A method for producing lithium sulfide includes: a preparation process (step S12) at which a raw material and a reducing agent are charged into a furnace, the raw material being mainly composed of lithium sulfate having a property of weight loss of 5% or more to 25% or less upon heating to 120° C.; and a temperature raising process (step S14) at which the raw material and the reducing agent are heated in the furnace to raise the temperature.

A method for producing lithium sulfide includes: a preparation process (step S12) at which a raw material and a reducing agent are charged into a furnace, the raw material being mainly composed of lithium sulfate having a property of weight loss of 5% or more to 25% or less upon heating to 120° C.; and a temperature raising process (step S14) at which the raw material and the reducing agent are heated in the furnace to raise the temperature.

A production method for a cathode material of a lithium sulfur battery includes, in sequence: a step of preparing a first dispersed solution in which a carbon particle is dispersed in a lithium sulfate solution; a step of adding a solvent in the first dispersed solution, the solvent being a solvent in which lithium sulfate is insoluble; a step of separating a precursor particle from the first dispersed solution in which the solvent is added; and a step of changing the precursor particle into a cathode active material particle by heating the precursor particle under an inert atmosphere.

Provided is a more appropriate method of producing lithium sulfide having high ionic conductivity and no by-products generated. The method of producing lithium sulfide includes a temperature rising step (Step S14) of reducing lithium sulfate fed into a furnace in a state of heating to a temperature of more than 700? C. under an atmosphere of a reduced pressure of 0.05 MPa or less.

Provided is a more appropriate method of producing lithium sulfide having high ionic conductivity and no by-products generated. The method of producing lithium sulfide includes a temperature rising step (Step S14) of reducing lithium sulfate fed into a furnace in a state of heating to a temperature of more than 700? C. under an atmosphere of a reduced pressure of 0.05 MPa or less.

A production method for a cathode material of a lithium sulfur battery includes, in sequence: a step of preparing a first dispersed solution in which a carbon particle is dispersed in a lithium sulfate solution; a step of adding a solvent in the first dispersed solution, the solvent being a solvent in which lithium sulfate is insoluble; a step of separating a precursor particle from the first dispersed solution in which the solvent is added; and a step of changing the precursor particle into a cathode active material particle by heating the precursor particle under an inert atmosphere.

A production method for a cathode material of a lithium sulfur battery includes, in sequence: a step of preparing a first dispersed solution in which a carbon particle is dispersed in a lithium sulfate solution; a step of adding a solvent in the first dispersed solution, the solvent being a solvent in which lithium sulfate is insoluble; a step of separating a precursor particle from the first dispersed solution in which the solvent is added; and a step of changing the precursor particle into a cathode active material particle by heating the precursor particle under an inert atmosphere.

Provided is a more appropriate method of producing lithium sulfide having high ionic conductivity and no by-products generated. The method of producing lithium sulfide includes a temperature rising step (Step S14) of reducing lithium sulfate fed into a furnace in a state of heating to a temperature of more than 700? C. under an atmosphere of a reduced pressure of 0.05 MPa or less.

Provided is a more appropriate method of producing lithium sulfide having high ionic conductivity and no by-products generated. The method of producing lithium sulfide includes a temperature rising step (Step S14) of reducing lithium sulfate fed into a furnace in a state of heating to a temperature of more than 700? C. under an atmosphere of a reduced pressure of 0.05 MPa or less.