The invention provides a
metal selenide thermoelectric material for intermediate temperate and a preparation process thereof, which relates to the field of
thermoelectric materials. The design point is as follows: the
chemical formula of the thermoelectric material is InxAgySe3, wherein x + y=2, 0.05<= y <=0.25. The preparation process comprises the following steps: putting elemental In, Ag and Se into a vacuum
quartz tube; synthesizing for 20-28 hours at the temperature of 1000-1100 DEG C; cooling the InxAgySe3 cast
ingot in a furnace to 600-650 DEG C, and then, immediately
quenching in water; crushing and ball-milling the quenched InxAgySe3 cast
ingot; carrying out
spark plasma sintering to prepare a block, wherein the
sintering temperature is 550-650 DEG C, the
sintering pressure is 40-60MPa, and the
holding time is 8-12 minutes;
coating a
sodium silicate concentrated solution on the surface of the sintered block material;
drying; and then, annealing for 20-28 hours in the vacuum
quartz tube, wherein the annealing temperature is 180-200 DEG C. The material provided by the invention is prepared by using a conventional
powder metallurgy method, thus the process is simple; the
transition metal element Ag is used for replacing the In element in the In2Se3 thermoelectric
alloy in an equimolar mode, thus the cost is lower; and the material has environment-friendly characteristics and does not have
noise, thus the material is suitable for being used as an environment-friendly energy material.