559 results about "Metallic lithium" patented technology

The invention relates to a doped modified argyrodite type solid electrolyte and a preparation method thereof, and belongs to the technical field of all-solid-state battery materials. The chemical formula of the electrolyte is Li < 5.5 + 2x + 2y > P < 1-x-y > Y < x > Bi < y > S < 4.5-1.5 x-1.5 y > O < 1.5 x + 1.5 y > Cl < 1.5 >, x is greater than or equal to 0.01 and less than or equal to 0.04, and y is greater than or equal to 0.01 and less than or equal to 0.04; the yttrium element and the bismuth element are doped at the P site of the argyrodite type electrolyte, and the oxygen element is doped at the S site of the argyrodite type electrolyte. After the argyrodite type electrolyte is in contact with metal lithium, an interface protection layer rich in lithium oxide can be formed in situ at an interface in a circulating process, so that lithium can be uniformly deposited, the generation of interface side reaction is inhibited, the interface stability of the argyrodite type electrolyte to a lithium metal negative electrode is improved, and the polarization voltage of a symmetrical battery is reduced; and the cycling stability of the all-solid-state lithium metal battery is enhanced.

The invention belongs to the technical field of all-solid-state sulfide lithium metal batteries, and relates to a lithium battery electrode containing an interface self-repairing coating as well as a preparation method and application of the lithium battery electrode. The electrode comprises a lithium metal negative electrode substrate and the interface self-repairing coating coated on the surface of the lithium metal negative electrode substrate, the interface self-repairing coating is internally provided with a dynamic reversible network, and the dynamic reversible network is constructed by disulfide bonds and hydrogen bonds. A layer of interface self-repairing coating is formed on the surface of a lithium metal negative electrode substrate to serve as a physical isolation barrier, metal lithium and sulfide electrolyte are isolated and prevented from being directly subjected to reduction reaction, and coating microcracks generated by volume change in lithium metal circulation can be repaired, so that the possibility of interface exposure caused by coating breakage is reduced, and the service life of the lithium metal negative electrode is prolonged. Meanwhile, good interface contact can be kept, the synergistic effect of stable interface impedance, lithium dendrite inhibition and long-term cycle performance improvement is achieved, and the long-term cycle stability of the all-solid-state lithium battery is improved.

A modified lithium-rich manganese-based positive electrode material, and a preparation method therefor and the use thereof. The modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based positive electrode material, wherein the bulk phase of the lithium-rich manganese-based positive electrode material is doped with a high-valent transition metal element, and the surface phase of the lithium-rich manganese-based positive electrode material has a lithium metal compound coating layer and an oxygen vacancy. In the modified lithium-rich manganese-based positive electrode material, the doping with a bulk-phase high-valence transition metal element, the coating with a surface-phase lithium metal compound coating layer and the construction of an oxygen vacancy are conducted at the same time; and by means of the co-action of the three, the rate capability and the cycling performance of the lithium-rich manganese-based positive electrode material can be significantly improved, which is of great significance for the further commercialization of the lithium-rich manganese-based positive electrode material.

The invention provides a negative plate of a solid-state battery. The negative plate comprises a current collector, a lithium-loving coating compounded on the current collector and a conductive layer compounded on the lithium-loving coating, the lithium-loving coating contains a lithium-loving element; the lithium-loving element comprises one or more of Mg, Pt, Sn, Ag, Al and Zn; and the conductive layer comprises a carbon material. By introducing the lithium-loving element and the high-potential material and utilizing a synergistic mechanism of the lithium-loving element and the high-potential material, the electrochemical window is further widened and the metal lithium deposition risk is reduced while the lithium deposition uniformity is improved. According to the negative electrode plate provided by the invention, the nucleation potential of the lithium-metal negative electrode plate and the resistance of the conductive material are controlled within a specific range, so that nucleation of lithium ions on the surface of the negative electrode current collector can be facilitated, meanwhile, the nucleation uniformity of the lithium ions on the surface of the negative electrode current collector can be improved, and the cycle life of the battery is further prolonged.

The invention belongs to the field of alkali metal batteries, and discloses an alkali metal alloy powder material and a preparation method, application and a product thereof, the alkali metal alloy powder material is alloy powder formed by an alkali metal element and at least one non-alkali metal element, the particle size is 1-100 microns, the atomic ratio of all elements in any single powder is highly consistent with the feeding ratio of raw materials, and the atomic ratio of all the elements in the powder is 1-100 microns. The high reducibility similar to alkali metal is maintained, the electronic conductivity is larger than 0.01 mS / cm, the average chemical valence state is smaller than 0.5 valence, and the electrochemical potential relative to metal lithium or metal sodium is 0-2 V. The preparation method comprises the following steps: heating and melting an alkali metal raw material to form an alkali metal melt, introducing a non-alkali metal raw material into the alkali metal melt, cooling to obtain an alkali metal alloy ingot, and physically grinding the alkali metal alloy ingot in a protective atmosphere to obtain powder with uniform components. The invention aims to provide a high-activity alkali metal alloy material in a powder form so as to fill the blank of the industry.

The invention discloses a reference electrode, and relates to the technical field of batteries. The reference electrode comprises a conductive assembly and a diaphragm assembly, the conductive assembly comprises an exposed conductor section and an insulating section, the exposed conductor section is wrapped in the diaphragm assembly, a coating is arranged on one side, facing the exposed conductor section, of the diaphragm assembly, and a metal lithium layer is plated on the surface of the exposed conductor section. Through the structure, the service life and the voltage stability of the reference electrode can be remarkably improved, so that the accuracy and the reliability of battery test data are guaranteed.

The invention discloses modified ultrathin lithium as well as a preparation method and application thereof. The modified ultrathin lithium provided by the invention comprises metal lithium and a doping agent doped in the metal lithium, the dopant is selected from metals having an electronegativity greater than the electronegativity of the metal lithium. The modified ultrathin lithium provided by the invention is used as the anode material of the lithium battery, so that the stability in dry air is remarkably improved, the reaction activity of the metal lithium is effectively reduced, the side reaction of an anode interface in the cycle process of the battery is inhibited, and the cycle life of the battery is remarkably prolonged. And on the other hand, the ultrathin lithium modification method provided by the invention is simple in preparation method and has very strong industrialization potential.

The invention discloses a synthesis method of nano magnesium metal and application of the nano magnesium metal in hydrogen storage, and the synthesis method of the nano magnesium metal comprises the following steps: dissolving lithium metal and 4, 4-bis (tert-butylbiphenyl) into a polar organic solvent to obtain a 4, 4-bis (tert-butylbiphenyl) lithium solution, and then adding the 4, 4-bis (tert-butylbiphenyl) lithium solution into the polar organic solvent to obtain the nano magnesium metal. Adding the 1, 4-bis (tert-butylbiphenyl) lithium solution into a non-polar alkane organic solvent to obtain a mixed solution; adding anhydrous magnesium chloride into a polar organic solvent to obtain an anhydrous magnesium chloride organic solvent solution; and adding the anhydrous magnesium chloride organic solvent solution into the mixed solution, carrying out a reaction in an argon atmosphere, and carrying out post-treatment to obtain the nano magnesium metal, wherein the molar mass ratio of the 4, 4-bis (tert-butylbiphenyl) to the anhydrous magnesium chloride is (0.5-3): 1. The nano magnesium metal synthesized by the synthesis method has the advantages of high hydrogen storage capacity, low hydrogen absorption and desorption operation temperature and high hydrogen absorption and desorption speed.

This invention provides a functional lithium metal anode, its preparation method, and a solid-state battery. The lithium metal composite anode of this invention has a three-layer structure, comprising: a current collector, an active material layer, and a functional layer. The active material layer is a lithium metal and / or lithium alloy layer. The functional layer contains boron nitride nanotubes, metal-organic frameworks (MOFs), a lithium salt, and a binder. In the functional layer, the boron nitride nanotubes are nanoscale fibrous materials with high mechanical strength, providing numerous active sites, improving the ionic conductivity of the interface layer, and effectively inhibiting the growth of lithium dendrites. The MOFs material has a three-dimensional porous structure, capable of storing a large number of lithium ions and regulating lithium ion deposition. The synergistic effect of the boron nitride nanotubes loaded with MOFs material improves the compatibility of the lithium metal anode with various solid-state electrolytes, reduces the generation of side reactions, and simultaneously increases the cycle performance and lifespan of the lithium metal solid-state battery.

The invention provides a lithium metal negative electrode protection layer, a preparation method and application thereof, and a lithium metal battery, and relates to the technical field of lithium metal batteries, the protection layer is formed on the surface of a metal lithium foil, and comprises a polymer and an inorganic substance; the polymer comprises polyvinylidene fluoride-hexafluoropropylene; the inorganic substance includes lithium phosphate. The components of the protective layer cooperate with each other, so that lithium dendrites can be physically inhibited, the first discharge specific capacity, the first coulombic efficiency and the cycle performance can be effectively improved, gas can be actively consumed, and the cycle stability and the safety performance of the lithium metal battery can be cooperatively improved from multiple dimensions; the technical problems that an existing protective layer cannot actively eliminate gas, the lithium dendrite inhibiting effect is poor, and the interface stability is poor are solved.

An alkali-metal removal system and method for in-situ vapor phase removal and downstream reclamation of metallic lithium from reusable lithium deposition process kit parts are provided. The system and method include preparing a cleaning gas containing vapor phase fluorinated alcohol. The system and method further include exposing parasitic lithium deposits to the cleaning gas containing the vapor phase fluorinated alcohol and etching metallic lithium from parts coated with parasitic lithium deposition. The system and method further include collecting reaction byproducts and unreacted cleaning gas. The system and method further include separating lithium compounds from the reusable cleaning gas.

The invention discloses an integrated positive electrode material, an oxide-based solid-state lithium-carbon dioxide battery and a preparation method. The integrated positive electrode material comprises a current collector, an active component and a lithium ion transmission medium, wherein the active component and the lithium ion transmission medium are loaded on the current collector; a high-conductivity carbon material is grown on the surface of the current collector in situ; the active component comprises an active element, and the active element is selected from at least one of copper, nickel, cobalt and iron; the lithium ion transmission medium comprises a lithium element. The solid-state lithium-carbon dioxide battery composed of the integrated positive electrode, the oxide solid-state electrolyte and the metal lithium negative electrode disclosed by the invention has the advantages of high discharge potential of 3.05 V, 260 circles of reversible stable charge-discharge cycles and the like at room temperature, and the greenhouse gas CO2 is efficiently utilized; the solid-state secondary battery is expected to be a novel solid-state secondary battery with high energy density and high safety.

The invention discloses a lithium molten salt separator based on surface tension difference, and belongs to the technical field of metal lithium production, the lithium molten salt separator comprises separation boxes, a filter screen is arranged in each separation box, a cover plate is arranged at the top of each separation box, a feeding port communicated with the cover plate is fixedly connected to the cover plate, a transverse plate is fixedly connected between the two separation boxes, and the transverse plate is fixedly connected to the top of each separation box. The top of the transverse plate is fixedly connected with a driving pressing assembly, the driving pressing assembly is used for pressing the cover plate and driving the cover plate to ascend, descend and steer, the bottom of the transverse plate is provided with a pushing assembly, the pushing assembly is used for pushing and discharging the fused salt, and the sides, close to each other, of the two separation boxes are fixedly connected with discharging ports communicating with the separation boxes. According to the invention, the inside of the filter box can be conveniently and rapidly overhauled and maintained, slight vibration can be conveniently provided during filtering, rapid filtering is facilitated, Li and Li-K fused salt are automatically separated by adopting a filtering mode, the problem of automatically discharging lithium-containing fused salt from a lithium collecting tube is solved, the operation is safe and simple, and the separation efficiency is high.

The invention relates to the technical field of batteries, in particular to a high-stability composite lithium metal negative electrode material, a preparation method of the high-stability composite lithium metal negative electrode material and a battery, and the preparation method comprises the following steps: immersing a copper foil into a soaking solution, and carrying out hydrothermal reaction to prepare a three-dimensional copper foil with a copper oxide three-dimensional structure; placing the three-dimensional copper foil in the electroplating solution for electroplating so as to electroplate and deposit an electroplating lithium layer on the surface of the three-dimensional copper foil to obtain a prefabricated negative electrode material; and infiltrating the prefabricated negative electrode material with an artificial SEI infiltration solution to form an SEI protection layer on the surface of the electroplated lithium layer. The negative electrode material prepared by the preparation method can be used for preparing a battery; according to the preparation method, a lithium-loving copper oxide coating layer is grown on the surface of a copper foil current collector in situ, a high-performance lithium metal layer is constructed through an electroplating process, and an artificial SEI layer is constructed on the basis of the structure to finally form the lithium metal composite negative electrode with a sandwich structure, so that the problem of dendritic crystal growth can be solved, and side reaction between metal lithium and electrolyte is reduced; volume expansion is relieved and the electrochemical performance of the battery is improved.

Disclosed are a negative electrode plate and use thereof. For the negative electrode plate provided in the present disclosure, a negative electrode active layer is coated with a safety function layer containing metal and ceramic, which effectively improve an electrode potential of a negative electrode and a nucleation energy barrier of metal lithium of a lithium-ion battery in a charging process at a low temperature and a high rate, thereby avoiding occurrence of a lithium precipitation phenomenon at the negative electrode. Because of good heat insulation performance of the ceramic, occurrence of a thermal runaway phenomenon in a nail penetration test may be effectively avoided, and safety performance of the battery may be improved. When the negative electrode plate is applied to the lithium-ion battery, the obtained lithium-ion battery has advantages of good cycling performance and high security.

The present application discloses a functionalized separator, a method for preparing the same, a lithium metal battery, and a device comprising the lithium metal battery. The functionalized separator comprises a porous substrate and a functional film layer provided on at least one side of the porous substrate, wherein the functional film layer comprises inorganic particles which are able to reversibly react with metal lithium to form a lithium alloy.

The invention provides a pre-lithiation silicon-based negative pole piece, a pre-lithiation method and a lithium ion battery, and particularly relates to the technical field of lithium batteries. The pre-lithiation method comprises the following steps: providing a silicon-based negative pole piece; forming a metal lithium film on the surface of the silicon-based negative pole piece; carrying out segmented isostatic pressing on the silicon-based negative pole piece with the metal lithium film formed on the surface so as to carry out pre-lithiation on the silicon-based negative pole piece; wherein the step of segmented isostatic pressing comprises the following substeps: applying a pressure of 200-500MPa to the silicon-based negative pole piece with the metal lithium film formed on the surface, and keeping the pressure for 0.5-5 minutes; and then the pressure is reduced to 50 MPa to 200 MPa, and the pressure is kept for 1 min to 6 h. According to the pre-lithiation method, the metal lithium can be quickly and uniformly pressed into and diffused into the silicon-based pole piece, the reaction of lithium and silicon is accelerated to realize thorough and uniform pre-lithiation, the longitudinal expansion of the silicon-based negative pole is inhibited and the transverse expansion of particles is guided while the first irreversible capacity loss is effectively compensated, so that the secondary irreversible capacity loss is effectively compensated. The density and the mechanical stability of the pole piece are improved.

The invention relates to a preparation device and method of an edge type copper-lithium composite belt, and relates to the technical field of batteries. Comprising a mounting back plate, a rolling forming system, a rolling compounding system and a buffering system, the rolling forming system is mounted at the left part of the mounting back plate and is used for rolling the metal lithium strip into a convex lithium strip; the buffer system is mounted in the middle of the mounting back plate and used for caching the special-shaped lithium strip; and the rolling compound system is mounted at the right part of the mounting back plate and is used for rolling the lithium strip and the copper foil into a compound strip. Stepped compounding is achieved, full-roller rolling and compounding are changed into rolling and compounding at the step, the stress degree of the lithium strip and the composite strip is reduced, the conditions of edge wrinkling, edge cracking and the like are avoided, and the product quality and the production efficiency are improved.

The invention relates to an alloy carbon-based interface layer composite negative electrode with high interface stability and a preparation method and application thereof.The alloy carbon-based interface layer composite negative electrode comprises a lithium-loving alloy and a three-dimensional mixed carbon-based interface framework layer arranged on the surface of the lithium-loving alloy, and the three-dimensional mixed carbon-based interface framework layer comprises a one-dimensional carbon fiber material and a zero-dimensional carbon particle material with the mass ratio being 1: 45-1: 4; according to the lithium-loving alloy, a lithium-loving layer is arranged on the surface of metal lithium, the lithium-loving layer accounts for 0.001 wt.%-20.0 wt.% of lithium metal, in the inert argon atmosphere, the three-dimensional mixed carbon-based interface framework layer and the pressed lithium-loving alloy are attached and rolled, and the carbon-based interface is modified to the surface of the lithium-loving alloy. Compared with the prior art, the preparation method has the advantages that huge volume change in negative electrode side long circulation can be slowed down, the problems of overgrowth of dendrites, loss of active lithium and the like are relieved, and the electrochemical performance and safety of the battery are improved.

The invention discloses a high-performance electrode, a preparation method thereof and a solid-state battery. The high-performance electrode comprises a positive electrode, a current collector and a negative electrode, and the current collector is located between the positive electrode and the negative electrode; the negative electrode comprises a metal lithium composite material layer, and the metal lithium composite material layer comprises a granular metal lithium composite material or a pressure-deformed granular metal lithium composite material. The metal lithium composite material comprises: a lithium-containing core; the middle layer is constructed on the surface of the inner core and comprises a first framework formed by interweaving a first framework material, a second framework formed by a second framework material inserted into the first framework, and a limiting polymer for fixing the relative positions of the first framework and the second framework; and a housing comprising a conductive polymer layer and a lithium fast ion conductor distributed in the conductive polymer layer. The high-performance electrode has excellent cycle performance and high safety characteristics.

The invention provides a lithium primary battery negative electrode with deep sea pressure bearing capacity and a preparation method thereof, and belongs to the technical field of deep sea lithium primary battery manufacturing, the lithium primary battery negative electrode comprises a negative electrode current collector, a lithium layer is arranged on the surface of the negative electrode current collector through electrochemical plating lithium, the surface of the lithium layer is coated with an SEI film layer, and an electroplating electrolyte of electrochemical plating lithium comprises a lithium salt and a solvent, the lithium salt comprises LiPF6, and the solvent comprises DMC. According to the present invention, with the electrochemical lithium plating method, the compact metal lithium layer can be deposited on the surface of the negative electrode current collector, and the metal lithium layer prepared through the method can maintain the close connection with the negative electrode current collector in the 0-127 MPa hydrostatic pressure environment, and can maintain the pressure resistance stability between the metal lithium layer and the SEI film in the pressure environment.

The invention discloses a bipolar electrode with a composite structure and a preparation method and application thereof. The bipolar electrode comprises a positive electrode, a current collector and a composite negative electrode, wherein the current collector is positioned between the positive electrode and the composite negative electrode; the composite negative electrode comprises a lithium negative electrode and a modification layer positioned on the surface of the lithium negative electrode, wherein the modification layer comprises a carbon fluoride material, lithium fluoride generated by in-situ reaction of the carbon fluoride material and the lithium negative electrode, a conductive agent and an organic polymer. And the modification layer plays a role in isolating the lithium negative electrode from the solid electrolyte, so that the problem that the solid electrolyte reacts with metal lithium is solved, and the stability of an interface is improved. And lithium fluoride in the modification layer plays a role in stabilizing the interface between the solid electrolyte and the lithium negative electrode. According to the bipolar electrode, the long cycle performance and the high safety characteristic of the battery are optimized through the reasonably designed structure.

The present application provides a lithium composite and a method for preparing the same. The lithium composite has a belt shape and comprises: a structure layer; a stress equalization layer disposed on at least one surface of the structure layer, the stress equalization layer comprising patterned metal lithium and / or lithium alloy and having a thickness in a range from 0.1 to 1 μm; and a lithium film having a width in a range from 185 to 1500 mm and a uniform thickness in a range from 0.5 to 30 μm, with a thickness tolerance within 20% of the thickness, wherein the lithium film is bound to the structure layer via the stress equalization layer to form the lithium composite.

The invention discloses a multi-dimensional carbon structure negative electrode material, and belongs to the field of lithium battery materials. The multi-dimensional carbon structure negative electrode material comprises a core layer, a middle layer and a shell layer which are sequentially arranged from inside to outside, the core layer comprises a three-dimensional conductive skeleton loaded with active particles; the material of the middle layer comprises amorphous carbon; the material of the shell layer comprises a metal oxide. The negative electrode material with the core-shell structure is obtained by preparing the multi-layer structure containing the core layer, the middle layer and the outer layer and optimizing the material of each layer. The outer layer and the middle layer can effectively inhibit disordered deposition of metal lithium on the outer surface, active particles of the core layer serve as lithium-loving sites to guide lithium to be nucleated and deposited in fiber coils preferentially, the uniformity and directionality of lithium deposition can be improved through cooperation of the three layers, and therefore growth of lithium dendrites is effectively inhibited; and the safety performance and the cycling stability of the prepared battery are enhanced.

The application discloses a solid-state electrolyte covered with a ZnI2 film and a preparation method and application thereof. After a compact LLZTO sheet is placed in a ZnI2 solution for a period of time and taken out, the surface of the LLZTO sheet is attached with ZnI2 crystal particles; when molten metal lithium is poured onto the surface of the LLZTO sheet with ZnI2, a reaction occurs to generate LiI and Li-Zn alloy, which is helpful to the infiltration of the metal lithium on the surface of the LLZTO sheet, thereby improving the interface problem between the solid-state electrolyte LLZTO and the lithium metal, greatly reducing the interface impedance, effectively inhibiting the generation of lithium dendrites, and improving the current density, surface capacity and cycle life of the solid-state battery.

The invention discloses a high-flux interface modification method of an oxide-based all-solid-state battery and a lithium ion battery, and belongs to the technical field of solid-state lithium ion batteries. The method comprises the following steps: mixing LTFSI, PVDF-HFP, m-fluorobenzamide and LLZO powder, and adding dimethylformamide to obtain a mixed raw material; adding an organic wet grinding solvent into the mixed raw material, and carrying out ball milling to obtain interface modification slurry; and coating one side of an LLZO electrolyte sheet with the interface modification slurry, and drying to complete interface modification. According to the interface modification method disclosed by the invention, the solid electrolyte has a lithium-loving property, can be in good contact with a metal lithium negative electrode, and can generate LiFamp through an in-situ reaction; and Li3N fills up interface defects and pores, and meanwhile, lithium dendrite growth and electron permeation can be inhibited, so that the interface structure of the obtained modified layer is stable. In addition, the lithium ion conductivity at the interface is further improved, the lithium ion flux at the interface is enhanced, the cycle life of the lithium battery is prolonged, and the preparation method is simple and suitable for industrial large-scale production.

The invention discloses a lithium metal negative electrode with a three-dimensional composite structure layer and a preparation method thereof, and relates to the technical field of lithium metal negative electrodes, the lithium metal negative electrode comprises a modified polymer base membrane, a lithium-loving transition layer and a lithium metal layer which are sequentially compounded from inside to outside; the modified polymer base membrane is a composite membrane of a polymer base material and a functional filler, the thickness is 10-30 microns, and the tensile strength is greater than or equal to 20 MPa; the thickness of the lithium-loving transition layer is 1-5 [mu] m, the interface peel strength is greater than or equal to 5 N / m, the lithium ion conductivity is greater than or equal to 1 * 10 <-4 > S / cm, and the lithium-loving transition layer is composed of a lithium-loving active component and a polyvinylidene fluoride binder; and the thickness of the lithium metal layer is 50-150 [mu] m. According to the lithium metal negative electrode with the three-dimensional composite structure layer, a three-layer composite structure with a modified polymer base membrane as a supporting framework, a lithium-loving transition layer as an interface bridge and a lithium metal layer as an active main body serves as a core, and the problems that an existing lithium metal negative electrode is prone to breakage, poor in interface adhesion and insufficient in cycling stability are solved.

The invention provides metal lithium surface protection slurry and a preparation method and application thereof, and the surface protection slurry comprises the following components by weight: 5-20 parts of a metal organic framework material (MOFs); 70 to 85 parts of a solvent; 3-6 parts of a conductive agent; 3-6 parts of a thickening agent; the MOFs material comprises an MOFs material taking a zinc-based metal matrix, a cobalt-based metal matrix, a vanadium-based metal matrix, an iron-based metal matrix, an aluminum-based metal matrix, a chromium-based metal matrix, a zirconium-based metal matrix or a lanthanide-series metal matrix as metal ions or metal cluster nodes, and the conductive agent comprises an organic polymer solid electrolyte material or an organic-inorganic composite solid electrolyte material. The surface protection slurry provided by the invention can form a protection layer with excellent lithium affinity, dendritic crystal resistance and stability on the surface of metal lithium.

The invention provides a three-electrode structure, an all-solid-state battery and a charging performance evaluation method, and relates to the technical field of all-solid-state batteries. The three-electrode structure comprises a positive pole piece, a negative pole piece and a lithium-indium pole piece, the positive pole piece and the negative pole piece are isolated by a solid electrolyte membrane, the lithium-indium pole piece is arranged in a middle layer of the positive pole and the negative pole, and the stoichiometric equation of the lithium-indium pole piece is LixIn (0lt; xlt; 1), and the lithium potential is 0.62 V. Compared with a lithium-plated copper wire, the sheet-shaped lithium indium is adopted as the reference electrode, so that the risk of puncturing a solid electrolyte membrane can be effectively reduced, and performance fluctuation and potential safety hazards caused by electrode puncturing can be reduced; in addition, the lithium potential of the lithium-indium pole piece is obviously higher than that of metal lithium, so that side reaction with solid electrolyte can be reduced; therefore, when the charging performance of the all-solid-state battery is evaluated, the interference caused by electrode puncture and side reaction can be remarkably reduced, so that the accuracy of the charging performance evaluation is remarkably improved.

The invention discloses a liquid-phase indirect preparation method of high-purity lithium sulfide, and belongs to the field of fine chemical engineering. The preparation method comprises the following steps: firstly, enabling metal lithium to react with high-purity naphthalene at low temperature in an ether solvent in an anhydrous oxygen-free argon atmosphere to generate naphthyl lithium; then introducing high-purity hydrogen sulfide and a naphthyl lithium carrier to react at room temperature to generate lithium hydrosulfide; then converting at 100-150 DEG C to generate lithium sulfide; and cooling, filtering in an argon atmosphere, washing with an ether solvent, and carrying out vacuum drying to obtain high-purity finely-dispersed lithium sulfide with the purity of more than 99.99%. Compared with the prior art, the lithium sulfide obtained by the preparation method disclosed by the invention is powder which is high in purity, uniform in granularity, fine in dispersion and relatively good in flowability, is stable in process and product quality, can be suitable for industrial-scale production of high-purity lithium sulfide, and has a very good popularization and application value.