LAUSR

Mesoporous metal oxides exhibit excellent physicochemical properties and are widely used in various fields, including energy storage/conversion, catalysis, and sensors. Although several soft‐template approaches are reported, high‐temperature calcination for both metal oxide formation and template removal is necessary, which limits direct synthesis on a plastic substrate for flexible devices. Here, a universal synthetic approach that combines thermal activation and oxygen plasma to synthesize diverse mesoporous metal oxides (V2O5, V6O13, TiO2, Nb2O5, WO3, and MoO3) at low temperatures (150–200 °C), which can be applicable to a flexible polymeric substrate is introduced. As a demonstration, a flexible micro‐supercapacitor is fabricated by directly synthesizing mesoporous V2O5 on an indium‐tin oxide‐coated colorless polyimide film. The energy storage performance is well maintained under severe bending conditions.