the electrolyte, naturally adjusting the morphology of the interface layer and adaptively repairing cracks and pores caused by the volume effect of the negative electrode (such as a metallic lithium negative electrode, or a metallic lithium and silicon alloy negative electrode, or a metallic lithium and tin alloy negative electrode), thereby ensuring close solid-solid contact between the negative electrode and the solid electrolyte during the stripping / electroplating process.

[0017] Preferably, in the use described in the present invention, the alkali metal halide is lithium halide and / or sodium halide.

[0018] Preferably, in the use of the present invention, the alkali metal halide is selected from one or more of LiI, LiBr, LiCl, LiF, NaI, NaBr, NaCl and NaF; more preferably, the alkali metal halide is selected from one or more of LiI, LiBr, NaI and NaBr; most preferably, the alkali metal halide is LiI and / or NaI.

[0019] Preferably, in the use described in the present invention, the alkaline earth metal halide is magnesium halide.

[0020] Preferably, in the use described in the present invention, the alkaline earth metal halide is MgI2 and / or MgBr2; more preferably, the alkaline earth metal halide is MgI2.

[0021] Preferably, in the use of the present invention, the halide-doped sulfide is selected from Na 3+x PS4Br x 、Li 3-x PS 4-x Br x 、Li 3+x PS4I x 、Li 3-x PS 4-x I x 、Li 6+x P2S8I x He Li 6+x P2S8Br x One or more of the following, wherein 0.1≤x≤2; more preferably, the halide-doped sulfide is Li 3+x PS4I x and / or Li 6+x P2S8I x , where 0.1≤x≤2.

[0022] Preferably, in the use described in the present invention, the dual ion conductor compound is a halide-doped sulfide, and the dual ion conductor compound is the electrolyte or the interface layer between the electrolyte and the negative electrode, or is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

[0023] Preferably, in the use described in the present invention, the dual ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides, and the dual ion conductor compound is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive.

[0024] Preferably, in the use according to the present invention, the dual ion conductor compound is used in combination with additional non-functional components.

[0025] Preferably, in the use described in the present invention, the dual ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides and when the dual ion conductor compound is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive, the dual ion conductor compound accounts for 0.1 wt % to 50 wt %, preferably 0.1 wt % to 30 wt % of the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

[0026] Preferably, in the use described in the present invention, the dual ion conductor compound is a halide-doped sulfide and when the dual ion conductor compound is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive, the dual ion conductor compound accounts for 0.1 weight% to 50 weight% of the positive electrode and accounts for more than 1 weight% and less than 100% of the electrolyte or the interface layer between the electrolyte and the negative electrode.

[0027] Preferably, in the use described in the present invention, the halogen anions of the dual ion conductor compound can migrate back and forth under the driving of the electric field during the charge and discharge process, thereby forming a dynamic adaptive interface layer of halide between the negative electrode and the electrolyte, naturally adjusting the morphology of the interface layer and adaptively repairing the cracks and pores caused by the volume effect of the negative electrode, so as to ensure close solid-solid contact between the negative electrode and the solid electrolyte during the stripping / electroplating process.

[0028] In another aspect, the present invention provides a method for improving the stability of the mechanical structure of the interface layer between the negative electrode and the electrolyte in an energy storage device, wherein the energy storage device includes a lithium ion energy storage device and a sodium ion energy storage device and includes a positive electrode, an electrolyte, and a negative electrode, the method comprising the following steps:

[0029] The dual ion conductor compound is used as an electrolyte or an interface layer between the electrolyte and the negative electrode, or is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive;

[0030] In the dual ion conductor compound, cations and halogen anions can simultaneously migrate back and forth between the interface layer and the electrolyte under the driving of the electric field during the charge and discharge process;

[0031] When the dual ion conductor compound is used as the electrolyte or the interface layer between the electrolyte and the negative electrode, the dual ion conductor compound is a halide-doped sulfide;

[0032] When the dual ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode, the dual ion conductor compound is selected from one or more of alkali metal halides, alkaline earth metal halides, and halide-doped sulfides.

[0033] Preferably, in the method of the present invention, the alkali metal halide is lithium halide and / or sodium halide.

[0034] Preferably, in the method of the present invention, the alkali metal halide is selected from one or more of LiI, LiBr, LiCl, LiF, NaI, NaBr, NaCl and NaF; more preferably, the alkali metal halide is selected from one or more of LiI, LiBr, NaI and NaBr; most preferably, the alkali metal halide is LiI and / or NaI.

[0035] Preferably, in the method of the present invention, the alkaline earth metal halide is magnesium halide.

[0036] Preferably, in the method described in the present invention, the alkaline earth metal halide is MgI2 and / or MgBr2; more preferably, the alkaline earth metal halide is MgI2.

[0037] Preferably, in the method of the present invention, the halide-doped sulfide is selected from Na 3+x PS4Br x 、Li 3-x PS 4-x Br x 、Li 3+x PS4I x 、Li 3-x PS 4-x I x 、Li 6+x P2S8I x He Li 6+x P2S8Br x One or more of the following, wherein 0.1≤x≤2; more preferably, the halide-doped sulfide is Li 3+x PS4I x and / or Li 6+x P2S8I x , where 0.1≤x≤2.

[0038] Preferably, in the method according to the present invention, the dual ion conductor compound is used in combination with additional non-functional components.

[0039] Preferably, in the method of the present invention, when the dual ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode, the dual ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides and the dual ion conductor compound accounts for 0.1 wt % to 50 wt %, preferably 0.1 wt % to 30 wt %, of the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

[0040] Preferably, in the method described in the present invention, when the dual ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode, the dual ion conductor compound is a halide-doped sulfide, and the dual ion conductor compound accounts for 0.1 weight% to 50 weight% of the positive electrode and accounts for more than 1 weight% and less than 100% of the electrolyte or the interface layer between the electrolyte and the negative electrode.

[0041] Preferably, in the method described in the present invention, the halogen anions of the dual ion conductor compound can migrate back and forth under the driving of the electric field during the charge and discharge process, thereby forming a dynamic adaptive interface layer of halide between the negative electrode and the electrolyte, naturally adjusting the morphology of the interface layer and adaptively repairing the cracks and pores caused by the volume effect of the negative electrode, so as to ensure close solid-solid contact between the negative electrode and the solid electrolyte during the stripping / electroplating process.

[0042] In another aspect, the present invention provides a dual ion conductor compound for improving the stability of the mechanical structure of the interface layer between the negative electrode and the electrolyte in an energy storage device, wherein the energy storage device includes a lithium ion energy storage device and a sodium ion energy storage device and includes a positive electrode, an electrolyte and a negative electrode;

[0043] In the dual ion conductor compound, cations and halogen anions can simultaneously migrate back and forth between the interface layer and the electrolyte under the driving of the electric field during the charge and discharge process;

[0044] The dual ion conductor compound is selected from one or more of alkali metal halides, alkaline earth metal halides and halide-doped sulfides.

[0045] Preferably, in the dual ion conductor compound of the present invention, the alkali metal halide is lithium halide and / or sodium halide.

[0046] Preferably, in the dual ion conductor compound of the present invention, the alkali metal halide is selected from one or more of LiI, LiBr, LiCl, LiF, NaI, NaBr, NaCl and NaF; more preferably, the alkali metal halide is selected from one or more of LiI, LiBr, NaI and NaBr; most preferably, the alkali metal halide is LiI and / or NaI.

[0047] Preferably, in the dual ion conductor compound of the present invention, the alkaline earth metal halide is magnesium halide.

[0048] Preferably, in the dual ion conductor compound of the present invention, the alkaline earth metal halide is MgI2 and / or MgBr2; more preferably, the alkaline earth metal halide is MgI2.

[0049] Preferably, in the dual ion conductor compound of the present invention, the halide-doped sulfide is selected from Na 3+x PS4Br x 、Li 3-x PS 4-x Br x 、Li 3+x PS4I x 、Li 3-x PS 4-x I x、Li 6+x P2S8I x He Li 6+x P2S8Br x One or more of the following, wherein 0.1≤x≤2; more preferably, the halide-doped sulfide is Li 3+x PS4I x and / or Li 6+x P2S8I x , where 0.1≤x≤2.

[0050] Preferably, in the dual ion conductor compound described in the present invention, the dual ion conductor compound is a halide-doped sulfide, and the dual ion conductor compound is an electrolyte or an interface layer between the electrolyte and the negative electrode, or is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

[0051] Preferably, in the dual ion conductor compound described in the present invention, the dual ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides, and the dual ion conductor compound is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive.

[0052] Preferably, in the dual ion conductor compound of the present invention, the dual ion conductor compound is used in combination with another non-functional component.

[0053] Preferably, in the dual ion conductor compound described in the present invention, the dual ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides and when the dual ion conductor compound is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive, the dual ion conductor compound accounts for 0.1 wt % to 50 wt %, preferably 0.1 wt % to 30 wt %, of the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

[0054] Preferably, in the dual ion conductor compound described in the present invention, the dual ion conductor compound is a halide-doped sulfide and when the dual ion conductor compound is uniformly dispersed in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode as an additive, the dual ion conductor compound accounts for 0.1 weight% to 50 weight% of the positive electrode and accounts for more than 1 weight% and less than 100% of the electrolyte or the interface layer between the electrolyte and the negative electrode.

[0055] Preferably, in the dual-ion conductor compound described in the present invention, the halogen anions of the dual-ion conductor compound can migrate back and forth under the driving of the electric field during the charge and discharge process, thereby forming a dynamic adaptive interface layer of halide between the negative electrode and the electrolyte, naturally adjusting the morphology of the interface layer and adaptively repairing the cracks and pores caused by the volume effect of the negative electrode, so as to ensure close solid-solid contact between the negative electrode and the solid electrolyte during the stripping / electroplating process.

[0056] In a specific embodiment of the present invention, the dual-ion conductor compound of the present invention can be applied to solid-state batteries with currently common polymer, chloride, and sulfide electrolyte systems. During the battery cycle, the halogen anions move and form a dense interface layer between the negative electrode and the electrolyte to achieve in-situ self-repair of the interface layer, maintaining good contact between the electrolyte and the negative electrode interface, and effectively alleviating problems such as interface unevenness and loss of electrical contact caused by the large volume effect of the high-specific-capacity negative electrode. For metallic lithium negative electrodes, the interface layer formed by self-repair can also inhibit the growth of dendrites of the metallic lithium negative electrode, thereby improving the cycle life of the solid-state battery.

[0057] In a specific embodiment of the present invention, the dual ion conductor compound can be used in combination with other commonly used solid electrolytes, for example, by the following method:

[0058] 100mL of acetonitrile was added to a stirring tank, and the polymer electrolyte, lithium salt and dual ion conductor were evenly mixed in a mortar to form a mixture. 3g of the mixture was weighed and placed in the stirring tank to form a blended component, and the blended component was stirred to obtain a slurry. The slurry was evenly coated on a PTFE template, and then the PTFE template coated with the slurry was placed in a 55°C oven and dried for 6h. After the temperature dropped to room temperature, the dried electrolyte membrane was punched into a disc with a diameter of 16mm, and the disc was quickly transferred to an argon-filled glove box for storage to obtain a polymer electrolyte sheet containing a self-healing additive.

[0059] In a specific embodiment of the present invention, the inorganic electrolyte with self-repairing function can be obtained by fully mixing the dual ion conductor compound with the sulfide electrolyte or chloride electrolyte by hand milling or ball milling.

[0060] In a specific embodiment of the present invention, the dual ion conductor compound can be uniformly dispersed in the positive electrode. Specifically, the dual ion conductor compound can be combined with PVDF as a binder, or the dual ion conductor compound can be combined with a C-containing material as a conductive agent and applied to the positive electrode. Furthermore, for example, this can be done by a method comprising the following steps:

[0061] The dual-ion conductor compound was added to a PVDF dispersion and stirred thoroughly to dissolve the dual-ion conductor compound to obtain a solution. After freeze-drying to completely remove moisture from the solution, the dehydrated product was placed in a vacuum oven and incubated at 120°C for 6 hours. After the temperature dropped to room temperature, the composite self-healing additive was quickly transferred to an argon-filled glove box for storage, resulting in a self-healing binder. The self-healing binder was then applied to the positive electrode.

[0062] Alternatively, a conductive agent precursor is mixed with a dual-ion conductor compound to obtain a mixture. The mixture is placed in a tube furnace and calcined at 700°C for 6 hours under argon gas to obtain a conductive agent with self-healing properties. The conductive agent with self-healing properties is then applied to the positive electrode. Preferably, the conductive agent precursor can be selected from at least one of a conductive polymer monomer, a sugar, asphalt, coke, an alkane gas, and an olefin gas. More preferably, the conductive agent precursor is selected from at least one of aniline monomer, sucrose, glucose, paraffin oil, methane, acetylene, and ethylene.

[0063] Furthermore, in the self-repairing additive of the dual ion conductor compound and the binder or conductive agent of the present invention, the mass fraction of the dual ion conductor compound is greater than 50%, preferably greater than 80%.

[0064] The present invention has the following beneficial effects:

[0065] The dual-ion conductor compound provided by the present invention can be applied to solid-state batteries with currently common polymer, chloride or sulfide electrolyte systems. During the battery cycle, the halogen anions of the dual-ion conductor move back and forth under the drive of the electric field, thereby forming a dynamic adaptive interface layer of halide between the negative electrode and the electrolyte, naturally adjusting the morphology of the interface layer and adaptively repairing the cracks and pores caused by the volume effect of the negative electrode, so as to ensure close solid-solid contact between the negative electrode and the solid electrolyte during the stripping / electroplating process. At the same time, the interface layer formed by self-repair can also inhibit the growth of dendrites of the metal lithium negative electrode, improve the cycle life of the solid-state battery, and achieve stable circulation under zero stacking pressure.

[0066] BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which:

[0068] FIG1A shows the initial impedance spectrum and the impedance spectrum after 50 cycles of the d1 battery prepared in an embodiment of the present invention;

[0069] FIG1B shows the initial impedance spectrum of the f1 battery prepared in the comparative example of the present invention and the impedance spectrum after 50 cycles;

[0070] FIG2 is a cross-sectional electron micrograph of the interface layer between the negative electrode and the electrolyte of the F1 battery prepared as a comparative example of the present invention after 50 cycles;

[0071] FIG3 is a cross-sectional electron micrograph of the interface layer between the negative electrode and the electrolyte of the D1 battery prepared in accordance with an embodiment of the present invention after 50 cycles;

[0072] FIG4 is an electron microscope image of LiI particles in the electrolyte of a d7 battery prepared in an embodiment of the present invention in an initial state and after 50 cycles, and the corresponding energy dispersive X-ray spectra;

[0073] FIG5 is a cross-sectional electron micrograph of the interface layer between the negative electrode and the electrolyte of the D7 battery prepared in accordance with an embodiment of the present invention after 50 cycles;

[0074] FIG6 is a cross-sectional electron micrograph and energy dispersive X-ray spectrum of the interface layer between the negative electrode and the electrolyte after the first discharge and first charge of the D1 battery prepared in accordance with an embodiment of the present invention;

[0075] FIG7 is an in-situ X-ray photoelectron spectrum of the interface layer between the negative electrode and the electrolyte of the d1 battery prepared in an embodiment of the present invention;

[0076] FIG8 shows the charge-discharge cycle capacity retention and coulombic efficiency of the d1 battery prepared in an embodiment of the present invention;

[0077] FIG9 shows a soft-pack battery prepared according to the d1 battery solution of an embodiment of the present invention and its cycle capacity retention under no stacking pressure;

[0078] FIG10 is a comparison of cycle data of a d10 battery prepared in an embodiment of the present invention and an f7 battery prepared in a comparative example;

[0079] FIG11 is a large-scale cross-sectional electron micrograph of the interface layer between the negative electrode and the electrolyte of the D5 battery prepared in accordance with an embodiment of the present invention after 50 cycles;

[0080] FIG12 is a cross-sectional electron micrograph and energy dispersive X-ray spectrum of the interface layer between the negative electrode and the electrolyte of the D5 battery prepared in an embodiment of the present invention after 50 cycles.

[0081] Best Mode for Carrying Out the Invention

[0082] The present invention will be further described in detail below in conjunction with specific embodiments. The examples given are only for illustrating the present invention, not for limiting the scope of the present invention.

[0083] Example 1

[0084] In this embodiment, NaI, LiBr, LiCl, Li 2.8 PS 3.8 Br 0.2 、Li7P2S8I、Li 1.4 PS2.4 Br 1.6 Or MgI2 as dual ion conductors. These dual ion conductors are uniformly dispersed in Li7P3S by grinding. 11 or PEO solid electrolyte, and with LiNi 0.8 Co 0.1 Mn 0.1 O2 is used as the positive electrode active material, and silicon and metallic Li are used as the negative electrode to assemble the solid-state battery.

[0085] 1. Li7P3S 11 The mixture was uniformly mixed with NaI in a mortar at a mass ratio of 19:1 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 0.8 Co 0.1 Mn 0.1 O2、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as a1.

[0086] 2. Li7P3S 11 The mixture was uniformly mixed with LiBr in a mortar at a mass ratio of 19:1 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 0.8 Co 0.1 Mn 0.1 O2、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as a2.

[0087] 3. Li7P3S 11 The mixture was uniformly mixed with LiCl in a mortar at a mass ratio of 19:1 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 0.8 Co 0.1 Mn 0.1 O2、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as a3.

[0088] 4. Li7P3S 11 、Li 2.8 PS 3.8 Br 0.2 The mixture was uniformly mixed with Li7P2S8I in a mortar at a mass ratio of 19:0.5:0.5 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 0.8 Co 0.1 Mn 0.1 O2、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as a4.

[0089] 5. Add 100mL of acetonitrile to a stirring tank, and evenly mix PEO, LiTFSI and NaI in a mortar at a mass ratio of 30:10:1 to form a mixture. Weigh 3g of the mixture and place it in the stirring tank to form a blending component. Stir the blending component to obtain a slurry. The slurry is evenly coated on the PTFE template, and then the PTFE template coated with the slurry is placed in a 55°C oven and dried for 6h. After the temperature drops to room temperature, the dried electrolyte membrane is punched into a disc with a diameter of 16mm, and the disc is quickly transferred to an argon-filled glove box for storage. LiNi 0.8 Co 0.1 Mn 0.1 The O2 electrode is used as the positive electrode and the metal Li is used as the negative electrode. The resulting battery is denoted as a5.

[0090] 6. Li7P3S 11 With Li 1.4 PS 2.4 Br 1.6 The mixture was uniformly mixed in a mortar at a mass ratio of 19:1 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 0.8 Co 0.1 Mn 0.1 O2、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a Si electrode sheet was placed on the other side of the electrolyte sheet, and the electrolyte sheet with the Si electrode sheet was kept at a pressure of 360 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as a6.

[0091] 7. Li7P3S 11 The mixture was uniformly mixed with MgI2 in a mortar at a mass ratio of 19:1 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve was kept at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 0.8 Co 0.1 Mn 0.1 O2、Li7P3S 11, Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as a7.

[0092] Table 1

[0093] Example 2

[0094] In this embodiment, LiBr is used as a dual ion conductor. A mixture obtained by mixing a dual ion conductor with a non-ionic conductor such as PVDF or carbon is used as a self-repairing additive, or a composite structure obtained by microstructurally compounding a dual ion conductor with a non-ionic conductor such as PVDF or carbon is used as a self-repairing additive, and the self-repairing additive is uniformly dispersed in Li4Ti5O 12 The positive electrode is obtained by Li7P3S 11 As a solid electrolyte, metallic Li is used as the negative electrode to assemble the solid-state battery.

[0095] 1. Weigh 5g of 40% PVDF dispersion and add the weighed dispersion into a beaker. Add 3g of LiBr to the dispersion and stir thoroughly to dissolve the LiBr completely to obtain a solution. After completely removing the water from the solution by freeze drying, transfer the dehydrated product into a vacuum oven and keep it at 120°C for 6h. After the temperature drops to room temperature, quickly transfer the composite self-healing additive into an argon-filled glove box for storage. Weigh Li7P3S 11 150 mg of solid electrolyte was placed in a ceramic sleeve with a diameter of 10 mm. The solid electrolyte in the ceramic sleeve was kept at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet. 12 、Li7P3S 11 , Super-P, and the composite self-healing additive LiBr-PVDF were mixed in a mortar at a mass ratio of 4.5:4:1:0.5 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as c1.

[0096] 2. Weigh 2.5 g of 40% PVDF dispersion and add the weighed dispersion into a beaker. Add 4 g of LiBr to the dispersion and stir thoroughly to dissolve the LiBr completely to obtain a solution. After completely removing the water from the solution by freeze drying, transfer the dehydrated product into a vacuum oven and keep it at 120°C for 6 hours. After the temperature drops to room temperature, quickly transfer the composite self-healing additive into an argon-filled glove box for storage. Weigh Li7P3S 11 150 mg of solid electrolyte was placed in a ceramic sleeve with a diameter of 10 mm. The solid electrolyte in the ceramic sleeve was kept at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet. 12 、Li7P3S 11 , Super-P, and the composite self-healing additive LiBr-PVDF were mixed in a mortar at a mass ratio of 4.5:4:1:0.5 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as c2.

[0097] 3. Add 5g C6H 12 After mixing O6 and 3g LiBr, the mixture was placed in a tube furnace and sintered at 700℃ with argon for 6h to obtain the carbon-coated self-healing additive LiBr@C. 11 150 mg of solid electrolyte was placed in a ceramic sleeve with a diameter of 10 mm. The solid electrolyte in the ceramic sleeve was kept at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet. 12 、Li7P3S 11 , the composite self-healing additive LiBr@C was mixed evenly in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as c3.

[0098] 4. Add 2.5g C6H 12After mixing O6 and 4g LiBr, the mixture was placed in a tube furnace and sintered at 700℃ for 6h with argon gas to obtain the carbon-coated self-healing additive LiBr@C. 11 150 mg of solid electrolyte was placed in a ceramic sleeve with a diameter of 10 mm. The solid electrolyte in the ceramic sleeve was kept at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet. 12 、Li7P3S 11 , the composite self-healing additive LiBr@C was mixed evenly in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as c4.

[0099] Table 2

[0100] Example 3

[0101] In this embodiment, Li 6+x P2S8Br x 、Li 3+x PS4I x 、Li 6+x P2S8I x 、Li 3-x PS 4-x I x Or LiI as a dual ion conductor compound. 6+x P2S8Br x 、Li 3+x PS4I x 、Li 6+x P2S8I x 、Li 3-x PS 4-x I x Or LiI as electrolyte or negative electrode interface layer, or evenly dispersed in Li4Ti5O by ball milling 12 Among the positive electrode, Li3PS4, and PEO solid electrolyte, metallic Li is used as the negative electrode to assemble the solid-state battery.

[0102] 1. Weigh 150 mg of Li 3.2 PS4I 0.2 Place it in a ceramic sleeve with a diameter of 10 mm, and place the Li 3.2 PS4I 0.2The electrolyte sheet was obtained by maintaining the pressure at 360 MPa for 10 min. 12 , Li3PS4, and Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as d1.

[0103] 2. A solid-state battery was prepared according to the protocol for battery d1. The difference from d1 lies in the use of a different dual-ion conductor. In this example, Li₄PS₄I was used as the dual-ion conductor. The resulting battery from this example is designated d2.

[0104] 3. Prepare a solid-state battery according to the scheme of battery d1. The difference from d1 is that the dual ion conductor is different. In this embodiment, the dual ion conductor is Li 4.6 PS4I 1.6 The battery obtained in this example is recorded as d3.

[0105] 4. Prepare a solid-state battery according to the scheme of battery d1. The difference from d1 is that the dual ion conductor is different. In this embodiment, the dual ion conductor is Li 2.8 PS 3.8 I 0.2 The battery obtained in this example is recorded as d4.

[0106] 5. Weigh 150 mg of Li3PS4 solid electrolyte and place it in a ceramic sleeve with a diameter of 10 mm. Keep the Li3PS4 in the ceramic sleeve under a pressure of 360 MPa for 10 minutes to obtain a Li3PS4 electrolyte sheet. 12, Li3PS4, and Super-P are mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture is used as a composite positive electrode. 5 mg of the mixture is weighed and placed on one side of the above-mentioned electrolyte sheet Li3PS4. The electrolyte sheet with the mixture is kept at a pressure of 360 MPa for 10 minutes to form a composite structure of Li3PS4 electrolyte sheet / composite positive electrode. A metal lithium foil with a thickness of 100 μm and an iodine element are placed in a sealed container and heated to 120°C for 5 hours to form a LiI interface layer / Li negative electrode composite structure. The LiI interface layer / Li negative electrode is cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet to form a Li3PS4 electrolyte sheet / LiI interface layer / Li negative electrode composite structure, and the electrolyte sheet with lithium foil is kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery is recorded as d5.

[0107] 6. Weigh 150 mg of Li3PS4 solid electrolyte and place it in a ceramic sleeve with a diameter of 10 mm. Keep the Li3PS4 in the ceramic sleeve under a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet. 12 、Li3PS4、Super-P、Self-repairing additive Li 7.6 P2S8Br 1.6 The mixture was mixed in a mortar at a mass ratio of 4.5:4:1:0.5 to obtain a mixture, which was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was maintained at a pressure of 360 MPa for 10 minutes. Then, a 100 μm thick metal lithium foil was cut into a 9 mm diameter disc and placed on the other side of the electrolyte sheet. The electrolyte sheet with the lithium foil was maintained at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as d6.

[0108] 7. Li6PS5Cl and LiI were uniformly mixed in a mortar at a mass ratio of 19:1 to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic housing with a diameter of 10 mm. The blended component placed in the ceramic housing was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 12, Li6PS5Cl, and Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as d7.

[0109] 8. Add 100mL of acetonitrile to a stirring tank, and evenly mix PEO, LiTFSI and Li7P2S8I in a mortar at a mass ratio of 30:10:3 to form a mixture. Weigh 3g of the mixture and place it in the stirring tank to form a blending component, and stir the blending component to obtain a slurry. The slurry is evenly coated on a PTFE template, and then the PTFE template coated with the slurry is placed in a 55°C oven and dried for 6h. After the temperature drops to room temperature, the dried electrolyte membrane is punched into a disc with a diameter of 16mm, and the disc is quickly transferred to an argon-filled glove box for storage. Li4Ti5O 12 The electrode is used as the positive electrode and the metal Li is used as the negative electrode. The resulting battery is recorded as d8.

[0110] 9. Weigh 150 mg of Li7P2S8Br solid electrolyte and place it in a ceramic sleeve with a diameter of 10 mm. Keep the Li7P2S8Br in the ceramic sleeve under a pressure of 360 MPa for 10 minutes to obtain a Li7P2S8Br electrolyte sheet. 12 , Li7P2S8Br, and Super-P were mixed evenly in a mortar in a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. A metallic lithium foil with a thickness of 100 μm and an iodine element were placed in a sealed container and heated to 120°C for 5 hours to form a LiI interface layer / Li negative electrode composite structure. The LiI interface layer / Li negative electrode was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet to form a Li7P2S8Br electrolyte sheet / LiI interface layer / Li negative electrode composite structure, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as d9.

[0111] 10. Weigh 150 mg of Li 3.2 PS4I 0.2 The solid electrolyte is placed in a ceramic housing with a diameter of 10 mm. 3.2 PS4I0.2 The Li 3.2 PS4I 0.2 Electrolyte sheet. Cut the 100μm thick lithium metal foil into two 9mm diameter discs and place them on both sides of the electrolyte sheet to form a Li / Li 3.2 PS4I 0.2 A battery was obtained by placing the electrolyte sheet with lithium foil under a pressure of 20 MPa for 5 min. The obtained battery was designated as d10.

[0112] Table 3

[0113] Example 4

[0114] In this embodiment, Na 3+x PS4Br x Or LiBr as a dual ion conductor, it is evenly dispersed in Li3PS4, Li7P3S by grinding, ball milling or liquid phase composite. 11 or Na3PS4 solid electrolyte, with Li4Ti5O 12 Or NaFePO4 as the positive electrode active material, metal Li or Na as the negative electrode, assemble a solid-state battery.

[0115] 1. Combine Na3PS4 with Na 3.2 PS4Br 0.2 Mix evenly in a mortar at a mass ratio of 19:1 to obtain a blended component. Weigh 150 mg of the blended component and place the weighed blended component in a ceramic sleeve with a diameter of 10 mm. The blended component placed in the ceramic sleeve is maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. NaFePO4, Na3PS4, and Super-P are mixed evenly in a mortar at a mass ratio of 5:4:1 to obtain a mixture and use the mixture as a composite positive electrode. Weigh 5 mg of the mixture and place the weighed mixture on one side of the electrolyte sheet. The electrolyte sheet with the mixture is maintained at a pressure of 360 MPa for 10 minutes, then a metal Na foil with a thickness of 100 μm is cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with Na foil is maintained at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery is recorded as e1.

[0116] 2. A solid-state battery was prepared according to the protocol for battery e1. The difference from e1 lies in the use of a different dual-ion conductor. In this example, Na₄PS₄Br was used as the dual-ion conductor. The resulting battery is designated e2.

[0117] 3. Prepare a solid-state battery according to the scheme of battery e1. The difference from e1 is that the dual ion conductor is different. In this embodiment, the dual ion conductor is Na 4.6 PS4Br 1.6 The battery obtained in this example is recorded as e3.

[0118] 4. Li7P3S 11 The mixture was ball-milled with LiBr at a mass ratio of 19:1 at 400 rpm for 36 h to obtain a blended component. 150 mg of the blended component was weighed and placed in a ceramic housing with a diameter of 10 mm. The blended component placed in the ceramic housing was maintained at a pressure of 360 MPa for 10 min to obtain an electrolyte sheet containing a self-healing additive. 12 、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as e4.

[0119] 5. 3.8g Li7P3S 11 0.2g LiBr was added to 10ml ethanol and stirred thoroughly with ultrasound to dissolve LiBr completely and Li7P3S 11 The solution was uniformly dispersed to obtain a solution. The solution was dried under vacuum at 120°C for 6 hours to obtain a powder. 150 mg of the powder was weighed and placed in a ceramic sleeve with a diameter of 10 mm. The powder in the ceramic sleeve was maintained at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 12 、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as e5.

[0120] Table 4

[0121] Comparative Example 1

[0122] In this comparative example, Li3N, Li3PS4 and LiBr are used as dual ion conductors. The dual ion conductors are uniformly mixed with PVDF as self-repairing additives, and the self-repairing additives are uniformly dispersed in Li7P3S 11 In solid electrolytes, or Li7P3S without self-healing additives 11 , Li3PS4, PEO as electrolyte, Li4Ti5O 12 As the positive electrode active material, metallic Li is used as the negative electrode to assemble a solid-state battery.

[0123] 1. Li7P3S 11 Weigh 150 mg of Li7P3S in a ceramic sleeve with a diameter of 10 mm. 11 The electrolyte sheet was obtained by maintaining the pressure at 360 MPa for 10 min. 12 、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as f1.

[0124] 2. Add 100mL of acetonitrile to a stirring tank, and evenly mix PEO and LiTFSI in a mortar at a mass ratio of 3:1 to form a mixture. Weigh 3g of the mixture and place it in the stirring tank to form a blending component, and stir the blending component to obtain a slurry. The slurry is evenly coated on the PTFE template, and then the PTFE template coated with the slurry is placed in a 55°C oven and dried for 6h. After the temperature drops to room temperature, the dried electrolyte membrane is punched into a disc with a diameter of 16mm, and the disc is quickly transferred to a glove box filled with argon for storage. Li4Ti5O 12 The electrode is used as the positive electrode and the metal Li is used as the negative electrode. The resulting battery is recorded as f2.

[0125] 3. Li7P3S 11 Mix Li3N in a mortar at a mass ratio of 19:1 to obtain a blended component. Weigh 150 mg of the blended component and place it in a ceramic housing with a diameter of 10 mm. Maintain the blended component in the ceramic housing at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive.12 、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as f3.

[0126] 4. Weigh 10g of 40% PVDF dispersion and add the weighed dispersion into a beaker. Add 1g of LiBr to the dispersion and stir thoroughly to dissolve the LiBr completely to obtain a solution. After completely removing the water from the solution by freeze drying, transfer the dehydrated product into a vacuum oven and keep it at 120°C for 6h. After the temperature drops to room temperature, quickly transfer the composite self-healing additive into an argon-filled glove box for storage. Weigh Li7P3S 11 150 mg of solid electrolyte was placed in a ceramic sleeve with a diameter of 10 mm. The solid electrolyte in the ceramic sleeve was kept at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet. 12 、Li7P3S 11 , Super-P, and the composite self-healing additive LiBr-PVDF were mixed in a mortar at a mass ratio of 4.5:4:1:0.5 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as f4.

[0127] 5. Li7P3S 11 Weigh 150 mg of Li7P3S in a ceramic sleeve with a diameter of 10 mm. 11 The electrolyte sheet was obtained by maintaining the pressure at 360 MPa for 10 min. 12 、Li7P3S 11, Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and 20 mg of LiBr was weighed and added to the metal lithium side. The electrolyte sheet with lithium foil and LiBr was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as f5.

[0128] 6. Li7P3S 11 Mix Li3PS4 in a mortar at a mass ratio of 19:1 to obtain a blended component. Weigh 150 mg of the blended component and place it in a ceramic housing with a diameter of 10 mm. Maintain the blended component in the ceramic housing at a pressure of 360 MPa for 10 minutes to obtain an electrolyte sheet containing a self-healing additive. 12 、Li7P3S 11 , Super-P were mixed in a mortar at a mass ratio of 5:4:1 to obtain a mixture, and the mixture was used as a composite positive electrode. 5 mg of the mixture was weighed and placed on one side of the electrolyte sheet. The electrolyte sheet with the mixture was kept at a pressure of 360 MPa for 10 minutes. Then, a metal lithium foil with a thickness of 100 μm was cut into a disc with a diameter of 9 mm and placed on the other side of the electrolyte sheet, and the electrolyte sheet with lithium foil was kept at a pressure of 120 MPa for 5 minutes to obtain a battery. The resulting battery was recorded as f6.

[0129] 7. Weigh 150 mg of Li₃PS₄ and place it in a 10 mm diameter ceramic housing. Hold the housing at 360 MPa for 10 minutes to obtain an electrolyte sheet. Cut 100 μm thick lithium metal foil into 9 mm diameter discs and place them on either side of the electrolyte sheet. The electrolyte sheet with lithium foil is then held at 120 MPa for 5 minutes to produce a symmetrical lithium battery. The resulting battery is designated f7.

[0130] Table 5

[0131] f1: Using Li7P3S 11 (Commonly used sulfide electrolyte) as the electrolyte, without adding the dual ion conductor component with self-healing function. The impedance of f1 increases rapidly and the battery life is short;

[0132] f2: uses PEO (a common polymer electrolyte) as the electrolyte and does not contain a self-healing dual-ion conductor. The impedance of f2 increases rapidly, resulting in a short battery life.

[0133] f3: Adding Li3N to Li7P3S 11 In the electrolyte (commonly used sulfide electrolyte), since Li3N is not a dual-ion conductor component with self-healing function, the impedance of f3 increases rapidly and the battery life is short;

[0134] f4: LiBr and PVDF are compounded in a solution at a mass ratio of 1:4 and then added to Li7P3S 11 (Commonly used sulfide electrolyte) electrolyte. Because too much PVDF blocks the migration path of Br ions, the self-healing function of the dual ion conductor cannot be achieved. The impedance of f4 increases rapidly, and the battery life is short;

[0135] f5: LiBr was added to the current collector side of the lithium metal anode, failing to achieve the self-healing function of the dual-ion conductor. The impedance of f5 increased rapidly, resulting in a short battery life.

[0136] f6: Add Li3PS4 to Li7P3S 11 In the electrolyte (commonly used sulfide electrolyte), since Li3PS4 is not a dual-ion conductor component with self-healing function, the impedance of f6 increases rapidly and the battery life is short.

[0137] f7: uses Li3PS4 (a common sulfide electrolyte) as the electrolyte, without the addition of a self-healing dual-ion conductor. The impedance of f7 increases rapidly, resulting in a short battery life.

[0138] The AC impedance spectra of battery d1 in Example 3 and battery f1 in Comparative Example 1, both in their original state and after 20 and 50 cycles, are shown in Figures 1A and 1B. Cross-sectional electron micrographs of f1, d1, and d7 after 50 cycles are shown in Figures 2, 3, and 5, respectively. Electron micrographs of the LiI particles in the electrolyte of d7, both in their original state and after 50 cycles, and the corresponding energy-dispersive X-ray spectra are shown in Figure 4. The in situ X-ray photoelectron spectra at the negative electrode interface of d1 during charge and discharge are shown in Figure 6.

[0139] Figure 1B shows a rapid increase in impedance for f1, while Figure 1A shows only a slight increase in impedance for d1. Figure 2 shows that without the addition of the self-healing dual-ion conductor component, numerous pores and cracks appeared at the lithium anode-electrolyte interface after cycling. The lithium anode and electrolyte interface were largely separated and no longer in contact. This also explains the excessive impedance after cycling f1.

[0140] Figure 3 shows the use of dual ion conductor Li 3.2 PS4I 0.2 As an electrolyte, after 50 cycles of d1, an adaptive interface layer is formed between the lithium negative electrode and the electrolyte, maintaining the interface conformity. Compared with Figure 2, the dual ion conductor Li3.2 PS4I 0.2 The self-healing function of the interface solves the problem of the lithium negative electrode losing contact with the electrolyte after charge and discharge cycles.

[0141] Figure 4 shows that after simply mixing 5% by mass of LiI in the Li6PS5Cl electrolyte, the LiI particles in the electrolyte decrease during the cycle. Figure 5 shows that a self-healing layer also appears between the lithium anode and the electrolyte.

[0142] Combined with Figure 3, it can be seen that LiI with self-healing function and sulfide electrolyte can achieve its self-healing function whether through doping or simple mixing.

[0143] Figure 7 shows that the signals of iodine (I3d, I4d) and lithium (Li1s) are enhanced during the discharge process, but the signal of phosphorus (P2p) does not appear, indicating that a LiI layer is formed at the negative electrode interface.

[0144] The cross-sectional electron micrographs of the battery d1 of Example 3 after the first discharge and charge and the corresponding energy dispersive X-ray spectra are shown in FIG6 .

[0145] Figure 6 shows that after the first discharge, a self-repairing layer of about 2.6 μm thick is formed between the lithium negative electrode and the electrolyte. After charging, the thickness of the self-repairing layer decreases to about 1.6 μm, indicating that the LiI self-repairing layer can migrate back and forth between the interface and the electrolyte during the charge and discharge process.

[0146] The cycle capacity retention and coulombic efficiency of the battery d1 of Example 3 are shown in Figure 8. The all-solid-state lithium metal soft pack battery assembled and prepared according to the scheme d1 and its cycle capacity retention are shown in Figure 9.

[0147] Figure 8 shows that after 2400 charge and discharge cycles, the capacity retention rate of the d1 battery is as high as 90.7%, and the coulombic efficiency is stably maintained at 99.9%.

[0148] Figure 9 shows that after the all-solid-state lithium metal soft-pack battery assembled and prepared according to the scheme d1 was cycled twice under an additional stacking pressure of 20 MPa, the stacking pressure was released and the capacity of the soft-pack battery remained at 95% during stable cycling, achieving stable cycling of the zero-pressure all-solid-state lithium metal soft-pack battery.

[0149] The battery d10 of Example 3 and the battery f7 of Comparative Example 1 were 2.5 mAh cm -2 Comparison of cycling data at surface capacity and f7 at 5 mAh cm -2 The cycling data under the surface capacity are shown in Figure 10. Figure 10 shows that compared with the battery f7 with Li3PS4 as the electrolyte, the polarization overpotential increases rapidly in the first 400 hours of the cycle, which leads to battery failure. 3.2 PS4I0.2 The polarization overpotential of the battery d10 as the electrolyte remains stable after 2400 hours of cycling. -2 The d10 of the present invention can also stably circulate for more than 2000 hours.

[0150] The large-scale cross-sectional electron micrographs of the battery d5 in Example 3 in its original state and after 50 cycles are shown in FIG11 , and the energy dispersive X-ray spectrum at its interface is shown in FIG12 .

[0151] Figure 11 shows that before cycling, there are pores at the interface between the LiI layer and the electrolyte due to solid-solid contact problems. After 50 cycles, the LiI layer is in close contact with the electrolyte, and the pores and cracks disappear.

[0152] Figure 12 shows that after 50 cycles, iodine is distributed throughout the region extending approximately 5 microns from the interface to the electrolyte layer. Combining Figures 11 and 6, it can be seen that during the charge and discharge process, the LiI self-healing layer can migrate back and forth between the interface layer and the electrolyte, adapting to the volume effect of the lithium anode, maintaining a conformal interface, and thus preventing contact failure between the anode and electrolyte.

Claims

1. Use of a dual-ion conductor compound in improving the mechanical structure stability of the interface layer between the negative electrode and the electrolyte in an energy storage device, the energy storage device including a lithium-ion energy storage device and a sodium-ion energy storage device and including a positive electrode, an electrolyte, and a negative electrode; wherein, during charge and discharge processes, cations and halogen anions of the dual-ion conductor compound can reciprocally migrate between the interface layer and the electrolyte under the drive of an electric field; the dual-ion conductor compound is selected from one or more of alkali metal halides, alkaline earth metal halides, and sulfides doped with halides.

2. The use according to claim 1, wherein, the alkali metal halide is lithium halide and / or sodium halide; preferably, the alkali metal halide is selected from one or more of LiI, LiBr, LiCl, LiF, NaI, NaBr, NaCl, and NaF; more preferably, the alkali metal halide is selected from one or more of LiI, LiBr, NaI, and NaBr; most preferably, the alkali metal halide is LiI and / or NaI; preferably, the alkaline earth metal halide is magnesium halide; Preferably, the alkaline earth metal halide is MgI 2 and / or MgBr 2 ; More preferably, the alkaline earth metal halide is MgI 2 ; Preferably, the halide-doped sulfide is selected from Na 3+x PS 4 Br x 、Li 3-x PS 4-x Br x 、Li 3+x PS 4 I x 、Li 3-x PS 4-x I x 、Li 6+x P 2 S 8 I x and Li 6+x P 2 S 8 Br x and one or more of the following, where 0.1 ≤ x ≤ 2; more preferably, the halide-doped sulfide is Li 3+x PS 4 I x and / or Li 6+x P 2 S 8 I x , where 0.1 ≤ x ≤ 2.

3. The use according to claim 1, wherein, the dual-ion conductor compound is a sulfide doped with a halide, and the dual-ion conductor compound is an electrolyte or the interface layer between the electrolyte and the negative electrode, or is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

4. The use according to claim 1, wherein, the dual-ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides, and the dual-ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode.

5. The use according to claim 1, wherein, the dual-ion conductor compound is used in combination with another non-functional component.

6. The use according to claim 4, wherein, when the dual-ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode, the dual-ion conductor compound accounts for 0.1 wt% - 50 wt% of the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode, preferably 0.1 wt% - 30 wt%.

7. The use according to claim 3, wherein, when the dual-ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interface layer between the electrolyte and the negative electrode, the dual-ion conductor compound accounts for 0.1 wt% - 50 wt% of the positive electrode, and more than 1 wt% and less than 100% of the electrolyte or the interface layer between the electrolyte and the negative electrode.

8. The use according to claim 1, wherein, the halogen anions of the dual-ion conductor compound can reciprocally migrate under the drive of an electric field during charge and discharge processes, thereby forming a dynamically adaptive interface layer of halide between the negative electrode and the electrolyte, naturally adjusting the interface layer morphology and adaptively repairing cracks and pores generated in the negative electrode due to volume effects to ensure tight solid-solid contact between the negative electrode and the solid electrolyte during the stripping / plating process.

9. A method for improving the mechanical structure stability of the interfacial layer between the negative electrode and the electrolyte in an energy storage device, the energy storage device including a lithium-ion energy storage device and a sodium-ion energy storage device and including a positive electrode, an electrolyte, and a negative electrode, the method comprising the following steps: Using a dual-ion conductor compound as the electrolyte or the interfacial layer between the electrolyte and the negative electrode, or uniformly dispersing it as an additive in the positive electrode, the electrolyte, or the interfacial layer between the electrolyte and the negative electrode; wherein, in the dual-ion conductor compound, cations and halogen anions can reciprocally migrate between the interfacial layer and the electrolyte under the drive of an electric field during the charge and discharge process; when the dual-ion conductor compound is used as the electrolyte or the interfacial layer between the electrolyte and the negative electrode, the dual-ion conductor compound is a sulfide doped with a halide; when the dual-ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interfacial layer between the electrolyte and the negative electrode, the dual-ion conductor compound is selected from one or more of alkali metal halides, alkaline earth metal halides, and sulfides doped with halides.

10. The method according to claim 9, wherein, the alkali metal halide is lithium halide and / or sodium halide; preferably, the alkali metal halide is selected from one or more of LiI, LiBr, LiCl, LiF, NaI, NaBr, NaCl, and NaF; more preferably, the alkali metal halide is selected from one or more of LiI, LiBr, NaI, and NaBr; most preferably, the alkali metal halide is LiI and / or NaI; preferably, the alkaline earth metal halide is magnesium halide; Preferably, the alkaline earth metal halide is MgI 2 and / or MgBr 2 ; More preferably, the alkaline earth metal halide is MgI 2 ; Preferably, the halide-doped sulfide is selected from Na 3+x PS 4 Br x 、Li 3-x PS 4-x Br x 、 Li 3+x PS 4 I x , Li 3-x PS 4-x I x , Li 6+x P 2 S 8 I x and Li 6+x P 2 S 8 Br x One or more of the following, wherein 0.1≤x≤2; more preferably, the halide-doped sulfide is Li 3+x PS 4 I x and / or Li 6+x P 2 S 8 I x , where 0.1≤x≤2.

11. The method according to claim 9, wherein, the dual-ion conductor compound is used in combination with other non-functional components.

12. The method according to claim 9, wherein, when the dual-ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interfacial layer between the electrolyte and the negative electrode, the dual-ion conductor compound is selected from one or more of alkali metal halides and alkaline earth metal halides, and the dual-ion conductor compound accounts for 0.1 wt% - 50 wt% of the positive electrode, the electrolyte, or the interfacial layer between the electrolyte and the negative electrode, preferably 0.1 wt% - 30 wt%.

13. The method according to claim 9, wherein, when the dual-ion conductor compound is uniformly dispersed as an additive in the positive electrode, the electrolyte, or the interfacial layer between the electrolyte and the negative electrode, the dual-ion conductor compound is a sulfide doped with a halide, and the dual-ion conductor compound accounts for 0.1 wt% - 50 wt% of the positive electrode, more than 1 wt% and less than 100% of the electrolyte or the interfacial layer between the electrolyte and the negative electrode.

14. The method according to claim 9, wherein, The halogen anions of the dual-ion conductor compound can reciprocally migrate under the drive of an electric field during charge and discharge processes, thereby forming a dynamically adaptive interfacial layer of halide between the negative electrode and the electrolyte, naturally adjusting the interfacial layer morphology and adaptively repairing the cracks and pores generated in the negative electrode due to volume effects to ensure close solid-solid contact between the negative electrode and the solid electrolyte during the stripping / plating process.

Images