Exploration of the high temperature phase evolution of electrochemically modified Sc2(WO4)3 via potassium discharge
The electrochemical modification of Sc2(WO4)3 via activation as an electrode against potassium metal is investigated, as well as the subsequent thermal evolution of activated Sc2(WO4)3. Upon discharge to 0.01 V versus K/K+, Sc2(WO4)3 delivers a capacity of 132 mAh g-1. On subsequent heating from 100 to 623 K the discharged electrode exhibits essentially the same thermal expansion as that of the pure powder. Between 673 and 973 K a trigonal K2WO4-type phase (P-3m1) is formed. Variable-temperature X-ray diffraction data indicates that upon heating from 923 K - 1023 K, this phase has a thermal expansion coefficient of -1.90(10) x 10-4 K-1.