Composite material, and method for manufacturing same
A compound A containing Li, S, and M elements (M is phosphorus or the like), and containing a crystal phase with an argyrodite-type crystal structure is prepared, and the compound A and a conductive material are mixed to obtain a composite material in which these materials are composited. The mixing is performed such that an amorphous degree N obtained by 100×(I 0 −I t )/I 0 is 97% or more, where an intensity of a peak A observed at 2θ=29.7°±1.00° in an XRD pattern of the compound A is taken as I 0 , and an intensity of a peak B observed at 2θ=29.7°±1.00° in an XRD pattern of the composite material is taken as I t . The atomic ratio of a halogen (X) element to the phosphorus (P) element contained in the compound A is preferably less than 1.0.
1. A method for producing a composite material, comprising:
a preparation step of preparing a compound A containing a lithium (Li) element, a sulfur(S) element and an M element and containing a crystal phase with an argyrodite-type crystal structure, wherein M comprises at least one selected from the group consisting of a phosphorus (P) element, a germanium (Ge) element, an antimony (Sb) element, a silicon (Si) element, a tin (Sn) element, an aluminum (Al) element, a titanium (Ti) element, an iron (Fe) element, a nickel (Ni) element, a cobalt (Co) element, and a manganese (Mn) element; and
a mixing step of mixing the compound A and a conductive material to obtain a composite material in which the compound A and the conductive material are composited;
wherein the mixing step is performed in such a manner that an amorphous degree N obtained by Formula (1) below is 97% or more:
Amorphous
degree
N
(
%
)
=
1
0
0
×
(
I
0
-
I
t
)
/
I
0
(
1
)
wherein I 0 represents an intensity of a peak A which is a diffraction peak observed at a position 2θ=29.7°±1.00° in an X-ray diffraction pattern obtained when the compound A is measured using an X-ray diffraction device using CuKα1 rays, and
I t represents an intensity of a peak B which is a diffraction peak observed at a position 2θ=29.7°±1.00° in an X-ray diffraction pattern obtained when the composite material is measured using an X-ray diffraction device using CuKα1 rays.
2. The method according to claim 1 , wherein the M element contained in the compound A contains at least a phosphorus (P) element.
3. The method according to claim 1 , wherein an atomic ratio of a halogen (X) element to the phosphorus (P) element contained in the compound A is less than 1.0.
4. The method according to claim 1 , wherein an atomic ratio of the lithium (Li) element to the phosphorus (P) element contained in the compound A is from 5.0 to 9.0.
5. The method according to claim 1 , wherein the conductive material is a carbon material or a metal material.