Significant Enhancement in the Power Density of Micro-Supercapacitors by the In Situ Growth of TiN/TiOxNy-Laminated Films

Micro-supercapacitors (MSCs) are considered promising micropower sources for Internet-of-things applications. Although the performances of MSCs have been significantly advanced by fabricating nanostructured materials and developing thin-film manufacturing technologies and device architectures, they are still limited by low energy densities and slow rate capabilities. In this work, we introduce a new in situ growth concept to fabricate on-chip micro-supercapacitors in which a highly conductive TiN film used as a current collector offers fast electron transport paths and porous TiOxNy film served as the pseudocapacitive electrode provides large capacitance. Such a design brings the device an ultrahigh power density (105.0 W cm(-3)) while keeping a high energy density (31.5 mWh cm(-3)) and excellent cycle stability. The TiN/TiOxNy laminated films with superior performances hold great promises for applications of miniaturized energy storage devices.