4708 results about "Sulfide compound" patented technology

The present invention provides a composite binder for a sulfide solid-state battery, a preparation method thereof and an application thereof, wherein the composite binder comprises a binder A, a binder B and a solvent, wherein the mass ratio of the binder A to the binder B is (1-10):(5-1), and the mass ratio of the total mass of the binder A and the binder B to the solvent is 1:(10-100). The present invention adopts a binder having a polar functional group and a low-polarity / non-polar binder for combination, thereby making the prepared composite binder have good compatibility with the sulfide solid electrolyte, that is, it does not affect the ionic conductivity of the sulfide solid electrolysis, and at the same time makes the sulfide solid electrolyte membrane have good mechanical properties and flexibility.

The invention discloses a positive electrode material and a preparation method thereof, a battery and a power utilization device. The positive electrode material comprises an inner core; the first coating layer comprises a first coating material, and the first coating material comprises at least one of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte and a polymer composite solid electrolyte; the first coating layer coats the inner core, the second coating layer coats the inner core, the first coating layer coats the second coating layer, the second coating layer comprises a second coating material, and the second coating material comprises a halide solid electrolyte. The coating layer plays a certain role in isolating the material of the inner core from the external environment, and the situation that the material in the inner core has side reaction with external substances or the property of the material is changed due to other reasons is reduced. Therefore, the performance stability of the positive electrode material is kept.

The invention relates to a method for preparing lithium sulfide, which comprises the following steps: respectively dissolving a sulfur source compound and a lithium source compound in alcohol under the protection of inert atmosphere, and then mixing the two alcohol solutions for double decomposition reaction to generate a lithium sulfide suspension; and then carrying out evaporative crystallization, supercritical fluid washing, centrifugal separation and freeze drying treatment to obtain a lithium sulfide product. The purity of the lithium sulfide prepared through the method can reach 99.9% or above, the lithium sulfide can be used as a positive electrode material of a lithium-sulfur battery or a raw material of a sulfide solid electrolyte in an all-solid-state battery, and the method is low in energy consumption, conforms to the concept of green chemistry and is suitable for large-scale industrial production.

The invention discloses an SF6 degradation device and method based on gas-liquid two-phase dielectric barrier discharge plasma. The device comprises a gas inlet control module, a dielectric barrier discharge reaction module, an alkaline solution tank and an alkaline solution supply module, the gas inlet control module comprises a gas distributing and mixing unit, an SF6 gas cylinder and an inert gas cylinder, wherein the SF6 gas cylinder and the inert gas cylinder are connected with the gas distributing and mixing unit. The dielectric barrier discharge reaction module comprises a dielectric barrier reactor and a plasma power supply externally connected to the dielectric barrier reactor, and the dielectric barrier reactor is used for exciting inert gas in the mixed gas into plasma by using an electric field and degrading SF6 gas in the mixed gas based on the electric field and the plasma to obtain low-fluorine sulfide. The plasma is utilized to excite the alkaline solution to generate hydroxyl ions, the low-fluorine sulfide is degraded based on the hydroxyl ions, and degraded tail gas is obtained; and the alkaline solution tank is connected with a gas outlet of the dielectric barrier reactor. According to the invention, efficient harmless degradation of SF6 can be realized.

The invention relates to a polymer binder for a sulfide solid-state battery as well as a preparation method and application of the polymer binder. The binding agent is formed by copolymerizing vinyl triethoxy silane, 4-vinyl phenylboronic acid lithium and styrene. Silane groups are introduced, the interface adhesiveness with sulfide electrolyte is enhanced through the coupling effect of the silane groups, meanwhile, water in a system is consumed through a condensation reaction, and the water content of an electrolyte membrane is reduced; 4-vinyl phenylboronic acid lithium provides dissociation lithium ions, the ionic conductivity of the binder is improved, and the negative influence on the conductivity of sulfide electrolyte is reduced; the styrene group improves the solubility of the binder in a non-polar solvent. The binder can be dissolved in solvents such as toluene, xylene and the like, and is mixed with sulfide electrolyte to form a film through a wet coating process, and the process compatibility is high. The binder disclosed by the invention has the characteristics of high cohesiveness, ionic conductivity and low water content, and the interface stability and electrochemical performance of the sulfide solid-state battery can be remarkably improved.

A sulfide solid electrolyte, which is able to adjust the morphology unavailable traditionally, or is readily adjusted so as to have a desired morphology, the sulfide solid electrolyte having a volume-based average particle diameter measured by laser diffraction particle size distribution measurement of 3 μm or more and a specific surface area measured by the BET method of 20 m2 / g or more; and a method of treating a sulfide solid electrolyte including the sulfide solid electrolyte being subjected to at least one mechanical treatment selected from disintegration and granulation.

The invention provides low-temperature rolled high-quality free-cutting steel and a production process thereof. The low-temperature rolled high-quality free-cutting steel comprises the following components: less than or equal to 0.10% of C, less than or equal to 0.006% of Si, 0.90-1.60% of Mn, 0.30-0.90% of P, 0.30-0.50% of S, less than or equal to 0.030% of Al, less than or equal to 0.0060% of N, less than or equal to 0.0140% of O and the balance of Fe and other inevitable impurities. Compared with the prior art, by controlling Mn / S to be 3.5-7.0, when the K value is equal to 2 * (Mn / S) + LF activity oxygen value, and K is larger than or equal to 35 and smaller than or equal to 69, the final sulfide is properly controlled. Low-temperature rolling is adopted, the sulfide hot brittleness interval is avoided, the plasticity of sulfide is relatively poor during rolling in the temperature interval, energy consumption is reduced, and meanwhile the phenomenon that the cutting performance of a finished product becomes poor due to the fact that the sulfide is lengthened in the rolling process is avoided. Finally, the high-quality free-cutting steel production process adopting low-temperature rolling is developed.

The invention relates to the technical field of batteries, in particular to a solid electrolyte material and a preparation method thereof, a solid electrolyte membrane and a battery. The solid electrolyte material has a core-shell structure, the core-shell structure comprises an inner core and a coating layer arranged on the surface of the inner core, the inner core comprises a sulfide electrolyte, and the coating layer comprises an amide compound. According to the solid electrolyte material disclosed by the invention, the coating layer containing the amide compound is arranged on the surface of the sulfide electrolyte, so that the air stability of the solid electrolyte material can be effectively improved, and meanwhile, the solid electrolyte material is ensured to have proper conductivity without influencing the charge-discharge performance of a battery.

The invention discloses high-purity lithium sulfide as well as a preparation method and application thereof. The preparation method comprises the step that lithium hydride, lithium hydroxide and a sulfur source are subjected to a heating reaction in a dry inert atmosphere, and the high-purity lithium sulfide is obtained. The molar ratio of lithium hydride to lithium hydroxide is X: (10-X), and X is 1-6. The invention also discloses the prepared high-purity lithium sulfide and application of the high-purity lithium sulfide in preparation of sulfide solid electrolyte. Lithium hydroxide and lithium hydride are mixed to serve as a lithium source in lithium sulfide preparation, the lithium hydroxide quickly and uniformly reaches the reaction temperature by means of the characteristic that the lithium hydride reacts with a sulfur source to release heat and produce gas, the lithium hydride reacts to produce gas, meanwhile, discharging of product water vapor is facilitated, and oxygen in the environment is isolated; and hardening and generation of a side reaction product lithium sulfate are prevented, the conversion rate of lithium hydroxide to lithium sulfide is improved, and the raw material and process cost for preparing lithium sulfide is remarkably reduced.

The invention relates to the field of friction materials, and discloses a high-reliability friction material for an electromagnetic brake and a preparation method of the high-reliability friction material. Raw materials of the friction material comprise benzoxazine, phenolic resin, butyronitrile rubber powder, modified basalt fibers, PBO pulp, ceramic fibers, plant fibers, carbon fiber powder, potassium titanate lamellar crystals, barite, light calcium carbonate, friction particles, wollastonite powder, aluminum-titanium powder, feldspar powder, aluminum oxide, zircon powder, garnet powder, crystalline flake graphite, artificial graphite, flexible graphite and composite metal sulfide. And polymer lubricating material micro powder. The friction material provided by the invention is suitable for a high-temperature and high-humidity environment, the stability of the braking performance of a brake is improved, and the phenomenon that the brake slips due to attenuation of braking torque is reduced.

The invention discloses a single-ion conductor polymer, a ternary composite binder solution, high-solid-content sulfide electrolyte slurry and a wet film forming method and application thereof, and belongs to the technical field of all-solid-state lithium batteries. The key technical problems in the wet membrane preparation of the sulfide electrolyte are solved through an innovative solvent-binder synergistic system, and the method specifically comprises the steps that 1, through the synergistic effect of a non-polar solvent and a weak-polar solvent, low-viscosity coating of high-solid-content slurry is achieved while the chemical stability of the sulfide electrolyte is guaranteed; 2, a poly (lithium styrenesulfonate-butyl acrylate), styrene butadiene rubber and polyisobutene ternary composite binder is designed, a lithium ion transmission channel is provided through a lithium sulfonate group, a benzene ring structure in the styrene butadiene rubber enhances the mechanical strength, long-chain alkane in the polyisobutene improves the interface adhesive force, and the mechanical strength is improved; the three components cooperate to realize balance of mechanical and electrochemical properties of the electrolyte membrane, so that the prepared electrolyte membrane has low porosity, high ionic conductivity and mechanical strength.

The invention discloses a preparation method and application of a sulfide solid electrolyte membrane based on a gradient polymer / ionic liquid composite binder, and an all-solid-state battery, and belongs to the technical field of all-solid-state batteries. The method comprises the following steps: firstly coating a polymer / ionic liquid / sulfide electrolyte composite layer through a gradient coating process, filling particle gaps under low pressure by utilizing the plasticizing effect of ionic liquid, and reducing the porosity of an interface; and then coating a polymer / sulfide electrolyte surface layer to provide mechanical support and inhibit side reaction of the electrode. According to the design, the electrolyte membrane still keeps high ionic conductivity under the working pressure of a commercial power battery module, and the interface impedance is reduced compared with that of a traditional homogeneous membrane. Through the innovative gradient structure and material combination, the ion transmission bottleneck of the sulfide electrolyte under the low-pressure condition is solved, excellent interface stability and process compatibility are achieved, and a key technical scheme is provided for all-solid-state battery industrialization.

The invention relates to a rubber blend, to a sulfur-crosslinkable rubber mixture comprising the rubber blend and to a vehicle tire comprising such a rubber mixture.The rubber blend comprisesat least one solution-polymerized diene polymer A of high molecular weight andat least one solution-polymerized polymer B of low molecular weight,wherein at least one of polymers A and B has been functionalized at the chain end and / or along the polymer chain and / or at a coupling site with at least one group selected from epoxy groups, hydroxyl groups, carboxyl groups, silane sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups and amino group-containing alkoxysilyl groups.

Preparation of anhydrous lithium sulfide (Li2S) purified suitably for applications in advanced batteries, and, in particular, for synthesis of solid electrolytes based on Li2S, including sulfide solid electrolytes of the type that may be described as crystalline (e.g., polycrystalline), amorphous (e.g., glass) and combinations thereof, such as sulfide glass-ceramic solid electrolyte materials.

The invention provides a sulfide electrolyte and a preparation method thereof, a solid-state battery and electronic equipment, the median particle size D50 and the specific surface area of the sulfide electrolyte are 10-5000 nm and 1-15 m < 2 > / g respectively, and the particle size distribution of the sulfide electrolyte meets the condition that (D90-D10) / D50 is greater than or equal to 0.9 and less than or equal to 2. The sulfide electrolyte provided by the invention is relatively small in particle size, relatively narrow in particle size distribution and relatively small in specific surface area, and the electrochemical performance of a solid-state battery can be effectively improved.

The invention provides a positive pole piece, a preparation method thereof and a sulfide all-solid-state battery. The positive pole piece comprises a positive current collector and a positive material layer arranged on the surface of the positive current collector, the positive electrode material layer comprises a modified positive electrode active material, an antioxidant, a sulfide electrolyte material, a conductive agent and a positive electrode binder, the modified positive electrode active material comprises an inner core and an oxide coating layer arranged on the surface of the inner core, and the inner core is a lithium-containing positive electrode active material. When the positive electrode plate containing the antioxidant and the modified positive electrode active material provided by the invention is applied to the sulfide all-solid-state battery, the synergistic effect of the antioxidant and the modified positive electrode active material can be exerted, so that the rate capability and the cycling stability of the sulfide all-solid-state battery are improved.

The invention provides a modified lithium sulfide solid electrolyte, a sulfide solid electrolyte, a preparation method thereof and a battery, and relates to the technical field of solid electrolyte materials. The preparation method of the sulfide solid electrolyte is different from a traditional doping technology, the high-stability sulfide solid electrolyte is prepared mainly through modification of lithium sulfide, the comprehensive performance of the sulfide solid electrolyte is improved, the ionic conductivity and chemical stability of the sulfide solid electrolyte are improved, and the service life of the sulfide solid electrolyte is prolonged. And the mechanical strength and the crack resistance are also obviously enhanced. The preparation method disclosed by the invention is simple, does not need to be carried out at high temperature, and does not need to use expensive raw materials and complex processes, so that the production cost is reduced, the application range of the sulfide solid electrolyte is expanded, and large-scale production and application of the sulfide solid electrolyte are favorably realized.

The invention discloses a desulfurizing tower and a desulfurizing method based on enhanced absorption of flat sheet membrane internals. The desulfurizing tower comprises a desulfurizing tower body, and a liquid distributor, the flat sheet membrane internals and fractal internals which are sequentially arranged in the desulfurizing tower body from top to bottom, according to the invention, high-concentration sulfur-containing gas is subjected to rapid pre-desulfurization at the tower bottom by utilizing the high turbulence characteristic of the fractal internals, so that the sulfide concentration can be instantly reduced, and the gas flow distribution is optimized; and the pre-desulfurized gas then enters a high-efficiency fine desulfurization area formed by the flat sheet membrane internals. According to the flat sheet membrane internal part, a plurality of vertically arranged flat sheets are utilized to form a fixed gas flowing channel, so that transverse movement of gas molecules is limited, and gas distribution is more uniform. And meanwhile, a layer of uniform and continuous absorbent liquid film is formed on the surface of the flat plate, so that the gas-liquid contact area is remarkably increased, and high efficiency and low energy consumption are achieved through full countercurrent contact and efficient gas-liquid mass transfer of gas and the absorbent liquid film under extremely low pressure drop.

The invention relates to the technical field of all-solid-state batteries, in particular to a halide sulfide double-layer coated positive electrode material and a preparation method and application thereof. The halide sulfide double-layer coated positive electrode material comprises a positive electrode material substrate, and a halide electrolyte coating layer and a sulfide electrolyte coating layer which sequentially coat the positive electrode material substrate. The halide electrolyte coating layer is located in the middle layer, compatibility with a positive electrode interface can be achieved by means of high oxidation resistance of the halide electrolyte coating layer, and the problem of the positive electrode interface occurring in sulfide electrolyte oxygenolysis is solved. The sulfide electrolyte coating layer is located on the outermost layer, air stability is excellent, processing in a dry environment can be met, and the problems that halide electrolyte is poor in chemical stability, cannot be processed and manufactured in an external environment and is high in density are solved. The halide sulfide double-layer coated positive electrode material has high interface stability and good chemical stability.

The invention relates to the technical field of new energy battery materials, in particular to a surface-coated sulfide solid electrolyte as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing and stirring a sulfide solid electrolyte and a first solvent to obtain a first mixed solution; mixing and stirring nanoparticles with oxygen-containing functional groups and a second solvent to obtain a second mixed solution; adding the second mixed solution into the first mixed solution, and stirring to obtain a third mixed solution; and carrying out vacuum drying on the third mixed solution to obtain the surface-coated sulfide solid electrolyte. The sulfide solid electrolyte is subjected to surface particle coating through simple mixing and vacuum drying, oxygen-containing functional groups are attached to the surfaces of the particles, so that the material is more oxygen-loving, the air stability of the sulfide solid electrolyte is improved, and the material still keeps high ionic conductivity and has good electrochemical performance. And moreover, the machining process is reduced, the machining cost is reduced, and the practical application value is higher.

The present invention relates to a positive electrode for an all-solid-state battery, the positive electrode comprising a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder, the sulfide-based solid electrolyte comprising a first sulfide-based solid electrolyte containing a bromine (Br) element and a second sulfide-based solid electrolyte not containing the bromine (Br) element, the positive electrode active material comprising a core capable of reversibly absorbing and releasing lithium ions; and a coating layer formed on a surface of the core, the coating layer comprising the first sulfide-based solid electrolyte, and the all-solid-state battery comprising the positive electrode.

The invention provides a sulfide solid electrolyte as well as a preparation method and application thereof. The molecular formula of the sulfide solid electrolyte is Li P < 1-b > M S < c > O < d > X < e >, wherein: 5lt; a < lt >; 6; 0 lt; blt; 1; 1.5 1t; clt; ct; 5, 0lt; dlt; 2.5, 4lt; c + dlt; 5, 1lt; lt, lt; 2; m is selected from one or more of Al, Ga, In, Ti, Sc, As, Sb, Bi, V or Nb; x is selected from one or more of Cl, Br or I. According to the sulfide solid electrolyte and the preparation method and application thereof, the stability of the conductivity of the sulfide solid electrolyte can be improved, the air stability is enhanced, the electrolyte / active substance interface property is improved, the service life of an all-solid-state lithium ion battery is prolonged, and the safety of the all-solid-state lithium ion battery is improved.

The present disclosure belongs to the technical field of all-solid-state batteries. Provided are a sulfide solid electrolyte membrane and a preparation method therefore, and an all-solid-state alkali metal ion battery. The sulfide solid electrolyte membrane is composed of sulfide particles containing a polymer coating, and the chemical composition of the sulfide particles containing a polymer coating is [EmMnSo]CαOβSγHδNζEa.

The invention discloses a preparation method and application of a composite sulfur positive electrode packaged by a sulfide-halide composite electrolyte spherical shell. The composite sulfur positive electrode packaged by the sulfide-halide composite electrolyte spherical shell provided by the invention has a core-shell structure, the inner core is a sulfur-carbon composite material, and the outer layer is a sulfide-halide composite electrolyte shell; the sulfur volume change effect in the charging and discharging process can be effectively relieved, uniform stress distribution and effective contact in the composite positive electrode are ensured, and the utilization rate of positive electrode active substances and the overall energy density of the battery are improved. Meanwhile, the composite sulfur positive electrode provided by the invention has high ionic conductivity at room temperature, can significantly improve the reaction kinetics of the positive electrode and improve the capacity and rate capability of the battery, can be used for assembling and preparing a solid-state lithium-sulfur battery, has good safety performance and high energy density, and has a wide application prospect.

The invention discloses a coal-fired flue gas multistage adsorption desulfurization device, the desulfurization device comprises a base, a flue gas inlet pipe, a slurry pipe, a flue gas discharge pipe, a slurry discharge pipe, an annular frame and a wet separation mechanism, the base is fixedly connected with the annular frame and the wet separation mechanism, the wet separation mechanism is fixedly connected with the flue gas inlet pipe, the slurry pipe, the flue gas discharge pipe and the slurry discharge pipe, and the annular frame is fixedly connected with the wet separation mechanism; the invention relates to the technical field of desulfurization towers, and ensures that no residual sulfide exists in discharged flue gas through wet desulfurization and multistage sulfide adsorption, thereby enhancing the desulfurization efficiency of coal-fired flue gas.

The invention provides a method for reducing the rubber crack propagation rate and a tire, and relates to the technical field of tire rubber.The method for reducing the rubber crack propagation rate comprises the steps that the maximum tearing energy in an application scene is obtained; determining the addition amount of organic polysulfide and sulfur in a vulcanizing agent according to the maximum tearing energy; and mixing the vulcanizing agent with the raw materials to obtain the target rubber material. When the maximum value of the tearing energy is large, the organic polysulfide is added into the sulfur, the organic polysulfide contains a plurality of thioalkyl chain segments, and in the vulcanization process, flexible alkyl chains can be connected into rubber macromolecules to form a composite cross-linked network structure which is more stable and higher in strength, so that the breaking tensile strength and the tearing strength of tire rubber are improved, and the service life of the tire rubber is prolonged. And the expansion rate of cracks can be reduced while bearing relatively high tearing energy, so that the service life is prolonged.

The invention discloses a transformer dynamic diagnosis and early warning system based on sulfide deposition characteristics, and the system comprises a monitoring unit which is used for monitoring the deposition state of sulfide in a transformer in real time, and obtaining sulfide deposition characteristic parameters during the operation period of the transformer; the first diagnosis unit is used for judging whether the current sulfide deposition characteristic parameter affects the insulation system or not and obtaining a first diagnosis result; the second diagnosis unit is used for acquiring a second diagnosis result according to the propagation and attenuation characteristics of the electric signals, the thermal signals and the vibration signals under different turn-to-turn discharge positions, types and intensities; the fault diagnosis unit is used for judging whether the insulation defect and the turn-to-turn discharge phenomenon in the transformer reach the early warning level or not according to the first diagnosis result and the second diagnosis result; and the early warning unit is used for generating corresponding fault early warning information according to the current early warning level, and reminding a user or operation and maintenance personnel to take preventive maintenance or emergency treatment measures in real time.

The invention provides a preparation method of an electron-ion mixed conductor sulfide electrolyte material, which is characterized by comprising the following steps: taking a sulfide solid electrolyte as an inner core, taking a two-dimensional transition metal layered material MXene as a surface coating layer, and coating the surface of the inner core with the two-dimensional transition metal layered material MXene, and carrying out ball milling and calcining to obtain the electron-ion mixed conductor sulfide electrolyte material. The two-dimensional transition metal layered material MXene is used as a surface coating layer, the air stability of the sulfide solid electrolyte is improved, calcination treatment is carried out, S in the sulfide solid electrolyte is combined with metal ions in MXene, the sulfide solid electrolyte has high electronic conductivity, the appearance of a space charge layer can be inhibited, and the performance of the sulfide solid electrolyte is improved. The electronic conductivity of the positive electrode is improved, the multiplying power of a battery cell is improved, the content of conductive carbon is reduced, and the intrinsic ion conductivity of sulfide electrolyte can be kept to the maximum extent.

The invention discloses a sulfide-based composite solid-state electrolyte, a preparation method thereof and a lithium metal solid-state battery, sulfide is subjected to specific bifunctional surface grafting modification by using a silane coupling reagent with sulfydryl and epoxy bonds, then the sulfide is introduced into a polymer precursor liquid, and the sulfide-based composite solid-state electrolyte is prepared through light-heat curing reaction synergy. A flexible and rigid cross-linked network is formed, the sulfide-based composite solid-state electrolyte with high ionic conductivity and high mechanical strength is obtained, the interface stability of the sulfide-based composite solid-state electrolyte in the charge-discharge process is ensured, for example, the sulfide-based composite solid-state electrolyte in the embodiment 1 has high ionic conductivity (3.81 mS / cm), and the interface stability of the sulfide-based composite solid-state electrolyte in the embodiment 2 is ensured. The lithium-lithium symmetric battery prepared by the method has the advantages of excellent flexibility, high tensile strength (7.9 Mpa) and wide electrochemical window (5.1 V), the lithium-lithium symmetric battery can stably circulate for 2000h, and the whole battery can stably circulate for 2000 circles at the room temperature at the rate of 4C, so that the lithium-lithium symmetric battery has great industrial application value.

The invention discloses a method for preparing battery-grade iron phosphate by recovering lithium iron phosphate battery black powder, which comprises the following steps of: performing reduction acid leaching on the lithium iron phosphate battery black powder to obtain acid leaching liquid; adding sodium silicate into the acid leaching solution to adjust the pH value of the solution to 2.5-4, removing aluminum and titanium to obtain a primary impurity-removed solution, deeply removing aluminum and titanium from the impurity-removed solution by adopting ion exchange resin, and removing copper and filtering by adopting sulfide to obtain a copper-removed solution; supplementing iron is added into the copper removal liquid, the pH is adjusted to 3.5-6.5, ferrous phosphate reacts and is separated out, and ferrous phosphate is obtained; the method comprises the following steps: carrying out acid leaching on ferrous phosphate to obtain a leaching solution, adjusting the molar ratio of iron to phosphorus in the leaching solution, carrying out oxidation precipitation, adjusting the pH value of the solution again, aging, filtering, washing and drying to obtain iron phosphate dihydrate, and finally calcining to obtain the anhydrous iron phosphate. According to the method, a process route for producing iron phosphate by an ammonium method is used for reference, iron and phosphorus in the black powder of the lithium iron phosphate battery are recycled and converted into battery-grade iron phosphate in a ferrous phosphate form, impurities such as aluminum, titanium and copper are effectively removed, and the impurities are prevented from being entrained in the iron phosphate.