 The research team demonstrated the ability to continuously tune the thermal conductivity of nanoscale films of La 0.5 senior 0.5 Q3 LSEO, by a factor of over 5, via a room-temperature electrolyte gate-induced non-volatile topotactic phase transformation from perovskite, with almost equal to 0.1, to an oxygen vacancy-ordered brown-millerite phase, with equal 0.5, accompanied by a metal insulator transition. This allowed for the wide-range continuous tuneability of LSEO thermal conductivity enabled by low voltage, below for V, room-temperature electrolyte gating, opening the door to non-volatile dynamic control of thermal transport in perovskite-based functional materials, for thermal regulation and management in device applications. This article was authored by Yin and Zhong, William M. Distiglian, Ruizier, and others.