A preparation method for EV-grade lithium sulfide includes: mixing and reacting sulfur powder, metallic lithium and a lithium-containing additive to obtain a crude lithium sulfide product, and then pulverizing and calcining the crude lithium sulfide product to remove excess sulfur powder to obtain the EV-grade lithium sulfide. The method being used for preparing the lithium sulfide is advantaged in simple process, strong operability, large-scale production, and being capable to meet the requirements for safe operation and EV-grade lithium sulfide, without toxic gas generation and secondary pollution.

A preparation method for EV-grade lithium sulfide includes: mixing and reacting sulfur powder, metallic lithium and a lithium-containing additive to obtain a crude lithium sulfide product, and then pulverizing and calcining the crude lithium sulfide product to remove excess sulfur powder to obtain the EV-grade lithium sulfide. The method being used for preparing the lithium sulfide is advantaged in simple process, strong operability, large-scale production, and being capable to meet the requirements for safe operation and EV-grade lithium sulfide, without toxic gas generation and secondary pollution.

EV-grade high-purity lithium sulfide and a preparation method therefor, including: A. mixing and well grinding a lithium source and a sulfur source to obtain a mixture; B. primary reaction: mixing the mixture with hydrazine hydrate in an inert atmosphere and reacting to obtain an intermediate slurry; C. secondary reaction: performing secondary reaction on the intermediate slurry in the inert atmosphere and drying to obtain a crude lithium sulfide product; and D. calcining and ball milling the crude lithium sulfide product to obtain the EV-grade high-purity lithium sulfide. The purity of the EV-grade high-purity lithium sulfide prepared by the method is above 99.9%, the whiteness thereof is above 80, and D5015 m; the method is characterized by simple process operation, high safety, low energy consumption, low equipment requirements and low production cost; therefore, the method is suitable for industrial production.

EV-grade high-purity lithium sulfide and a preparation method therefor, including: A. mixing and well grinding a lithium source and a sulfur source to obtain a mixture; B. primary reaction: mixing the mixture with hydrazine hydrate in an inert atmosphere and reacting to obtain an intermediate slurry; C. secondary reaction: performing secondary reaction on the intermediate slurry in the inert atmosphere and drying to obtain a crude lithium sulfide product; and D. calcining and ball milling the crude lithium sulfide product to obtain the EV-grade high-purity lithium sulfide. The purity of the EV-grade high-purity lithium sulfide prepared by the method is above 99.9%, the whiteness thereof is above 80, and D5015 m; the method is characterized by simple process operation, high safety, low energy consumption, low equipment requirements and low production cost; therefore, the method is suitable for industrial production.

One embodiment of the present disclosure includes a method of producing high-purity alkali metal sulfide including mixing an alkali metal sulfide salt precursor and a reducing agent to form a mixture, reducing the mixture to obtain alkali metal sulfide; and purifying the obtained alkali metal sulfide.

One embodiment of the present disclosure includes a method of producing high-purity alkali metal sulfide including mixing an alkali metal sulfide salt precursor and a reducing agent to form a mixture, reducing the mixture to obtain alkali metal sulfide; and purifying the obtained alkali metal sulfide.

A method for preparing high-purity lithium sulfide by using industrial-grade butyllithium includes the following steps: step A: under an inert gas condition, thoroughly mixing 1.5-2.5 g of lithium chloride, 0.5 L of an industrial-grade n-butyllithium solution (2.5 mol/L) and 1.5-2.5 L of n-hexane to obtain a mixed solution, and charging the mixed solution into a sealed container; step B: under the sealed condition, firstly introducing H.sub.2S gas into a gas-washing bottle through a submerged pipe at a rate of 10.5 L/h, then introducing into the mixed solution through the submerged pipe, controlling the reaction temperature at 25-40 C., and continuously stirring for reaction for 4-6 h to obtain a reaction slurry; and step C: under an inert gas condition, filtering the reaction slurry with a G3 sand core funnel to obtain a crude lithium sulfide solid wet material.

A method for preparing high-purity lithium sulfide by using industrial-grade butyllithium includes the following steps: step A: under an inert gas condition, thoroughly mixing 1.5-2.5 g of lithium chloride, 0.5 L of an industrial-grade n-butyllithium solution (2.5 mol/L) and 1.5-2.5 L of n-hexane to obtain a mixed solution, and charging the mixed solution into a sealed container; step B: under the sealed condition, firstly introducing H.sub.2S gas into a gas-washing bottle through a submerged pipe at a rate of 10.5 L/h, then introducing into the mixed solution through the submerged pipe, controlling the reaction temperature at 25-40 C., and continuously stirring for reaction for 4-6 h to obtain a reaction slurry; and step C: under an inert gas condition, filtering the reaction slurry with a G3 sand core funnel to obtain a crude lithium sulfide solid wet material.