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×(l-l)/l 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 l, 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 It. The atomic ratio of a halogen (X) element to the phosphorus (P) element contained in the compound A is preferably less than 1.0.