Pure V2O5 high-electricity transmission properties at low temperatures by structural changes

Abstract

There have been many studies concentrating on high-temperature thermoelectric properties of non-doping V2O5 thin films and doping ones, but high power factor (PF) of V2O5 thermoelectrics have been rarely reported up to now, particularly low temperature ones. In this work, the thermoelectric performance of pure V2O5 at low temperature is reported where V2O5 commercial powders are successfully prepared into sintered blocks by spark plasma sintering (SPS) and annealing steps. It is clear that the annealing temperature plays a major role on the electrical transport properties due to the microstructure changes. At annealing temperature (623 K), the maximum Seebeck coefficient (205 K) and PFmax (186 K) arrive at −618 μV/K and 2.17 × 10−4 W/K2m, respectively, based on growth of grains, the reduction of grain boundaries and defect concentration. The PF is 2 orders of magnitude higher than the annealed of V2O5 film reported so far (Adv Mater Technol 2016;1:1600077). This research may provide an alternative strategy for the preparation of high-performance V2O5 thermoelectric devices.