488 results about "Lithium fluoride" patented technology

The invention relates to a method for preparing a pyrochlore oxyfluoride solid electrolyte by a one-step solid phase method, which comprises the following steps: uniformly mixing lithium carbonate (Li2CO3), lanthanum oxide (La2O3), niobium pentoxide (Nb2O5) and lithium fluoride (LiF), and carrying out high-temperature one-time sintering under protective gas to synthesize a Li2-xLa (1 + x) / 3Nb2O6F (LLNOF solid electrolyte material. The synthesis route is optimized, a single fluorine source is used, and the types of raw materials are reduced; according to the method, secondary sintering is not needed, the pure-phase electrolyte powder can be obtained by adopting one-step sintering synthesis, the steps are simple, the efficiency is high, the cost is reduced, and the resource consumption is reduced. According to the obtained LLNOF electrolyte material powder, the synthesis temperature ranges from 900 DEG C to 1100 DEG C, heating to 1100 DEG C or above is not needed, the requirement for heating equipment is low, large-scale mass production can be conducted, the sample yield is large, and energy consumption is low. Required synthesis equipment is simple and easy to obtain, and the ionic conductivity is good. The lithium ion conductor with high conductivity and stability in air is synthesized through a one-step method.

The invention provides a positive active material with a lithium fluoride layer as well as a preparation method and application of the positive active material. The positive active material comprises a high-nickel ternary positive material and the lithium fluoride layer covering the surface of the high-nickel ternary positive material, and the thickness of the lithium fluoride layer is 10-100 nm. In the positive electrode active material with the lithium fluoride layer, the surface of the high-nickel ternary positive electrode material is covered with the lithium fluoride layer, and lithium fluoride has excellent chemical stability, conductivity and lithium ion transmission rate, so that the positive electrode active material is coated with the lithium fluoride layer with the thickness of 10-100nm, thereby ensuring that the positive electrode active material has relatively good ion transmission performance; the internal strain and phase change of the high-nickel ternary positive electrode material are inhibited, and the risk that the high-nickel ternary positive electrode material generates cracks is reduced; the interface performance is improved, and the active material is isolated from the electrolyte, so that the risk of side reaction between the high-nickel ternary positive electrode material and the electrolyte is reduced, and the high-nickel ternary positive electrode material is prevented from being dissolved and delithiated.

The invention provides a modified lithium metal negative electrode and a preparation method and application thereof, and belongs to the technical field of lithium batteries. The modified lithium metal negative electrode comprises a negative electrode conductive substrate and an interface passivation layer formed on the surface of the negative electrode conductive substrate, and the interface passivation layer comprises lithium oxide, lithium sulfide, lithium nitride, lithium fluoride and a fluorocarbon compound; the interface passivation layer is obtained by putting lithium metal into chloroform for dipping treatment to obtain modified lithium metal and then performing plasma treatment. According to the lithium ion battery, the interface passivation film containing the lithium oxide, the lithium sulfide, the lithium nitride, the lithium fluoride and the fluorocarbon is formed on the negative electrode conductive substrate, and in the repeated charging and discharging process of the lithium ion battery, due to the existence of the interface passivation film, non-uniform deposition of lithium ions can be avoided, so that growth of lithium dendrites is inhibited. Furthermore, the coulombic efficiency and the cycling stability of the charge-discharge cycle of the lithium ion battery can be improved, and the service life of the lithium ion battery is prolonged.

The invention discloses high-toughness ultrathin flexible glass and a preparation method thereof, and relates to the technical field of glass manufacturing. The ultrathin flexible glass is prepared from the following raw materials: silicon dioxide, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, a modified nano reinforced phase, a high-temperature melting regulator and cerium dioxide. The modified nano reinforced phase is prepared by the following steps: pre-treating silicon carbide and silicon nitride with hydrochloric acid, and mixing with nano zirconium oxide to obtain a mixture; and modifying the mixture with a silane coupling agent to obtain the modified nano reinforced phase. The high-temperature melting regulator is a mixture of lithium borate, sodium sulfate and lithium fluoride. The preparation method of the ultra-thin flexible glass comprises the following steps: preparing the modified nano reinforced phase, melting and homogenizing the glass, forming the glass substrate, and preparing the ultra-thin flexible glass. The ultra-thin flexible glass prepared by the invention has relatively high fracture toughness and structural rigidity, excellent flexibility and bending fatigue durability, and excellent thermal shock resistance.

The invention provides a solid electrolyte modified positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: a) dissolving an inorganic oxide electrolyte intermediate product in a mixed solution of water and an organic matter containing functional groups, adjusting the pH value to 2-9, adding lithium fluoride, stirring, and then evaporating and drying to obtain a first gel product; b) performing puffing treatment on the first-time gel product obtained in the step a), adding the first-time gel product and a ternary positive electrode material into a solvent, performing ultrasonic dispersion, stirring, and performing evaporation drying to obtain a second-time gel product; and c) sintering the second gel product obtained in the step b) in an oxygen-free environment to obtain the solid electrolyte modified positive electrode material. According to the invention, through cooperation of liquid-phase coating and high-temperature solid-phase diffusion treatment, a sintered stone structure with high ionic conductivity and high stability is introduced to the surface of the ternary material, and the problem of cyclic cracking of the ternary positive electrode material can be effectively solved.

The invention discloses a preparation method and application of a safe electrolyte, and belongs to the technical field of electrolytes.The preparation method comprises the steps that a carbonic ester solvent, imidazolyl ionic liquid, a lithium salt and a composite additive are dried and dewatered, the carbonic ester solvent and the imidazolyl ionic liquid are prepared into an electrolyte organic solvent in a water-free and oxygen-free glove box, and the electrolyte organic solvent is added into a lithium ion battery; adding the lithium salt and the composite additive into the electrolyte organic solvent, and uniformly mixing to obtain the safe electrolyte; the safe electrolyte keeps the liquid-state high ionic conductivity characteristic in a normal working temperature interval, liquid-solid phase change is rapidly generated when the temperature of the battery rises to a critical threshold value, a three-dimensional net-shaped solid-state barrier layer is formed, a lithium ion transmission path is cut off so as to restrain the hot chain reaction, meanwhile, lithium fluoride salt with dynamic coordination capacity is introduced into the safe electrolyte system, and therefore the safety performance of the lithium ion battery is improved. A stable oxidation-reduction potential window is maintained in the phase change process, the integrity of electrical performance after high-temperature phase change is ensured, the electrolyte reversibly recovers to be in a liquid state after cooling, and the performance of the battery is basically not attenuated.

The invention belongs to the technical field of hybrid supercapacitors, and discloses a coal-based hard carbon negative electrode material with high slope lithium storage capacity and a preparation method and application of the coal-based hard carbon negative electrode material. Washing the pulverized coal subjected to impurity removal with ultrapure water until the pH value is neutral, and then drying; pre-oxidizing the pulverized coal in an air atmosphere at 280-320 DEG C for 110-130 minutes, switching a gas atmosphere into a protective atmosphere after the pre-oxidation is finished, continuously heating, carbonizing at 1180-1220 DEG C for 110-130 minutes, washing with an acid solution to be neutral after the carbonization is finished, and drying to obtain a carbon material subjected to heat treatment; impregnating the surface of the carbon material subjected to heat treatment with lithium fluoride; and carrying out heat treatment on the material A at 280-320 DEG C in a protective atmosphere for 280-320 minutes to obtain the coal-based hard carbon negative electrode material with high slope lithium storage capacity. The power and capacity performance of the hybrid super capacitor can be improved, the intrinsic safety of the device can be further improved, and the hybrid super capacitor has great practical significance.

The present invention provides a synthesis system and a synthesis method for lithium hexafluorophosphate. The synthesis system comprises a gas-liquid reaction kettle and a built-in microbubble generation unit provided in the gas-liquid reaction kettle; a material inlet and a gas inlet are formed in the side wall of the gas-liquid reaction kettle; the built-in microbubble generation unit comprises a first microbubble generator and a second microbubble generator, the first microbubble generator is provided below the liquid level in the gas-liquid reaction kettle and connected to the material inlet, and the second microbubble generator is provided at the bottom end of the gas-liquid reaction kettle and connected to the gas inlet; a plurality of layers of perforated plates are successively provided in the gas-liquid reaction kettle from top to bottom; through holes of said perforated plates are staggered, and said perforated plates are provided between the first microbubble generator and the second microbubble generator. The synthesis system of the present invention increases the area of mass transfer between lithium fluoride liquid and phosphorus pentafluoride gas, increases the reaction rate, and reduces energy consumption.

The invention belongs to the technical field of regeneration of waste storage battery positive electrode materials, and particularly relates to a regeneration method of waste lithium iron phosphate and regenerated lithium iron phosphate. The regeneration method of the waste lithium iron phosphate provided by the invention comprises the following steps: mixing a waste lithium iron phosphate positive electrode material containing PVDF, an alkaline lithium source, an iron source and an accelerant, and then sequentially carrying out two stages of calcination treatment in a non-oxidizing atmosphere: in the first stage of calcination treatment, enabling the accelerant to promote the combination of iron and fluorine to generate iron trifluoride; second-stage calcination treatment is carried out to complete carbonization and lithium supplementation of PVDF; the accelerant is ammonium salt. According to the present invention, the reaction between the fluorine generated by PVDF pyrolysis and the iron source is promoted by using the accelerator to generate iron trifluoride so as to inhibit the generation of lithium fluoride, such that the iron trifluoride doping modification is achieved, the hydrocarbon component generated by PVDF pyrolysis is carbonized to form the carbon layer so as to improve the conductivity, and the obtained regenerated lithium iron phosphate has excellent specific capacity and excellent cycle performance.

Provided are a wide-temperature-range solid-state electrolyte, a preparation method thereof and use thereof in solid-state lithium metal batteries. The preparation method includes: dissolving a lithium salt and a magnesium salt in a solvent to obtain a mixed salt solution; and mixing the mixed salt solution with an ammonia fluoride solution, subjecting a resulting mixture to reaction, and subjecting a resulting reaction product to centrifugation, washing, and drying in sequence to obtain magnesium-doped lithium fluoride nanoparticles; and mixing the magnesium-doped lithium fluoride nanoparticles, a liquid plasticizer, a polymer monomer and a thermal initiator to obtain a liquid precursor, and subjecting the liquid precursor to curing to obtain the wide-temperature-range solid-state electrolyte, where the polymer monomer is a mixture of ethoxylated trimethylolpropane triacrylate and hexafluorobutyl methacrylate.

The invention relates to the technical field of electrolyte membrane preparation, in particular to a solid electrolyte membrane and a preparation method and application thereof. The solid electrolyte membrane is prepared from the following components in parts by weight: 45 parts of CD-PEO-SN, 15 parts of Li-MOF-SO4, 10 parts of lithium sulfide, 10 parts of lithium fluoride, 5 parts of silicon dioxide, 10 parts of JIC ionic liquid and 5 parts of ppy-NG. The conductivity of the solid electrolyte membrane provided by the invention is 1.8 * 10 <-4 > S / cm; the mechanical strength is 18MPa; the cycle life: the capacity retention rate gt after 1000 times of cycle at 1C; 92%; the process controllability is as follows: the components are uniformly dispersed; and the interface impedance is 75 omega.cm < 2 >.

The invention belongs to the technical field of electrochemical energy storage, and particularly relates to a battery capable of supplementing lithium or sodium in situ, which comprises a positive plate, a negative plate and an electrolyte, and is characterized in that the electrolyte contains a component A, and a positive electrode and / or a negative electrode contains a component B; the structural general formula of the component A is X-Y, and X is lithium fluorosulfonate, sodium fluorosulfonate, lithium difluorophosphate or sodium difluorophosphate; y is boron trifluoride or phosphorus pentafluoride; the component B is at least one of lithium oxalate, sodium oxalate, lithium fluoride and sodium fluoride. Compared with the prior art, the component A and the component B are simultaneously added into the battery disclosed by the invention, so that the battery shows more excellent cycle performance and high-temperature performance. The combination mode has better performance compared with the mode that the component B is independently used in the electrode material or the component A is independently used in the electrolyte.

The invention discloses a lithium fluoride in-situ coated sulfide solid electrolyte and a preparation method thereof, and belongs to the technical field of solid-state lithium batteries, the preparation method comprises the following steps: mixing a sulfide solid electrolyte with lithium tetrafluoroborate to obtain mixed powder, and under the disturbance of inert gas flow, carrying out a heat-preservation and pressure-maintaining reaction to obtain the lithium fluoride in-situ coated sulfide solid electrolyte. After the reaction is finished, naturally cooling to room temperature to obtain a lithium fluoride coated sulfide solid electrolyte; the mass fraction of the lithium tetrafluoroborate in the mixed powder is 1-10%. The lithium tetrafluoroborate used in the preparation method provided by the invention is a common salt, no gas or liquid is generated in the reaction process, the preparation method is environment-friendly, the process is simple, and later industrial preparation is facilitated; the lithium tetrafluoroborate has the advantages of low cost and environmental friendliness; and particularly, the sulfide solid electrolyte can be uniformly dispersed and uniformly coated on the surface under airflow disturbance.

The invention relates to the technical field of silica powder surface modification, in particular to a novel silica powder surface modification method and application of a composite material of the novel silica powder surface modification method. Silica powder surface modification comprises the steps that silica powder is subjected to surface chemical modification through a titanate coupling agent, active functional groups are introduced, and the interface bonding force between the silica powder and MXene is enhanced; high-quality preparation of MXene: etching an MAX phase by adopting hydrofluoric acid (HF) or lithium fluoride / hydrochloric acid (LiF / HCl), and obtaining few layers of MXene nanosheets through ultrasonic stripping to ensure high conductivity and large specific surface area; the modified silica powder and MXene dispersion liquid are uniformly mixed, MXene stacking is inhibited, the specific surface area is increased, and the ion transmission efficiency is improved; mXene nanosheets grow on the surface of the silica powder in situ to form a core-shell structure, so that the interface bonding strength and the mechanical property are enhanced; the composite material is applied to the fields of electromagnetic shielding, energy storage, flexible electronics and the like.

Described herein is a composite comprising a fluorinated polymer and nanoparticles of lithium fluoride. The lithium fluoride has an average BET surface area of at least 10 m2 / g. The fluorinated polymer includes a fluorinated polymer backbone chain and a plurality of groups represented by formula —SO2X, in which each X is independently —NZH, —NZSO2(CF2)1-6SO2X′, —NZ[SO2(CF2)dSO2NZ]1-10SO2(CF2)dSO2X′, or —OZ, and Z is independently a hydrogen, an alkali-metal cation, or a quaternary ammonium cation, X′ is independently —NZH or —OZ, and each d is independently 1 to 6. A polymer electrolyte membrane, an electrode, and a membrane electrode assembly including the composite are also provided.

The invention relates to the technical field of electroluminescent devices, in particular to a large-current quantum dot electroluminescent device and a preparation method thereof. The device comprises a substrate, a cathode, an electron transport layer, a quantum dot light-emitting layer, a current focusing layer, a hole transport layer, a hole generation layer and an anode which are tightly stacked in sequence, the current focusing layer is provided with a slit which is used for regulating and controlling the injection path of hole current to the quantum dot light-emitting layer and improving the bearable current density threshold value of the device. The material of the current focusing layer is one or more of lithium fluoride, magnesium fluoride and aluminum oxide; and the hole generation layer is used for efficiently enhancing hole injection. The invention further provides a preparation method for preparing each layered structure through spin coating and vacuum evaporation deposition. The electroluminescent device has the advantages that the hole generation layer and the current aggregation layer are utilized to construct the electroluminescent device capable of realizing large-current driving, the problem that carrier injection in the device under large-current driving is limited is solved, and the current tolerance and the luminous intensity of the device are effectively improved.

The invention relates to a method for high-value recovery of a positive electrode material of a waste lithium iron phosphate battery, which mainly comprises the following steps: adding a lithium iron phosphate positive electrode material, ammonium chloride and hydrogen peroxide into a ball milling tank for grinding, controlling the mass ratio of the ammonium chloride to the lithium iron phosphate positive electrode material to be 5: 2-7: 2, and controlling the volume mass ratio of the hydrogen peroxide to the lithium iron phosphate positive electrode material to be (18-22): 1mL / g; after grinding, washing out the mixture from the ball-milling tank by using deionized water, and then carrying out water leaching treatment to fully leach out metal lithium; excessive ammonium fluoride is added into the filtrate, and reaction liquid and a product lithium fluoride are obtained after reaction; and carrying out adsorption treatment on the reaction liquid by using defluorination resin, regenerating the defluorination resin through elution, combining and concentrating the collected effluent and eluent to obtain an ammonium chloride solution, and recycling the ammonium chloride solution to a chlorination reaction stage. According to the invention, through H2O2 reinforced mechanical chlorination coupling fluorination reaction, nearly total recovery of the waste lithium iron phosphate battery positive electrode material and high value of the product are realized, and the process is simpler and more environment-friendly.

The invention discloses an interface modification layer as well as a preparation method and application thereof. The interface modification layer comprises an electron barrier layer and a lithium-philic interlayer which are sequentially arranged on the surface of a solid electrolyte, the material of the electron blocking layer is selected from at least one of lithium oxyphosphorus nitride, lithium fluoride, lithium nitride, lithium chloride, lithium bromide, lithium iodide and lithium oxynitride, and the material of the lithium-loving interlayer is selected from at least one of germanium, silver, gallium, sodium, potassium, magnesium, aluminum, calcium, strontium, barium and titanium. The interface modification layer can prevent lithium nucleation induced by electron leakage in the solid electrolyte, reduce the risk of short circuit, reduce the interface impedance, improve the lithium ion flux uniformity and interface wettability, and improve the overall performance and cycle stability of the battery.

The preparation method comprises the following steps: mixing cobalt acetate, a modified ligand, a modified additive and DMF (Dimethyl Formamide), carrying out ultrasonic treatment, adding deionized water and a modified filler, carrying out ultrasonic treatment, carrying out heating reaction, carrying out centrifugation to remove a supernatant, and carrying out drying treatment to prepare the rapid-charge high-capacity artificial graphite negative electrode material, when the cobalt acetate, the modified ligand, the modified additive and the modified filler are subjected to blending reaction, carboxyl on the modified ligand and carboxyl on the modified additive can form coordinate bonds with cobalt ions of the cobalt acetate, then a cobalt metal organic framework is formed on the surface of the modified filler, and a fluorine element in the modified ligand can react with lithium to form lithium fluoride; electron penetration is effectively blocked, and side reactions are reduced; the lithium ion diffusion energy barrier is reduced, rapid charging and discharging are achieved, pyridine groups on the surface of the modified filler can provide lone pair electrons and serve as binding sites of lithium ions, pseudocapacitance is formed, and then the capacity is increased.

The invention provides a high-toughness austenitic stainless steel welding rod for 5Ni steel and a preparation method of the high-toughness austenitic stainless steel welding rod. The welding rod comprises a core wire and a coating coated on the surface of the core wire, and based on the total amount of the core wire, the core wire comprises the following components in percentage by mass: less than or equal to 0.09% of C, less than or equal to 0.15% of Si, 1.6-2.5% of Mn, 18.5-20.5% of Cr, 12.5-14.5% of Ni, 2.1-3.2% of Mo and 0.06-0.18% of Ti; 0.12-0.24% of Al, less than or equal to 0.007% of S, less than or equal to 0.008% of P, less than or equal to 0.006% of O, less than or equal to 0.001% of H, less than or equal to 0.012% of S + P, and the balance Fe and inevitable impurities. On the basis of the total amount of the coating, the coating comprises, by mass, 28-38% of carbonate, 15-20% of fluorite, 1-3% of lithium fluoride and sodium fluoride, 8-12% of synthetic mica, 3-6% of potassium silicotitanate, 2-4% of zircon sand, 9-15% of electrolytic manganese metal, 2-4% of ferrotitanium, 2-5% of passivated nickel-magnesium alloy, 1-3% of atomized ferrosilicon, 1-3% of lanthanum cerium fluoride, 1-3% of tungsten and molybdenum, 3-5% of nitrided ferrochromium and 1-2% of CMC. The welding rod is good in all-position welding controllability, extremely low in air hole sensitivity and excellent in low-temperature toughness, and can meet the requirements for high-quality and efficient welding of 5Ni steel.

The invention discloses preparation of a C3N5 / MXene composite material and application of the C3N5 / MXene composite material in an aqueous zinc ion battery, and the preparation method of the C3N5 / MXene composite material comprises the following steps: taking 3-amino-1, 2, 4-triazole as a raw material, calcining, carrying out a hydrothermal reaction, washing and drying to obtain C3N5 powder; the preparation method comprises the following steps: adding lithium fluoride into hydrochloric acid, uniformly stirring, adding Ti3AlC2, continuously stirring, etching, centrifuging, washing, adding deionized water again, carrying out ultrasonic treatment under protective gas, centrifuging, and collecting supernate to obtain a single-few-layer MXene dispersion liquid; the preparation method comprises the following steps: adding C3N5 powder into deionized water, uniformly dispersing to obtain a C3N5 dispersion liquid, then adding a single-few-layer MXene dispersion liquid into the C3N5 dispersion liquid, and after the reaction is completed, centrifugally collecting precipitate and drying to obtain the C3N5 / MXene composite material. When the C3N5 / MXene composite material prepared by the method is used as a negative electrode of an aqueous zinc ion battery, the problems of dendritic crystal growth, hydrogen evolution reaction and the like of a traditional zinc negative electrode can be solved, and the electrochemical performance of the battery is remarkably improved.

The present invention provides a sulfide-polymer composite solid electrolyte and a preparation method thereof, belonging to the field of batteries. In the present invention, lithium sulfide reacts with phosphorus pentasulfide to generate a partially crystallized sulfide network, and high-valent metal ions are doped to optimize the lattice structure, enhancing conductivity and chemical stability; the crystalline phase provides an efficient ion migration channel, and the amorphous region reduces the grain boundary effect and improves the conduction uniformity; a metal chloride and lithium fluoride coating layer is used to isolate moisture and oxygen, and polyaniline coating reduces the interfacial impedance and enhances the cycle stability. The crystallinity is reduced and the amorphous region is increased by sulfonated polyether ether ketone, providing a low-impedance path for lithium ions; the polyethylene glycol chain segment improves the flexibility and ion migration ability, and the three-dimensional network structure is formed by crosslinking to enhance the mechanical strength and interfacial stability. The inorganic phase and the polymer act synergistically to construct a bicontinuous ion conductive network to improve the comprehensive performance.

The invention provides positive electrode slurry of a low-temperature lithium carbon fluoride battery and a slurry homogenizing method, the positive electrode slurry comprises a positive electrode active material, perfluorooctyl sulfonate, a binder, a conductive agent and a solvent, and the mass ratio of the positive electrode active material to the perfluorooctyl sulfonate is (85-90): (1-6); the homogenizing method comprises the following steps: uniformly mixing a positive electrode active material, perfluorooctyl sulfonate and a conductive agent according to a ratio to obtain a first mixture; dissolving a binder in a solvent according to a ratio to obtain a second mixture; and uniformly mixing the first mixture and the second mixture to obtain the positive electrode slurry of the low-temperature lithium carbon fluoride battery. The perfluorooctyl sulfonate is introduced into the positive electrode slurry, and through the synergism of the following effects: the diffusion path of lithium ions is reduced, the desolvation energy barrier of the lithium ions is reduced, the conductive agent is uniformly dispersed and participates in electrochemical reaction to generate fluoride with conductivity better than that of lithium fluoride, and the electrochemical performance of the low-temperature lithium carbon fluoride battery is improved.

The invention discloses a metal fluoride molten salt coated silicon-based negative electrode material and a preparation method thereof, and relates to the technical field of lithium ion battery negative electrode materials. The lithium fluoride-containing coating layer is constructed on the surface of the silicon negative electrode material by using the low-melting-point composite metal fluoride molten salt at a relatively low temperature through a molten salt coating method, so that the first effect and the cycling stability of the silicon-based negative electrode material can be effectively improved, and the preparation method has a good application prospect.

The invention discloses a preparation method of a carbon composite material doped with multiple metal elements. The preparation process comprises the following steps: S1, dispersing a porous carbon precursor, organic lithium fluoride, an organic rare earth compound and an organic catalyst in a solvent, performing hydrothermal reaction, and drying to obtain a porous carbon precursor loaded with lithium / rare earth element / catalyst; s2, uniformly mixing the obtained material with an activating agent and a doping agent, and activating at the temperature of 900-1100 DEG C to obtain multi-metal element doped porous carbon; and S3, carrying out reduction treatment and surface passivation treatment on the multi-metal element doped porous carbon to obtain the multi-metal element porous carbon composite material. According to the obtained material, lithium-doped and rare earth-doped porous carbon is utilized to improve the electronic conductivity of the material and increase the interlayer spacing of the carbon material, a carbon nanotube is grown by utilizing a catalyst to improve the conductivity of the material and reduce expansion, and through reduction and passivation treatment, the surface activity of the material is reduced, and the first efficiency is improved.

Disclosed in the present invention are a lithium metal composite material, and a preparation method therefor and the use thereof. The lithium metal composite material comprises a lithium-containing core, wherein a modification layer is arranged on the surface of the lithium-containing core; the modification layer comprises carbon nanotubes and a carbon fluoride material; and the carbon nanotubes are interwoven to form a cage-shaped structure, and the carbon fluoride material is present on at least one of the surface of the lithium-containing core, the surface of the cage-shaped structure and pores in the cage-shaped structure. The carbon nanotubes in the modification layer are interwoven to form the cage-shaped structure, which can provide space for the volume change of the lithium-containing core and can also provide support for the carbon fluoride material. Fluorine in the carbon fluoride material reacts with the lithium in the lithium-containing core in situ to generate lithium fluoride, thereby constructing a stable SEI film on the surface of the lithium-containing core. The modification layer constructs a stable electron transport network while modifying the surface of the lithium-containing core, thereby effectively regulating the current density and solving the problem of lithium dendrites generated due to a non-uniform current.

The invention discloses a lithium / carbon fluoride battery electrolyte based on an aprotic polar solvent, and belongs to the technical field of lithium / carbon fluoride battery preparation. Based on the discharge characteristic of the lithium / carbon fluoride battery, the electrolyte is designed as a starting point, and an organic solvent formed by mixing an aprotic polar solvent and an ether solvent, a lithium salt and a fluorine ion acceptor jointly form the electrolyte, so that the discharge reaction kinetics of the lithium / carbon fluoride battery is improved by utilizing the regulation and control effect of the aprotic polar solvent. The electrolyte provides a favorable environment for fluorocarbon bond breakage, reduces a discharge reaction energy barrier, can improve a discharge reaction platform, can reduce adverse effects caused by poor conductor lithium fluoride, reduces discharge polarization, and can effectively promote interfacial ion transmission and charge transfer. When the electrolyte is applied to the lithium / carbon fluoride battery, the energy density can be effectively improved.

The invention relates to a preparation method of phosphorus pentafluoride, which comprises the following steps: mixing a fluorocarbon compound with a phosphorus oxide compound and an oxidizing agent, reacting in a dry closed environment at high temperature and high pressure, collecting gas, and purifying to obtain the phosphorus pentafluoride. The invention also discloses a preparation method of lithium hexafluorophosphate, which comprises the following step: carrying out gas-solid reaction on the obtained phosphorus pentafluoride and lithium fluoride in a fluidized bed to prepare the lithium hexafluorophosphate. The method solves the problems of low purity of lithium hexafluorophosphate, difficulty in treatment of byproducts, low production efficiency and the like in the prior art.

The invention discloses an ultralow-temperature high-toughness non-magnetic steel flux-cored wire for a controllable nuclear fusion device and a preparation method of the ultralow-temperature high-toughness non-magnetic steel flux-cored wire. A special stainless steel strip is adopted to wrap a metal powder type flux core, and the flux core accounts for 29.6%-30.4% of the total mass of the flux-cored wire; the flux core comprises the following components: 14%-18% of electrolytic manganese, 21%-23% of chromium metal, 0.3%-1.0% of ferrotitanium, 4.4%-5.0% of nitrided ferrochromium, 27.5%-28.5% of nickel powder, 0.5%-1.0% of 52 # ferrosilicon, 8%-9% of molybdenum powder, 0.1%-0.3% of lithium fluoride and the balance of atomized iron powder. The problems that an existing non-magnetic steel welding material is insufficient in toughness and high in magnetic conductivity at the ultralow temperature of-269 DEG C are solved by optimizing flux-cored alloy elements of (nickel-chromium-nitrogen) synergistic stable austenite, matching with a manufacturing process of sealed baking and roller die drawing forming of powder at the temperature of 120-140 DEG C and a welding process protected by argon (Ar) with the purity of 99.999%. The AKV2 of a welded joint is larger than or equal to 34J at the temperature of-269 DEG C, the tensile strength is larger than or equal to 620 MPa, the relative permeability is smaller than or equal to 1.02, the problems that nitrogen of an existing solid welding wire is difficult to control, and hardening is easy can be solved, and the welding wire is completely matched with the extreme working condition of a controllable nuclear fusion device.

A negative electrode active material, a negative electrode including the same, a secondary battery including the same and a method for preparing a negative electrode active material are provided. The negative electrode active material comprises silicon-based particles comprising SiOx (0<x<2) and a lithium (Li) compound; a carbon layer provided on at least a part of a surface of the silicon-based particles; lithium fluoride (LiF); and carbon fluoride (CFa, 0<a<4), wherein a content (atomic percentage) of F is 10 at % or more and a content of Li is less than 10 at % according to a surface analysis of the negative electrode active material by X-ray photoelectron spectroscopy.