SOLID ELECTROLYTE AND METHOD FOR PRODUCING SAME
A solid electrolyte contains: a lithium (Li) element; a phosphorus (P) element; a sulfur (S) element; and an X element, where X represents at least one halogen element. The solid electrolyte has a peak P 1 and a peak P 2 when, in an X-ray diffraction pattern obtained by measuring the solid electrolyte with an X-ray diffractometer (XRD) using CuKα1 rays and CuKα2 rays, a diffraction pattern in at least any one of a range of 2θ=25.6±0.8°, a range of 2θ=30.2±0.8°, and a range of 2θ=31.6±0.8° is subjected to peak separation. The peak P 1 and the peak P 2 are derived from different phases.
1 . A solid electrolyte comprising:
a lithium (Li) element;
a phosphorus (P) element;
a sulfur (S) element; and
an X element, where X represents at least one halogen element,
wherein the solid electrolyte has a peak P 1 and a peak P 2 when, in an X-ray diffraction pattern obtained by measuring the solid electrolyte with an X-ray diffractometer (XRD) using CuKα1 rays and CuKα2 rays, a diffraction pattern in at least any one of a range of 28=25.6±0.8°, a range of 28=30.2±0.8°, and a range of 2θ=31.6±0.8° is subjected to peak separation, and
the peak P1 and the peak P2 are derived from different phases.
2 . The solid electrolyte according to claim 1 ,
wherein the solid electrolyte has the peak P1 and the peak P2 when, in the X-ray diffraction pattern obtained by measuring the solid electrolyte with an X-ray diffractometer (XRD) using CuKα1 rays and CuKα2 rays, diffraction patterns in the ranges of 28=25.6±0.8°, 28=30.2±0.8°, and 28=31.6±0.8° are subjected to peak separation.
3 . The solid electrolyte according to claim 1 ,
wherein the X element includes at least chlorine (Cl).
4 . The solid electrolyte according to claim 1 ,
wherein the molar ratio (X/P) of the X element to the phosphorus (P) element is greater than 1.0.
5 . The solid electrolyte according to claim 1 ,
wherein an angle difference Δ2θ between the peak P1 and the peak P2 is 0.04° or more.
6 . The solid electrolyte according to claim 1 ,
wherein the solid electrolyte has a crystal phase of an argyrodite-type crystal structure.
7 . A method for producing a solid electrolyte, comprising the steps of:
obtaining a raw material composition by mixing a lithium (Li) element source, a phosphorus (P) element source, a sulfur (S) element source, and a halogen (X) element source; and
calcining the raw material composition at a temperature of higher than 500° C. and lower than 700° C.
8 . An electrode material mixture comprising:
the solid electrolyte according to claim 1 ; and
an active material.
9 . A solid electrolyte layer comprising the solid electrolyte according to claim 1 .
10 . A battery comprising:
a positive electrode layer;
a negative electrode layer; and
a solid electrolyte layer provided between the positive electrode layer and the negative electrode layer,
wherein the battery contains the solid electrolyte according to claim 1 .